KR100952648B1 - Heat pump accumulating heat from air in water - Google Patents

Abstract

PURPOSE: A heat pump accumulating heat from air in water is provided to induce enough low temperature evaporation without a separate thermoelectric device when the temperature of exterior air falls below a specific temperature. CONSTITUTION: A heat pump accumulating heat from air in water comprises an auxiliary evaporator(HE3), refrigerant bypass pipes(P10,P11), an electronic valve(S1) for refrigerant bypass, and a refrigerant bypass pipe expansion valve(EV3). The auxiliary evaporator is installed between an exterior heat exchanger expansion valve(EV1) and water heat exchangers(HE1,HE2). Through the refrigerant bypass pipes, a part of liquid refrigerant flowing from the water heat exchangers into the auxiliary evaporator is turned back to the auxiliary evaporator and heat-exchanged with the liquid refrigerant before reaching the exterior heat exchanger expansion valve and than bypassed to a lower pressure pipe(P12). The electronic valve for refrigerant bypass opens only when the temperature of exterior air falls below a specific temperature. The refrigerant bypass pipe expansion valve expands the liquid refrigerant which bypasses just before flowing into the auxiliary evaporator so that the bypassed liquid refrigerant is heat-exchanged with the liquid refrigerant flowing from the water heat exchanger in the auxiliary evaporator.

Description

Heat source shrinkage heat pump with improved efficiency {HEAT PUMP ACCUMULATING HEAT FROM AIR IN WATER}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air heat source shrinking heat pump for improved efficiency, and more particularly, even when the outdoor temperature drops to a low temperature below zero (0 ° C.). The number of high-efficiency air heat sources that can maintain the evaporation amount of the refrigerant in the heat exchanger and the refrigerant circulation in the refrigerant circulation circuit at a certain level or more, thereby minimizing the deterioration of the coefficient of performance of the heat pump and continuing the heat pump operation and heat storage in the shrinkage tank without interruption. It relates to a heat storage heat pump.

Heat pumps move heat from a low temperature to a high temperature. A compressed refrigerant circulation circuit that compresses and circulates CFC refrigerants or HFC refrigerants and heat exchanges them, is widely used as a heat pump because it is possible to simply move the heat of a low temperature to a high place through phase change of the refrigerant. The heat pump uses not only the heat of the compressor (heat due to power consumption in the compressor), but also the amount of heat contained in the air outside the building (air heat source) as a heat source for heating or hot water inside the building. It is well known that heat pumps are much more efficient than electrothermal heaters in this regard.

Therefore, in recent years, an air heat source shrinkage heat pump that absorbs heat from outside air and stores it in water using a compressed refrigerant circulation circuit has been widely used. It is a method of correcting the unbalance of power demand during the day and night and improving the efficiency of thermal power generation.It operates the refrigerating circuit during the time when the power demand is low, and heats or cools the heat in the heat storage tank, or uses it in the time when the power demand is high. Air heat source shrinkage heat pumps are widely used. Air heat source shrinkage heat pump recovers the heat or cold heat generated by the condensation or evaporation of refrigerant in the compressed refrigerant circulation circuit as water with a very large heat capacity and stores it in the heat storage tank. It is a system used for such.

Thermal heat storage is achieved by absorbing heat from the outside air by evaporation of the refrigerant and then allowing heat exchange between the refrigerant and water in the water heat exchanger (condensation of the refrigerant). In continuous circulation, the heat from the heat exchanger is stored in the heat storage tank.

Therefore, the heat source heat shrinkage heat pump is a very important selection criterion is the energy efficiency or grade factor (heat output from the condenser / heat applied to the compressor). The coefficient of performance of air heat source shrinkage heat pump should be maintained at least 2 ~ 4 times (2 ~ 4 times the amount of heat applied to the compressor).

In general, the heat coefficient of the heat pump decreases as the difference between the evaporator temperature and the condenser temperature increases, and as the difference between the evaporator temperature and the condenser temperature decreases.

