KR101142914B1 - Hot water and cool water product system using 2-steps heat pump cycles - Google Patents

Abstract

PURPOSE: A cool and warm air manufacturing system using 2-steps heat pump cycles is provided to reduce power consumption by obtaining an output without operating 2-steps heat pump cycles by force. CONSTITUTION: A cool and warm air manufacturing system using 2-steps heat pump cycles comprises a first heat pump cycle(100), a second heat pump cycle(200), a hot water tank(1), a water circulation pipe(300) and a fifth heat exchanger(320). The first heat pump cycle comprises a first compressor(110) compressing a first refrigerant to the high pressure, a first four-way valve, a first and a second heat exchangers(120,130)and a first expansion valve(140) The second heat pump cycle comprises a second compressor(210) compressing a second refrigerant to the high pressure and high temperature, a third heat exchanger(220), a second expansion valve(240)and a fourth heat exchanger(230). The hot water tank stores the hot water by collecting the heat of a second refrigerant flowing into the heat exchanger of the 2-steps heat pump cycles. The water circulation pipe is connected in order to circulate in the first heat exchanger of the first heat pump cycle and fourth heat exchanger of the second heat pump cycle continuously and offers the heat of the first refrigerant to the second refrigerant by water.

Description

HOT WATER AND COOL WATER PRODUCT SYSTEM USING 2-STEPS HEAT PUMP CYCLES}

The present invention relates to a hot water and cold water production system using a heat pump, and more particularly, by indirectly heat-exchanging the refrigerant of two heat pump cycles with water to increase the buffering between the refrigerant to increase the heat exchange efficiency, the cold water The present invention relates to a hot water and cold water production system using an improved heat exchanger two-stage heat pump cycle.

In general, the heat pump system is basically a cooling cycle and a heating cycle in the same unit, the cooling and heating are combined, one unit performs the cooling by the cooling cycle in the summer, the reverse cycle in the winter System to perform heating and hot water supply.

The conventional heat pump system includes a compressor for compressing a refrigerant gas at a high temperature and a high pressure, an air side heat exchanger for heat exchange with air, a cold / hot water heat exchanger for heat exchange with water circulating in an indoor cooling and heating space, and circulating water. A hot water supply heat exchanger for hot water supply, an electronic four-way valve that switches the flow direction of the refrigerant discharged from the compressor for each cold and heating mode to an air side heat exchanger, a cold / hot water heat exchanger or a hot water supply heat exchanger, and the refrigerant liquid discharged from each heat exchanger at a low temperature. It expands to low pressure and selectively operates the cooling and heating expansion valve which operates selectively according to the cooling and heating modes, sends the refrigerant in the gas state to the compressor, evaporates the liquid refrigerant, and then temporarily stores the liquid separator sent to the compressor and the refrigerant. In addition, by separating the non-condensing or non-condensing gas contained in the refrigerant liquid to expand the cooling liquid in the liquid state The receiver group is made to send toward the valve.

In such a conventional heat pump system, an operation cycle for cooling is performed by the high temperature and high pressure refrigerant gas compressed by the compressor being sent to the air side heat exchanger through an electronic four-way valve, and deprived of heat by external air from the air side heat exchanger. Condensation. The refrigerant liquid condensed in the air side heat exchanger is expanded to a low temperature and low pressure state through a cooling and heating expansion valve, and then flows into the cold and hot water heat exchanger. Since the water circulated in the load side of the cold and hot water heat exchanger flows through the water inlet pipe, the refrigerant introduced into the cold and hot water heat exchanger is evaporated by the heat source of water and is phase-changed into the refrigerant gas of low temperature and low pressure. In this process, the water flowing through the hot and cold water heat exchanger is cooled to about 7 ° C., and the cooled water is sent to a necessary place in the room through the outlet pipe to cool the room.

Here, the refrigerant gas evaporated from the cold / hot water heat exchanger is introduced into the liquid separator through an electronic four-way valve, and the liquid is separated and then returned to the compressor in a gas state to complete the cooling cycle.

