WO2024048995A1

WO2024048995A1 - Heat pump system and control method therefor

Info

Publication number: WO2024048995A1
Application number: PCT/KR2023/010287
Authority: WO
Inventors: 김태일; 이석호; 장민; 한상윤; 장석현
Original assignee: 삼성전자주식회사
Priority date: 2022-09-02
Filing date: 2023-07-18
Publication date: 2024-03-07

Abstract

A heat pump system according to one aspect of the disclosed invention may comprise: a compressor for compressing a refrigerant; a refrigerant-water heat exchanger for allowing heat to be exchanged between the compressed refrigerant and water; an expansion valve for expanding the refrigerant condensed in the refrigerant-water heat exchanger; an outdoor heat exchanger for allowing heat to be exchanged between the refrigerant expanded in the expansion valve and outdoor air; an outdoor fan provided to be adjacent to the outdoor heat exchanger; and a control unit for turning off the compressor and the outdoor fan on the basis of an abnormal state of the refrigerant-water heat exchanger, and turning on the compressor in the off state of the outdoor fan.

Description

Heat pump system and its control method

The disclosed invention relates to a heat pump system and a control method thereof, and relates to a heat pump-type system capable of supplying hot water through heat exchange and a control method thereof.

In general, heat moves naturally from the high temperature side to the low temperature side, but some external action must be applied to move the heat from the low temperature side to the high temperature side. This is the principle of a heat pump. Heat pumps perform cooling, heating (Air to Air), and water supply (Air to Water) using heat generated and recovered during the cycle of compression, condensation, and evaporation of refrigerant.

A multi-type cooling and heating device using a heat pump method (hereinafter referred to as an 'air conditioning system') is composed of an outdoor unit, an indoor unit, and a hydro unit, and transfers heat from the heat pump to the indoor air. It is used for floor heating, cooling and heating of indoor air, etc.

In the heat pump system of a conventional air conditioner, during heating operation, the outdoor unit exchanges heat with air through an evaporator and the temperature of the internal air is adjusted to the user's needs through a condenser of the indoor unit.

The EHS (Eco Heating/cooling Solution) system exchanges heat with the air in the outdoor unit, but heat exchanges the refrigerant and water through a heat exchanger inside the indoor or outdoor unit to adjust the water temperature to suit the user's needs. It supplies.

Based on heating operation, the EHS system is divided into a mono system that has both an evaporator and a condenser in the outdoor unit, and a split system that has an evaporator in the outdoor unit and a condenser on the indoor side. The supplied water is used for underfloor heating, radiators, domestic hot water, and fan coils. It is used as a unit, etc.

In the process of making cold or hot water through heat exchange with a refrigerant, the water temperature may drop below the freezing temperature, causing freezing of the heat exchanger.

Conventionally, in order to prevent freezing of such heat exchangers, antifreeze or anti-freeze valves were applied or a temperature sensor was installed to detect freezing.

One aspect of the disclosed invention is that when the heat exchanger operates abnormally, such as when the risk of freezing of the heat exchanger is detected due to a malfunction of the flow path switching valve, the outdoor fan and expansion valve are controlled to control the outdoor fan and expansion valve when the system is stopped and restarted. Provided is a heat pump system and its control method that can allow a heat exchanger to operate normally by operating normally.

A heat pump system according to one aspect of the disclosed invention includes a compressor that compresses a refrigerant; a refrigerant-water heat exchanger in which heat is exchanged between the compressed refrigerant and water; an expansion valve that expands the refrigerant condensed in the refrigerant-water heat exchanger; an outdoor heat exchanger in which heat is exchanged between the refrigerant expanded in the expansion valve and outdoor air; an outdoor fan provided adjacent to the outdoor heat exchanger; A condensation temperature sensor that detects the temperature of the refrigerant condensed in the refrigerant-water heat exchanger; An inlet temperature sensor that detects the temperature of water entering the refrigerant-water heat exchanger; A water outlet temperature sensor that detects the temperature of water heat exchanged in the refrigerant-water heat exchanger; and determining whether the refrigerant-water heat exchanger is in an abnormal state based on detection results of the condensation temperature sensor, the inlet temperature sensor, and the outlet temperature sensor, and based on the abnormal state of the refrigerant-water heat exchanger, the compressor and the It may include a control unit that turns off the outdoor fan and turns on the compressor when the outdoor fan is turned off.

The control unit may determine that the refrigerant-water heat exchanger operates normally when the detected temperature of the condensed refrigerant is higher than the inlet temperature and the sensed outlet temperature is higher than the detected inlet temperature.

