WO2014174792A1

WO2014174792A1 - Heat pump system

Info

Publication number: WO2014174792A1
Application number: PCT/JP2014/002116
Authority: WO
Inventors: 竹内　清
Original assignee: 株式会社デンソー
Priority date: 2013-04-22
Filing date: 2014-04-15
Publication date: 2014-10-30
Also published as: JP2014214886A; DE112014002083T5; JP5958411B2

Abstract

This heat pump system (100) is provided with a heat exchanger (2) which exchanges heat between a refrigerant and a fluid, a heating device (6, 60) through which the fluid heated by the heat exchanger flows, a fluid circulation device (5, 23) which circulates the fluid to pass through the heat exchanger, a control valve (9) which controls flow of the refrigerant, an evaporator (7) which absorbs heat from the outside air, and a control device (10). During defrost operation of the evaporator (7), the control device (10) opens the control valve (9) more than during non-defrost operation, and operates the fluid circulation device (5, 23) to pass the fluid through the heat exchanger (2).

Description

Heat pump system

Cross-reference of related applications

This disclosure is based on Japanese Patent Application No. 2013-89541 filed on April 22, 2013, the contents of which are incorporated herein.

This disclosure relates to a heat pump system using a refrigeration cycle.

In the hot water supply apparatus described in Patent Document 1, the high-temperature and high-pressure refrigerant discharged from the compressor flows through the heat exchanger (heat radiator), and the heat exchanger (evaporator) uses the outside air as a heat source via the electronic expansion valve. ) And return to the compressor. On the radiator side, the water in the tank is supplied from the water supply pump, and the water and the refrigerant exchange heat.

During the defrosting operation of the evaporator, the feed water pump is stopped and the opening of the electronic expansion valve is increased to defrost. Moreover, in patent document 1, it has a bypass circuit so that a high voltage | pressure refrigerant may flow into an evaporator from the refrigerant | coolant exit of a compressor, without letting a radiator pass. There has been proposed a defrosting method in which a flow rate adjusting valve such as an electromagnetic valve is arranged in a bypass circuit, and this flow rate adjusting valve is opened during defrosting operation to introduce high-temperature refrigerant into the evaporator.

JP 2001-108256 A

According to Patent Document 1, in order to increase the refrigerant temperature reaching the evaporator inlet, it is necessary to increase the discharge pressure during the defrosting operation, and the power consumption or power consumption of the compressor during the defrosting operation is high. Get higher. Therefore, a heat pump system that can save power consumption or power consumption of the compressor during the defrosting operation and quickly terminate the defrosting operation is desired.

This disclosure is intended to provide a heat pump system that performs highly efficient defrosting by performing defrosting operation in a short time while suppressing power consumption or power consumption during defrosting operation.

The description of the above patent document can be introduced or incorporated by reference as an explanation of the technical elements described in this specification.

In the present disclosure, the heat pump system includes a compressor that compresses the refrigerant, a heat exchanger that performs heat exchange between the refrigerant compressed by the compressor and the fluid, and a heating fluid that includes a fluid heated by the heat exchanger. A heating device, a fluid circulation device that circulates the heating fluid so as to pass through the heating device and the heat exchanger, a control valve that controls a flow of the refrigerant that has passed through the heat exchanger, and a refrigerant that has passed through the control valve flows. An evaporator that absorbs heat from outside air, and a control device that controls the fluid circulation device and the control valve are provided. At the start of the defrosting operation of the evaporator, the control device makes the opening degree of the control valve larger than that during the non-defrosting operation, and operates the fluid circulation device to flow the fluid to the heat exchanger.

According to this, during the defrosting operation of the evaporator, the control device increases the opening degree of the control valve and operates the fluid circulation device to flow the fluid to the heat exchanger. Therefore, the heat which a heating apparatus holds with a heat exchanger can be supplied to a refrigerant | coolant, and the defrosting operation of an evaporator can be performed. Accordingly, it is possible to provide a heat pump system in which high-efficiency defrosting is performed by performing the defrosting operation in a short time while suppressing power consumption or power consumption during the defrosting operation.

For example, the heat pump system further includes an internal heat exchanger. The internal heat exchanger is a high pressure side heat exchange section provided between the heat exchanger and the expansion valve, a low pressure side heat exchange section provided between the evaporator and the compressor, and exchanges heat with the high pressure side heat exchange section. It consists of. A control valve for defrosting is provided between the refrigerant outflow side of the heat exchanger and the refrigerant inflow side of the evaporator.