In the conventional heating operation cycle, the high-temperature, high-pressure refrigerant gas compressed by the compressor is sent to the cold / hot water heat exchanger through the electronic four-way valve to make the inlet water temperature flowing through the cold / hot water heat exchanger at about 45 ° C. to be used for indoor heating. In this process, the refrigerant gas is condensed and phase-changed into the refrigerant liquid, and the refrigerant liquid from the cold / hot water heat exchanger flows into the receiver through the four-way valve, and then flows into the cooling / heating expansion valve in a liquid state and expands to low temperature and low pressure. The refrigerant liquid passing through the heating and cooling expansion valve is introduced into the air side heat exchanger to absorb the heat source of the outside air and evaporate. The evaporated refrigerant gas is returned to the compressor through the liquid separator through the electronic four-way valve to complete the heating cycle.

On the other hand, in the hot water supply, the hot and high-pressure refrigerant gas is sent to the hot water heat exchanger instead of the cold / hot water heat exchanger through the electronic four-way valve in the heating operation cycle, thereby increasing the inlet water temperature of about 20 ° C. so that hot water of approximately 70 ° C. or less is achieved. do.

However, such a conventional heat pump system is a system for discharging cold water and hot water in parallel, and has many problems in supplying hot water. In other words, in order to increase the temperature of the hot water to a high temperature of about 50 ℃ or more, the compressor must be operated for a long time, which gives the compressor an unfavorable side, and causes frost on the pipe between the compressor and the evaporator. Therefore, in the related art, in order to supply hot water, there is an inefficient aspect such as installing a separate auxiliary heater.

In order to solve this problem, a hot water (heating) production system using two heat pump cycles has been proposed.

In the hot water production system using a two-stage heat pump cycle according to the prior art, the refrigerant flowing through the condenser of the primary side heat pump cycle and the evaporator of the secondary side heat pump cycle directly exchanges heat to produce hot water in the secondary side heat pump cycle, There is a problem that a trouble occurs during heat exchange due to the heat exchange of the refrigerant to the refrigerant having a large temperature difference.

In addition, the conventional hot water production system using a two-stage heat pump cycle is not able to produce cold water because only hot water is produced, and even if cold water is produced, it cannot be used for cooling because the temperature of cold water is low.

Domestic Patent Application No. 2008-0051156 Domestic registered patent no.0796452

The present invention is to solve the problems described above, by indirect heat exchange of the two heat pump cycle refrigerant with water capable of buffering the refrigerant to provide hot water at an appropriate temperature with a small heat source without using excessive driving of the compressor And heat the water first with the high temperature secondary refrigerant discharged from the third heat exchanger of the second heat pump cycle and then heat exchange again with the fourth heat exchanger to improve the evaporation efficiency of the secondary refrigerant to produce high temperature hot water. The purpose is to provide a hot and cold water production system using a two-stage heat pump cycle with improved heat exchange to cool the room.

The hot water and cold water production system using the heat exchanger improved two-stage heat pump cycle according to the present invention, the heat pump cycle consisting of a compressor, a four-way valve, a heat exchanger, an expansion valve in two stages, respectively, the first and second heat pumps The first refrigerant and the second refrigerant of the cycle is configured to heat exchange through the water, wherein the water is configured to heat exchange with the high temperature secondary refrigerant discharged from the heat exchanger of the second heat pump cycle through a separate heat exchanger do.

According to the hot water and cold water production system using the two-stage heat pump cycle with improved heat exchange according to the present invention, the heat is recovered from the raw water (or air) through the one-stage heat pump cycle, and the refrigerant and the first stage of the two-stage heat pump cycle By indirectly exchanging the refrigerant in the heat pump cycle with water, the desired output can be obtained without forcibly driving the compressor of each heat pump cycle, which can reduce power consumption and reduce costs. The first heat exchanger with the high temperature secondary refrigerant discharged from the third heat exchanger of the pump cycle and then heat exchanged again with the fourth heat exchanger to improve the evaporation efficiency of the secondary refrigerant can produce hot water of high temperature and can cool the room .