In addition, as shown in Table 1, the heat coefficient of the heat pump increases as the superheat and supercooling degree of the coolant are maintained to a suitable level for heat absorption and heat release of the coolant, and becomes smaller when out of the range. Referring to Table 1, the coolant supercooling degree or the coolant subcooling degree is too small (less than or equal to a) or too large (more than or equal to c), and the heat coefficient of the heat pump decreases to an appropriate level (2 or less).

The air heat source heat shrinkage heat pump having the above characteristics is restricted in evaporation conditions that it must absorb heat from low temperature outside air during the heat storage in winter, and water absorbed the latent heat of refrigerant condensation in the water heat exchanger. Due to the circulation of the heat storage tank and the water heat exchanger, the water heat exchanger inlet temperature is approximately equal to the temperature of the water in the heat storage tank, and the condensation conditions of the condensation and supercooling of the refrigerant are not easy.

Generally, the compressor has a constant discharge refrigerant pressure (high pressure side pressure) (for compressors using CFC refrigerant or HFC refrigerant) within 23 Kg / cm 2 or 25 Kg / cm 2) and suction refrigerant pressure (low pressure side pressure) ( Compressors using CFC refrigerants or HFC refrigerants are usually designed to operate within a range of 2Kg / cm 2 or more. Therefore, the heat pump having such a compressor is provided with a high pressure switch and a low pressure switch and configured to stop the compressor operation when the high pressure side pressure or the low pressure side pressure of the compressor is out of the allowable range.

In the case of the heat pump, when the air heat source is used as the heat source, the decrease in the coefficient of performance due to the decrease in the outside temperature is inevitable. In particular, when the outside air temperature drops below zero degrees Celsius, the evaporation of condensed water vapor in the evaporator decreases the amount of air passing through the coil, and the heat transfer to the refrigerant is blocked. Accordingly, the heat absorption capacity and evaporation capacity of the refrigerant are reduced. As a result, the pressure and superheat of the steam refrigerant discharged from the outdoor heat exchanger is significantly lowered, and the performance coefficient of the heat pump is also significantly lowered. If the heat absorption and evaporation is not properly reduced, the amount of circulating refrigerant is reduced, and the low saturation of the low pressure refrigerant is reduced, resulting in poor compression due to wet compression in the compressor, and in the water heat exchanger where condensation occurs, the amount of intake refrigerant is increased, which reduces the amount of heat generated. It can also cause a drop in grade factor. It is difficult to absorb heat from the low outside temperature, transport it to the room, and regenerate it. In particular, since the operation of the compressor is stopped when the pressure of the steam refrigerant falls below the design pressure of the compressor, the heat pump using the air heat source can be frequently stopped in the heat shrinkage operation when the outside air temperature drops below zero. In general, heat pumps are installed with electric heaters to compensate for these problems. Even in this method, the inherent problems of heat pumps cannot be overcome.

Shrinkage heat pump performs sensible heat exchange and latent heat exchange in a water heat exchanger such as a plate heat exchanger, and since the heated water is circulated through the heat storage tank and the heat exchanger, the temperature of the water obtained in the heat exchanger is almost equal to that of the heat storage tank. As a result, if a certain amount of heat is accumulated in the heat storage tank, the temperature of the water obtained by the heat exchanger is also increased. When the inlet temperature of the water heat exchanger rises above the condensation temperature of the coolant, the condensation defect of the coolant is caused in the water heat exchanger. Accordingly, the discharge pressure of the compressor is increased, and the supercooling degree of the coolant drops drastically. The lower the supercooling degree of the refrigerant, the lower the coefficient of performance of the heat pump, thus making it impossible to accumulate with high efficiency. In particular, if the compressor discharge pressure becomes too large, the compressor is stopped due to the overload of the compressor as described above.

In addition, when the air heat source shrinkage heat pump is operated in winter, the temperature difference between the liquid refrigerant temperature of the water heat exchanger and the steam refrigerant of the outdoor heat exchanger increases, thereby increasing the work of the compressor.