The control unit may control the opening degree of the expansion valve to be equal to or greater than the first opening degree based on the abnormal state of the refrigerant-water heat exchanger.

The control unit may determine whether the refrigerant-water heat exchanger is in an abnormal state based on detection results of the condensation temperature sensor, the inlet temperature sensor, and the outlet temperature sensor after controlling the compressor, the outdoor fan, and the expansion valve.

The control unit may determine whether the temperature detected by the condensation temperature sensor exceeds a predetermined temperature when the refrigerant-water heat exchanger is in an abnormal state.

The control unit, when it is determined that the temperature detected by the condensation temperature sensor exceeds a predetermined temperature, controls the outdoor fan to rotate at a rotation speed higher than the reference rotation speed, and the expansion valve rotates at a second opening degree or more. It can be controlled as much as possible.

The control unit controls the outdoor fan to rotate at a rotation speed higher than the standard rotation speed, and when a predetermined time has elapsed after controlling the expansion valve to open at a second opening degree or higher, turns off the compressor and the outdoor fan. You can.

It further includes a high-pressure pressure sensor that detects the high-pressure pressure of the refrigerant compressed in the compressor, and the control unit is configured to determine that, when the refrigerant-water heat exchanger is in an abnormal state, the high-pressure pressure detected by the high-pressure sensor changes to a predetermined pressure. You can judge whether it exceeds it or not.

The control unit, when it is determined that the pressure detected by the high pressure sensor exceeds the predetermined pressure, controls the outdoor fan to rotate at a rotation speed higher than the reference rotation speed, and the expansion valve opens at a second opening degree or more. It can be controlled as much as possible.

A method of controlling a heat pump system according to one aspect of the disclosed invention includes: detecting the temperature of a refrigerant condensed in a refrigerant-water heat exchanger; detecting the temperature of water entering the refrigerant-water heat exchanger; detecting the temperature of water heat exchanged in the refrigerant-water heat exchanger; determine whether the refrigerant-water heat exchanger is in an abnormal state based on the detection results of the plurality of temperatures; turning off the compressor and outdoor fan when it is determined that the refrigerant-water heat exchanger is in an abnormal state; It may include turning on the compressor when the outdoor fan is turned off.

Determining whether the refrigerant-water heat exchanger is in an abnormal state is determined by determining that the temperature of the detected condensed refrigerant is higher than the temperature of the water entering the heat exchanger and the temperature of the water through which the detected heat exchange occurred is the temperature of the water entering the detected heat exchanger. If the temperature is higher than the water temperature, it may include determining that the refrigerant-water heat exchanger is operating normally.

It may further include controlling the opening degree of the expansion valve to be greater than or equal to the first opening degree based on the abnormal state of the refrigerant-water heat exchanger.

It may further include determining whether the refrigerant-water heat exchanger is in an abnormal state based on the detection results of the plurality of temperatures after controlling the compressor, outdoor fan, and expansion valve.

The method may further include determining whether the temperature detected by the condensation temperature sensor exceeds a predetermined temperature when the refrigerant-water heat exchanger is in an abnormal state.

When it is determined that the detected condensed refrigerant temperature exceeds a predetermined temperature, controlling the outdoor fan to rotate at a rotation speed higher than the reference rotation speed and controlling the expansion valve to open at a second opening degree or higher; More may be included.

Controlling the outdoor fan to rotate at a rotational speed higher than the standard rotational speed, and controlling the expansion valve to open at a second opening degree or higher, and then turning off the compressor and the outdoor fan when a predetermined time has elapsed; It can be included.

detecting high pressure of refrigerant compressed in the compressor; If the refrigerant-water heat exchanger is in an abnormal state, the method may further include determining whether the detected high pressure of the refrigerant exceeds a predetermined pressure.

When it is determined that the detected high pressure of the refrigerant exceeds a predetermined pressure, controlling the outdoor fan to rotate at a rotation speed higher than the reference rotation speed and controlling the expansion valve to open at a second opening degree or higher; More may be included.

According to one aspect of the disclosed invention, when the heat exchanger operates abnormally, such as when the risk of freezing of the heat exchanger is detected due to a malfunction of the flow path switching valve, the flow path is switched by controlling the outdoor fan and expansion valve when restarting the system after stopping. By allowing the valve to operate normally, the heat exchanger can be ensured to operate normally.

1 is a diagram illustrating the configuration of a heat pump system according to an embodiment.

Figure 2 is a diagram showing the flow of refrigerant during a heating operation of a heat pump system according to an embodiment.

Figure 3 is a diagram showing the flow of refrigerant during cooling operation of a heat pump system according to an embodiment.

