CN116670436A

CN116670436A - Heat pump system and control method thereof

Info

Publication number: CN116670436A
Application number: CN202280008879.7A
Authority: CN
Inventors: 李东哲; 王远鹏; 左计学; 夏兴祥; 陈卫星; 潘翠连; 管清杭; 李守山; 王庆波; 傅华
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2021-06-08
Filing date: 2022-06-08
Publication date: 2023-08-29

Abstract

A heat pump system comprising at least one heat pump indoor unit comprising an overlapping heat exchanger (11) and a terminal heat exchanger assembly (16). The cascade heat exchanger (11) comprises: a first heat exchange part (12) and a second heat exchange part (14), wherein the first heat exchange part (12) is connected with a low-temperature-stage circulation pipeline (13), and a first refrigerant is arranged in the low-temperature-stage circulation pipeline (13); the second heat exchange part (14) is connected with a high-temperature-stage circulation pipeline (15), a second refrigerant is arranged in the high-temperature-stage circulation pipeline (15), and the second heat exchange part (14) is configured to exchange heat with the first heat exchange part (12). The terminal heat exchanger assembly (16) includes: a third heat exchange part (18), a fourth heat exchange part (19) and a terminal heat exchange part (17), wherein the third heat exchange part (18) is connected with the low-temperature-stage circulating pipeline (13); the fourth heat exchange part (19) is connected with the high-temperature-stage circulating pipeline (15); the terminal heat exchange part (17) is connected with indoor terminal equipment, and the terminal heat exchange part (17) is configured to exchange heat with the third heat exchange part (18), or exchange heat with the fourth heat exchange part (19), or exchange heat with the third heat exchange part (18) and the fourth heat exchange part (19).

Description

Heat pump system and control method thereof

The present application claims the priority of the chinese patent application of application number 202110639064.6, filed on 8 th 6 th 2021, and the priority of the chinese patent application of application number 202110709626.X, filed on 25 th 6 th 2021, and the priority of the chinese patent application of application number 202123050748.7, filed on 7 th 12 th 2021, and the priority of the chinese patent application of application number 202210374161.1, filed on 11 th 4 th 2022, which are all incorporated herein by reference.

Technical Field

The disclosure relates to the technical field of heat pumps, and in particular relates to a heat pump system and a control method thereof.

Background

The heat pump system uses electric energy as driving force, uses outdoor ambient air as heat source, provides heat for the regulated object, and has the characteristics of high energy efficiency and low energy consumption compared with electric water heater, gas water heater and the like, so that the heat pump system has received wide attention in the industry.

Disclosure of Invention

In one aspect, some embodiments of the present application provide a heat pump system. The heat pump system comprises at least one heat pump indoor unit, and the heat pump indoor unit comprises a cascade heat exchanger and a terminal heat exchanger assembly. The cascade heat exchanger includes: the first heat exchange part is connected with a low-temperature-level circulating pipeline, and a first refrigerant is arranged in the low-temperature-level circulating pipeline; the second heat exchange part is connected with a high-temperature-stage circulating pipeline, a second refrigerant is arranged in the high-temperature-stage circulating pipeline, and the second heat exchange part is configured to exchange heat with the first heat exchange part. The terminal heat exchanger assembly includes: the third heat exchange part is connected with the low-temperature-stage circulating pipeline; the fourth heat exchange part is connected with a high-temperature-stage circulating pipeline; the terminal heat exchange portion is connected with the indoor terminal device, and the terminal heat exchange portion is configured to perform heat exchange with the third heat exchange portion, or perform heat exchange with the fourth heat exchange portion, or perform heat exchange with the third heat exchange portion and the fourth heat exchange portion.

In another aspect, some embodiments of the present application provide a control method for the heat pump system described above. The heat pump system is any one of the heat pump systems described in the above embodiments, and the control method of the heat pump system includes: determining whether a heat pump system meets preset conditions, wherein the preset conditions comprise a low-temperature heating condition, a defrosting condition, a high-temperature heating condition or a rapid heating condition; if the heat pump system meets the low-temperature heating condition or the defrosting condition, the terminal heat exchange part is controlled to exchange heat with the third heat exchange part; if the heat pump system meets the high-temperature heating condition, the terminal heat exchange part and the fourth heat exchange part are controlled to exchange heat; and if the heat pump system meets the rapid heating condition, controlling the terminal heat exchange part to exchange heat with the third heat exchange part and the fourth heat exchange part.

Drawings

In order to more clearly illustrate the technical solutions of the present disclosure, the drawings that need to be used in some embodiments of the present disclosure will be briefly described below, and it is apparent that the drawings in the following description are only drawings of some embodiments of the present disclosure, and other drawings may be obtained according to these drawings to those of ordinary skill in the art. Furthermore, the drawings in the following description may be regarded as schematic diagrams, not limiting the actual size of the products, the actual flow of the methods, the actual timing of the signals, etc. according to the embodiments of the present disclosure.

FIG. 1 is a block diagram of a heat pump system according to some embodiments;

FIG. 2 is a block diagram of another heat pump system according to some embodiments;

FIG. 3 is a schematic diagram of a refrigerant cycle when the heat pump system is operating in a low temperature heating mode, according to some embodiments;

FIG. 4 is a schematic diagram of a refrigerant cycle when the heat pump system is operating in defrost mode according to some embodiments;

FIG. 5A is a schematic diagram of a refrigerant cycle when the heat pump system is operating in a high temperature heating mode, according to some embodiments;

FIG. 5B is a schematic diagram of a refrigerant cycle when the heat pump system is operating in a rapid heating mode, according to some embodiments;

FIG. 6A is a block diagram of yet another heat pump system according to some embodiments;

FIG. 6B is a schematic diagram of a refrigerant cycle when the heat pump system is operating in a high temperature heating mode, according to some embodiments;

FIG. 7 is a block diagram of yet another heat pump system according to some embodiments;

FIG. 8 is a block diagram of yet another heat pump system according to some embodiments;

FIG. 9 is a block diagram of yet another heat pump system according to some embodiments;

FIG. 10 is a schematic diagram of the operation of a heat pump system to produce medium temperature water according to some embodiments;

FIG. 11 is a schematic diagram of the operation of a heat pump system to produce high temperature water according to some embodiments;

FIG. 12 is a schematic diagram of the operation of a heat pump system defrost according to some embodiments;

FIG. 13 is a block diagram of yet another heat pump system according to some embodiments;

FIG. 14 is a block diagram of a heat pump system in a one-to-one connection mode according to some embodiments;

FIG. 15 is a block diagram of a heat pump system in a one-drive-multiple-split mode according to some embodiments;

FIG. 16 is a block diagram of a heat pump system in another one-to-many manner in accordance with some embodiments;

FIG. 17 is a block diagram of a heat pump system in a further one-to-many manner in accordance with some embodiments;

FIG. 18 is a block diagram of yet another heat pump system according to some embodiments;

fig. 19 is a schematic diagram of the operation of a relay reversing device according to some embodiments;

fig. 20 is a schematic diagram of the operation of another relay reversing device according to some embodiments;

FIG. 21 is a block diagram of yet another heat pump system according to some embodiments;

FIG. 22 is a flow chart of pump evacuation control prior to pump characterization testing by the heat pump system according to some embodiments;

FIG. 23 is a flow chart of a heat pump system performing a water pump characteristic test according to some embodiments;

FIG. 24 is a graph of a water pump characteristic test of a heat pump system according to some embodiments;

FIG. 25 is a flow chart of pump evacuation control prior to a heat pump system performing a line characteristic test, according to some embodiments;

FIG. 26 is a flow chart of a heat pump system performing a circuit characteristic test according to some embodiments;

FIG. 27 is a graph of a line characteristic test of a heat pump system according to some embodiments;

FIG. 28 is a flow chart of a heat pump system fixed speed control according to some embodiments;

FIG. 29 is a graph of a water pump-circuit characteristic test of a heat pump system according to some embodiments;

FIG. 30 is a flow chart of a heat pump system flow control according to some embodiments;

FIG. 31 is a flow chart of a heat pump system constant temperature differential control according to some embodiments;

fig. 32 is a flow chart of a method of controlling a heat pump system according to some embodiments.

Detailed Description

The following description of the embodiments of the present disclosure will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present disclosure. All other embodiments obtained by one of ordinary skill in the art based on the embodiments provided by the present disclosure are within the scope of the present disclosure.

The heat pump system may perform a refrigerant cycle using outdoor ambient air or other medium as a heat source by using a compressor, a condenser, a throttle device, and an evaporator to supply heat to indoor end devices. The present disclosure is not limited to the type of heat pump system, and the following embodiments exemplify a heat pump system as an air source heat pump.

In general, an air source heat pump is limited by the pressure ratio of a compressor and the physical properties of a refrigerant in the use process, hot water with the temperature of 55-60 ℃ or higher cannot be prepared, and the prepared water temperature is obviously attenuated when the outdoor temperature is reduced. For example, the highest heating temperature of the air source heat pump can only reach 60 ℃, and although the highest heating temperature can meet the requirements of most domestic hot water and winter heating, the high-temperature hot water at 80-90 ℃ can not be directly prepared through the traditional air source heat pump product for use scenes such as hospitals, foods, hotels and the like with more high-temperature water application. For the production of hot water at high temperature, a cascade heat pump system may be used.

The cascade heat pump system comprises a low-temperature-level circulating system and a high-temperature-level circulating system, and can be used for preparing high-temperature hot water by simultaneously working the low-temperature-level circulating system and the high-temperature-level circulating system. However, the cascade heat pump system has poor flexibility, and when the set water temperature is low, the cascade heat pump system must also start the low-temperature-stage circulation system and the high-temperature-stage circulation system at the same time, which causes that the high-temperature-stage circulation system cannot generate enough pressure difference, and the pressure ratio deviates from the normal operation range, so that the reliable operation of the high-temperature-stage circulation system is not facilitated. Moreover, when the set water temperature is low, starting the high-temperature-stage circulation system can cause high energy consumption of the cascade heat pump system.

To this end, some embodiments of the present disclosure provide a heat pump system, as shown in fig. 1, including a heat pump indoor unit 10. The heat pump indoor unit 10 includes a cascade heat exchanger 11 and a terminal heat exchanger assembly 16.

In some embodiments, as shown in fig. 1, the cascade heat exchanger 11 includes a first heat exchange portion 12 and a second heat exchange portion 14. The first heat exchange portion 12 is connected to a low-temperature-stage circulation line 13, and a first refrigerant is provided in the low-temperature-stage circulation line 13. The second heat exchanging portion 14 is connected to the high-temperature-stage circulation line 15, the second refrigerant is present in the high-temperature-stage circulation line 15, and the second heat exchanging portion 14 is configured to exchange heat with the first heat exchanging portion 12.

In some embodiments, the cascade heat exchanger 11 may also be referred to as an evaporative condenser. For example, the first heat exchanging portion 12 and the second heat exchanging portion 14 in the cascade heat exchanger 11 function differently depending on the cooling or heating mode of the heat pump system. When the heat pump system heats, the first refrigerant in the first heat exchange part 12 condenses to release heat, and the second refrigerant in the second heat exchange part 14 absorbs the heat released by the first refrigerant in the first heat exchange part 12; when the heat pump system is refrigerating, the first refrigerant in the first heat exchange portion 12 evaporates to absorb heat, and the second refrigerant in the second heat exchange portion 14 exchanges heat with the first refrigerant in the first heat exchange portion 12.

The first refrigerant may be the same as or different from the second refrigerant. For example, the first refrigerant and the second refrigerant may be any one of the refrigerants such as R410A, R a, R12, R22, R32, R290, and R744, respectively. The following embodiment exemplifies the case where the first refrigerant is R410A and the second refrigerant is R134 a.

In some embodiments, as shown in fig. 1, the terminal heat exchanger assembly 16 includes a terminal heat exchange portion 17, a third heat exchange portion 18, and a fourth heat exchange portion 19. The third heat exchange part 18 is connected with the low-temperature-stage circulating pipeline 13, the fourth heat exchange part 19 is connected with the high-temperature-stage circulating pipeline 15, and the terminal heat exchange part 17 is connected with indoor terminal equipment. The terminal heat exchange portion 17 includes therein a medium to be heated, which is mainly water. The indoor end device may be a water terminal such as a floor heating, radiator or water heater, etc.

The terminal heat exchanging portion 17 is configured to exchange heat with the third heat exchanging portion 18, or with the fourth heat exchanging portion 19, or with the third heat exchanging portion 18 and the fourth heat exchanging portion 19.

In some embodiments, the modes of operation of the heat pump system include, but are not limited to, a heating mode and a cooling mode. Heating modes include, but are not limited to, low temperature heating modes, high temperature heating modes, and fast heating modes. The cooling mode includes, but is not limited to, a defrost mode. When the heat pump system meets the low-temperature heating condition, the heat pump system works in a low-temperature heating mode; the low-temperature heating condition includes, but is not limited to, that the set temperature (such as the water temperature required by the user) is lower than the first preset temperature, and the low-temperature heating mode can produce medium-temperature water. When the heat pump system meets the high-temperature heating condition, the heat pump system works at the high-temperature heating mode; the high-temperature heating condition includes, but is not limited to, the set temperature is higher than a third preset temperature, and the high-temperature heating mode can produce high-temperature water. When the heat pump system meets the defrosting condition, the heat pump system works in a defrosting mode; the defrosting conditions include, but are not limited to, the temperature of the terminal heat exchanging part 17 being higher than a second preset temperature. When the heat pump system meets the rapid heating condition, the heat pump system works in a rapid heating mode, and the rapid heating mode can also prepare high-temperature water.