According to this, the efficiency of the refrigeration cycle can be improved by the internal heat exchanger, the temperature of the fluid heated by the heat exchanger can be increased efficiently, and the increased temperature can be used to shorten the temperature. Defrosting can be efficiently performed in time. Further, at the time of defrosting, it is possible to defrost in a short time while bypassing the internal heat exchanger and preventing the refrigerant from flowing through the control valve and taking heat away from the internal heat exchanger.

For example, the heat pump system further includes a fluid temperature detection unit that detects the temperature of the heated fluid, and a refrigerant temperature detection unit that detects the temperature of the refrigerant compressed by the compressor. The control device determines whether or not a value obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit is higher than the temperature of the heated fluid detected by the fluid temperature detection unit. And when it is high, the rotation speed of the compressor is reduced by a predetermined amount from the rotation speed of the compressor at the start of the defrosting operation.

According to this, when the temperature obtained by subtracting the predetermined temperature from the temperature of the refrigerant is higher than the temperature of the fluid detected by the fluid temperature detector, the rotation speed of the compressor is decreased by a predetermined amount. In addition, since the discharge temperature is lowered, the refrigerant can sufficiently absorb heat from the fluid.

For example, the heat pump system further includes a fluid temperature detection unit that detects the temperature of the heated fluid, and a refrigerant temperature detection unit that detects the temperature of the refrigerant compressed by the compressor. The control device determines whether or not a value obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit is higher than the temperature of the heated fluid detected by the fluid temperature detection unit. And when it is high, the opening degree of the control valve is made a predetermined amount larger than the opening degree of the control valve at the start of the defrosting operation.

According to this, since the opening degree of the control valve is increased by a predetermined amount when the temperature obtained by subtracting the predetermined temperature from the refrigerant temperature is higher than the temperature of the fluid detected by the fluid temperature detecting unit, the high pressure side of the compressor The pressure can be reduced to reduce the power or power of the compressor. Further, the temperature of the discharged refrigerant, which is the temperature on the discharge side of the compressor, is lowered so that the refrigerant can sufficiently absorb heat from the feed water through the heat exchanger.

It is a block diagram of the heat pump system which shows 1st Embodiment. It is a flowchart which shows control of the heat pump system of 1st Embodiment. It is explanatory drawing explaining the shortening effect of defrost operation time compared with 1st Embodiment and a comparative example. It is a Mollier diagram at the time of the defrost operation in 1st Embodiment. It is a block diagram of the heat pump system which shows 2nd Embodiment. It is a flowchart which shows control of the heat pump system of 3rd Embodiment. It is a block diagram of the heat pump system which shows 5th Embodiment. It is a block diagram of the heat pump system which shows 6th Embodiment. It is a flowchart which shows control of the heat pump system in a modification.

Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where a part of the configuration is described in each form, the other forms described above can be applied to the other parts of the configuration.

Not only combinations of parts that clearly indicate that the combination is possible in each embodiment, but also the embodiments are partially combined even if they are not clearly specified unless there is a problem with the combination. It is also possible.

(First embodiment)
The heat pump system 100 of 1st Embodiment is demonstrated in detail using FIG. 1 thru | or FIG. In FIG. 1, a compressor 1 is composed of an electric compressor in which a compressor is driven by an electric motor to compress refrigerant. In this embodiment, the refrigerant is carbon dioxide, but other refrigerants can also be used.

The water-refrigerant heat exchanger 2 performs heat exchange between the refrigerant compressed by the compressor 1 and an antifreeze liquid (hereinafter, also simply referred to as water, hot water, or water supply) that is a fluid flowing inside. A warm water pipe 3 through which water heated by the water refrigerant heat exchanger 2 flows, a floor heating panel 4, and a circulation pump 5 that circulates water so as to pass through the water refrigerant heat exchanger 2 are a floor heating device 6. Is provided.

The refrigerant that has passed through the water refrigerant heat exchanger 2 from the compressor 1 flows in the refrigeration cycle toward the evaporator 7 that forms an external heat exchanger that absorbs heat from the outside air. A control valve 9 is provided between the water-refrigerant heat exchanger 2 and the evaporator 7. The opening degree of the control valve 9 is controlled by a control signal from the control device 10. The compressor 1, the water refrigerant heat exchanger 2, the control valve 9, and the evaporator 7 constitute a refrigeration cycle apparatus 50 that pumps heat from the outside air. The refrigeration cycle apparatus 50 is integrated with the floor heating apparatus 6.

The control device 10 controls at least the circulation pump 5 and the control valve 9. And the control apparatus 10 makes the opening degree of the control valve 9 larger than the time of normal operation according to the start of the defrosting operation of the evaporator 7, and when the circulation pump 5 is stopped, the circulation pump 5 Rotate.