Figure 4 is a diagram showing the structure of a flow path switching valve.

Figure 5 is a diagram showing a control block diagram of a heat pump system according to an embodiment.

FIG. 6 is a diagram illustrating a plurality of sensors included in a heat pump system according to an embodiment.

FIG. 7 is a flowchart showing detecting an abnormal state of a refrigerant-water heat exchanger and controlling a heat pump system based on the abnormal state according to an embodiment.

FIG. 8 is a flowchart showing re-determination of whether the refrigerant-water heat exchanger operates normally after the control according to FIG. 7.

Figure 9 is a diagram showing a control block diagram of a heat pump system according to an embodiment.

FIG. 10 is a flowchart of a control method of a heat pump system for protecting the heat pump system based on condensation temperature according to an embodiment.

Figure 11 is a diagram showing a control block diagram of a heat pump system according to another embodiment.

FIG. 12 is a flowchart of a heat pump system control method for protecting the heat pump system based on high pressure according to another embodiment.

The embodiments described in this specification and the configurations shown in the drawings are only preferred examples of the disclosed invention, and at the time of filing this application, there may be various modifications that can replace the embodiments and drawings in this specification.

In addition, the same reference numbers or symbols shown in each drawing of this specification indicate parts or components that perform substantially the same function.

Additionally, the terms used herein are used to describe embodiments and are not intended to limit and/or limit the disclosed invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to indicate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. The existence or addition of numbers, steps, operations, components, parts, or combinations thereof is not excluded in advance.

Additionally, in this specification, when a component is said to be “connected” or “coupled” with another component, this includes not only directly connected or combined, but also indirectly connected or combined.

In addition, terms including ordinal numbers such as “first”, “second”, etc. used in this specification may be used to describe various components, but the components are not limited by the terms, and the terms It is used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and similarly, the second component may also be named a first component without departing from the scope of the present invention. The term “and/or” includes any of a plurality of related stated items or a combination of a plurality of related stated items.

Hereinafter, embodiments according to the present invention will be described with reference to the attached drawings.

Heat pump system 1 may include a compressor 102, a refrigerant-water heat exchanger 112, an expansion valve 110, an outdoor heat exchanger 108, a flow path diverter valve 106, and an accumulator 104. there is.

The compressor 102 compresses the low-temperature, low-pressure refrigerant sucked in through the inlet side 102a to form high-temperature, high-pressure refrigerant, and then discharges the high-temperature, high-pressure refrigerant through the outlet side 102b. The compressor 102 may be configured as an inverter compressor whose compression capacity varies depending on the input frequency, or may be configured as a combination of a plurality of constant-speed compressors with a constant compression capacity. The inlet side 102a of the compressor 102 is connected to the accumulator 104, and the outlet side 102b of the compressor 102 is connected to the flow path switching valve 106. The flow path switching valve 106 is also connected to the accumulator 104.

The accumulator 104 may be installed between the inlet side 102a of the compressor 102 and the flow path switching valve 106. When the condensed liquid refrigerant flows in through the flow path switching valve 106, the accumulator 104 temporarily stores the mixture of oil and refrigerant, and separates the non-vaporized liquid refrigerant to prevent the liquid refrigerant from being sucked into the compressor 102. By doing so, damage to the compressor 102 can be prevented. The gas refrigerant separated from the accumulator 104 is sucked into the inlet side 102a of the compressor 102.

The flow path switching valve 106 may be configured as a four-way valve, and switches the flow of refrigerant discharged from the compressor 102 according to the operation mode (cooling or heating), thereby forming a refrigerant flow path necessary for operation in the corresponding mode. . The flow path switching valve 106 includes a first port 106a connected to the outlet side 102b of the compressor 100, a second port 106b connected to the outdoor heat exchanger 108, and a refrigerant-water heat exchanger. It may have a third port 106c connected to the exchanger 112 side, and a fourth port 106d connected to the accumulator 104, which is the inlet side 102a of the compressor 100.

The outdoor heat exchanger 108 operates as a condenser in cooling mode and as an evaporator in heating mode. A first expansion valve 110 is connected to one side of the outdoor heat exchanger 108. An outdoor fan 109 may be installed in the outdoor heat exchanger 108 to increase heat exchange efficiency between the refrigerant and outdoor air.

The expansion valve 110 may be configured as an electronic expansion valve, and can expand the refrigerant, control the flow rate of the refrigerant, and block the flow of the refrigerant when necessary. The expansion valve 110 may be replaced with an expansion device of another structure that performs this function.