1 is a schematic diagram of a hot water and cold water production system using a two-stage heat pump cycle with improved heat exchange according to the present invention.
Figure 2 is a schematic diagram showing another example of a hot water and cold water production system using a heat exchange improved two-stage heat pump cycle according to the present invention.
3 and 4 are each a schematic diagram showing the indoor cooling mode,
3 is in the cooling mode by the secondary heat pump cycle,
4 is a cooling mode by the primary heat pump cycle.

As shown in Figure 1, the hot water production system using a two-stage heat pump cycle according to the present invention, the secondary heat for producing hot water through heat exchange with the primary heat pump cycle 100 and the primary heat pump system 100 It consists of a pump cycle 200.

The primary heat pump cycle 100 may include a first compressor 110 for compressing a primary refrigerant at high temperature and high pressure, a first and second heat exchangers 120 and 130 for condensing or evaporating the primary refrigerant, and a first or second one. The first expansion valve 140 for reducing the primary refrigerant condensed by the heat exchangers 120 and 130 and the direction of the primary refrigerant compressed by the first compressor 110 to the first or second heat exchangers 120 and 130. A first four-way valve (not shown) for switching. That is, by controlling the flow of the primary refrigerant by the first four-way valve, the first heat exchanger 120 is used as a condenser or evaporator, and the second heat exchanger 130 is opposite to the first heat exchanger 120. It is used as.

When the second heat exchanger 130 is used as an evaporator, the primary refrigerant is evaporated by air cooling, water cooling, or the like.

The secondary heat pump cycle 200 is condensed by the second compressor 210 for compressing the secondary refrigerant at high temperature and high pressure, the third heat exchanger 220 for condensing the secondary refrigerant, and the third heat exchanger 220. The second expansion valve 240 for depressurizing the secondary refrigerant and the fourth heat exchanger 230 for evaporating the secondary refrigerant depressurized by the second expansion valve 240.

The secondary refrigerant passing through the fourth heat exchanger 230 of the secondary heat pump cycle 200 exchanges heat with the primary refrigerant passing through the first heat exchanger 120 of the primary heat pump cycle 100.

Here, the primary refrigerant and the secondary refrigerant are heat exchanged through water (where water refers to all heat exchangers with the primary and secondary refrigerants), for example, the first heat exchanger 120 and the fourth heat exchanger. The water circulation pipe 300 continuously circulating 230 is configured. The water circulation pipe 300 is tubular with water flowing therein and is connected to the first heat exchanger 120 and the fourth heat exchanger 230 so that water circulates through the first and fourth heat exchangers 120 and 230. The water is forced to circulate by the pump 310 to recover the heat of the primary refrigerant flowing along the first heat exchanger 120 to deliver to the secondary refrigerant of the fourth heat exchanger (230).

Water can circulate only the first and fourth exchangers (120, 230), but the thermal bridge efficiency is weak, it will be difficult to produce hot water at a desired temperature, between the fourth heat exchanger (230) and the first heat exchanger (120) A fifth heat exchanger 320 is installed to allow heat exchange between the refrigerant and water. The fifth heat exchanger 320 has a structure having two flow paths, and the first flow path is connected to both the first heat exchanger 120 and the fourth heat exchanger 230 and guides the circulation of water. Is a flow path at both ends connected to the third heat exchanger 220 and the second expansion valve 240 to guide circulation of the secondary refrigerant.

That is, the fifth heat exchanger 320 discharges water (water discharged from the fourth heat exchanger 230 and flows into the first heat exchanger 120) and secondary refrigerant (third heat exchanger 220). Secondary refrigerant flowing into the second expansion valve 240 is heat exchanged.

As viewed from the side of the secondary refrigerant, the secondary refrigerant in the high temperature state discharged from the third heat exchanger 220 has relatively low temperature water (temperature is lowered due to heat being taken away by the secondary refrigerant passing through the fourth evaporator 230). Heat exchange efficiency is improved by heat exchange with the fourth heat exchanger 230 to increase the heat exchange efficiency of water (water discharged from the first heat exchanger 120 and then introduced into the fourth heat exchanger 230) while passing through the fourth heat exchanger 230. . The hot water will vary in temperature depending on the temperature of the secondary refrigerant of the secondary heat pump cycle 200, and the fifth heat exchanger 320 lowers the temperature of the secondary refrigerant introduced into the fourth heat exchanger 230 to evaporate efficiency. As a result, the temperature of the secondary refrigerant passing through the third heat exchanger 220 is increased.