During the operation of the floor heating device 6 that is not performing the defrosting operation, the high-temperature and high-pressure refrigerant compressed by the compressor 1 warms the water in the floor heating device 6 through the water-refrigerant heat exchanger 2 ( For example, 35 ° C.). Accordingly, the floor in the house is heated by heat radiation from the floor heating panel 4 laid under the floor. During this time, water circulates between the water-refrigerant heat exchanger 2 and the floor heating panel 4 by the circulation pump 5.

Further, the opening degree of the control valve 9 is controlled, and this control valve 9 functions as an expansion valve disposed on the refrigerant inflow side of the evaporator 7. For this reason, the refrigerant evaporates in the evaporator 7 and the evaporator 7 absorbs heat from the outside air. The refrigerant that has absorbed heat is sucked into the compressor 1 and pressurized. Thus, in the process in which the water of the floor heating apparatus 6 is heated, frost adheres to the evaporator 7 and the need for defrosting arises. When the need for defrosting occurs, the water in the floor heating device 6 is sufficiently heated.

The defrosting operation is started at a known timing such as when frosting of the evaporator 7 is detected. For example, the defrosting operation is started when the difference between the outside air temperature and the refrigerant temperature downstream of the evaporator 7 exceeds a predetermined temperature TA. Further, the defrosting operation is terminated when the refrigerant temperature downstream of the evaporator 7 becomes equal to or higher than the predetermined temperature TB. During this defrosting operation, the circulation pump 5 is controlled to continue to rotate. Further, during the defrosting operation, the compressor 1 is controlled so as to continue to operate. Thereby, the water (warm water) in the floor heating device 6 is circulated between the floor heating panel 4 and the water refrigerant heat exchanger 2.

Further, when the defrosting operation is started, the opening degree of the control valve 9 is larger by a predetermined amount than in the normal operation during non-defrosting, for example, fully opened. Thus, the refrigerant heated by the compressor 1 and further heated by the hot water in the floor heating device 6 passes through the control valve 9 having an increased opening and flows into the evaporator 7 to heat the evaporator 7. Thus, the defrosting operation is performed.

The liquid flowing in the water refrigerant heat exchanger 2 is not limited to water or antifreeze. Therefore, the water refrigerant heat exchanger 2 is also referred to as a liquid refrigerant heat exchanger. A water temperature detection sensor 11 that detects the temperature of water heated by the water refrigerant heat exchanger 2 is provided. During the defrosting operation, the control device 10 monitors a signal from a water temperature detection sensor 11 that detects the temperature of water (water supply) between the water refrigerant heat exchanger 2 and the circulation pump 5.

Further, a refrigerant discharge temperature sensor 12 that detects the temperature of the refrigerant compressed by the compressor 1 is provided on the discharge side of the compressor 1. The control device 10 monitors the refrigerant discharge temperature from the refrigerant discharge temperature sensor 12.

When the temperature obtained by subtracting a predetermined temperature from the refrigerant temperature detected by the refrigerant discharge temperature sensor 12 is higher than the temperature of the hot water detected by the water temperature detection sensor 11, the control device 10 rotates the compressor 1. Decrease the number by a predetermined amount.

FIG. 2 shows control of the heat pump system 100 of the first embodiment. During the defrosting operation, the control of FIG. 2 is repeatedly executed by the control device 10 at predetermined intervals. When the control starts in S21 of FIG. 2, in S22, the relationship between the water temperature detected by the water temperature detection sensor 11 and the refrigerant discharge temperature is determined.

If the temperature obtained by subtracting the predetermined temperature α from the refrigerant discharge temperature is not smaller than the water temperature, the process proceeds to S23. In S23, the rotation speed of the compressor 1 is reduced by a predetermined amount, the discharge temperature is lowered, and the refrigerant can absorb heat from the hot water via the water / refrigerant heat exchanger 2. As a result, the power or power consumed by the compressor 1 can be saved.

In S22, when the temperature obtained by subtracting the predetermined temperature α from the refrigerant discharge temperature is lower than the feed water temperature detected by the feed water temperature detection sensor 11, the control is finished in S24. The control of FIG. 2 is repeated at predetermined time intervals during the defrosting operation period. α is a temperature difference necessary for sufficient heat transfer from water to the refrigerant, and is determined in advance through experiments or the like.