By way of example, the rapid heating mode means that the heat pump system needs to be heated to the fourth preset temperature in a short time, for example, when the indoor end device is a water heater, and when the user uses the water heater, the heat pump system needs to complete heating in a short time, so the heat pump system enters the rapid heating mode.

In some embodiments, the operation mode of the heat pump system is related to parameters such as the instruction sent by the user, the water inlet temperature of the terminal heat exchange 17, etc. For example, if a command for entering the rapid heating mode sent by a user is received and the water inlet temperature of the water circulation loop is low, the heat pump system enters the rapid heating mode. For another example, if a defrost command sent by a user is received, the heat pump system enters defrost mode.

In embodiments of the present disclosure, lower includes less than or equal to, and higher includes greater than or equal to.

In the embodiments of the present disclosure, the first preset temperature may be less than or equal to the third preset temperature. The values of the first preset temperature, the second preset temperature, the third preset temperature and the fourth preset temperature are not limited in the embodiment of the disclosure.

When the heat pump system is operated in the low-temperature heating mode, the low-temperature-stage circulation system is operated, and the terminal heat exchanging part 17 exchanges heat with the third heat exchanging part 18. When the heat pump system is operated in the high-temperature heating mode, the high-temperature-stage circulation system is operated, and the terminal heat exchange portion 17 exchanges heat with the fourth heat exchange portion 19. When the heat pump system is operated in the rapid heating mode, the low temperature stage circulation system and the high temperature stage circulation system are operated simultaneously, and the terminal heat exchange part 17 exchanges heat with the third heat exchange part 18 and the fourth heat exchange part 19 simultaneously to reach a user-set temperature in a short time. When the heat pump system is operated in the defrost mode, the low-temperature-stage circulation system is operated, and the terminal heat exchanging part 17 exchanges heat with the third heat exchanging part 18. The difference between the heat pump system operating in the defrosting mode and the low-temperature heating mode is that the flow direction of the first refrigerant in the defrosting mode is opposite to that in the low-temperature heating mode.

According to the heat pump system provided by the embodiment of the disclosure, under the scene of low set water temperature, the high-temperature-level circulating system is not required to be started, so that the problem that the reliability of the system operation is low due to the fact that the high-temperature-level circulating system cannot generate enough pressure difference can be avoided, and the reliable operation of the heat pump system is ensured. Moreover, the terminal heat exchange part 17 can exchange heat with the third heat exchange part 18 connected with the low-temperature-stage circulation pipeline and the fourth heat exchange part 19 connected with the high-temperature-stage circulation pipeline at the same time, so that the use scene with higher set water temperature can be satisfied. Therefore, the heat pump system provided by the embodiment of the disclosure has higher flexibility and lower energy consumption.

Some embodiments of the present disclosure further provide a heat pump system, as shown in fig. 2, which further includes a heat pump outdoor unit 1, where the heat pump outdoor unit 1 and the heat pump indoor unit 10 together form a high-temperature-stage circulation system and a low-temperature-stage circulation system. The heat pump outdoor unit 1 includes an outdoor heat exchanger 32, a second compressor 30, and a four-way valve 31, and the outdoor heat exchanger 32, the second compressor 30, and the four-way valve 31 are connected through a low-temperature-stage circulation line 13. The outdoor heat exchanger 32 includes a fin-tube heat exchanger. The second compressor 30 may also be referred to as a low temperature stage compressor. The second compressor 30 may be the same as or different from the first compressor 33.

Illustratively, the low temperature stage circulation system includes a low temperature stage circulation line 13, with a first refrigerant R410A in the low temperature stage circulation line 13. The high-temperature-stage circulation system includes a high-temperature-stage circulation line 15, and a second refrigerant R134a is provided in the high-temperature-stage circulation line 15.

In some embodiments, the heat pump indoor unit 10 may further include a first valve element 22, a second valve element 23, and a third valve element 24, and by controlling the communication and the disconnection of the first valve element 22, the second valve element 23, and the third valve element 24, it may be realized that the heat pump system configures whether the high temperature stage circulation system operates according to actual usage requirements.

As shown in fig. 2, a first valve element 22 is provided between the first heat exchange portion 12 and the low-temperature-stage circulation line 13, the first valve element 22 being configured to regulate the flow rate of the first refrigerant into the first heat exchange portion 12. A second valve element 23 is arranged between the second heat exchanging portion 14 and the fourth heat exchanging portion 19, the second valve element 23 being configured to regulate the flow of the second refrigerant into the second heat exchanging portion 14 and the fourth heat exchanging portion 19. A third valve element 24 is provided between the third heat exchange portion 18 and the low-temperature-stage circulation line 13, the third valve element 24 being configured to regulate the flow of the first refrigerant into the third heat exchange portion 18.

Illustratively, the valve elements (e.g., first, second, and third valve elements 22, 23, 24) provided by the embodiments of the present disclosure are electronic expansion valves that are adjustable in opening between fully open and fully closed. The operating states of the first valve element 22, the second valve element 23, and the third valve element 24 may include, for example, a communication state, an off state, a throttle state, and the like.

In some embodiments, the heat pump indoor unit 10 further includes a first compressor 33, and the first compressor 33 is connected to the high-temperature-stage circulation line 15. The first compressor 33 may also be referred to as a high temperature stage compressor.

The operation principle of the heat pump system in the different operation modes, and the operation states of the first valve element 22, the second valve element 23, the third valve element 24 and the first compressor 33 will be described below with reference to fig. 2, taking the heat pump system as an example in the low temperature heating mode, the defrosting mode, the high temperature heating mode and the rapid heating mode.

As shown in fig. 3, when the heat pump system is operating in the low temperature heating mode, the first compressor 33 is stopped (stopped). The first valve element 22 is configured to operate in an off state to shut off the passage between the first heat exchange portion 12 and the low-temperature-stage circulation line 13. The third valve element 24 is configured to operate in an open state to communicate a passage between the third heat exchange portion 18 and the low-temperature-stage circulation line 13. The first refrigerant in the outdoor heat exchanger 32 absorbs heat from the outdoor environment or other external medium, and after being evaporated, enters the second compressor 30 to be compressed, so as to obtain a high-temperature and high-pressure gaseous first refrigerant, and the first refrigerant enters the low-temperature-stage circulation pipeline 13 of the heat pump system. Since the first valve element 22 closes the refrigerant passage between the first heat exchange portion 12 and the low-temperature-stage circulation line 13, the first refrigerant cannot circulate through the first heat exchange portion 12, but enters the third heat exchange portion 18 and exchanges heat with the medium (e.g., water) in the terminal heat exchange portion 17. The first refrigerant releases heat in the third heat exchange portion 18, and heats water in the terminal heat exchange portion 17 to a set temperature, thereby realizing low-temperature-level heating of the heat pump system. After the first refrigerant completes heating the medium in the terminal heat exchange portion 17, the first refrigerant flows out of the third heat exchange portion 18, passes through the third valve element 24 in the open state, and returns to the heat pump outdoor unit 1. Then, the pressure is reduced by the throttle 29 provided in the heat pump outdoor unit 1 to return to the low temperature and low pressure state. The flow path of the first refrigerant when the heat pump system is operating in the low temperature heating mode is shown as F1 in fig. 3.

When the heat pump system is operated in a heating mode, the outdoor heat exchanger 32 is used as an evaporator, and when the outdoor temperature is low, frosting may occur in the outdoor heat exchanger 32. In order to improve the heating effect of the heat pump system, heat can be transferred to the third heat exchange portion 18 through the medium in the terminal heat exchange portion 17, so that the temperature of the first refrigerant can be increased, and the defrosting speed of the outdoor heat exchanger 32 can be increased, thereby improving the heating effect of the heat pump system.

In some embodiments, the heat pump system may operate in the defrost mode when the temperature of the terminal heat exchange portion 17 is higher than a second preset temperature. For example, when the temperature of the terminal heat exchanging portion 17 is greater than or equal to 8 ℃, the heat pump system operates in the defrost mode. The temperature of the terminal heat exchange portion 17 includes the temperature of water or other medium in the terminal heat exchange portion 17.

For example, the heat pump system may periodically operate in defrost mode. For example, if the temperature of the terminal heat exchanging portion 17 is 8 ℃ or higher every 48 hours, the heat pump system enters the defrosting mode.

As shown in fig. 4, when the heat pump system is operated in the defrost mode, the first compressor 33 stops operating. The first valve element 22 is configured to operate in an off state to shut off the passage between the first heat exchange portion 12 and the low-temperature-stage circulation line 13. The third valve element 24 is configured to operate in a throttled state. The four-way valve 31 in the low-temperature-stage circulation system is commutated. The first refrigerant in the third heat exchange portion 18 exchanges heat with water in the terminal heat exchange portion 17, absorbs heat, and evaporates. Since the first valve element 22 closes the passage between the first heat exchanging portion 12 and the low-temperature-stage circulation line 13, the first refrigerant having absorbed heat cannot enter the low-temperature-stage circulation line 13 through the cascade heat exchanger 11, but flows into the outdoor heat exchanger 32 after being compressed in the second compressor 30, and is discharged to the outside heat exchanger 32 to complete defrosting. Then, the third valve element 24, which again passes through the throttle state, returns to the terminal heat exchanging portion 17. The flow path of the first refrigerant when the heat pump system is operating in defrost mode is shown as F3 in fig. 4. As can be seen from fig. 3 and 4, the flow direction F3 of the first refrigerant when the heat pump system operates in the defrost mode is opposite to the flow direction F1 of the first refrigerant when the heat pump system operates in the low temperature heating mode. Thus, the defrost mode may also be referred to as a reverse cycle defrost mode.

As shown in fig. 5A, when the heat pump system is operating in the high temperature heating mode, the first compressor 33 is operated. The first valve element 22 is configured to operate in an open state to communicate a passage between the first heat exchange portion 12 and the low-temperature-stage circulation line 13. The second valve element 23 is configured to operate in a throttled state to communicate the passage between the second heat exchanging portion 14 and the fourth heat exchanging portion 19. The third valve element 24 is configured to operate in an off state to shut off the passage between the third heat exchange portion 18 and the low-temperature-stage circulation line 13. The first refrigerant in the outdoor heat exchanger 32 absorbs heat from the outdoor environment or other external medium, evaporates, and then enters the second compressor 30 to be compressed, and the obtained high-temperature and high-pressure gaseous first refrigerant enters the first heat exchanging part 12 in the cascade heat exchanger 11. At this time, the first heat exchanging portion 12 is operated in a condensed state, and the second heat exchanging portion 14 is operated in an evaporated state. The second refrigerant in the second heat exchange portion 14 absorbs heat released by the first refrigerant in the first heat exchange portion 12, then evaporates and enters the first compressor 33 to be compressed, the obtained high-temperature and high-pressure gaseous second refrigerant enters the fourth heat exchange portion 19 to exchange heat with water in the terminal heat exchange portion 17, and the water in the terminal heat exchange portion 17 is heated to a set temperature, so that high-temperature heating of the heat pump system is realized. The flow path of the first refrigerant when the heat pump system is operating in the high temperature heating mode is shown as F1 in fig. 5A, and the flow path of the second refrigerant is shown as F2 in fig. 5A.

As shown in fig. 5B, when the heat pump system is operated in the rapid heating mode, the first valve element 22 is configured to operate in an open state to communicate the passage between the first heat exchanging portion 12 and the low temperature stage circulation line 13. The second valve element 23 is configured to operate in a throttled state to communicate the passage between the second heat exchanging portion 14 and the fourth heat exchanging portion 19. The third valve element 24 is configured to operate in an open state to communicate a passage between the third heat exchange portion 18 and the low-temperature-stage circulation line 13.

Therefore, the difference between the operation of the heat pump system in the rapid heating mode and the operation of the heat pump system in the high temperature heating mode is that the third valve element 24 is configured to operate in the open state when the heat pump system is operated in the rapid heating mode, so that the high-temperature and high-pressure gaseous first refrigerant compressed by the second compressor 30 may enter the first heat exchanging portion 12 of the cascade heat exchanger 11 or the third heat exchanging portion 18 to exchange heat with the terminal heat exchanging portion 17. The working principle of the high-temperature high-pressure gaseous first refrigerant entering the first heat exchange portion 12 of the cascade heat exchanger 11 for heat exchange is the same as that of the heat pump system when operating in the high-temperature heating mode, and will not be described herein. In the rapid heating mode, the water in the terminal heat exchange part 17 can be heated by the high-temperature-stage circulation system and the low-temperature-stage circulation system at the same time, so that the purpose of rapid heating is achieved. The flow path of the first refrigerant when the heat pump system is operating in the rapid heating mode is shown as F1 in fig. 5B, and the flow path of the second refrigerant is shown as F2 in fig. 5B.

In some embodiments, corresponding stop valves (27, 28) and nano-valves (25, 26) can be arranged at the connecting pipelines of the heat pump indoor unit 10 and the heat pump outdoor unit 1. The terminal heat exchanger 17 may be provided with valves (20, 21) or a receiver (not shown in fig. 2) for controlling the water path connection.