Inside the hot water heat exchanger 112, a plurality of heat exchange plates through which the refrigerant passes and heat exchange plates through which water passes are installed alternately, and heat exchange is performed between the heat exchange plates through which the refrigerant passes and the heat exchange plates through which the water passes. Cold/hot water is produced through the system. The refrigerant compressed in the compressor 102 may be delivered to the refrigerant-water heat exchanger 112. The cold water/hot water generated in the refrigerant-water heat exchanger 112 is provided to the water tank, fan coil unit, floor cooling/heating device, etc. and is used for cold/hot water supply and cooling/heating.

The control unit 10 operates the flow path switching valve 106 to create a refrigerant flow path in which the first port (106a) and the third port (106c) are connected, and the second port (106b) and the fourth port (106d) are connected. can be formed.

Accordingly, the refrigerant discharged from the compressor 102 may flow into the refrigerant-water heat exchanger 112 through the flow path switching valve 106.

The refrigerant flowing into the refrigerant-water heat exchanger 112 flows to the outdoor heat exchanger 108 through the hot water heat exchanger 112. The refrigerant that has passed through the outdoor heat exchanger 108 can be sucked back into the compressor 102 through the flow path switching valve 106.

Accordingly, the heat pump system (1) is compressor (102) → flow path switching valve (106) → hot water heat exchanger (112) → expansion valve (110) → outdoor heat exchanger (108) → flow path switching valve (106) → accumulator. Heating operation can be performed by configuring a refrigerant cycle that circulates in the order of (104) → compressor (102).

The heat pump system 1 of the present invention may further include a subcooling heat exchanger 114.

The supercooling heat exchanger 114 may be located between the refrigerant-water heat exchanger 112 and the expansion valve 110 to flow refrigerant to the compressor 102.

That is, in this case, the compressor 102 can perform two-stage refrigerant compression.

The compressor 102 includes a first compression section where the refrigerant that has passed through the refrigerant-water heat exchanger 112 is introduced and compressed, the refrigerant that has passed through the first compression section, the refrigerant-water heat exchanger 112, and the expansion valve 110. ) may include a second compression section in which the refrigerant branched and injected from the supercooling heat exchanger 114 located between the refrigerants flows in and is compressed.

In other words, refrigerant injection into the compressor 102 according to the supercooling heat exchanger 114 can be achieved by extracting the refrigerant that has passed through the refrigerant-water heat exchanger 112 and injecting only the vapor refrigerant into the injection port of the compressor 102. .

Accordingly, the compressor 102 can additionally compress not only the refrigerant that has passed through the refrigerant-water heat exchanger 112 according to the existing cycle, but also the refrigerant that is branched and injected from the supercooling heat exchanger 114.

Accordingly, the efficiency of the compressor 102 can be improved by supplying vapor refrigerant to the injection port of the compressor 102, and the capacity of the condenser can be increased by increasing the flow rate of the refrigerant on the condenser side. In addition, efficient operation can be performed by further securing the degree of subcooling of the refrigerant on the discharge side in the refrigerant-water heat exchanger (112, internal heat exchanger).

The control unit 10 operates the flow path switching valve 106 to create a refrigerant flow path in which the first port (106a) and the second port (106b) are connected, and the third port (106c) and the fourth port (106d) are connected. form

Accordingly, the refrigerant discharged from the compressor 102 flows to the indoor unit through the flow path switching valve 106 and the outdoor heat exchanger 108. At this time, the outdoor heat exchanger 108 operates as a condenser.

The refrigerant flowing into the indoor unit passes through the refrigerant-water heat exchanger 112, and the refrigerant passing through the refrigerant-water heat exchanger 112 is sucked into the compressor 102 again through the flow path switching valve 106.

Accordingly, the heat pump system (1) is compressor (102) → flow path switching valve (106) → outdoor heat exchanger (108) → hot water heat exchanger (112) → flow path switching valve (106) → accumulator (104) → compressor ( 102) Cooling operation can be performed by configuring a refrigerant cycle that circulates in order.

The above has explained the basic configuration of the heat pump system (1) and the flow of refrigerant.

Figure 4 is a diagram showing the structure of a flow path switching valve.

As described above, the heating and cooling operations of the heat pump system 1 can be controlled according to the operation of the flow path switching valve 106.

Specifically, when an electrical signal is input to the pilot valve 107 in the flow path switching valve 106, the pilot valve 107 applies pressure to the slider in the flow path switching valve 106 to control the position of the slider to switch the flow path. You can.

If the pressure applied by the pilot valve 107 is not properly transmitted to the slider due to foreign matter, etc., occurring in the pilot valve 107, an error in flow path switching may occur.