FIG. 3 is used to compare the defrosting in the first embodiment with the conventional defrosting (comparative example) and explain the effect of shortening the defrosting operation time. In FIG. 3, the vertical axis represents the defrosting time ratio, and the defrosting time ratio in the conventional defrosting control is 1. In the first embodiment, the defrosting time ratio is about 0.3, and the time can be reduced by about 70%.

In the conventional defrosting operation, it was common to perform defrosting only with the energy of the compressor 1. On the other hand, in this embodiment, the defrosting operation can be performed in a short time and with high efficiency by warming the refrigerant with warm water boiled using outside air heat during normal operation.

FIG. 4 is a Mollier diagram during the defrosting operation. In FIG. 4, the vertical axis represents pressure (p), and the horizontal axis represents specific enthalpy (h). In FIG. 4, the increase in the refrigerant pressure by the compressor is indicated between a → b. Between b-> c, the specific enthalpy of the refrigerant is increased due to the refrigerant being heated by the water-refrigerant heat exchanger (the refrigerant absorbs heat from the hot water). Between c → d, the decompression of the refrigerant by the control valve 9 is shown. Between d → a, the specific enthalpy is reduced by heating the evaporator to defrost.

In the defrosting operation as a comparative example, the defrosting operation is performed only with the energy of the compressor 1. In FIG. 4, the Mollier diagram at the time of the defrost operation of a comparative example is partially shown with the broken line. In the Mollier diagram at the time of the defrosting operation of the comparative example, the increase in the refrigerant pressure by the compressor 1 is shown between a and bb. Between bb and db shows the decompression of the refrigerant when the refrigerant on the high-pressure side of the compressor 1 is led to the evaporator 7 through the solenoid valve and the capillary. Between db → a, the specific enthalpy is reduced by heating the evaporator to defrost. The defrosting capability of the comparative example corresponds to the length between a and db, and the defrosting capability of the above embodiment corresponds to the length between a and d, and the defrosting capability is improved. When the coefficient of performance of the defrosting operation of the comparative example is COP = 1, the coefficient of performance of the defrosting operation of the embodiment is COP = 1 + α, and α corresponds to the amount of heat absorbed by the refrigerant from the hot water.

In a normal water heater, it is common to stop the flow of water in the water-refrigerant heat exchanger 2 during the defrosting operation in order to prevent water from being deprived of heat. However, when it is used as the floor heating device 6, it is not necessary to stop the water during the defrosting operation because the heat capacity of the hot water is large. Accordingly, when switching from the heating operation mode to the defrosting operation, heat is always supplied to the water-refrigerant heat exchanger 2 by continuing to flow water (for example, heat of warm water composed of return water at 30 ° C.).

In addition to the floor heating device, various heating devices using hot water can be adopted. In any case, in addition to the heat capacity of the heating device itself (terminal device itself), the heat capacity of the hot water in the hose and hot water piping up to the heating device itself can be utilized.

In the water / refrigerant heat exchanger 2, in order to transfer heat from water to the refrigerant, the compression pressure of the compressor 1 can be reduced (power consumption can be reduced) by intentionally reducing the discharge pressure. Further, the discharge pressure decreases, the density of the refrigerant in the water-refrigerant heat exchanger 2 is reduced, the amount of refrigerant flowing into the evaporator 7 is increased correspondingly, and the effect of further shortening the defrosting operation time is also accompanied. Will occur.

In the first embodiment, the water refrigerant heat exchanger 2 in FIG. 1 constitutes a fluid refrigerant heat exchanger, the floor heating device 6 constitutes a heating device, the circulation pump 5 constitutes a fluid circulation device, and control is performed. The opening degree of the valve 9 can be adjusted by the control device 10 from fully closed to fully open.

The water refrigerant heat exchanger 2 corresponds to a fluid refrigerant heat exchanger, and is also referred to as a fluid refrigerant heat exchanger 2 hereinafter. The floor heating device 6 corresponds to the heating device 6 and is also referred to as a heating device 6 hereinafter. The circulation pump 5 corresponds to a fluid circulation device and is also referred to as a fluid circulation device 5 hereinafter.

The heat pump system 100 includes a refrigeration system device 50 and a floor heating device 6, and includes a compressor 1 that compresses a refrigerant, and a fluid refrigerant heat exchanger 2 that performs heat exchange between the refrigerant compressed by the compressor 1 and a fluid. Have

A fluid circulation device 5 that circulates the fluid through the fluid refrigerant heat exchanger 2 is provided in the heating device 6 through which the fluid heated by the fluid refrigerant heat exchanger 2 flows. Furthermore, a control valve 9 that controls the flow of the refrigerant that has passed through the fluid refrigerant heat exchanger 2, an evaporator 7 in which the refrigerant that has passed through the control valve 9 flows and absorbs heat from the outside air, and at least the fluid circulation device 5 and the control valve 9 Is provided. The control device 10 increases the degree of opening of the control valve 9 during the defrosting operation of the evaporator 7 than during the non-defrosting operation, and operates the fluid circulation device 5 to flow the fluid to the fluid refrigerant heat exchanger 2. .