In some embodiments, the terminal heat exchange portion 17 may further include a first sub-terminal heat exchange portion 36 and a second sub-terminal heat exchange portion 37. The first sub-terminal heat exchange portion 36 is in series communication with the second sub-terminal heat exchange portion 37.

As shown in fig. 6A, the terminal heat exchanger assembly 16 may include a first terminal heat exchanger 34 and a second terminal heat exchanger 35, which first terminal heat exchanger 34 and second terminal heat exchanger 35 may be implemented, for example, as water fluorine heat exchangers. The first terminal heat exchanger 34 includes a first sub-terminal heat exchange portion 36 and a third heat exchange portion 18, and water in the first sub-terminal heat exchange portion 36 exchanges heat with a first refrigerant in the third heat exchange portion 18; the second terminal heat exchanger 35 includes a second sub-terminal heat exchange portion 37 and a fourth heat exchange portion 19, and the water in the second sub-terminal heat exchange portion 37 exchanges heat with the second refrigerant in the fourth heat exchange portion 19.

As shown in fig. 6B, the heat pump system may be used to produce high temperature water, such as water above 60 ℃. When the heat pump system produces high temperature water, the heat pump system is operated in a high temperature heating mode, and the first compressor 33 is operated. The first valve element 22 is configured to operate in an open state to communicate a passage between the first heat exchange portion 12 and the low-temperature-stage circulation line 13. The second valve element 23 is configured to operate in a throttled state to communicate the passage between the second heat exchanging portion 14 and the fourth heat exchanging portion 19. The third valve element 24 is configured to operate in an open state to open a passage between the third heat exchange portion 18 and the low-temperature-stage circulation line 13. The first refrigerant in the outdoor heat exchanger 32 absorbs heat from the outdoor environment or other external medium, evaporates, and then enters the second compressor 30 to be compressed, thereby forming a high-temperature and high-pressure gaseous first refrigerant. The high-temperature and high-pressure gaseous first refrigerant enters the first heat exchange portion 12. In the cascade heat exchanger 11, the first heat exchange portion 12 operates in a condensed state, the second heat exchange portion 14 operates in an evaporated state, the second refrigerant in the second heat exchange portion 14 exchanges heat with the first refrigerant in the first heat exchange portion 12, the second refrigerant absorbs heat and evaporates, the evaporated second refrigerant enters the first compressor 33 to be compressed, the gaseous second refrigerant with high temperature and high pressure enters the fourth heat exchange portion 19 in the second terminal heat exchanger 36 to exchange heat with water in the second sub-terminal heat exchange portion 37, and the water is heated to 60 ℃ or higher. The flow path of the first refrigerant when the heat pump system produces high temperature water is shown as F4 in fig. 6B, and the flow path of the second refrigerant is shown as F5 in fig. 6B.

Therefore, the heat pump system shown in fig. 6A may also operate in the low-temperature heating mode, the defrosting mode and the rapid heating mode, and the operating principle of the heat pump system when operating in the low-temperature heating mode, the defrosting mode and the rapid heating mode may be referred to the related descriptions of fig. 3, 4 and 5B, which are not repeated herein.

In some embodiments, other ways of connection exist for the first terminal heat exchanger 34 and the second terminal heat exchanger 35, unlike the heat pump systems shown in fig. 6A and 6B. As shown in fig. 7, 8 and 9, the second valve element 23 may also be connected to the first port of the fourth heat exchanging portion 19 and the first port of the second heat exchanging portion 14, respectively. One end of the first compressor 33 is connected to the second port of the fourth heat exchanging portion 19, and the other end of the first compressor 33 is connected to the second port of the second heat exchanging portion 14. The second valve element 23, the fourth heat exchange portion 19, the first compressor 33 and the second heat exchange portion 14 constitute a high-temperature-stage circulation system.

In some embodiments, the heat pump outdoor unit 1 further comprises a fourth valve element 104. As shown in fig. 7 and 9, both ends of the fourth valve element 104 are connected to the first port of the third heat exchanging portion 18 and the first port of the outdoor heat exchanger 32, respectively; the first end and the second end of the four-way valve 31 are respectively connected with the second interface of the first heat exchange part 12 and the second interface of the outdoor heat exchanger 32; the third end and the fourth end of the four-way valve 31 are respectively connected with two ends of the second compressor 30; the second interface of the third heat exchange portion 18 is connected to the second interface of the first heat exchange portion 12. The fourth valve element 104, the third heat exchanging portion 18, the first heat exchanging portion 12, the four-way valve 31, the second compressor 30, and the outdoor heat exchanger 32 constitute a low-temperature-stage circulation system.

In some embodiments, as shown in fig. 8, two ends of the fourth valve element 104 are respectively connected to the second interface of the first heat exchange portion 12 and the first interface of the outdoor heat exchanger 32, the first end and the second end of the four-way valve 31 are respectively connected to the second interface of the third heat exchange portion 18 and the second interface of the outdoor heat exchanger 32, the third end and the fourth end of the four-way valve 31 are respectively connected to two ends of the second compressor 30, and the first interface of the third heat exchange portion 18 is connected to the first interface of the first heat exchange portion 12.

To further improve the reliability of the heat pump system, in some embodiments, the heat pump indoor unit 10 may further include a water inlet pipe, a water pump 402, a first electric three-way valve 401, and a water outlet pipe.

In some embodiments, as shown in fig. 7, the inlet of the water pump 402 is connected to the water inlet pipe, and the outlet of the water pump 402 is connected to the inlet of the first electric three-way valve 401. The first outlet of the first electric three-way valve 401 is connected to the first interface of the first sub-terminal heat exchange portion 36, and the second outlet of the first electric three-way valve 401 is connected to the first interface of the second sub-terminal heat exchange portion 37. The second interface of the first sub-terminal heat exchange portion 36 and the second interface of the second sub-terminal heat exchange portion 37 are both connected to the water outlet pipe.

In some embodiments, as shown in fig. 8 and 9, an inlet of the water pump 402 is connected to the water inlet pipe, and an outlet of the water pump 402 is connected to the first interface of the first sub-terminal heat exchanging part 36. The second interface of the first sub-terminal heat exchange portion 36 is connected to the inlet of the first electric three-way valve 401, and the first outlet of the first electric three-way valve 401 is connected to the first interface of the second sub-terminal heat exchange portion 37. The second interface of the second sub-terminal heat exchange portion 37 and the second outlet of the first electric three-way valve 401 are both connected to the water outlet pipe.

In some embodiments, the heat pump system shown in fig. 7 may also produce medium and high temperature water. Illustratively, the low-temperature water may have a temperature of 40 ℃ to 60 ℃ and the high-temperature water may have a temperature of 60 ℃ to 80 ℃.

As shown in fig. 10, when the heat pump system shown in fig. 7 produces medium-temperature water, the second compressor 30 is operated, the first compressor 33 is stopped, the high-temperature-stage circulation system is not operated, and the low-temperature-stage circulation system is operated. The inlet of the first electric three-way valve 401 communicates with the first outlet of the first electric three-way valve 401, i.e. the first electric three-way valve 401 is in a straight-through state. The water of the water intake pipe flows into the first sub-terminal heat exchange part 36 through the water pump 402. At this time, the high-temperature and high-pressure gaseous first refrigerant compressed by the second compressor 30 passes through the first heat exchange portion 12, and the high-temperature-stage circulation system is not operated, so that the first refrigerant does not exchange heat in the cascade heat exchanger 11. When the first refrigerant enters the third heat exchange portion 18 from the first heat exchange portion 12, the first refrigerant exchanges heat with water in the first sub-terminal heat exchange portion 36 in the first terminal heat exchanger 34 to produce hot water at 40-60 ℃. The arrows in fig. 10 may represent the heat transfer direction during the medium temperature water production process.

As shown in fig. 11, when the heat pump system shown in fig. 7 is producing high-temperature water, the first compressor 33 and the second compressor 30 are operated, and both the low-temperature-stage circulation system and the high-temperature-stage circulation system are in operation. The inlet of the first electric three-way valve 401 is in communication with the second outlet of the first electric three-way valve 401, i.e. the first electric three-way valve 401 is in a bent-over state. The water of the water inlet pipe flows into the second sub-terminal heat exchange part 37 through the water pump 402. At this time, in the low-temperature-stage circulation system, the high-temperature and high-pressure gaseous first refrigerant compressed by the second compressor 30 enters the first heat exchange portion 12, and heat is released from the first heat exchange portion 12; the second refrigerant in the high-temperature-stage circulation system absorbs the heat emitted by the first heat exchange part 12 in the second heat exchange part 14, then enters the fourth heat exchange part 19, and exchanges heat with the water in the second sub-terminal heat exchange part 37 in the first terminal heat exchanger 35 to prepare hot water at 60-80 ℃. Illustratively, the temperature of the high-temperature water is associated with a second refrigerant used in the high-temperature-stage circulation system. For example, when the second refrigerant is R134a, the temperature of the high-temperature water may reach 80 ℃. The arrows in fig. 11 may represent the heat transfer direction during the high temperature water production process.

Fig. 12 is a schematic diagram of the operation of the heat pump system of fig. 7 when operating in defrost mode. As can be seen from fig. 7 and 12, the heat pump system shown in fig. 7 operates in the defrosting mode in a similar manner to the low temperature heating mode. The difference is that the flow direction of the first refrigerant when the heat pump system shown in fig. 7 operates in the defrost mode is opposite to the flow direction of the first refrigerant when it operates in the low temperature heating mode. The arrows in fig. 12 may represent the transfer direction of heat in the defrost mode.

The heat pump system shown in fig. 8 and 9 may also be operated in a low-temperature heating mode, a defrosting mode, a high-temperature heating mode and a rapid heating mode, and the operating principle of the heat pump system shown in fig. 7 to 9 when operated in different modes may be referred to the above description of fig. 3 to 5B and fig. 10 to 12, which will not be repeated here.

In some embodiments, to further improve the reliability of the heat pump system, the heat pump indoor unit may further include a temperature sensing assembly. The temperature sensing assembly is configured to detect the temperature of the medium in the terminal heat exchange portion 17. The heat pump system is configured to operate in a low temperature heating mode, a defrost mode, a high temperature heating mode, or a rapid heating mode in response to the temperature of the medium in the terminal heat exchange portion 17 detected by the temperature sensing assembly.

As shown in fig. 7, the temperature sensing assembly may include a first temperature sensor 301, a second temperature sensor 302, a third temperature sensor 303, a fourth temperature sensor 304, a fifth temperature sensor 305, a sixth temperature sensor 403, and a seventh temperature sensor 404.

The first temperature sensor 301 is disposed between the four-way valve 31 and the first heat exchanging portion 12, the second temperature sensor 302 is disposed between the first heat exchanging portion 12 and the third heat exchanging portion 18, and the third temperature sensor 303 is disposed between the third heat exchanging portion 18 and the fourth valve element 104. The fourth temperature sensor 304 is provided at the outlet of the first compressor 33, the fifth temperature sensor 305 is provided between the fourth heat exchanging portion 19 and the second valve element 23, the sixth temperature sensor 403 is provided between the water pump 402 and the first electric three-way valve 401, and the seventh temperature sensor 404 is provided at the outlet pipe.

In some embodiments, as shown in fig. 13, the fourth valve element 104 may include an indoor valve element 1041 and an outdoor valve element 1042. Wherein the second compressor 30, the four-way valve 31, the outdoor heat exchanger 32, and the outdoor valve element 1042 may be disposed at the heat pump outdoor unit 1; a water pump 402, a first electric three-way valve 401, a cascade heat exchanging portion 11, a terminal heat exchanging assembly 16, a second valve element 23, a first compressor 33, and an indoor valve element 1041 may be provided in the heat pump indoor unit 10.

In some embodiments, the heat pump system may include one heat pump indoor unit 10, or may include a plurality of heat pump indoor units 10. As shown in fig. 14, when the heat pump system includes one heat pump indoor unit 10, the heat pump indoor unit 10 and the heat pump outdoor unit 1 constitute a one-to-one heat pump system. As shown in fig. 15, when the heat pump system includes a plurality of heat pump indoor units 10, the plurality of heat pump indoor units 10 and the heat pump outdoor unit 1 constitute a one-to-many heat pump system.

In some embodiments, as shown in fig. 16, the heat pump indoor unit 10 may also be connected to the same heat pump outdoor unit 1 together with other indoor units (such as indoor units for adjusting the ambient temperature), to form a one-to-multiple multi-unit heat pump system. For example, as shown in fig. 17, the other indoor units may be at least one air-cooled indoor unit 2, and the at least one air-cooled indoor unit 2 and the heat pump indoor unit 10 are connected together to the heat pump outdoor unit 1.

When a plurality of different types of indoor terminal apparatuses connected to the terminal heat exchanging part 17 simultaneously have operational demands for cooling and heating, a large amount of water in the buffer tank may be in a state of being changed from cold water to hot water or from hot water to cold water. To reduce the buffer tank load, in some embodiments, as shown in fig. 18, the heat pump indoor unit 10 further includes a relay reversing device 201, a buffer tank 202, and indoor end devices 205,206,207. The indoor end devices 205,206,207 comprise a domestic hot water tank and at least one space heating/cooling device, at least two of the indoor end devices 205,206,207 being switched in operation.