In winter, when the outdoor temperature is low, in most cases, users want to operate the heat pump system (1) for heating in order to increase the indoor temperature. Accordingly, even though a refrigerant flow path for heating operation must be formed, the pressure is not transmitted and the flow path is switched. A case may occur where the first port (106a) and the second port (106b) in the valve 106 are connected, and a refrigerant flow path is formed where the third port (106c) and the fourth port (106d) are connected.

At this time, the temperature of the water passing through the refrigerant-water heat exchanger 112 falls below the freezing temperature, causing freezing of the water, and freezing of the refrigerant-water heat exchanger 112 may occur due to the freezing of the water.

Therefore, for normal operation of the flow path switching valve 106, it is necessary to remove foreign substances in the pilot valve 107.

Refrigerant-Water Heat Exchanger Below, the process of controlling the configuration within the heat pump system 1 to resolve the abnormal condition of the refrigerant-water heat exchanger 112 due to the abnormal operation of the flow path switching valve 106 will be described in detail. .

FIG. 5 is a diagram illustrating a control block diagram of a heat pump system according to an embodiment, and FIG. 6 is a diagram illustrating a plurality of sensors included in the heat pump system according to an embodiment.

In addition, FIG. 7 is a flowchart showing detecting an abnormal state of the refrigerant-water heat exchanger and controlling the heat pump system based on this, and FIG. 8 shows a process to determine again whether the refrigerant-water heat exchanger operates normally after control according to FIG. 7. This is a flowchart showing what to do.

The heat pump system 1 may include a compressor 102, a refrigerant-water heat exchanger 112, an outdoor heat exchanger 108, an outdoor fan 109, an expansion valve 110, and a control unit 10, The control unit 10 may include a processor 11 and a memory 12.

In addition, the heat pump system 1 may further include a condensation temperature sensor 120, an outlet temperature sensor 122, and an inlet temperature sensor 126. The condensation temperature sensor 120 is a refrigerant-water heat exchanger ( 112), the temperature of the condensed refrigerant can be detected as it exchanges heat with water in the process of passing through it.

The outlet water temperature sensor 122 can detect the temperature of water heat-exchanged in the process of passing through the refrigerant-water heat exchanger 112.

The inlet temperature sensor 126 can detect the temperature of water flowing into the refrigerant-water heat exchanger 112 before heat exchange with the refrigerant in the refrigerant-water heat exchanger 112.

Various information detected by these plural sensors can be used in the control process of the control unit 10, which will be described later, and will be described in detail.

Compressor 102 compresses the refrigerant, and a refrigerant-water heat exchanger can perform heat exchange between the compressed refrigerant and incoming water. The expansion valve 110 may expand the refrigerant condensed through the refrigerant-water heat exchanger 112.

The outdoor heat exchanger 108 performs heat exchange between the refrigerant expanded in the expansion valve and outdoor air, and this outdoor heat exchanger 108 includes an outdoor fan 109 to increase heat exchange efficiency between the refrigerant and outdoor air. Can be installed.

The control unit 10 includes a memory 12 that stores control programs and control data for controlling the expansion valve 110, the outdoor fan 109, and the compressor 102, and the control program and control data stored in the memory 12. It may include a processor 11 that generates a control signal according to . The memory 12 and the processor 11 may be provided integrally or may be provided separately.

The memory 12 can store temperature and pressure detected by various sensors, and can store programs and data for controlling the expansion valve 110, outdoor fan 109, and compressor 102.

The memory 12 may include volatile memory such as Static Random Access Memory (S-RAM) or Dynamic Random Access Memory (D-Lab) for temporarily storing data. In addition, the memory 12 includes non-volatile memory such as Read Only Memory (ROM), Erasable Programmable Read Only Memory (EPROM), and Electrically Erasable Programmable Read Only Memory (EEPROM) for long-term storage of data. It can be included.

The processor 11 may include various logic circuits and operation circuits, process data according to a program provided from the memory 12, and generate control signals according to the processing results.

Referring to FIG. 7, the control unit 10 may determine whether the refrigerant-water heat exchanger is in an abnormal state based on the detection results of the condensation temperature sensor, the water inlet temperature sensor, and the outlet temperature sensor (701).

As described above, if the flow path switching of the flow path switching valve 106 is not performed normally due to foreign substances in the pilot valve 107, the flow path for heating operation may not be properly formed, such as in winter when the outdoor temperature is low. You can.

At this time, it is possible to determine whether the refrigerant-water heat exchanger 112 is operating normally by comparing the temperature of the water exchanging heat with the refrigerant-water heat exchanger 112.