According to this, the control device 10 increases the opening degree of the control valve 9 and operates the fluid circulation device 5 to flow the fluid to the fluid refrigerant heat exchanger 2 during the defrosting operation of the evaporator 7. Therefore, the heat which the heating apparatus 6 with which the fluid heated with the fluid refrigerant | coolant heat exchanger 2 is filled can be supplied to a refrigerant | coolant, and the defrosting operation of the evaporator 7 can be performed. Thereby, a heat pump system using a highly efficient refrigeration cycle can be provided by performing the defrosting operation in a short time while suppressing power consumption or power consumption during the defrosting operation.

The fluid refrigerant heat exchanger 2 includes a liquid refrigerant heat exchanger 2 that performs heat exchange between the refrigerant compressed by the compressor 1 and the liquid, and the heating device 6 is heated by the liquid refrigerant heat exchanger 2. It consists of a floor heating device that is a hot water device 6 that dissipates heat. The fluid circulation device 5 includes a pump 5 that circulates liquid through the hot water device 6 and the liquid refrigerant heat exchanger 2.

According to this, the control device 10 increases the opening degree of the control valve 9 and rotates the pump 5 when the evaporator 7 is defrosted. Therefore, the heat which the liquid which flows into the hot water apparatus 6 which radiates the liquid heated with the liquid refrigerant heat exchanger 2 can be supplied to a refrigerant | coolant. Accordingly, the defrosting operation of the evaporator 7 can be promptly terminated. As a result, it is possible to provide a heat pump system that performs highly efficient defrosting by performing the defrosting operation in a short time while keeping the power consumption or power consumption during the defrosting operation low.

1 and 2, the water temperature detection sensor 11 constitutes a fluid temperature detection unit, and the refrigerant discharge temperature sensor 12 constitutes a refrigerant temperature detection unit. The heat pump system 100 includes a fluid temperature detection unit 11 that detects the temperature of the fluid heated by the fluid refrigerant heat exchanger 2 and a refrigerant temperature detection unit 12 that detects the temperature of the refrigerant compressed by the compressor 1. Then, the following control is performed.

That is, it is determined whether or not a temperature obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit 12 is higher than the temperature of the fluid detected by the fluid temperature detection unit 11. And when high, the control apparatus 10 is reducing the rotation speed of the compressor 1 predetermined amount rather than the time of a defrost operation start.

According to this, when the temperature obtained by subtracting the predetermined temperature from the temperature of the refrigerant is higher than the temperature of the fluid detected by the fluid temperature detecting unit 11, the rotational speed of the compressor 1 is decreased by a predetermined amount. Electric power or power can be reduced, and the refrigerant can sufficiently absorb heat from the fluid.

(Second Embodiment)
A second embodiment will be described. In the following embodiments, the same components as those in the first embodiment described above are denoted by the same reference numerals, description thereof is omitted, and different configurations will be described. In addition, about 2nd Embodiment or less, the same code | symbol as 1st Embodiment shows the same structure, Comprising: The description which precedes is used.

The heat pump system showing the second embodiment will be described with reference to FIG. The control shown in FIG. 2 is executed. In FIG. 5, the compressor 1 compresses the refrigerant. The water-refrigerant heat exchanger 2 performs heat exchange between the refrigerant compressed by the compressor 1 and an antifreeze liquid (hereinafter, also simply referred to as water, hot water, or water supply) that is a fluid flowing inside. A circulation pump 5 that circulates the feed water so as to pass through the water-refrigerant heat exchanger 2 is provided in the floor heating panel 4 and the hot water pipe 3 through which water flows.

Between the water-refrigerant heat exchanger 2 and the evaporator 7, a high-pressure side heat exchanger 15a and an electronic expansion valve 16 are connected. The electronic expansion valve 16 is controlled in its open / closed state by a control signal from the control device 10 and is also simply referred to as an expansion valve. The defrosting electromagnetic valve 9 constituting the control valve 9 is closed during normal time (when not defrosting) and is open during defrosting. Therefore, at normal times, the refrigerant flows through the high-pressure side heat exchanging portion 15 a and the expansion valve 16 to the evaporator 7.