As shown in fig. 18, the buffer tank 202 includes a first water inlet a', a first water outlet B, a first return water inlet C, and a second water outlet D. The relay reversing device 201 has a second water inlet a 'communicating with the water outlet of the terminal heat exchange portion 17, a third water outlet B' communicating with the water return port of the terminal heat exchange portion 17, and a second water return port C 'and a fourth water outlet D' communicating with the main piping of the indoor terminal equipment 205,206, 207.

The relay reversing device 201 further includes a first through leg, a first bypass leg, a second through leg, and a second bypass leg.

The first straight-through branch is directly communicated with the second water inlet A 'and the fourth water outlet D'. The first bypass branch includes a first sub-bypass branch and a second sub-bypass branch. The first sub bypass branch is communicated with the second water inlet A 'and the first water inlet A, and the second sub bypass branch is communicated with the first water outlet B and the fourth water outlet D'. The first through branch is communicated with the first bypass branch in a switching way, so that a communication pipeline from the terminal heat exchange part 17 to the indoor terminal equipment 205,206 and 207 is realized.

As shown by the solid arrows in fig. 19, when the first straight-through branch is connected, the first bypass branch is not connected, and at this time, the water flowing out from the water outlet of the terminal heat exchanging portion 17 does not exchange heat with the buffer water tank 202. As shown by the solid arrows in fig. 20, when the first bypass branch is connected, the first bypass branch is not connected, and at this time, the water flowing out from the water outlet of the terminal heat exchanging portion 17 exchanges heat with the buffer water tank 202.

The second straight-through branch is directly communicated with the second water return port C 'and the third water outlet B'. The second bypass branch includes a third sub-bypass branch and a fourth sub-bypass branch. The third sub bypass branch is communicated with the second water return port C 'and the first water return port C, and the fourth sub bypass branch is communicated with the second water outlet D and the third water outlet B'. The second through branch and the second bypass branch are communicated, so that communication pipelines between the indoor terminal devices 205,206 and 207 and the terminal heat exchange part 17 are realized.

As indicated by the broken-line arrows in fig. 19, when the second through-branches are in communication, the second bypass branches are not in communication, and at this time, the water flowing back from the indoor terminal apparatuses 205,206,207 to the terminal heat exchanging portion 17 does not exchange heat through the buffer tank 202. As indicated by the dashed arrow in fig. 20, when the second bypass branch is in communication, the second straight-through branch is not in communication, at which time water flowing back from the indoor end devices 205,206,207 to the end heat exchange portion 17 exchanges heat through the buffer tank 202.

In some embodiments, the relay reversing device 201 may implement switching between the through branch and the bypass branch through a plurality of electric three-way valves or a plurality of one-way valves.

As shown in fig. 18 to 20, the relay reversing device 201 includes a second electric three-way valve 2011, a third electric three-way valve 2012, a fourth electric three-way valve 2013, and a fifth electric three-way valve 2014.

The first end of the second electric three-way valve 2011 is communicated with the second water inlet A ', the second end of the second electric three-way valve 2011 is communicated with the first end of the third electric three-way valve 2012, the second end of the third electric three-way valve 2012 is communicated with the fourth water outlet D', the third end of the second electric three-way valve 2011 is communicated with the first water inlet A, and the third end of the third electric three-way valve 2012 is communicated with the first water outlet B.

As indicated by the solid arrows in fig. 19, when the first end of the second electric three-way valve 2011 communicates with the second end of the second electric three-way valve 2011, and the first end of the third electric three-way valve 2012 communicates with the second end of the third electric three-way valve 2012, a first straight branch is formed. At this time, the water flowing out from the water outlet of the terminal heat exchanging portion 17 flows to the indoor terminal equipment sides 205,206,207 through the first straight-through branch.

As indicated by solid arrows in fig. 20, when the first end of the second electric three-way valve 2011 and the third end of the second electric three-way valve 2011 are connected, a first sub bypass branch is formed; when the second end of the third electric three-way valve 2012 and the third end of the third electric three-way valve 2012 communicate, a second sub-bypass branch is formed. At this time, the water flowing out from the water outlet of the terminal heat exchanging portion 17 flows to the indoor terminal devices 205,206,207 through the first sub-bypass branch, the buffer tank 202, and the second sub-bypass branch.

Similarly, the first end of the fourth electric three-way valve 2013 communicates with the third water outlet B ', the second end of the fourth electric three-way valve 2013 communicates with the first end of the fifth electric three-way valve 2014, the second end of the fifth electric three-way valve 2014 communicates with the second water return port C', the third end of the fourth electric three-way valve 2013 communicates with the second water outlet D, and the third end of the fifth electric three-way valve 2014 communicates with the first water return port C.

As indicated by the dashed arrow in fig. 19, when the first end of the fourth electric three-way valve 2013 and the second end of the fourth electric three-way valve 2013 are in communication, and the first end of the fifth electric three-way valve 2014 and the second end of the fifth electric three-way valve 2014 are in communication, a second straight-through branch is formed. At this time, the return water on the indoor terminal equipment 205,206,207 side flows back to the return water port of the terminal heat exchange portion 17 through the second straight-through branch.

As indicated by the broken-line arrow in fig. 20, when the first end of the fourth electric three-way valve 2013 and the third end of the fourth electric three-way valve 2013 are connected, a third sub bypass branch is formed; when the second end of the fifth electric three-way valve 2014 and the third end of the fifth electric three-way valve 2014 are in communication, a fourth sub bypass branch is formed. At this time, the return water from the indoor terminal equipment 205,206,207 flows back to the return water port of the terminal heat exchange portion 17 through the fourth sub-bypass branch, the buffer tank 202, and the third sub-bypass branch.

In some embodiments, when controlling the first straight-through branch communication, the second straight-through branch communication must also be controlled; when controlling the communication of the first bypass branch, the corresponding control of the communication of the second bypass branch is necessary.

In some embodiments, the relay reversing device 201 may also implement switching between the through branch and the bypass branch through a plurality of check valves. For example, the relay reversing device 201 may include a first check valve, a second check valve, and a third check valve.

The first end of the first one-way valve is respectively connected with the second water inlet A 'and one end of the second one-way valve, the other end of the first one-way valve is respectively connected with the fourth water outlet D' and one end of the third one-way valve, the other end of the second one-way valve is connected with the first water inlet A, and the other end of the third one-way valve is connected with the first water outlet B.

When the first one-way valve is closed, the first straight-through branch is communicated; the first sub-bypass branch is closed when the second one-way valve is closed and the second sub-bypass branch is closed when the third one-way valve is closed.

Similarly, a plurality of check valves may also be employed to construct the second straight-through branch, the third sub-bypass branch, and the fourth sub-bypass branch, which are not described in detail herein.

To further enhance the flow capacity of the water in the relay reversing device 201, in some embodiments, the relay reversing device further comprises a first booster pump 2015 and a second booster pump 2016, as shown in fig. 18. A first booster pump 2015 is provided on the line between the second water inlet a' and the second electric three-way valve 2011 to increase the pressure of water on the line. A second booster pump 2016 is provided in the line between the third electric three-way valve 2012 and the fourth water outlet D' to increase the pressure of the water in the line.

In some embodiments, the domestic hot water tank 206 and the space heating/cooling devices 205,207 may belong to different types of indoor end devices. For example, domestic hot water tank 206 is in a heating mode when operating; while the space heating/cooling devices 205,207 may be operated in either a heating mode or a cooling mode.

In some embodiments, a powered three-way valve may be used between the indoor end devices 205,206,207 to effect the switching operation. As shown in fig. 18, the switching operation between the domestic hot water tank 206 and the two space heating/cooling apparatuses 205,207 can be achieved by the electric three-way valve 203 and the electric three-way valve 204. The first end of the electric three-way valve 203 is communicated with the fourth water outlet D', the second end of the electric three-way valve 203 is communicated with the water inlet side of the air disc 205, and the third end of the electric three-way valve 203 is communicated with the first end of the electric three-way valve 204; the second end of the electric three-way valve 204 is communicated with the water inlet side of the domestic hot water tank 206, and the third end of the electric three-way valve 204 is communicated with the water inlet side of the floor heater 207. When a space heating/refrigerating device is additionally arranged, an electric three-way valve can be correspondingly additionally arranged, and adjacent ports of the electric three-way valves are communicated with each other. In other embodiments, the switching operation between the indoor end equipments 205,206,207 may also be configured by providing a plurality of check valves, which will not be described herein.

The following describes the operation principle of the relay reversing device 201 when the domestic hot water tank 206 is heated and the space heating/cooling devices 205,207 are cooled or heated, or when the space heating/cooling devices 205,207 are switched between the cooling and heating modes.

In some embodiments, the buffer tank 202 may be used as a thermal storage device or a cold storage device.

(1) Buffer tank 202 as a thermal storage device

(1-1) during winter season, when the space heating/cooling devices 205,207 are heating and the domestic hot water tank 206 is also heating:

by collecting the temperature and target temperature of the water in the indoor terminal devices 205,206,207, the relay reversing device 201 is controlled so that the water flowing out of the water outlet of the terminal heat exchange portion 17 exchanges heat with or without passing through the buffer water tank 202.

In some embodiments, the control of the relay reversing device 201 may be controlled by the heat pump indoor unit 10, or may be controlled by a separate controller. The independent controller control prevents the buffer tank 202 from being able to communicate with the auxiliary heat source in the event of a failure of the heat pump indoor unit 10, thereby providing a heat source for the indoor end devices 205,206, 207. The auxiliary heat source can be, for example, a gas wall-mounted furnace, a solar water heater, a gas water heater or the like.

a. When the temperature difference between the water temperature and the target temperature of the indoor end devices 205,206,207 is within a preset temperature range (e.g., -5 ℃), the relay reversing device 201 is controlled to connect the first bypass branch to the buffer water tank 202 (the first bypass branch is disconnected), and at this time, the heat of the water in the buffer water tank 202 is used to provide a heat source for the indoor end devices 205,206, 207. Under the conditions of heating and small water temperature fluctuation, the heat quantity in the buffer water tank 202 is used, so that the temperature stability during space heating can be ensured, and the user comfort is improved.

b. When the difference between the water temperature and the target temperature of the indoor terminal devices 205,206 and 207 is not within the preset temperature range and the domestic hot water tank 206 heats, the relay reversing device 201 is controlled to enable the first through branch to be communicated, water flowing out of the water outlet of the terminal heat exchange part does not pass through the buffer water tank 202, the heating capacity of the heat pump system is utilized to provide a heat source for the indoor terminal devices 205,206 and 207, and the pressure of the buffer water tank 202 is reduced.

c. When the difference between the water temperature and the target temperature of the indoor terminal equipment 205,206 and 207 is not within the preset temperature range and the space heating/refrigerating equipment 205 and 207 heats, the relay reversing device 201 is controlled to enable the first bypass branch to be communicated with the buffer water tank 202, water flowing out of the water outlet of the terminal heat exchange part passes through the buffer water tank 202, heat in the buffer water tank 202 is fully utilized, temperature stability during space heating is ensured, and user comfort is improved.

(1-2) during a transitional season, such as spring or autumn, the space heating/cooling devices 205,207 automatically switch operation (referred to as an automatic operation mode), and the domestic hot water tank 206 still needs to be heated:

by collecting the outdoor ambient temperature, it is determined whether the space heating/cooling device 205,207 is required to perform cooling or heating.

a. When the space heating/refrigerating devices 205 and 207 need to heat, the relay reversing device 201 is controlled to enable the first bypass branch to be communicated with the buffer water tank 202, water flowing out of the water outlet of the terminal heat exchange portion 17 passes through the buffer water tank 202, heat in the buffer water tank 202 is fully utilized, stability of temperature during heating is ensured, and user comfort is improved.

When the space heating/refrigerating devices 205 and 207 need to be refrigerated, the relay reversing device 201 is controlled to enable the first through branch to be communicated, water flowing out of the water outlet of the terminal heat exchange part 17 does not pass through the buffer water tank 202, refrigeration of the space heating/refrigerating devices 205 and 207 is achieved by utilizing the refrigerating capacity of the heat pump system, and the pressure of the buffer water tank 202 is reduced.

b. In the automatic operation mode, when the space heating/cooling devices 205,207 are switched to the domestic hot water tank 206, the processes of heating the space heating/cooling devices 205,207 and the domestic hot water tank 206 are as described in (1-1), and will not be described herein.

c. In the automatic operation mode, when the space heating/refrigerating devices 205 and 207 perform the switching operation between refrigerating and heating of the domestic hot water tank 206, the relay reversing device 201 is controlled to enable the first through branch to be communicated, water flowing out of the water outlet of the terminal heat exchange part 17 does not pass through the buffer water tank 202, the condition that the water in the buffer water tank 202 is changed from cold water to hot water or from hot water to cold water is avoided, the load of the buffer water tank 202 is reduced, and meanwhile, the energy waste is avoided.

(1-3) the heat pump system may further include an auxiliary heat source 102, the auxiliary heat source 102 being configured to provide heat to the buffer tank 202. Illustratively, the auxiliary heat source 102 and the heat pump system cooperate to provide heat to the water in the buffer tank 202.

In some embodiments, auxiliary heat source 102 communicates with buffer tank 202 via a connecting line. When the buffer tank 202 is used as a heat storage device, the auxiliary heat source 102 is operated, and the start and stop of the auxiliary heat source 102 can be controlled by the heat pump system.