Therefore, the secondary refrigerant flowing through the third heat exchanger 220 of the secondary heat pump cycle 200 increases the temperature of the water stored in the hot water tank 1 to produce hot water.

The present invention can produce cold water (for indoor cooling, etc.), the low temperature of the primary refrigerant flowing through the first heat exchanger 120 or the fourth heat exchanger 230 used as an evaporator, respectively, in the water circulation pipe 300 or An indoor air conditioner 400 (or a cold water tank) for receiving water whose temperature is lowered by losing heat to the secondary refrigerant is provided.

The cooling circulation pipe 330 is branched to the water circulation pipe 300. Cooling circulation pipe 330 is circulated in the indoor air conditioner 400, both ends are connected in fluid communication with the water circulation pipe (300).

Cooling circulation pipe 330 is preferably opened only when the indoor air conditioner 400 operates, for this purpose, the first valve 331 for opening and closing the cooling circulation pipe 330, the middle of the water circulation pipe 300 A second valve 332 is provided between the both ends of the cooling circulation pipe 330 to open and close the water circulation pipe 300. That is, when the indoor air conditioner 400 operates, the first valve 331 is opened while the second valve 332 is closed, and when the indoor air conditioner 400 is stopped, the first valve 331 is closed while the second valve 331 is closed. The valve 332 is open.

During cold water production, only one or both of the first and second heat pump cycles 100 and 200 are selected and operated. For example, when the cooling is selected by the user, the controller controls only one of the first and second compressors 110 and 210 to operate. The controller first operates the second heat pump cycle 200 to simultaneously produce hot water and cold water, and if hot water of a predetermined temperature (detected by the temperature sensor 2) in the hot water tank 1 maintains a constant water level ( The second heat pump cycle 200 is stopped and the primary heat pump cycle 100 is controlled to operate.

The indoor air conditioner 400 receives cold water only when cooling the room through the first and second valves 331 and 332 to cool the room.

2 is another example of the present invention, the secondary refrigerant discharged from the third heat exchanger 220 of the secondary heat pump cycle 200 does not go through the fifth heat exchanger 320, the second expansion valve 240 It is configured to be supplied directly to, the connecting pipe 250 for connecting the third heat exchanger 220 and the fifth heat exchanger 320, the third heat exchanger 220 and the second expansion valve 240 for connecting minutes The engine 260 is branched, and the third and fourth valves 251 and 261 are installed at the connection pipe 250 and the branch pipe 260. That is, the third and fourth valves 251 and 261 are controlled to be opened and closed in opposite directions. When the third valve 251 is opened, as described above, heat exchange between the water and the secondary refrigerant is performed, and the fourth valve 261 is opened. When the secondary refrigerant discharged from the third heat exchanger 220 is supplied directly to the second expansion valve 240 without passing through the fifth heat exchanger 320, the water and the secondary refrigerant are supplied only from the fourth heat exchanger 230. Heat exchange.

Control of the third and fourth valves 2551 and 261 may be variously performed according to the temperature of the primary and secondary refrigerants (detected by the temperature sensor) and the mode selection (cooling, hot water supply, etc.) Since specific opening and closing control is omitted, the description is omitted.

The operation of the hot and cold water production system using a two-stage heat pump cycle with improved heat exchange according to the present invention is as follows.

1. Hot water production (hot water, etc.) (see Figure 1).

When the hot water mode is selected, the controller runs both primary and secondary heat pump cycles (100, 200).

Accordingly, the primary refrigerant is the first compressor 110-the first four-way valve-the first heat exchanger (condenser) 120-the first expansion valve 140-the second heat exchanger of the primary heat pump cycle 100. (Evaporator) 130-Phase change while continuously circulating the first compressor (110).