The refrigerant that has taken the heat of vaporization from the outside air in the evaporator 7 is guided to the suction side of the compressor 1 through the other low-pressure side heat exchange section 15b. As a result, the refrigerant absorbs heat from the outside air and heats the water supplied to the floor heating panel 4 via the water / refrigerant heat exchanger 2. The high-pressure side heat exchanging part 15a and the low-pressure side heat exchanging part 15b are coupled so as to be able to transfer heat, and constitute an internal heat exchanger 15 as a whole.

The defrosting solenoid valve 9 is controlled to be opened or closed by a control signal from the control device 10. The control device 10 controls at least the circulation pump 5 and the control valve 9. And the control apparatus 10 opens the control valve 9 according to the start of the defrost operation of the evaporator 7, closes the expansion valve 16, and rotates it when the circulation pump 5 has stopped.

During operation of the floor heating device 6 in normal operation, the high-temperature and high-pressure refrigerant compressed by the compressor 1 heats the water in the floor heating device 6 through the water-refrigerant heat exchanger 2. As a result, the floor in the house is heated by heat radiation from the floor heating panel 4 laid under the floor. During this time, water circulates between the water-refrigerant heat exchanger 2 and the floor heating panel 4 by the circulation pump 5.

In the process in which the feed water of the floor heating device 6 is heated, frost adheres to the evaporator 7 and defrosting is required. When the need for defrosting occurs, the water in the floor heating device 6 is sufficiently heated. The defrosting operation is started at a known timing such as when frosting of the evaporator 7 is detected.

During this defrosting operation, the circulation pump 5 continues to rotate, and the water (warm water) in the floor heating device 6 circulates between the floor heating panel 4 and the water refrigerant heat exchanger 2. When the defrosting operation is started, the defrosting electromagnetic valve 9 is opened. Thereby, the refrigerant heated by the compressor 1 and further heated by the water in the floor heating device 6 flows through the pipe 8 and bypasses the opened defrosting electromagnetic valve 9 side to the evaporator 7. The defrosting of the evaporator 7 is performed. By having this bypass flow path 80, the refrigerant | coolant temperature fall in the internal heat exchanger 15 can be prevented, and a defrosting efficiency improves.

During the defrosting operation, the defrosting solenoid valve 9 is opened from the closed state, and the expansion valve 16 is closed from the opened state, so that the refrigerant flows through the bypass passage 80. Moreover, when the aperture of the defrosting electromagnetic valve 9 is large, the discharge refrigerant pressure can be lowered, and the density of the refrigerant in the water refrigerant heat exchanger 2 is lowered. Therefore, the amount of refrigerant held by the water refrigerant heat exchanger 2 decreases, and instead, the amount of refrigerant flowing through the evaporator 7 increases.

In the second embodiment, the refrigerant outflow side of the water refrigerant heat exchanger 2 and the refrigerant inflow side of the evaporator 7 are connected by the high-pressure side heat exchanging portion 15a and the expansion valve 16. Moreover, the refrigerant | coolant outflow side of the evaporator 7 and the compressor 1 are connected by the low voltage | pressure side heat exchange part 15b. An internal heat exchanger 15 is configured by coupling the high-pressure side heat exchange unit 15a and the low-pressure side heat exchange unit 15b so as to transfer heat to each other. The internal heat exchanger 15 improves the efficiency of the refrigeration cycle during normal operation. The control shown in FIG. 2 can be adopted as the control.

In the second embodiment, as shown in FIG. 5, the refrigerant outflow side of the fluid refrigerant heat exchanger 2 and the refrigerant inflow side of the evaporator 7 are connected by the high-pressure side heat exchange unit 15 a and the expansion valve 16. Then, the refrigerant outflow side of the evaporator 7 and the compressor 1 are connected by a low-pressure side heat exchange section 15b. And the high-pressure side heat exchange part 15a and the low-pressure side heat exchange part 15b are couple | bonded so that heat may be mutually transmitted, and the internal heat exchanger 15 is comprised.

According to this, the efficiency of the refrigeration cycle can be improved by the internal heat exchanger 15, the temperature of the fluid heated by the fluid refrigerant heat exchanger 2 can be increased efficiently, and the increased heat can be reduced. It can be used for efficient defrosting in a short time. Further, at the time of defrosting, the internal heat exchanger 15 is bypassed, the refrigerant flows through the control valve 9, and it is possible to defrost in a short time while preventing the internal heat exchanger 15 from taking heat away.

(Third embodiment)
A third embodiment will be described. A different part from embodiment mentioned above is demonstrated. Control of the heat pump system according to the third embodiment will be described with reference to FIG. Although FIG. 1 or FIG. 5 can be used for the entire configuration diagram, FIG. 1 is used in this third embodiment.