In the switching operation of the space heating/cooling devices 205,207 and the domestic hot water tank 206, the target temperature of the buffer tank 202 may be changed according to the indoor end devices 205,206,207, and the auxiliary heat source 102 and the heat pump indoor unit 10 may supply heat to the water in the buffer tank 202.

During the space heating/cooling devices 205,207 cooling and domestic hot water tank 206 heating switching operation: when the space heating/refrigerating equipment 205 and 207 refrigerates, the relay reversing device 201 is controlled to enable the first through branch to be communicated, water flowing out of the water outlet of the terminal heat exchange part 17 does not pass through the buffer water tank 202, and the refrigerating water is prevented from flowing into the buffer water tank 202; when the domestic hot water tank 206 heats, the relay reversing device 201 is controlled to communicate the first bypass branch with the buffer water tank 202, and water flowing out of the water outlet of the terminal heat exchange portion 17 passes through the buffer water tank 202 to utilize heat provided by the auxiliary heat source 102.

For example, when the auxiliary heat source 102 is a solar water heater, the water in the buffer water tank 202 can be heated by satisfying the solar heatable temperature condition, so that the energy is effectively utilized.

In some embodiments, the heat pump system may further comprise an alarm device that can alarm in time to alert the user when the heat pump system fails (e.g., when the compressor fails).

For the heat pump system with the auxiliary heat source 102, the cooling mode cannot be performed when the heat pump indoor unit 10 fails, but the heating mode can enter the emergency operation mode, and the auxiliary heat source 102 can be used for heating the water in the buffer water tank 202, so as to further meet the heating requirements of the indoor end devices 205,206 and 207.

(2) Buffer tank 202 as cold storage device

During summer or transition seasons, the space heating/cooling devices 205,207 cool and the domestic hot water tank 206 heat and switch operation:

when the space heating/refrigerating devices 205 and 207 are refrigerating, the relay reversing device 201 is controlled to enable the first bypass branch to be communicated with the buffer water tank 202, water flowing out of the water outlet of the terminal heat exchange portion 17 passes through the buffer water tank 202, and the water temperature is enabled to be in a lower state for a long time by utilizing the cold accumulation capacity of the buffer water tank 202, so that user comfort is improved.

When the domestic hot water tank 206 heats, the relay reversing device 201 is controlled to enable the first through branch to be communicated, water flowing out of the water outlet of the terminal heat exchange part 17 does not pass through the buffer water tank 202, the purpose that the water in the buffer water tank 202 is changed from cold water into hot water and the load of the buffer water tank 202 is reduced is avoided, and meanwhile, energy waste is avoided.

When there is a domestic hot water tank 206 and more than three space heating/cooling apparatuses switching operation, the operation process at the time of switching is similar as above.

In some embodiments, when the indoor end device includes at least two space heating/cooling devices, operation is switched between the space heating/cooling devices. As shown in fig. 18, when the space heating/cooling device 205 (a fan tray) and the space heating/cooling device 207 (floor heating) are switched to operate: if the buffer tank 202 is used as a heat storage device, for example, in winter, the process of heating the floor heating 207 and the air tray 205 is as described in (1-1), and will not be described in detail herein. If the buffer tank is used as a cold storage device, for example, in summer or in a transitional season, the fan tray 205 and the floor heater 207 select one of them to cool. At this time, the relay reversing device 201 is controlled to communicate the first bypass branch with the buffer water tank 202, and water flowing out of the water outlet of the terminal heat exchange portion passes through the buffer water tank 202, so that the cold accumulation capacity in the buffer water tank 202 is fully utilized, the water temperature in the system is kept in a lower state for a long time, and the user comfort is improved. When there are a plurality of space heating/cooling apparatuses, the operation process at the time of switching is similar to that described above, and will not be repeated here.

According to some embodiments provided by the disclosure, by arranging the relay reversing device 201 and the buffer water tank 202, the pressure of the buffer water tank 202 can be effectively reduced, the energy loss is reduced, and the user experience degree is effectively improved while different requirements of indoor terminal equipment 205,206 and 207 are met.

In order to achieve automatic adjustment of the rotational speed of the water pump, without manual repeated debugging, in some embodiments of the present disclosure, the heat pump indoor unit 10 may further include a pressure detection device, a flow detection device, a temperature detection device, a water pump self-circulation line, a water system full-circulation line, and a controller.

As shown in fig. 21, the pressure detecting means is for detecting the upstream pressure and the downstream pressure of the water pump 402, and includes a water pressure sensor 8-2 for detecting the upstream pressure of the water pump 402 and a water pressure sensor 8-1 for detecting the downstream pressure of the water pump 402.

The flow detection means comprises a water flow meter 9 for detecting the flow through the water pump 402.

The water pump self-circulation pipeline comprises a water pump 402 and an electric regulating valve 5. The water system full circulation line includes a water pump 402, an indoor heat exchanger 32 and indoor end equipment. Namely, the water pump self-circulation pipeline and the water system full-circulation pipeline share the water pump 402. The water pump 402 may be a variable frequency water pump.

The controller is coupled to the pressure detection device and the flow detection device and is configured to perform a water pump characteristic test through the water pump self-circulation line and a line characteristic test through the water system full-circulation line based on at least one of an upstream pressure of the water pump, a downstream pressure of the water pump, or a flow rate of the water pump.

In some embodiments, the switching of the water pump self-circulation line and the water system full-circulation line may be achieved through a sixth electric three-way valve. As shown in fig. 21, the sixth electric three-way valve may include an electric three-way valve 3-1 and an electric three-way valve 3-2.

In some embodiments, the heat pump indoor unit 10 further includes a temperature detecting device for detecting the outlet water temperature and the return water temperature of the terminal heat exchange portion 17. As shown in fig. 21, the temperature detection device may include, for example, a water outlet temperature sensor 501 and a water return temperature sensor 502.

In some embodiments, the heat pump indoor unit 10 further includes an automatic exhaust valve 6-1 and a safety valve 7-1 located in a full circulation line of the water system, and an automatic exhaust valve 6-2 and a safety valve 7-2 located in a self circulation line of the water pump.

As shown in fig. 21, the water system full circulation pipeline comprises a water pump 402, a water pressure sensor 8-1, an electric three-way valve 3-1, an indoor heat exchanger 32, an automatic exhaust valve 6-1, a safety valve 7-1, a water outlet temperature sensor 501, indoor terminal equipment, a backwater temperature sensor 502, an electric three-way valve 3-2, a water flow meter 9 and a water pressure sensor 8-2 which are sequentially connected through pipelines. The self-circulation pipeline of the water pump comprises a water pump 402, a water pressure sensor 8-1, an electric three-way valve 3-1, an automatic exhaust valve 6-2, a safety valve 7-2, an electric regulating valve 5, an electric three-way valve 3-2, a water flow meter 9 and a water pressure sensor 8-2 which are sequentially connected through pipelines.

For example, the water pump 402 may implement automatic adjustment of different rotational speeds according to control input parameters. The electric three-way valve 3-1 and the electric three-way valve 3-2 can be switched among different pipelines according to control signals, so that the conversion of waterways is realized. The electric control valve 5 may have a plurality of opening degree adjusting functions. The automatic exhaust valve 6-1 and the automatic exhaust valve 6-2 can release the redundant air in the pipeline. When the pipeline pressure exceeds the limit value, the safety valve 7-1 and the safety valve 7-2 release the pressure to play a role in protection. The water pressure sensors 8-1 and 8-2 may collect water pressure downstream and upstream of the water pump 402 for resistance determination. The water flow meter 9 may measure the flow of water into and out of the water pump 402. The water outlet temperature sensor 501 and the backwater temperature sensor 502 are used for detecting the temperatures of the water outlet and backwater of the terminal heat exchange part 17, and participate in the adjustment of the rotation speed of the water pump during the constant temperature difference control.

In some embodiments, the water pump self-circulation line and the water system full-circulation line include a first water replenishment port and a second water replenishment port, respectively. As shown in fig. 21, the first water replenishment port includes a water replenishment port 1, and the second water replenishment port includes a water replenishment port 2. Wherein, the water supplementing port 1 is positioned between the water pump 402 and the electric three-way valve 3-2, and the water supplementing port 2 is positioned between the indoor terminal equipment 205 and the electric three-way valve 3-2.

To improve the accuracy of the pump and line characteristics tests, in some embodiments, the controller is configured to perform pump drain control prior to performing the pump and line characteristics tests.

The heat pump indoor unit 10 can realize the automatic emptying and the automatic testing of the water pump characteristic of the water pump self-circulation pipeline through the water pump self-circulation, and realize the automatic emptying and the automatic testing of the pipeline characteristic of the whole water system full-circulation pipeline through the water system full-circulation.

The following describes the operation principle of the heat pump system shown in fig. 21 when it is operated in the heating mode, the cooling mode, the self-circulation mode of the water pump, and the full-circulation mode of the water system, respectively.

1. Heating mode

As shown in fig. 21, the heat pump outdoor unit 1 acquires heat from the outdoor air or other medium, compresses the refrigerant by the compressor, and then the refrigerant enters the terminal heat exchange unit 16 in the heat pump indoor unit 10, and exchanges heat with the terminal heat exchange portion 17 to heat the water in the terminal heat exchange portion 17. The pipeline (6) is communicated with the pipeline (7) by controlling the inner valve core of the electric three-way valve 3-1. The pipeline (4) is communicated with the pipeline (5) by controlling the inner valve core of the electric three-way valve 3-2. The electric control valve 5 is completely closed and the water pump 402 is operated. The electronic expansion valve 2 is controlled and regulated according to the control rule of the heat pump system.

When the heat pump system is in the heating operation mode, as shown in fig. 21, the refrigerant flows through the refrigerant gas pipe, the pipeline (1), the pipeline (2) and the pipeline (3) of the heat pump outdoor unit 1 to reach the refrigerant liquid pipe of the heat pump outdoor unit 1, so as to form a refrigerant circulation loop. The water flows through the pipeline (4), the pipeline (5), the pipeline (6), the pipeline (7), the pipeline (8) and the pipeline (4) to form a circulation loop of the water system.

2. Refrigeration mode

As shown in fig. 21, heat of the heat pump indoor unit 10 is transferred to the liquid refrigerant through the water system. The liquid refrigerant passes through the refrigerant pipeline and releases heat to the outdoor air after the pressure is increased by the compressor. The pipeline (6) is communicated with the pipeline (7) by controlling the inner valve core of the electric three-way valve 3-1. The pipeline (4) is communicated with the pipeline (5) by controlling the inner valve core of the electric three-way valve 3-2. The electric control valve 5 is completely closed and the water pump 402 is operated. The electronic expansion valve 2 is controlled and regulated according to the control rule of the heat pump system.

When the heat pump system is in the cooling operation mode, as shown in fig. 21, the refrigerant flows through the refrigerant liquid pipe, the pipeline (3), the pipeline (2), the pipeline (1) and the refrigerant gas pipe of the heat pump outdoor unit 1 to form a refrigerant circulation loop. The water flows through the pipeline (4), the pipeline (5), the pipeline (6), the pipeline (7), the pipeline (8) and the pipeline (4) to form a circulation loop of the water system.

3. Self-circulation mode of water pump

This mode is applicable to the situation that the heat pump set carries out the water resistance check during installation and debugging. The heat pump system can only start the cooling/heating mode if this mode is off.

As shown in fig. 21, the pipe (6) is made to communicate with the pipe (9) by controlling the internal spool of the electric three-way valve 3-1. The pipeline (10) is communicated with the pipeline (5) by controlling the inner valve core of the electric three-way valve 3-2. The electric control valve 5 is adjusted according to the set opening difference. The water pump 402 is operated. The electronic expansion valve 2 is fully closed.

When the heat pump system operates in the water pump self-circulation mode, the refrigerant circulation loop is in a closed state. The water flow of part of the system pipelines in the heat pump system forms a water system circulation loop through the pipeline (5), the pipeline (6), the pipeline (9), the pipeline (10) and the pipeline (5).

When the heat pump system runs in the self-circulation mode of the water pump, automatic emptying control is needed to be carried out firstly, and then automatic testing of the characteristics of the water pump is carried out.

The controller is used for supplementing water through the water supplementing port 1 when the pressure P1 at the downstream of the water pump is lower than the lower limit value M of the pressure of the water system after the water pump is started from the circulating system; when the pressure P1 downstream of the water pump is higher than the lower limit value M of the water system pressure, the water pump 402 is controlled to intermittently operate until the pressure P1 downstream of the water pump 402 is between the lower limit value M and the upper limit value N of the water system pressure, and the absolute value of the difference between the downstream pressure of the water pump 402 at the first time and the downstream pressure at the second time is lower than the water pressure fluctuation limit value K within the third preset time period.

For example, the first time and the second time may be any time, for example, when the first time is the nth time, the second time may be a time preceding the first time, such as the n-1 th time. The third preset duration may be any duration, for example, the third preset duration may be t5 time.

In the automatic emptying control in the self-circulation mode of the water pump, the water filling port 1 can not be closed until the automatic emptying is finished. When the controller controls the water pump 402 to operate intermittently, the rotational speeds of the adjacent two water pumps 402 are different.