Specifically, the temperature of the condensed refrigerant detected by the condensation temperature sensor 120 is higher than the water temperature detected by the water intake temperature sensor (example 703), and the water outlet temperature detected by the water outlet temperature sensor is higher than the water temperature detected by the water water temperature sensor. If it is higher than the temperature (example of 705), it can be determined that the refrigerant-water heat exchanger 112 is operating normally.

That is, the temperature of the condensed refrigerant detected by the condensation temperature sensor 120 is lower than the inlet temperature detected by the inlet temperature sensor (No in 703), or the outlet temperature detected by the outlet temperature sensor is lower than the inlet temperature detected by the inlet temperature sensor. If it is lower than the temperature (No in 705), it can be determined that the refrigerant-water heat exchanger 112 is operating abnormally.

The control unit 10 may turn off the compressor and the outdoor fan based on the abnormal state of the refrigerant-water heat exchanger 112 (707).

That is, as described above, if it is determined to be in an abnormal state, such as a risk of freezing of the refrigerant-water heat exchanger 112, the compressor 102 and the outdoor fan 109 are installed to protect the heat pump system 1. can be turned off.

Thereafter, when restarting the heat pump system 1, only the compressor 102 can be turned on while the outdoor fan 109 is turned off (709).

When only the compressor 102 is turned on while the outdoor fan 109 is stopped, the amount of air discharged to the outside of the outdoor heat exchanger 108 decreases and the internal high pressure may increase as the temperature increases.

As the temperature and internal high pressure increase, the viscosity of foreign substances generated in the pilot valve 107 in the flow path switching valve 106 weakens and pressure is applied, thereby allowing the foreign substances in the pilot valve 107 to be removed.

As foreign substances in the pilot valve 107 are removed and pressure is normally applied to the slider in the flow path switching valve 106, the existing cooling operation flow path can be changed to a heating operation flow path.

That is, the first port (106a) and the second port (106b) are connected, and the third port (106c) and the fourth port (106d) are connected. ) is connected, and the second port (106b) and the fourth port (106d) can be changed to be connected to form a heating operation refrigerant flow path.

The control unit 10 may control the opening degree of the expansion valve 110 to be greater than or equal to the first opening degree based on the abnormal state of the refrigerant-water heat exchanger 112 (711).

At this time, the first opening degree may mean an opening degree of 20% based on the maximum opening degree of the expansion valve 110. It is not limited to this and may be set at an appropriate ratio to resolve the abnormal state of the refrigerant-water heat exchanger 112.

The internal high pressure can be increased by controlling the opening degree of the expansion valve 110 to be greater than or equal to the first opening degree.

As described above, as the temperature and internal high pressure increase, the viscosity of foreign substances generated in the pilot valve 107 in the flow path switching valve 106 weakens and pressure is applied, thereby allowing the foreign substances in the pilot valve 107 to be removed.

Thereafter, the control unit 10 may determine whether the refrigerant-water heat exchanger 112 is operating normally and control the expansion valve 110, the outdoor fan 109, and the compressor 102 according to the determination result.

Referring to FIG. 8, the control unit 10 controls the compressor 102, the outdoor fan 109, and the expansion valve 110, and then detects the detection results 801 of the condensation temperature sensor 120, the inlet temperature sensor, and the outlet temperature sensor. Based on this, it can be determined again whether the refrigerant-water heat exchanger 112 is in an abnormal state.

Specifically, the temperature of the condensed refrigerant detected by the condensation temperature sensor 120 is higher than the water temperature detected by the water intake temperature sensor (example 803), and the water outlet temperature detected by the water outlet temperature sensor is higher than the water temperature detected by the water water temperature sensor. If it is higher than the temperature (example of 805), it can be determined that the refrigerant-water heat exchanger 112 is operating normally (807).

At this time, when comparing and judging the sensed temperature, inaccurate results may be obtained due to factors such as the deviation between the actual temperature and the sensed temperature, so the temperature of the condensed refrigerant detected by the condensation temperature sensor 120 is the intake temperature. If it is higher than the value obtained by subtracting the first constant from the inlet temperature detected by the sensor, and the outlet water temperature detected by the outlet temperature sensor is higher than the value obtained by subtracting the second constant from the inlet temperature detected by the inlet temperature sensor, the refrigerant-water heat exchanger (112) It can be determined that it is operating normally.

At this time, the first constant and the second constant may be constants determined based on the deviation between the actual temperature and the sensed temperature and the optimal condensation temperature.

The temperature of the condensed refrigerant detected by the condensation temperature sensor 120 is lower than the inlet temperature detected by the inlet temperature sensor (No in 805), or the outlet temperature detected by the outlet temperature sensor is lower than the inlet temperature detected by the inlet temperature sensor. If it is low (No in 807), it is determined that the refrigerant-water heat exchanger 112 is operating abnormally, and control to be described later can be performed.