1 is closed during normal operation, but is opened to the opening for defrosting during defrosting operation. The control of FIG. 6 is repeatedly executed at a predetermined interval during the defrosting operation in which the control valve 9 is open. When the control starts in S61, the relationship between the water supply temperature detected by the water temperature detection sensor 11 (FIG. 1) and the refrigerant discharge temperature detected by the refrigerant discharge temperature sensor 12 is determined in S62. If the temperature obtained by subtracting the predetermined temperature α from the refrigerant discharge temperature is not smaller than the feed water temperature, the process proceeds to S63.

In S63, the opening degree of the control valve 9 in FIG. 1 is further increased by a predetermined amount. As a result, the discharge temperature (discharge pressure) which is the temperature on the discharge side of the compressor 1 is lowered, and the refrigerant can absorb heat from the feed water via the water / refrigerant heat exchanger 2.

In S62, when the feed water temperature is higher than the temperature obtained by subtracting the predetermined temperature α from the refrigerant discharge temperature, the control is terminated in S64. The control in FIG. 6 is repeated at predetermined time intervals during the defrosting operation period.

In the third embodiment, the fluid temperature detector 11 that detects the temperature of the fluid heated by the fluid refrigerant heat exchanger 2 and the refrigerant temperature detector 12 that detects the temperature of the refrigerant compressed by the compressor 1. And have. Then, it is determined whether or not a temperature obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit 12 is higher than the temperature of the fluid detected by the fluid temperature detection unit 11. And when high, the control apparatus 10 is performing control which makes the opening degree of the control valve 9 predetermined amount larger than the time of a defrost operation start.

According to this, since the opening degree of the control valve 9 is increased by a predetermined amount when the temperature obtained by subtracting the predetermined temperature from the refrigerant temperature is higher than the temperature of the fluid detected by the fluid temperature detection unit 11, the compressor 1 The pressure on the high pressure side is reduced, and the power or power of the compressor 1 can be reduced. Further, the discharge temperature, which is the temperature on the discharge side of the compressor 1, is lowered so that the refrigerant can sufficiently absorb heat from the water supply via the water / refrigerant heat exchanger 2.

(Fourth embodiment)
In the fourth embodiment, parts different from the above-described embodiment will be described. The fourth embodiment is a combination of the overall configuration of FIG. 5 and the control of FIG. However, as the defrosting control valve 9 in FIG. 5, a valve whose opening degree can be controlled in a plurality of stages is adopted. A fourth embodiment will be described with reference to FIGS. 5 and 6. The control valve 9 in FIG. 5 is closed during normal operation and opened during defrosting.

6 The control in FIG. 6 is repeatedly executed at a predetermined interval during the defrosting operation. When the control starts in S61, the relationship between the feed water temperature detected by the feed water temperature detection sensor 11 and the refrigerant discharge temperature detected by the refrigerant discharge temperature sensor 12 is determined in S62. If the temperature obtained by subtracting the predetermined temperature α from the refrigerant discharge temperature is not smaller than the feed water temperature, the process proceeds to S63.

In S63, the opening degree of the defrosting electromagnetic valve 5 in FIG. 5 is further increased by a predetermined amount. As a result, the pressure on the high pressure side of the compressor 1 decreases, and the power or power consumed by the compressor 1 can be saved. If the feed water temperature is higher than the temperature obtained by subtracting the predetermined temperature α from the refrigerant discharge temperature in S62, the control is terminated in S64. The control in FIG. 6 is repeated at predetermined time intervals during the defrosting operation period.

As described above, the fourth embodiment combines the overall configuration of FIG. 5 and the control of FIG. That is, in the heat pump system 100 having the refrigeration cycle apparatus 50 having the internal heat exchanger 15 and the floor heating apparatus 6, the opening degree of the control valve 9 during the defrosting operation is controlled as shown in FIG.

Therefore, the temperature of the warm water of the floor heating device 6 is efficiently increased by the internal heat exchanger 15, and the opening of the control valve 9 is controlled so that the refrigerant efficiently absorbs heat from the warm water during the defrosting operation. The high pressure on the discharge side of 1 is reduced. As a result, the power or power for driving the compressor 1 can be reduced, and defrosting that ends in a short time is efficiently performed.

(Fifth embodiment)
In the fifth embodiment, parts different from the above-described embodiment will be described. A heat pump system according to the fifth embodiment will be described with reference to FIG. In FIG. 7, the heating device 6 includes an indoor heating device 6 that warms the temperature of the air flowing through the room (including the interior). The indoor heating device of the present disclosure includes an internal heating device.