In some embodiments, the water pump 402 may operate at a maximum speed, or at any speed below the maximum speed. For example, the water pump 402 may operate at a maximum speed a, which is a value greater than 0 and less than 1.

As shown in fig. 22, the pump-evacuation control method of the heat pump unit before the pump characteristic test includes S1 to S11.

S1, starting the water pump in a self-circulation mode.

S2, P1 is more than M, if yes, the step S4 is carried out, and if not, the step S3 is carried out.

S3, supplementing water by the water supplementing port 1, and entering the step S2.

S4, the water pump 402 operates at the highest rotation speed. the time t1 passes.

S5, the water pump 402 stops running. the time t2 passes.

S6, the highest rotation speed of the water pump 402 is operated. time t3 passes.

S7, stopping the operation of the water pump 402. time t4 passes.

S8, the water pump 402 operates at the highest rotation speed.

S9, M is less than P1 and less than N, if yes, the step S10 is carried out, and if not, the step S4 is carried out.

S10, | (P1 (n) -P1 (n-1) | < K, and maintaining the set time t5, if yes, proceeding to step S11, otherwise proceeding to step S4.

S11, completing the emptying control.

Wherein, P1: the water pressure sensor 8-1 detects the pressure and the pressure MPa;

p2: the water pressure sensor 8-2 detects the pressure and MPa;

m: the lower limit value of the pressure of the water system is MPa;

n: the upper limit value of the pressure of the water system is MPa;

p1 (n): the water pressure at the moment n is MPa;

p1 (n-1): the water pressure at the moment n-1 is MPa;

k: water pressure fluctuation limit value, MPa;

a: rotation speed ratio,%;

t1-t5: duration, s.

After the pump is emptied, a pump characteristic test may be performed.

The controller carries out water pump characteristic test through water pump self-circulation pipeline, includes: firstly, controlling the water pump to conduct from a circulating pipeline, controlling the water pump to run at a first rotation speed, and controlling the electric regulating valve 5 to maintain a first opening corresponding to the first rotation speed within a first preset duration; then, calculating an average value of the downstream pressure and the upstream pressure difference of the pressure detection device in a first preset duration to obtain a first operation parameter, wherein the first operation parameter corresponds to the lift of the water pump, and comprises a first rotating speed and a first opening; secondly, calculating an average value of the flow detected by the flow detection device in a first preset time length to obtain an average value of the flow of the water pump corresponding to a first operation parameter; and finally, obtaining a test result of the water pump characteristic test according to the lift of the water pump corresponding to the plurality of operation parameters and the flow average value of the water pump corresponding to the plurality of operation parameters, wherein the plurality of operation parameters comprise a first operation parameter, and the test result of the water pump characteristic test comprises a water pump characteristic curve.

The first rotation speed of the water pump 402 may be multiple, each rotation speed may correspond to multiple openings of the electric control valve 5, and the water pump 402 needs to maintain a set duration at each opening corresponding to each rotation speed. Calculating an average value delta P of the downstream pressure and the upstream pressure difference detected by the set long internal pressure detection device, wherein delta P is the pump lift; meanwhile, calculating the flow average value Q detected by the flow detection device in the set time of each rotating speed. The first preset duration may be any duration, for example, the first preset duration may be time t 11.

The following describes a method for testing the water pump characteristics of the heat pump unit with reference to fig. 23:

s1, emptying control is completed.

S2, the water pump 402 operates at the highest rotation speed.

S3, program 1: the electric control valve 5 is fully closed and then opened (opening 20%). time t11 passes, Δp and Q corresponding to a coordinate point of 20% of the opening of the electric control valve 5 shown in fig. 24 are calculated.

S4, program 2: the electric control valve 5 is opened (opening degree 50%). time t11 passes, Δp and Q corresponding to a coordinate point of 50% of the opening of the electric control valve 5 shown in fig. 24 are calculated.

S5, program 3: the electric control valve 5 is opened (opening degree 70%). time t11 passes, Δp and Q corresponding to a coordinate point of 70% of the opening of the electric control valve 5 shown in fig. 24 are calculated.

S6, program 4: the electric control valve 5 is opened (opening degree 100%). time t11 passes, Δp and Q corresponding to coordinate points of 100% of the opening of the electric control valve 5 shown in fig. 24 are calculated.

According to the coordinate point of 20% of the opening of the electric control valve 5, the coordinate point of 50% of the opening of the electric control valve 5, the coordinate point of 70% of the opening of the electric control valve 5, and the coordinate point of 100% of the opening of the electric control valve 5 shown in fig. 24, when the water pump 402 is operated at the maximum rotation speed, the water pump characteristic curve corresponding to the maximum rotation speed of the water pump 402 can be obtained.

And S7, running 75% of the maximum rotation speed of the water pump 402.

S8, repeating S3 to S7.

Repeating S3 to S7 may obtain a pump characteristic curve corresponding to 75% of the maximum rotation speed of the water pump 402 according to the operation of the water pump 402 at 75% of the maximum rotation speed.

And S9, running 50% of the highest rotation speed of the water pump 402. And if the set lower limit rotating speed of the water pump is reached, ending the test after the operation is finished.

S10, repeating S3 to S7.

Repeating S3 to S7 can obtain a pump characteristic curve corresponding to 50% of the maximum rotation speed of the water pump 402 according to the operation of the water pump 402 at 50% of the maximum rotation speed.

S11, the maximum rotation speed of the water pump 402 is 25%, and the curve of the maximum rotation speed x25% of the water pump 402 is shown in fig. 24. And if the set lower limit rotating speed of the water pump is reached, ending the test after the operation is finished.

S12, repeating S3 to S7.

Repeating S3 to S7 may obtain a pump characteristic curve corresponding to 25% of the maximum rotation speed of the water pump 402 according to the operation of the water pump 402 at 25% of the maximum rotation speed.

S13, the lower limit rotation speed of the water pump 402, as shown in fig. 24.

S14, repeating S3 to S7.

Repeating S3 to S7 can obtain a pump characteristic curve corresponding to the lower limit rotation speed of the water pump 402 according to the operation of the water pump 402 at 50% of the maximum rotation speed.

And S15, finishing the automatic test of the water pump characteristics.

Wherein Δp: the lift of the water pump, delta P is the average value of the pressure difference (P1-P2) before and after the water pump in t11 time, and MPa;

p1: the water pressure sensor 8-1 detects the pressure and the pressure of MPa;

p2: the water pressure sensor 8-2 detects the pressure and MPa;

q: the water flowmeter 9 detects the average value, m, of the data at time t11 ³ /h；

t11: the electric control valve 5 fixes the duration of the opening, s.

In some embodiments, the heat pump system automatically draws a water pump characteristic curve from the water pump characteristic automatic test data. The curve is embedded in an internal program of the heat pump system, and can be displayed on a user side controller interface, so that convenience is brought to installation and maintenance personnel to check waterways.

4. Full circulation mode of water system

As shown in fig. 21, the pipe (6) is made to communicate with the pipe (7) by controlling the internal spool of the electric three-way valve 3-1. The pipeline (4) is communicated with the pipeline (5) by controlling the inner valve core of the electric three-way valve 3-2. The electric control valve 5 is completely closed. The water pump 402 is operated. The electronic expansion valve 2 is fully closed. And when the heat pump system is in the water system full-circulation mode, the refrigerant circulation loop is in a closed state. The water flow of part of the system pipelines in the heat pump system forms a water system circulation loop through the pipeline (5), the pipeline (6), the pipeline (7), the pipeline (8), the pipeline (4) and the pipeline (5).

When the heat pump system is in a water system full-circulation mode, automatic emptying control is needed, and then automatic testing of pipeline characteristics is needed.

The controller is used for supplementing water through the water supplementing port 2 when the downstream pressure P1 of the water pump is lower than the lower limit value M of the water system pressure after the water system is started in a full cycle mode; when the downstream pressure P1 of the water pump is higher than the lower limit value M of the water system pressure, the water pump 402 is controlled to intermittently operate until the downstream pressure P1 of the water pump 402 is between the lower limit value M and the upper limit value N of the water system pressure, and the absolute value of the difference between the downstream pressure of the water pump 402 at the first time and the downstream pressure at the second time is lower than the water pressure fluctuation limit value K within the third preset time period. The first time and the second time may be any time, for example, when the first time is the nth time, and the second time may be a time preceding the first time, such as (n-1) time. The third preset duration may be any duration, for example, the third preset duration may be t5 time.

In the automatic draining control in the water system full circulation mode, the water replenishing port 2 can not be closed until the automatic draining is finished. When the controller controls the water pump 402 to operate intermittently, the rotational speeds of the adjacent two water pumps 402 are different.

As shown in fig. 25, the pump-down control method of the heat pump unit before the pipeline characteristic test is performed is as follows:

s1, starting the water system in a full-cycle mode.

S3, supplementing water by the water supplementing port 2, and entering the step S2.

S4, the water pump 402 operates at the highest rotation speed. the time t6 passes.

S5, the water pump 402 stops running. the time t7 passes.

S6, the highest rotation speed of the water pump 402 is operated. time t8 passes.

S7, stopping the operation of the water pump 402. time t9 passes.

S8, the water pump 402 operates at the highest rotation speed.

S11, completing the emptying control.

p2: the water pressure sensor 8-2 detects the pressure and MPa;

m: the lower limit value of the pressure of the water system is MPa;

n: the upper limit value of the pressure of the water system is MPa;

p1 (n): the water pressure at the moment n is MPa;

p1 (n-1): the water pressure at the moment n-1 is MPa;

k: water pressure fluctuation limit value, MPa;

a: rotation speed ratio,%;

t6-t10: duration, s.

After the water pump is emptied, a pipeline characteristic test can be performed.

The controller carries out pipeline characteristic test through water system full cycle pipeline, includes: firstly, controlling the full-cycle management conduction of a water system, and controlling a water pump to run at a second rotating speed for a second preset time period; then, calculating the average value of the downstream pressure of the pressure detection device and the pressure difference in the second preset time period to obtain the pipeline internal resistance corresponding to the second rotating speed; then, calculating an average value of the flow detected by the flow detection device in a second preset duration to obtain a flow average value corresponding to a second rotating speed; finally, according to the pipeline internal resistance corresponding to the multiple rotating speeds and the flow average value corresponding to the multiple rotating speeds, obtaining a test result of the pipeline characteristic test; the test results of the line characteristic test include a line characteristic curve.

The number of second rotational speeds of the water pump 402 may be plural, and each rotational speed needs to be maintained for a set period of time, and an average value Δp 'of the downstream pressure and the upstream pressure difference detected by the pressure detecting device in the set period of time is calculated, where Δp' is the resistance in the pipeline; at the same time, an average value Q' of the flow rates detected by the flow rate detecting means is calculated in the set period of time. The second preset duration may be any duration, for example, the second preset duration may be t 12. The following is a method for testing pipeline characteristics with reference to fig. 26:

s1, emptying control is completed.

S2, the water pump 402 operates at the highest rotation speed. the time t12 passes, Δp 'and Q' are calculated, which correspond to the coordinate points of the highest rotation speed of the water pump 402 shown in fig. 27.

And S3, running 75% of the maximum rotation speed of the water pump 402. the time t12 passes, Δp 'and Q' are calculated, which correspond to the coordinate points of 75% of the maximum rotation speed of the water pump 402 shown in fig. 27.

And S4, running 50% of the highest rotation speed of the water pump 402. the time t12 passes, Δp 'and Q' are calculated, which correspond to coordinate points of 50% of the maximum rotation speed of the water pump 402 shown in fig. 27.

And S5, the maximum rotation speed of the water pump 402 is 25 percent. the time t12 passes, Δp 'and Q' are calculated, which correspond to coordinate points of 25% of the maximum rotation speed of the water pump 402 shown in fig. 27.

The line characteristic curve can be obtained from the coordinate point of the highest rotation speed of the water pump 402, the coordinate point of 75% of the highest rotation speed of the water pump 402, the coordinate point of 50% of the highest rotation speed of the water pump 402, and the coordinate point of 50% of the highest rotation speed of the water pump 402 shown in fig. 24.

And S6, finishing the automatic test of the water pump characteristics.

Wherein Δp': the resistance in the pipeline is controlled by the pressure of the air,

ΔP' is the average value of the pressure difference (P1-P2) before and after the water pump 402 in t12 time, MPa;

p1: the water pressure sensor 8-1 detects the pressure and the pressure of MPa;

p2: the water pressure sensor 8-2 detects the pressure and MPa;

q': the water flowmeter 9 detects the average value, m, of the data at time t12 ³ /h；

t12: the duration of operation of the water pump 402 at a fixed rotational speed, s.

In some embodiments, the heat pump system automatically draws a line characteristic curve from the line characteristic automatic test data. The curve is embedded in an internal program of the heat pump system, and can be displayed on a user side controller interface, so that convenience is brought to installation and maintenance personnel to check waterways.

In order to meet different requirements of users on water temperature control, the heat pump system can define three different water pump control functions of fixed rotating speed, fixed water quantity and fixed water temperature difference in a heating mode and a refrigerating mode.