The present invention, which is designed to solve the problem of reducing the winter coefficient and the operation stop of the conventional air heat source shrinkage heat pump described above, even if the outside temperature drops to below zero degrees Celsius, sufficient low temperature evaporation may occur in the outdoor heat exchanger without a separate heating device. The purpose of the present invention is to provide an air heat source shrinkage heat pump that has improved efficiency.

Another object of the present invention is to provide an air heat source shrinkage heat pump that improves efficiency by maintaining a certain level of superheat of the refrigerant even when the outside air temperature drops to below zero degrees Celsius.

Still another object of the present invention is to provide an air heat source shrinkage heat pump that improves efficiency so that heat storage can be continued even when the temperature of water obtained by the heat exchanger in the heat storage tank rises above the temperature of the saturated liquid refrigerant.

Air heat source shrinkage heat pump according to the present invention to achieve the above object

An auxiliary evaporator provided between the water heat exchanger and the expansion valve for the outdoor heat exchanger such that the liquid refrigerant heat-exchanged with water in the water heat exchanger passes before reaching the expansion valve for the outdoor heat exchanger; Some of the liquid refrigerant flowing into the auxiliary evaporator from the water heat exchanger is discharged from the auxiliary evaporator, and then returned to the auxiliary evaporator before reaching the expansion valve for the outdoor heat exchanger, and after exchanging heat with the liquid refrigerant flowing from the water heat exchanger, A refrigerant bypass pipe leading to bypass the pipe; A solenoid valve for refrigerant bypass provided in the refrigerant bypass pipe and opened only when the outside air temperature drops below a predetermined temperature; And a bypass for allowing the bypassing liquid refrigerant to expand the bypassing liquid refrigerant immediately before the auxiliary evaporator flows into the auxiliary evaporator, thereby allowing the bypassed liquid refrigerant to exchange heat with the liquid refrigerant flowing from the water heat exchanger in the auxiliary evaporator. Tube expansion valve; characterized in that configured to include.

According to the present invention having the above-described configuration, when the outside air temperature drops below zero degrees Celsius, the solenoid valve for the refrigerant bypass is opened, and a portion of the refrigerant is expanded while entering the auxiliary evaporator instead of the outdoor heat exchanger, thereby expanding from the water heat exchanger to the auxiliary evaporator. At the same time, the liquid refrigerant is supercooled, and at the same time, it is evaporated and overheated and bypassed to the low pressure pipe, so that a sufficient low temperature evaporation occurs in the outdoor heat exchanger without a separate heating device, and the superheat of the compressor suction steam is sufficiently increased. Therefore, the performance degradation of the heat pump is minimized, and the abnormal rise of the compressor high pressure side pressure and the abnormal drop of the compressor low pressure side pressure are prevented, thereby maintaining the low temperature evaporation shrinkage heat operation of the heat pump.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the heat source heat shrinkage heat pump according to the present invention having the above-described configuration and effect will be described in detail.

1 is a block diagram of an air heat source shrinkage heat pump according to the present invention.

Referring to Figure 1, the air heat source shrinkage heat pump according to the present invention is connected to each other by the refrigerant pipes (P1 ~ P9, P12) and two parallel connected compressors (1a, 1b) to form a compressed refrigerant circulation cycle, Four-way valves (7) in which four ports (a, b, c, d) are connected to the high pressure side of the compressor (1a, 1b) and the water heat exchanger (HE1, HE2) and the low pressure side of the compressor and the outdoor heat exchanger (HE4), respectively. ), Two water heat exchangers HE1 and HE2 connected in series with each other, a valve valve for water heat exchanger and EV2 and a check valve C4 connected in parallel thereto, and a heat exchanger that is a heat exchanger between a condensation refrigerant and a compressor suction refrigerant. (9), the auxiliary evaporator HE3, the expansion valve for the outdoor heat exchanger and the check valve C4 connected in parallel thereto, and the outdoor heat exchanger HE4.