FIG. 9 is a control block diagram of a heat pump system according to an embodiment, and FIG. 10 is a flowchart of a control method of a heat pump system for protecting the heat pump system based on condensation temperature according to an embodiment. It is a drawing.

As described above, if the refrigerant-water heat exchanger 112 is determined to be in an abnormal state even after controlling the outdoor fan 109 and the expansion valve 110 of the control unit 10, the operation of the heat pump system 1 must be stopped. A need may arise.

At this time, if the internal high pressure becomes too high due to the stop of the outdoor fan 109 and the low-opening control of the expansion valve 110, damage to the heat pump system 1 may occur, so this internal high pressure is considered high. If detected, the pressure needs to be lowered.

Accordingly, the control unit 10 can determine whether the temperature detected by the condensation temperature sensor 120 exceeds a predetermined temperature.

At this time, the predetermined temperature may be set to an appropriate temperature to protect the heat pump system 1 by preventing damage to the heat pump system 1.

When the control unit 10 determines that the temperature detected by the condensation temperature sensor 120 exceeds the predetermined temperature (example 1001), the control unit 10 controls the outdoor fan 109 to rotate at a rotation speed higher than the reference rotation speed. (1003), the expansion valve 110 can be controlled to have an opening degree equal to or higher than the second opening degree (1005).

Here, the reference rotation speed and second opening degree may be appropriate rotation speed and opening degree values that can protect the heat pump system 1 by lowering the high pressure inside the heat pump system 1.

By rotating the outdoor fan 109 at a rotation speed higher than the standard rotation speed and allowing the expansion valve 110 to open at a second opening degree or higher, the internal high pressure can be reduced to protect the heat pump system 1.

Thereafter, when the control unit 10 determines that the internal high pressure has sufficiently decreased, it can turn off the operation of the compressor 102 and the outdoor fan 109.

Afterwards, the control to resolve the abnormal state of the refrigerant-water heat exchanger 112 described above can be performed again.

FIG. 11 is a control block diagram of a heat pump system according to another embodiment, and FIG. 12 is a flowchart of a control method of a heat pump system for protecting the heat pump system based on high pressure according to another embodiment. It is a drawing.

The heat pump system 1 may further include a high pressure sensor 130 that detects the high pressure of the refrigerant compressed in the compressor 102.

9 and 10 show that when the high-pressure pressure sensor 130 is not separately included, the internal high-pressure pressure is detected using the condensation temperature sensor 120, and in this embodiment, a high-pressure pressure sensor ( 130) is included.

When the refrigerant-water heat exchanger 112 is in an abnormal state, the control unit 10 may determine whether the high pressure sensed by the high pressure sensor 130 exceeds a predetermined pressure.

At this time, the predetermined pressure may be set to an appropriate pressure to protect the heat pump system 1 by preventing damage to the heat pump system 1.

When the control unit 10 determines that the high pressure detected by the high pressure sensor 130 exceeds the predetermined pressure (example of 1201), the control unit 10 controls the outdoor fan 109 to rotate at a rotation speed higher than the reference rotation speed. (1203), and the expansion valve 110 can be controlled to open the second opening degree or higher (1205).

According to the disclosed heat pump system and its control method, when the heat exchanger operates abnormally, such as when the risk of freezing of the heat exchanger is detected due to a malfunction of the flow path switching valve, etc., the outdoor fan and expansion valve are controlled when the system is stopped and restarted. By allowing the flow path switching valve to operate normally, the heat exchanger can be operated normally.

Meanwhile, the disclosed embodiments may be implemented in the form of a recording medium that stores instructions executable by a computer. Instructions may be stored in the form of program code, and when executed by a processor, may create program modules to perform operations of the disclosed embodiments. The recording medium may be implemented as a computer-readable recording medium.

Computer-readable recording media include all types of recording media storing instructions that can be decoded by a computer. For example, there may be read only memory (ROM), random access memory (RAM), magnetic tape, magnetic disk, flash memory, and optical data storage devices.

As described above, the disclosed embodiments have been described with reference to the attached drawings. A person skilled in the art to which the present invention pertains will understand that the present invention can be practiced in forms different from the disclosed embodiments without changing the technical idea or essential features of the present invention. The disclosed embodiments are illustrative and should not be construed as limiting.