At the fixed speed function, the water pump 402 will operate at the set speed. Under the function of water metering, the circulating water flow of the heat pump system is kept at a set value through the variable frequency adjustment of the rotating speed of the water pump 402. Under the function of the fixed water temperature difference, the water temperature difference (refrigeration mode: water temperature difference=backwater temperature-water outlet temperature; heating mode: water temperature difference=water outlet temperature-backwater temperature) of the heat pump system is kept at a set value through frequency conversion adjustment of the rotating speed of the water pump 402. The user can set different maximum rotation speeds and lower limit rotation speeds of the water pump according to the requirements.

1. Fixed rotation speed function

This function is applicable to the case where the heat pump system is normally operated in the cooling/heating mode. The heat pump system can only start this function if the cooling/heating mode is on. Under this function, the water pump 402 will operate at a set rotational speed.

The pipeline (6) is communicated with the pipeline (7) by controlling the inner valve core of the electric three-way valve 3-1. The pipeline (4) is communicated with the pipeline (5) by controlling the inner valve core of the electric three-way valve 3-2. The electric control valve 5 is completely closed. The water pump 402 operates at a set rotational speed. The electronic expansion valve 2 is controlled and regulated according to the control rule of the heat pump system.

As shown in fig. 28, the constant rotation speed control method is:

s1, setting the rotating speed on an operation interface by a user. Default maximum rotational speed, if not actively set by the user, will be performed at the maximum rotational speed.

S2, starting a refrigerating/heating mode.

S3, the water pump 402 operates according to the set rotating speed.

S4, the refrigerating/heating mode is closed. time t13 elapsed, t13: the water pump delays the stop time s.

S5, the water pump 402 stops running.

2. Constant water flow function

This function is applicable to the case where the heat pump system is normally operated in the cooling/heating mode. This function can only be activated if the heat pump system cooling/heating mode is on.

The pipeline (6) is communicated with the pipeline (7) by controlling the inner valve core of the electric three-way valve 3-1. The pipeline (4) is communicated with the pipeline (5) by controlling the inner valve core of the electric three-way valve 3-2. The electric control valve 5 is completely closed. The water pump 402 is operated. The electronic expansion valve 2 is controlled and regulated according to the control rule of the heat pump system.

Under this function, the unit installation or maintenance personnel can set the water flow required by the operation of the heat pump system as required. The heat pump system will form a pump-line characteristic from the pump characteristic (fig. 24) measured in the pump self-circulation mode and the line characteristic (fig. 27) measured in the water system full-circulation mode, as shown in fig. 29.

The controller is further configured to: firstly, acquiring a first water flow; then, according to the first water flow and the pipeline characteristic curve, obtaining the rotating speed corresponding to the first water flow; and finally, controlling the water pump to run at a rotating speed corresponding to the first water flow.

The first water flow is required water flow, for example, the required water flow set by a user, a working point corresponding to a characteristic curve of a pipeline is obtained according to the required water flow, and a water pump rotating speed corresponding to the characteristic curve of the water pump passing through the working point is selected as a target rotating speed of the water pump to control the water pump to operate.

For example, when the user sets the water flow rate to 0.6m ³ As shown in fig. 29, the heat pump system firstly obtains a corresponding working point (such as working point 1) on the pipeline characteristic through the water flow, and selects a water pump rotation speed curve (the highest rotation speed of the water pump 4 is multiplied by 25%) which also passes through the point, wherein the water pump rotation speed (the highest rotation speed of the water pump 4 is multiplied by 25%) corresponding to the curve can be used as the determined water pump running rotation speed.

In some embodiments, the controller may also obtain the target rotational speed of the water pump by linearly interpolating adjacent water pump characteristics when the operating point is not on the measured water pump characteristics.

For example, the user sets the water flow to 0.5m ³ As shown in FIG. 29, the heat pump system obtains the pipeline characteristics through the water flowAnd (3) the corresponding working point (such as the working point 2) is not on the measured water pump characteristic curve, and the proper water pump rotating speed is finally obtained by linearly interpolating the adjacent water pump characteristic curves (the highest rotating speed of the water pump 4 is multiplied by 25 percent and the lower limit rotating speed of the water pump 4).

The rotational speed of the water pump is dynamically adjusted according to real-time data measured by the water flow meter 9 in the running process, as shown in fig. 30:

s1, the water pump 402 operates at a constant flow rate rotation speed. the time t14 passes.

S2、△R1(n)＝η1*{△Q(n)-△Q(n-1)}+η2*△Q(n)。△R2(n)＝η3*Q(n-1)。

S3、△R(n)＝△R1(n)+△R2(n)。

S4, R (n) =r (n-1) +Δr (n). Step S1 is entered.

Wherein, R (n) is the water pump rotation speed ratio (the ratio of the water pump rotation speed to the highest rotation speed,%);

r (n-1) is the rotation speed ratio (the ratio of the water pump to the highest rotation speed,%);

DeltaR (n): water pump rotational speed variation ratio at time n (constant water flow control),%;

ΔR1 (n): PID controlled pump speed variation ratio at time n (constant water flow control),%;

ΔR2 (n): water pump rotational speed variation ratio (constant water flow control) for overshoot and undershoot control at time n,%;

eta 1, eta 2, PID control constant (< 0) of constant water flow control;

eta 3, determining the overshoot and undershoot control constants of water flow control;

delta Q (n) =q (n) -Qs (n), the difference between the water flow rate detected by the water flow meter 9 at time n and the set water flow rate;

q (n) is water flow rate at time n, unit m ³ /h；

Qs (n) set water flow at time n, unit m ³ /h；

And t14, running time of the water pump at the fixed water quantity rotating speed, s.

3. Water temperature difference determining function

This function is applicable to the case where the heat pump system is normally operated in the cooling/heating mode. The heat pump system can only start the cooling/heating mode if this mode is on.

The pipeline (6) is communicated with the pipeline (7) by controlling the inner valve core of the electric three-way valve 3-1. The pipeline (4) is communicated with the pipeline (5) by controlling the inner valve core of the electric three-way valve 3-2. The electric control valve 5 is completely closed. The water pump 402 is operated. The electronic expansion valve 2 is controlled and regulated according to the air source heat pump control rule.

The controller is further configured to: firstly, acquiring a water temperature difference required by a user; then, according to the current water outlet temperature and the water return temperature of the terminal heat exchange part, the current water temperature difference is obtained; then, calculating target water flow according to the current water temperature difference, the current water flow detected by the flow detection device and the water temperature difference required by the user; and finally, controlling the water pump to run at a preset maximum rotation speed, and controlling the water pump to run at a target rotation speed corresponding to the target water flow after the running is stable.

The target water flow includes a demand water flow, determined by the current water temperature difference and the current water flow. The water pump 402 is controlled to operate based on the desired water flow rate to achieve a target rotational speed of the water pump.

For example, the water temperature difference required by the operation of the heat pump system can be set by a machine set installation or maintenance personnel according to the requirement (refrigeration mode: water temperature difference=backwater temperature-outlet water temperature; heating mode: water temperature difference=outlet water temperature-backwater temperature). In the initial stage of operation of the heat pump system, the water pump 402 will operate at a set maximum rotational speed. After the initial stage is finished, namely after the operation parameters of the heat pump system are stable, the heat pump system can acquire the backwater temperature, the water outlet temperature and the water flow in real time, and according to the relation (Q1xDeltaT 1=Q2xDeltaT 2) between the water temperature difference and the water flow, the water flow corresponding to the set water temperature difference is calculated, and the water flow Q2=the current water flow Q1 x the current water temperature difference DeltaT 1/the set water temperature difference DeltaT 2 corresponding to the set water temperature difference is calculated. And then the corresponding initial constant temperature difference rotating speed of the water pump is obtained by a control mode with the same constant water flow function as the water flow function. The rotational speed of the water pump is dynamically adjusted according to the temperature values detected by the water outlet temperature sensor 501 and the water return temperature sensor 502 in the running process, as shown in fig. 31:

S1, the water pump 402 operates at a constant temperature difference rotating speed. the time t15 passes.

S2、△R3(n)＝η4*{△tr(n)-△tr(n-1)}+η5*△tr(n)。△R4(n)＝η6*△tr(n)。

S3、△R＇(n)＝△R3(n)+△R4(n)。

S4, R (n) =r (n-1) +Δr' (n). Step S1 is entered.

DeltaR' (n): water pump rotation speed change ratio at time n (constant water temperature difference control),%;

Δr3 (n): the rate of change of water pump rotational speed (constant water temperature difference control) by PID control at time n,%;

ΔR4 (n): water pump rotation speed change ratio (constant water temperature difference control) for overshoot and undershoot control at time n,%;

eta 4 and eta 5, PID control constant (< 0) of constant water temperature difference control;

η6 is a control constant for overshoot and undershoot of the constant water temperature difference control;

deltatr (n) is the difference between the measured water temperature difference and the set water temperature difference at time n, deltatr (n) = Deltatt (n) -Deltats (n);

deltat (n) is the measured water temperature difference at time n in units of DEG C;

deltats (n) is the set water temperature difference at time n, in units of DEG C;

t15: and (3) running time s of the water pump at the constant temperature difference rotating speed.

The heat pump system shown in fig. 21 can realize the water pump characteristic test and the pipeline characteristic test, and can realize the automatic adjustment of the rotation speed of the water pump according to the test result, and repeated debugging is not needed. Meanwhile, the control of the fixed rotating speed, the fixed flow and the fixed temperature difference of the heat pump system can be realized according to the needs of users.

Some embodiments of the present disclosure provide a control method of a heat pump system, which may be the heat pump system described in any one of the foregoing embodiments. As shown in fig. 32, the control method of the heat pump system includes: steps 321 to 324.

Step 321, determining whether the heat pump system meets preset conditions, wherein the preset conditions comprise a low-temperature heating condition, a defrosting condition, a high-temperature heating condition or a rapid heating condition.

And step 322, if the heat pump system meets the low-temperature heating condition or the defrosting condition, controlling the terminal heat exchange part to exchange heat with the third heat exchange part.

The low temperature heating condition includes, but is not limited to, the set temperature being lower than a first preset temperature; the defrosting conditions include, but are not limited to, the temperature of the terminal heat exchanging part 17 being higher than a second preset temperature, which may be 8 deg.c, for example.

In some embodiments, the first compressor 33 is controlled to be shut down when the heat pump system meets a low temperature heating condition or a defrost condition; alternatively, the first compressor 33 is controlled to stop, while the first valve element 22 and the second valve element 23 are controlled to be turned off, and the third valve element 24 is controlled to be communicated.

Step 323, if the heat pump system meets the high-temperature heating condition, the terminal heat exchange part is controlled to exchange heat with the fourth heat exchange part.

The high temperature heating condition comprises that the set temperature is higher than a third preset temperature.

When the heat pump system satisfies the high temperature heating condition, the first compressor 33 is controlled to operate; alternatively, the first compressor 33 is controlled to operate while the first valve element 22 and the second valve element 23 are controlled to communicate, and the third valve element 24 is controlled to be turned off.

Step 324, if the heat pump system meets the rapid heating condition, the terminal heat exchange part is controlled to exchange heat with the third heat exchange part and the fourth heat exchange part.

The rapid heating condition includes that the heat pump system needs to be heated to a fourth preset temperature in a short time. For example, when the water heater is started and the set temperature is 40 ℃, the heat pump system needs to be heated to 40 ℃ in a short time.

When the heat pump system satisfies the rapid heating condition, the first compressor 33 is controlled to operate; alternatively, the first compressor 33 is controlled to operate while the first valve element 22, the second valve element 23, and the third valve element 24 are controlled to communicate.

According to the control method of the heat pump system, when the heat pump system meets low-temperature heating conditions, the terminal heat exchange part is controlled to exchange heat with the third heat exchange part, and at the moment, the low-temperature-level circulating system operates, and the high-temperature-level circulating system stops operating. Compared with the low-temperature heating condition that the low-temperature level circulation system and the high-temperature level circulation system are required to be started at the same time, the control method of the heat pump system provided by the embodiment of the disclosure can avoid the problem that the reliability of the system operation is lower due to the fact that the high-temperature level circulation system cannot generate enough pressure difference by controlling the high-temperature level circulation system to stop operating, and ensures the reliable operation of the heat pump system. That is, the control method of the heat pump system provided by the embodiment of the disclosure can independently control whether the low-temperature-level circulation system and the high-temperature-level circulation system are operated, and has higher flexibility and lower energy consumption.