The secondary refrigerant is the second compressor 210 of the secondary heat pump cycle 200-the third heat exchanger (condenser) 220-the second expansion valve 240-the fourth heat exchanger 230-the second compressor The phase is changed while continuously cycling 210.

As such, the primary refrigerant passing through the second heat exchanger (evaporator) 130 of the primary heat pump cycle 100 exchanges heat with external air and raw water while the primary and secondary heat pump cycles 100 and 200 are operating. .

The primary refrigerant heat-exchanged with external air or raw water passes through the first heat exchanger (condenser) 120 through the first compressor 110, and at this time, the primary refrigerant and the secondary refrigerant exchange heat through water. . In more detail, the water circulating through the water circulation pipe 300 recovers heat of the primary refrigerant while passing through the first heat exchanger 120, and then passes through the fourth heat exchanger 230. The heat recovered from the secondary refrigerant is lost to the secondary refrigerant, and the water is circulated continuously in the first heat exchanger 120 to the fourth heat exchanger 230 through the water circulation pipe 300. Is delivered to the secondary refrigerant through which the primary refrigerant is condensed and the secondary refrigerant is evaporated.

The secondary refrigerant exchanged with the primary refrigerant passes through the third heat exchanger 220 via the second compressor 210. The secondary refrigerant flowing through the third heat exchanger 220 is condensed by heat exchange with the supply water, and the supply water is heated to produce hot water.

Hereinafter, the operation of the fifth heat exchanger 320 applied to the present invention will be described in detail. In the fifth heat exchanger 320, water [the fourth heat exchanger 230 is discharged from the first heat exchanger 120 to the first heat exchanger 120). The incoming water] and the secondary refrigerant (the secondary refrigerant discharged from the third heat exchanger 220 and introduced into the second expansion valve 240) are heat exchanged. At this time, the secondary refrigerant in the high temperature state discharged from the third heat exchanger 220 is heat exchanged with relatively low temperature water (temperature is lowered by the heat is lost to the secondary refrigerant passing through the fourth evaporator 230) expansion efficiency This improves the heat exchange efficiency of the water (water flowing into the fourth heat exchanger 230 after being discharged from the first heat exchanger 120) while passing through the fourth heat exchanger 230, thereby increasing the efficiency of the third heat exchanger ( The temperature of the secondary refrigerant supplied to 220 is increased to a high temperature. As a result, the raw water of the hot water tank 1 recovers high temperature heat of the secondary refrigerant and is produced as hot water of high temperature.

When the cooling mode is not selected and the hot water mode such as the hot water supply is selected, the first valve 331 is closed and the second valve 332 is opened so that water is not supplied to the indoor air conditioner 400.

2. In cooling mode.

end. Cooling and hot water production (see Figure 3).

When the cooling mode is selected in the summer, the controller starts only the secondary heat pump cycle 200 and stops the primary heat pump cycle 100.

Therefore, the water flowing through the water circulation pipe 300 is supplied to the indoor air conditioner 400 after the fourth heat exchanger (evaporator) 230 is deprived of heat to the secondary refrigerant and lowered to a low temperature, and passes through the indoor air conditioner 400. The low temperature water is exchanged with the air supplied to the room to lower the temperature of the air so that the room is cooled.

At this time, the third heat exchanger 230 of the second heat pump cycle 200 is a condenser, so that the high temperature secondary refrigerant passes, thereby producing hot water.

When the third and fourth valves 251 and 261 are not applied, the water that has been heat-exchanged with the secondary refrigerant while passing through the fourth heat exchanger 230 exchanges heat with the secondary refrigerant discharged from the third heat exchanger 220, thereby providing slight efficiency. This can fall.

When the third and fourth valves 251 and 261 are applied, since the secondary refrigerant is supplied to the second expansion valve 240 without passing through the fifth heat exchanger 320, the water is supplied to the secondary refrigerant in the fourth heat exchanger 230. Heat exchange.

I. cooling.

The secondary heat pump cycle 200 is operated first with the cooling mode selected to produce hot water while cooling the room as described above, and the controller generates the hot water tank 1 through the temperature sensor 2 and the water level sensor 3. Check the temperature and amount of the hot water stored in real time, and if the appropriate temperature and / or the appropriate amount of hot water is stored in the hot water tank (1), the secondary heat pump cycle 200 is stopped and the primary heat pump cycle (100) (See Fig. 4).