Claims

A compressor that compresses refrigerant;

a refrigerant-water heat exchanger in which heat is exchanged between the compressed refrigerant and water;

an expansion valve that expands the refrigerant condensed in the refrigerant-water heat exchanger;

an outdoor heat exchanger in which heat is exchanged between the refrigerant expanded in the expansion valve and outdoor air;

an outdoor fan provided adjacent to the outdoor heat exchanger;

A condensation temperature sensor that detects the temperature of the refrigerant condensed in the refrigerant-water heat exchanger;

An inlet temperature sensor that detects the temperature of water entering the refrigerant-water heat exchanger;

A water outlet temperature sensor that detects the temperature of water heat exchanged in the refrigerant-water heat exchanger; and

Determine whether the refrigerant-water heat exchanger is in an abnormal state based on the detection results of the condensation temperature sensor, the inlet temperature sensor, and the outlet temperature sensor,

A control unit that turns off the compressor and the outdoor fan based on an abnormal state of the refrigerant-water heat exchanger, and turns on the compressor when the outdoor fan is turned off.
According to clause 1,

The control unit,

A heat pump system that determines that the refrigerant-water heat exchanger is operating normally when the detected temperature of the condensed refrigerant is higher than the inlet temperature and the sensed outlet temperature is higher than the detected inlet temperature.
According to clause 2,

The control unit,

A heat pump system that controls the opening degree of the expansion valve to be greater than or equal to a first opening degree based on the abnormal state of the refrigerant-water heat exchanger.
According to clause 3,

The control unit,

A heat pump system that determines whether the refrigerant-water heat exchanger is in an abnormal state based on detection results of the condensation temperature sensor, the inlet temperature sensor, and the outlet temperature sensor after controlling the compressor, outdoor fan, and expansion valve.
According to clause 4,

The control unit,

A heat pump system that determines whether the temperature detected by the condensation temperature sensor exceeds a predetermined temperature when the refrigerant-water heat exchanger is in an abnormal state.
According to clause 5,

The control unit,

If the temperature detected by the condensation temperature sensor is determined to exceed a predetermined temperature,

A heat pump system that controls the outdoor fan to rotate at a rotation speed higher than the standard rotation speed and controls the expansion valve to open at a second opening degree or higher.
According to clause 6,

The control unit,

A heat pump system that controls the outdoor fan to rotate at a rotation speed higher than the standard rotation speed and turns off the compressor and the outdoor fan when a predetermined time has elapsed after controlling the expansion valve to open at a second opening degree or higher.
According to clause 4,

It further includes a high pressure sensor that detects the high pressure of the refrigerant compressed in the compressor,

The control unit,

A heat pump system that determines whether the high pressure detected by the high pressure pressure sensor exceeds a predetermined pressure when the refrigerant-water heat exchanger is in an abnormal state.
According to clause 8,

The control unit,

If it is determined that the pressure detected by the high pressure pressure sensor exceeds a predetermined pressure,

A heat pump system that controls the outdoor fan to rotate at a rotation speed higher than the standard rotation speed and controls the expansion valve to open at a second opening degree or higher.
According to clause 9,

The control unit,

A heat pump system that controls the outdoor fan to rotate at a rotation speed higher than the standard rotation speed and turns off the compressor and the outdoor fan when a predetermined time has elapsed after controlling the expansion valve to open at a second opening degree or higher.
Sensing the temperature of the refrigerant condensed in the refrigerant-water heat exchanger;

detecting the temperature of water entering the refrigerant-water heat exchanger;

detecting the temperature of water heat exchanged in the refrigerant-water heat exchanger;

determine whether the refrigerant-water heat exchanger is in an abnormal state based on the detection results of the plurality of temperatures;

If it is determined that the refrigerant-water heat exchanger is in an abnormal state, the compressor and outdoor fan are turned off;

A control method of a heat pump system comprising: turning on the compressor when the outdoor fan is turned off.
According to clause 11,

To determine whether the refrigerant-water heat exchanger is in an abnormal state,

If the detected temperature of the condensed refrigerant is higher than the temperature of the water entering the heat exchanger and the detected temperature of the water through which heat exchange occurred is higher than the detected temperature of the water entering the heat exchanger, the refrigerant-water heat exchanger operates normally. A control method of a heat pump system including determining that
According to clause 12,

Controlling the opening degree of the expansion valve to be equal to or greater than the first opening degree based on the abnormal state of the refrigerant-water heat exchanger.
According to clause 13,

After controlling the compressor, outdoor fan, and expansion valve, determining whether the refrigerant-water heat exchanger is in an abnormal state based on the detection results of the plurality of temperatures.
According to clause 14,

If the refrigerant-water heat exchanger is in an abnormal state, determining whether the temperature detected by the condensation temperature sensor exceeds a predetermined temperature.