The discharge pipes P1 and P2 of the two parallel connected compressors 1a and 1b are provided with check valves C1 and C2 to prevent backflow of the compressed refrigerant. In addition, the high pressure side refrigerant pipe P3 of the compressor is provided with a high pressure switch 3 for compressor control, and the low pressure side refrigerant pipe P12 of the compressor is provided with a low pressure switch 5 for compressor control. Compressor operation is stopped when it goes up or down at 23Kg / cm2 on the high pressure side and 2Kg / cm2) on the low pressure side.

It is preferable to use two compressors having the same capacity in parallel as the compressors 1a and 1b. This is the discharge amount of the compressor when the heat storage is performed on a hot day of summer when the temperature difference between the water temperature of the heat storage tank and the external period is very small. This is because the driving can be reduced.

As the water heat exchangers HE1 and HE2, it is preferable to use two water heat exchangers having the same capacity as the total capacity of the two compressors 1a and 1b in series. According to the present invention, by connecting two water heat exchangers HE1 and HE2 in series, the pressure of the high pressure side of the compressors 1a and 1b can be prevented to some extent from an abnormal condensation.

Two flow paths separated from each other are formed in the water heat exchangers HE1 and HE2, and the heat of the coolant is transferred to the water while the coolant passes through the other flow path as one flow path. Water is first introduced into the secondary heat exchanger (HE2) and firstly heated, and the first heated water in the secondary heat exchanger (HE2) is re-introduced to the primary heat exchanger (HE1) to be heated again. In the first heat exchanger (HE1), the superheat of the compressed refrigerant is removed and some condensation takes place, and the water is heated. In the second heat exchanger (HE2), the water is mainly heated by latent heat of condensation. Thus, water heated to 35 ° C.-45 ° C. in the secondary heat exchanger HE2 is heated to a higher temperature (approximately 55 ° C. and around) in the primary heat exchanger HE1. The water inlet pipe WP1 for introducing water to the secondary heat exchanger HE2 is provided with a pump 19, and the end of the water inlet pipe WP1 is connected to a heat storage tank (not shown in the drawing) for public use. Inlet pipe (WP1) is provided with a water temperature sensor 15 that can measure the temperature of the water flowing into the secondary heat exchanger (HE2) from the heat storage tank is used for the purpose described later. The water withdrawn from the primary heat exchanger (HE1) is returned to the heat storage tank through the discharge pipe (WP2) with the heat retained.

The expansion valve (EV2) for the water heat exchanger is a refrigerant flow direction by the four-way valve compressor (1a, 1b)-> outdoor heat exchanger (HE4)-> auxiliary evaporator (the refrigerant bypass solenoid valve S1 is closed at this time) )-> Liquid heat exchanger (9)-> Expansion valve for water heat exchanger (EV2)-> Hydraulic heat exchanger (HE1, HE2)-> Compressor (1a, 1b) It is intended for use. The refrigerant passes through the expansion valve EV2 for the heat exchanger only when the refrigerant flows into the heat exchangers HE1 and HE2, and the expansion valve EV2 for the heat exchanger when the refrigerant is discharged from the heat exchangers HE1 and HE2. A check valve C4 is provided in parallel with the expansion valve EV2 for the water heat exchanger to bypass.

The heat exchanger (9) allows heat exchange between the liquid refrigerant condensed in the water heat exchangers (HE1, HE2) and the vapor refrigerant evaporated in the outdoor heat exchanger (HE4), and vaporizes the wet refrigerant in the steam so that the wet steam enters the compressor. This prevents the liquid refrigerant from being overcooled to some extent to prevent flash gas from being generated when passing through the expansion valve.

An outdoor air temperature sensor 17 is provided at or near the outdoor heat exchanger HE4.