The foregoing is merely a specific embodiment of the disclosure, but the protection scope of the disclosure is not limited thereto, and any person skilled in the art who is familiar with the technology of the disclosure will recognize that the changes or substitutions are intended to be included in the protection scope of the disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

A heat pump system, comprising: the indoor unit of heat pump, the indoor unit of heat pump includes:

a cascade heat exchanger, the cascade heat exchanger comprising:

the first heat exchange part is connected with a low-temperature-stage circulating pipeline, and a first refrigerant is arranged in the low-temperature-stage circulating pipeline;

the second heat exchange part is connected with a high-temperature-stage circulating pipeline, a second refrigerant is arranged in the high-temperature-stage circulating pipeline, and the second heat exchange part is configured to exchange heat with the first heat exchange part;

a terminal heat exchanger assembly, the terminal heat exchanger assembly comprising:

the third heat exchange part is connected with the low-temperature-stage circulating pipeline;

the fourth heat exchange part is connected with the high-temperature-stage circulating pipeline;

and the terminal heat exchange part is connected with indoor terminal equipment and is configured to exchange heat with the third heat exchange part, or exchange heat with the fourth heat exchange part, or exchange heat with the third heat exchange part and the fourth heat exchange part.
The heat pump system of claim 1, wherein the heat pump indoor unit further comprises:

a first valve element disposed between the first heat exchange portion and the low-temperature-stage circulation line, the first valve element configured to regulate a flow rate of the first refrigerant in the first heat exchange portion;

a second valve element disposed between the second heat exchange portion and the fourth heat exchange portion, the second valve element configured to regulate a flow rate of the second refrigerant in the second heat exchange portion and the fourth heat exchange portion; and

and a third valve element disposed between the third heat exchange portion and the low-temperature-stage circulation line, the third valve element configured to regulate a flow rate of the first refrigerant in the third heat exchange portion.
The heat pump system of claim 2, wherein the heat pump indoor unit further comprises a first compressor;

when the heat pump system meets a low-temperature heating condition or a defrosting condition, the first compressor is stopped, the first valve element and the second valve element are configured to work in an off state, the third valve element is configured to work in a communicating state, and the medium in the terminal heat exchange part exchanges heat with the first refrigerant in the third heat exchange part;

When the heat pump system meets high-temperature heating conditions, the first compressor operates, the first valve element and the second valve element are configured to work in a communicating state, the third valve element is configured to work in a closing state, and the medium in the terminal heat exchange part exchanges heat with the second refrigerant in the fourth heat exchange part;

when the heat pump system meets the rapid heating condition, the first compressor is operated, the first valve element, the second valve element and the third valve element are all configured to work in a communication state, and the medium in the terminal heat exchange part exchanges heat with the first refrigerant and the second refrigerant in the third heat exchange part and the fourth heat exchange part respectively.
A heat pump system according to any one of claims 1-3, wherein the terminal heat exchange portion comprises:

a first sub-terminal heat exchange portion, in which a medium exchanges heat with a first refrigerant in the third heat exchange portion; and

and the medium in the second sub-terminal heat exchange part exchanges heat with the second refrigerant in the fourth heat exchange part.
The system of claim 4, wherein the heat pump indoor unit further comprises a first compressor and a second valve element; wherein,

The second valve element is respectively connected with the first interface of the fourth heat exchange part and the first interface of the second heat exchange part, one end of the first compressor is connected with the second interface of the fourth heat exchange part, and the other end of the first compressor is connected with the second interface of the second heat exchange part.
The heat pump system of claim 5, further comprising a heat pump outdoor unit comprising an outdoor heat exchanger, a second compressor, a four-way valve, and a fourth valve element; wherein,

two ends of the fourth valve element are respectively connected with the first interface of the third heat exchange part and the first interface of the outdoor heat exchanger, two ends of the four-way valve are respectively connected with the first interface of the first heat exchange part and the second interface of the outdoor heat exchanger, the other two ends of the four-way valve are respectively connected with two ends of the second compressor, and the second interface of the third heat exchange part is connected with the second interface of the first heat exchange part; or alternatively, the first and second heat exchangers may be,

the two ends of the fourth valve element are respectively connected with the second interface of the first heat exchange part and the first interface of the outdoor heat exchanger, two ends of the four-way valve are respectively connected with the second interface of the third heat exchange part and the second interface of the outdoor heat exchanger, the other two ends of the four-way valve are respectively connected with two ends of the second compressor, and the first interface of the third heat exchange part is connected with the first interface of the first heat exchange part.
The heat pump system of claim 6, wherein the heat pump indoor unit further comprises a water intake pipe, a water pump, a first electric three-way valve, and a water outlet pipe;

the inlet of the water pump is connected with the inlet pipeline, the outlet of the water pump is connected with the inlet of the first electric three-way valve, the first outlet of the first electric three-way valve is connected with the first interface of the first sub-terminal heat exchange part, the second outlet of the first electric three-way valve is connected with the first interface of the second sub-terminal heat exchange part, and the second interface of the first sub-terminal heat exchange part and the second interface of the second sub-terminal heat exchange part are both connected to the water outlet pipeline; or alternatively, the first and second heat exchangers may be,

the inlet of the water pump is connected with the water inlet pipeline, the outlet of the water pump is connected with the first interface of the first sub-terminal heat exchange part, the second interface of the first sub-terminal heat exchange part is connected with the inlet of the first electric three-way valve, the first outlet of the first electric three-way valve is connected with the first interface of the second sub-terminal heat exchange part, and the second interface of the second sub-terminal heat exchange part and the second outlet of the first electric three-way valve are both connected to the water outlet pipeline.
The heat pump system according to any one of claims 1-7, wherein the heat pump indoor unit further comprises:

The buffer water tank is provided with a first water inlet, a first water outlet, a first water return port and a second water outlet;

the indoor terminal equipment comprises a domestic hot water tank and at least one space heating/refrigerating equipment, and at least two of the domestic hot water tank and the at least one space heating/refrigerating equipment are switched to run;

the relay reversing device is provided with a second water inlet communicated with the water outlet of the terminal heat exchange part, a third water outlet communicated with the water return port of the terminal heat exchange part, and a second water return port and a fourth water outlet communicated with the main pipelines of all the indoor terminal devices; the relay reversing device further includes:

the first through branch is communicated with the second water inlet and the fourth water outlet;

a first bypass branch, the first bypass branch comprising:

the first sub bypass branch is communicated with the first water inlet and the second water inlet;

the second sub bypass branch is communicated with the first water outlet and the fourth water outlet; the first through branch is communicated with the first bypass branch in a switching way;

the second straight-through branch is communicated with the second water return port and the third water outlet;

a second bypass branch, the second bypass branch comprising:

a third sub bypass branch communicated with the first water return port and the second water return port;

A fourth sub bypass branch communicated with the second water outlet and the third water outlet; the second through branch is communicated with the second bypass branch in a switching way.
The heat pump system of claim 8, wherein the relay reversing device comprises: the second electric three-way valve, the third electric three-way valve, the fourth electric three-way valve and the fifth electric three-way valve;

the first end of the second electric three-way valve is communicated with the second water inlet, the second end of the second electric three-way valve is communicated with the first end of the third electric three-way valve, the second end of the third electric three-way valve is communicated with the fourth water outlet, the third end of the second electric three-way valve is communicated with the first water inlet, and the third end of the third electric three-way valve is communicated with the first water outlet;

the first end of the fourth electric three-way valve is communicated with the third water outlet, the second end of the second electric three-way valve is communicated with the first end of the fifth electric three-way valve, the second end of the fifth electric three-way valve is communicated with the second water return port, the third end of the fourth electric three-way valve is communicated with the second water outlet, and the third end of the fifth electric three-way valve is communicated with the first water return port.
The heat pump system of claim 9, wherein the relay steering device further comprises:

a first booster pump disposed on the pipeline between the second water inlet and the first end of the second electric three-way valve to increase the pressure of water on the pipeline;

the second booster pump is arranged on the pipeline between the second end of the third electric three-way valve and the fourth water outlet so as to increase the pressure of water on the pipeline.
The heat pump system of claim 9, wherein the heat pump indoor unit further comprises:

the auxiliary heat source is communicated with the buffer water tank through a connecting pipeline; the auxiliary heat source comprises a gas wall-mounted furnace, a solar water heater or a gas water heater;

the space heating/cooling device comprises a fan tray and/or a floor heater.
The heat pump system according to any one of claims 1-7, wherein the heat pump indoor unit further comprises: a pressure detection device configured to detect an upstream pressure and a downstream pressure of the water pump;

a flow detection device configured to detect a flow rate through the water pump;

the water pump self-circulation pipeline is provided with the water pump and the electric regulating valve;

the water system full circulation pipeline is provided with the water pump, the terminal heat exchange part and the indoor terminal equipment; and

And a controller coupled to the pressure detection device and the flow detection device and configured to perform a water pump characteristic test through the water pump self-circulation line and a line characteristic test through the water system full-circulation line based on at least one of an upstream pressure of the water pump, a downstream pressure of the water pump, or a flow rate of the water pump.
The heat pump system of claim 12, wherein the controller is configured to:

controlling the water pump to run at a first rotation speed, and controlling the electric regulating valve to maintain a first opening corresponding to the first rotation speed within a first preset duration;

calculating an average value of the downstream pressure and the upstream pressure difference detected by the pressure detection device within the first preset time period to obtain a first operation parameter, wherein the first operation parameter corresponds to the lift of the water pump, and the first operation parameter comprises the first rotating speed and the first opening;

calculating an average value of the flow detected by the flow detection device within the first preset time length to obtain an average value of the flow of the water pump corresponding to the first operation parameter;

obtaining a test result of the water pump characteristic test according to the lifts of the water pumps corresponding to the operation parameters and the flow average values of the water pumps corresponding to the operation parameters; the plurality of operating parameters includes the first operating parameter, and the test result of the characteristic test of the water pump includes a water pump characteristic curve.
The heat pump system of claim 12, wherein the controller is configured to:

controlling the water pump to run at a second rotating speed for a second preset time period;

calculating the average value of the downstream pressure detected by the pressure detection device and the pressure difference in the second preset time period to obtain the pipeline internal resistance corresponding to the second rotating speed;

calculating an average value of the flow detected by the flow detection device within the second preset time length to obtain a flow average value corresponding to the second rotating speed;

obtaining a test result of the pipeline characteristic test according to the pipeline internal resistance corresponding to a plurality of rotating speeds and the flow average value corresponding to the rotating speeds; the test result of the pipeline characteristic test comprises a pipeline characteristic curve.
The heat pump system of claim 12, the water pump self-circulation line comprising a first water replenishment port, the water system full-circulation line comprising a second water replenishment port;

the controller is further configured to:

before the water pump characteristic test or the pipeline characteristic test is carried out, and after the water pump self-circulation system or the water system is started in a full-circulation mode, when the downstream pressure of the water pump is lower than the lower limit value of the pressure of the water system, water is supplemented through the first water supplementing port or the second water supplementing port; when the downstream pressure of the water pump is higher than the lower limit value of the water system pressure, controlling the water pump to intermittently run until the water pump is completely emptied;

When the water pump is completely emptied, the downstream pressure of the water pump is between the lower limit value and the upper limit value of the water system pressure, and the absolute value of the difference between the downstream pressure of the water pump at the first moment and the downstream pressure at the second moment is lower than the water pressure fluctuation limit value within a third preset duration.
The heat pump system of claim 14, the controller further configured to:

acquiring a first water flow;

obtaining a rotating speed corresponding to the first water flow according to the first water flow and the pipeline characteristic curve;

and controlling the water pump to run at a rotating speed corresponding to the first water flow.
The heat pump system according to claim 12, wherein the heat pump indoor unit further comprises a temperature detection device for detecting a water outlet temperature and a water return temperature of the terminal heat exchange portion;

the controller is further configured to:

acquiring a water temperature difference required by a user;

obtaining a current water temperature difference according to the current water outlet temperature and the current water return temperature of the terminal heat exchange part;

calculating target water flow according to the current water temperature difference, the current water flow detected by the flow detection device and the water temperature difference required by the user;

and controlling the water pump to run at a preset maximum rotation speed, and controlling the water pump to run at a target rotation speed corresponding to the target water flow after running stably.
A control method of a heat pump system according to any one of claims 1 to 17, the method comprising:

determining whether the heat pump system meets preset conditions, wherein the preset conditions comprise a low-temperature heating condition, a defrosting condition, a high-temperature heating condition or a rapid heating condition;

if the heat pump system meets the low-temperature heating condition or the defrosting condition, controlling the terminal heat exchange part to exchange heat with the third heat exchange part;

if the heat pump system meets the high-temperature heating condition, controlling the terminal heat exchange part and the fourth heat exchange part to exchange heat;

and if the set temperature meets the rapid heating condition, controlling the terminal heat exchange part to exchange heat with the third heat exchange part and the fourth heat exchange part.
The method of claim 18, wherein the heat pump indoor unit further comprises a first compressor, one end of the first compressor is connected to the second interface of the fourth heat exchange portion, and the other end of the first compressor is connected to the second interface of the second heat exchange portion; the method further comprises the steps of:

when the heat pump system meets the low-temperature heating condition or the defrosting condition, controlling the first compressor to stop;

And when the heat pump system meets the high-temperature heating condition or the rapid heating condition, controlling the first compressor to operate.
The method of claim 19, wherein the heat pump indoor unit further comprises: a first valve element, a second valve element and a third valve element, wherein the first valve element is arranged between the first heat exchange part and the low-temperature-stage circulating pipeline, the second valve element is arranged between the second heat exchange part and the fourth heat exchange part, and the third valve element is arranged between the third heat exchange part and the low-temperature-stage circulating pipeline;

the controlling the first compressor to stop when the heat pump system satisfies the low temperature heating condition or the defrosting condition includes: when the heat pump system meets the low-temperature heating condition or the defrosting condition, controlling the first compressor to stop, controlling the first valve element and the second valve element to be closed, and controlling the third valve element to be communicated;

when the heat pump system meets the high temperature heating condition or the rapid heating condition, controlling the first compressor to operate, including: when the heat pump system meets the high-temperature heating condition, controlling the first compressor to operate, controlling the first valve element to be communicated with the second valve element, and controlling the third valve element to be turned off; and when the heat pump system meets the rapid heating condition, controlling the first compressor to operate, and controlling the first valve element, the second valve element and the third valve element to be communicated.