Therefore, the primary heat pump cycle 100 circulates the primary refrigerant as opposed to the production of hot water so that the first heat exchanger 120 becomes an evaporator. Water in the water circulation pipe 300 is supplied to the indoor air conditioner 400 after the temperature is lowered by heat exchange with the low temperature primary refrigerant flowing through the first heat exchanger 120.

1: hot water tank, 2: temperature sensor
100: 1st heat pump cycle, 110, 210: 1st, 2nd compressor
120, 130, 220, 230, 320: the first to fifth heat exchanger,
140,240: 1st, 2nd expansion valve, 300: water circulation pipe
310: pump,

Claims (4)

The first compressor 110 for compressing the primary refrigerant at high temperature and high pressure, the first four-way valve for changing the direction of the refrigerant compressed by the first compressor, the primary refrigerant conveyed through the first four-way valve condensing or First expansion for reducing the primary refrigerant condensed through the first and second heat exchangers (120,130) and the first or second heat exchangers (120,130) to be evaporated and supplied to the second or first heat exchangers (130,120). A primary heat pump cycle (100) consisting of valves (140);
A second compressor 210 compressing the secondary refrigerant at high temperature and high pressure, a third heat exchanger 220 condensing the secondary refrigerant compressed through the compressor, and a secondary condensed through the third heat exchanger 220 A second heat pump cycle (200) comprising a second expansion valve (240) for reducing the refrigerant, and a fourth heat exchanger (230) for evaporating the secondary refrigerant expanded by the expansion valve;
A hot water tank (1) for recovering heat of the secondary refrigerant flowing through the third heat exchanger of the secondary heat pump cycle to store hot water;
Connected to the first heat exchanger 120 of the primary heat pump cycle and the fourth heat exchanger 230 of the secondary heat pump cycle, and recovers heat of the primary refrigerant through water to recover the secondary heat. A water circulation pipe 300 for supplying the refrigerant;
While installed between the third heat exchanger 220 and the second expansion valve 240 of the secondary heat pump cycle 200 is connected to the water circulation pipe 300 in the third heat exchanger 220 By inducing heat exchange between the discharged secondary refrigerant and the water discharged from the fourth heat exchanger 230, the fifth heat exchanger 320 for supplying the secondary refrigerant heat-exchanged with the water to the second expansion valve 240 is provided. Hot and cold water production system using an improved heat exchanger two-stage heat pump cycle. The cooling pipe of claim 1, wherein both ends are branched from the water circulation pipe to circulate water flowing through the water circulation pipe; An indoor air conditioner 400 to which the air cooling circulation pipe 330 is connected; And a first and second valves 331 and 332 which open and close the cooling circulation pipe and the water circulation pipe, respectively, and selectively supply the water flowing through the water circulation pipe to the indoor air conditioner. Hot and cold water production system using heat pump cycle. The method according to claim 2, Temperature sensor (2) for sensing the temperature of the hot water tank; A water level sensor 3 for detecting a hot water level of the hot water tank; And a controller for controlling the operation of the first and second heat pump cycles. In the indoor cooling mode, the controller is configured to perform secondary operation when a predetermined temperature and a predetermined amount of hot water are maintained in the hot water tank based on the detected value of the water level sensor. Hot water and cold water production system using a heat exchange improved two-stage heat pump cycle characterized in that the heat pump cycle is stopped and the primary heat pump cycle is operated. The inflow side of the second expansion valve 240 according to any one of claims 1 to 3, branched from a connection pipe 250 connecting the third heat exchanger 220 and the fifth heat exchanger 320. And a third and fourth valves 251 and 261 for opening and closing the branch pipe 260 and the connecting pipe 250 and the branch pipe 260, respectively, and the secondary refrigerant discharged from the third heat exchanger is Hot water and cold water production system using a two-stage heat pump cycle heat exchange is improved that is configured to be supplied to the second expansion valve 240 or the fifth heat exchanger (320).

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