The present invention provides an auxiliary evaporator (HE3) between the water heat exchangers (HE1, HE2) and the expansion valve (EV1) for the outdoor heat exchanger to expand the liquid refrigerant heat-exchanged with the water in the heat exchangers (HE1, HE2) for the outdoor heat exchanger. Before reaching the valve EV1, a part of the liquid refrigerant flowing into the auxiliary evaporator HE3 from the water heat exchangers HE1 and HE2 is discharged from the auxiliary evaporator HE3. After returning to the auxiliary evaporator HE3 before reaching the expansion valve EV1 for the outdoor heat exchanger, heat exchange is performed by evaporation with the liquid refrigerant flowing from the water heat exchanger to induce the bypass to the low pressure pipe P12. There is. To this end, the liquid refrigerant output pipe (6) of the auxiliary evaporator (HE3), the auxiliary evaporator (HE3) and the refrigerant bypass pipe (P10, P11) for connecting the low pressure pipe (P12) of the compressor (1a, 1b) is provided. do. The auxiliary evaporator HE3 is formed with two separate flow paths, such as the water heat exchangers HE1 and HE2, and in one flow path, the liquid refrigerant condensed in the water heat exchangers HE1 and HE2 is supercooled while passing through the other flow path. The superheated liquid refrigerant evaporates after evaporation. To this end, a refrigerant bypass pipe expansion valve EV3 is provided at the inlet of the auxiliary evaporator HE3, thereby expanding the liquid refrigerant bypassing just before the bypassing liquid refrigerant flows into the auxiliary evaporator HE3. Evaporation is facilitated in the auxiliary evaporator HE3.

The use of the auxiliary evaporator HE3 is unnecessary at the time when the outside temperature maintains the temperature of the Celsius image. This is because the outdoor heat exchanger HE4 can sufficiently absorb the heat required for the heat storage when the outdoor air temperature is the celsius image, and thus it is not necessary to increase the supercooling degree of the condensate and the superheat of the evaporative refrigerant is also easily achieved.

Therefore, the refrigerant bypass pipes P10 and P11 are provided with a refrigerant bypass solenoid valve S1 to be controlled to open only when the outside temperature drops below a predetermined temperature (usually 0 ° C). In this way, when the outside air temperature drops to below zero degrees Celsius, the solenoid valve S1 for the refrigerant bypass is opened so that a part of the refrigerant expands while entering the auxiliary evaporator HE3 instead of the outdoor heat exchanger HE4, thereby expanding the water heat exchanger HE1. , Supercool the liquid refrigerant flowing from HE2) to the sub-evaporator (HE3) and at the same time it is evaporated and overheated and bypassed to the low pressure pipe (P12), so even when the outside air falls below 0 ° C during the heat storage, the supercooling of the liquid refrigerant The temperature is sufficiently high to facilitate low temperature evaporation in the outdoor heat exchanger, and the refrigerant not introduced into the outdoor heat exchanger is sufficiently evaporated and overheated in the auxiliary evaporator (HE3) and joined with the refrigerant evaporated in the outdoor heat exchanger in the low pressure pipe to the compressor. Since it is added, it is possible to solve the problem of reducing the refrigerant circulation amount and the deterioration of superheat due to the decrease in the outside air at once.

Another feature of the present invention is a water bypass pipe (WP3) to the water inlet pipe (WP1) and the outlet pipe (WP2) of the water heat exchanger (HE1, HE2) so that a part of the water discharged can be bypassed to the inlet pipe (WP1) side. And a water bypass solenoid valve S2 in the water bypass pipe WP3, so that the water bypass solenoid valve while the water temperature of the water inlet pipe WP1 is below a predetermined temperature. Open (S2) to allow a portion of the water in the outlet pipe (WP2) to enter the inlet pipe (WP1). When the water bypass pipe WP3 and the water bypass solenoid valve S2 are restarted after stopping the shrinkage heat pump, the water temperature of the heat storage tank becomes too low, and the pressure on the high pressure side of the compressor is temporarily lower than the designed pressure. Not only is it necessary to prevent it from falling, but it is also necessary to prevent the initial thermal coefficient of the shrinkage heat pump from falling down.

The opening and closing of the solenoid valves S1 and S2, the switching of the four-way valves, and the driving of the compressors 1a and 1b according to the output temperature from the temperature sensors 15 and 17 are all known public heat pump controllers ( Not shown).

2 is a refrigerant flow chart during the normal evaporative shrinkage heat operation of the air heat source shrinkage heat pump according to the present invention, Figure 3 is a refrigerant flow chart during the low temperature evaporation shrinkage heat operation of the air heat source shrinkage heat pump according to the present invention.

Figure 2 shows a case where the heat source heat shrinkage heat pump according to the present invention when the outside air temperature is greater than 0 ° C evaporates heat from the outside air and accumulates in the water while the normal evaporation.

At this time, the refrigerant is compressed into a high-temperature, high-pressure gas refrigerant in the compressor (1a, 1b), sent to the water heat exchanger (HE1, HE2) by the four-way valve (7), while the superheat is removed from the primary water heat exchanger (HE1) Partially condensed, mostly condensed in the secondary water heat exchanger (HE2) to form a liquid refrigerant, and expanded in an expansion valve (EV1) for an outdoor heat exchanger through a check valve (C4), a liquid heat exchanger (9) and a secondary evaporator (HE3). It is then evaporated in the outdoor heat exchanger, and the wet steam is removed from the heat exchanger 9 and then returned to the compressors P1 and P2. In this process, the pump 19 circulates water between the heat exchangers HE1 and HE2 and the heat storage tank to store the heat amount obtained from the heat exchangers HE1 and HE2 in the heat storage tank.

Figure 3 shows a case where the air heat source shrinkage heat pump according to the present invention when the outside air temperature falls below 0 ℃ evaporate the heat amount from the outside air and accumulates in the water while the low temperature evaporation.

Since most of the refrigerant's evaporation temperature is around -30 ℃ or less and the outside air temperature is higher than theft temperature, the heat pump can carry heat from the outside air even if the outside air temperature falls below 0 ℃. have. However, in practice, when the outdoor heat exchanger drops below zero degrees Celsius, the water vapor condensed on the surface freezes, and when the outdoor heat exchanger becomes severe, the air passes through the outdoor heat exchanger coil. The amount is reduced and heat transfer to the refrigerant is interrupted. This makes it difficult to evaporate in outdoor heat exchangers. However, even in the case of the same type of refrigerant, evaporation is easily performed at low temperatures as the degree of subcooling of the liquid refrigerant before expansion is increased. This is because the smaller the amount of heat retained (enthalpy) of the refrigerant, the easier it is to receive heat from the outside. Therefore, when the outside air temperature falls below 0 ° C, it is necessary to make the subcooling degree of the liquid refrigerant as large as possible.

Referring to FIG. 3, for low temperature evaporative shrinkage heat operation, the controller opens the refrigerant bypass solenoid valve S1 when the outside air temperature input from the outside air temperature sensor 17 drops below 0 ° C.

Then, the refrigerant passes through the compressor (1a, 1b)-> four-way valve (7)-> primary water heat exchanger (HE1)-> secondary water heat exchanger (HE2)-> liquid heater (9) sequentially and saturated liquid refrigerant The liquid refrigerant passing through the auxiliary evaporator (HE3) is divided into a part of the expansion of the expansion valve (EV1) for the outdoor heat exchanger, and the rest of the refrigerant is passed through the refrigerant bypass pipe (P10). It flows into the pass pipe expansion valve EV3 and is expanded. Therefore, the evaporation occurs not only in the outdoor heat exchanger but also in the auxiliary evaporator (HE3), and the latent heat of evaporation is taken from the liquid refrigerant flowing into the auxiliary evaporator (HE3) from the water heat exchangers (HE1 and HE2). The supercooling degree of is increased to the low temperature evaporation in the outdoor heat exchanger. Therefore, even if the outside air temperature is 0 ° C. or less, evaporation in the outdoor heat exchanger is smooth, and the amount of circulation of the refrigerant is not reduced. At this time, although the amount of refrigerant that takes heat from the outside air in the outdoor heat exchanger decreases, the efficiency of the compressor is improved because the degree of superheat of the entire steam introduced into the compressor increases by evaporation and overheating of the refrigerant in the auxiliary evaporator HE3. Since the decrease in efficiency due to the decrease in the amount of refrigerant flowing into the heat exchanger to some extent it is possible to minimize the decrease in the heat pump performance coefficient as a whole, it is possible to continue to shrink heat without interruption of the heat pump operation.

1 is a block diagram of an air heat source shrinkage heat pump according to the present invention.

Figure 2 is a flow diagram of the refrigerant during normal evaporation shrinkage heat operation of the air heat source shrinkage heat pump according to the present invention.

3 is a flow chart of a refrigerant during low temperature evaporation thermal storage operation of the air heat source shrinkage heat pump according to the present invention.

            Explanation of symbols on the main parts of the drawings

1a, 1b: compressor 3: high pressure switch

5: low pressure switch 7: 4 way valve

9: liquid heater 11: filter drier

13a, 13b: heat storage tank connection terminal 15, 17: temperature sensor

19: pump C1 ~ C5: check valve

EV1: Expansion valve for outdoor unit EV2: Expansion valve for water heat exchanger

EV3: Refrigerant bypass pipe expansion valve HE1, HE2: Water heat exchanger

HE3: Auxiliary Evaporator HE4: Outdoor Heat Exchanger

P1 ~ P12: Refrigerant pipe S1: Refrigerant bypass solenoid valve

S2: Solenoid valve for water bypass WP1 ~ WP4: Water pipe

Claims (3)

Auxiliary provided between the water heat exchangers HE1 and HE2 and the expansion valve EV1 for the outdoor heat exchanger so that the liquid refrigerant heat-exchanged with the water in the water heat exchangers HE1 and HE2 passes before reaching the expansion valve EV1 for the outdoor heat exchanger. Evaporator (HE3); Some of the liquid refrigerant flowing from the water heat exchangers HE1 and HE2 into the auxiliary evaporator HE3 is discharged from the auxiliary evaporator HE3 and before reaching the expansion valve EV1 for the outdoor heat exchanger HE3. The refrigerant bypass pipes (P10, P11) to return to the low pressure pipe (P12) and then exchange heat with the liquid refrigerant flowing from the water heat exchanger; A refrigerant bypass solenoid valve S1 provided in the refrigerant bypass pipes P10 and P11 and opened only when the outside air temperature drops below a predetermined temperature; And The refrigerant which bypasses the liquid refrigerant to be bypassed immediately before the liquid evaporator HE3 flows into the auxiliary evaporator HE3, thereby allowing the liquid refrigerant to bypass to exchange heat with the liquid refrigerant introduced from the hydrothermal exchanger in the auxiliary evaporator. Bypass pipe expansion valve (EV3); air heat source shrinkage heat pump with improved efficiency comprising a. The method of claim 1, The refrigerant bypass solenoid valve (S1) is an air heat source heat shrinkage heat pump with improved efficiency, characterized in that only open when the outside air temperature drops to minus Celsius. The method of claim 1, Water inlet pipes WP1 and WP2 of the water heat exchangers HE1 and HE2 are provided with a water bypass pipe WP3 so that a portion of the water can be bypassed to the inlet pipe WP1 side, and the water The bypass pipe WP3 is provided with a solenoid valve S2 for water bypass, and the solenoid valve S2 for water bypass is opened while the water temperature of the inlet pipe WP1 is below a predetermined temperature. An efficiency heat-shrinkable heat pump with improved efficiency, characterized in that a portion of the water of the pipe (WP2) can be introduced into the water inlet (WP1).

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