Compressor 1 compresses the refrigerant. In this embodiment, the refrigerant consists of carbon dioxide, but other refrigerants can be used. The condenser 2 constituting the fluid refrigerant heat exchanger performs heat exchange between the refrigerant compressed by the compressor 1 and the air flowing inside.

The air heated by the condenser 2 increases the temperature in a space of a predetermined size such as a room as warm air. The temperature of the warm air is detected by a blowing temperature sensor 11 that is the fluid temperature detecting unit 11. A blower 5 that circulates air in the room so as to pass through the condenser 2 is provided. The refrigerant that has passed through the condenser 2 from the compressor 1 flows toward the evaporator 7 that forms an external heat exchanger that absorbs heat from the outside air.

Between the condenser 2 and the evaporator 7, a high-pressure side heat exchanging portion 15a and a first electronic expansion valve 16 (also simply referred to as a first expansion valve 16) are connected. The second electronic expansion valve 9 (also simply referred to as the second expansion valve 9) constituting the control valve for defrosting is fully closed except during defrosting. Accordingly, the refrigerant in the normal state flows through the high pressure side heat exchange unit 15 a and the first expansion valve 16 to the evaporator 7.

The refrigerant that has expanded in the evaporator 7 and has taken the heat of vaporization from the outside air passes through the low-pressure side heat exchange section 15b and is guided to the suction side of the compressor 1. Thereby, the refrigerant absorbs heat from the outside air and heats the air passing through the condenser 2 via the condenser 2. This air circulates in the room and heats the room.

Control can be performed by the method shown in FIG. 2 or the method shown in FIG. As a modification, as shown in FIG. 9, the method of FIG. 2 and the method of FIG. 6 can be used simultaneously. The fifth embodiment employs the method of FIG. The opening degree of the second expansion valve 9 that forms the control valve for defrosting is controlled by a control signal from the control device 10. The control device 10 controls at least the rotation of the blower 5 and the opening degree of the second expansion valve 9 constituting the control valve for defrosting. Then, the control device 10 switches the second expansion valve 9 from closed to open in response to the start of the defrosting operation of the evaporator 7. And when the air blower 5 has stopped, the air blower 5 is rotated.

When the indoor heating operation is “when the defrosting operation is not performed”, the high-temperature and high-pressure refrigerant compressed by the compressor 1 raises the temperature of the air via the condenser 2. As a result, the temperature in a predetermined space such as a room rises. During this time, air passes through the condenser 2 by the blower 5 and circulates in the room.

During the process of heating the indoor air, frost adheres to the evaporator 7 and needs to be defrosted. When the need for defrosting arises, the temperature of the room air has risen sufficiently. The defrosting operation is started at a known timing such as when frosting of the evaporator 7 is detected. During the defrosting operation, the blower 5 continues to rotate, and the indoor air circulates through the condenser 2.

Further, when the defrosting operation is started, the opening degree of the second expansion valve 9 constituting the control valve for defrosting becomes the defrosting opening degree from the fully closed state during the normal operation during non-defrosting. On the other hand, the first expansion valve 16 is fully closed. Thereby, the refrigerant heated by the compressor 1 and further heated by the circulating air having a high temperature via the condenser 2 bypasses the second expansion valve 9 side having the defrosting opening degree and bypasses it. The evaporator 7 flows through the flow path 80 and the evaporator 7 is defrosted.

In the fifth embodiment, the refrigerant outflow side of the condenser 2 and the refrigerant inflow side of the evaporator 7 are connected by the high-pressure side heat exchange unit 15a and the first expansion valve 16. Moreover, the refrigerant | coolant outflow side of the evaporator 7 and the compressor 1 are connected by the low voltage | pressure side heat exchange part 15b. An internal heat exchanger 15 is configured by coupling the high-pressure side heat exchange unit 15a and the low-pressure side heat exchange unit 15b so as to transfer heat to each other.

And, during the defrosting, the control of FIG. 6 is repeatedly executed at a predetermined interval. In S62 of FIG. 6, if the temperature detected by the blowing temperature sensor 11 as the fluid temperature is not higher than the temperature obtained by subtracting the predetermined temperature α from the refrigerant discharge temperature, the opening of the second expansion valve 9 of FIG. Controlled to increase.

In the above-described fifth embodiment, a fluid refrigerant heat exchanger is configured by the condenser 2 through which air flows, as shown in FIG. That is, the condenser 2 includes an air refrigerant heat exchanger that performs heat exchange between the refrigerant compressed by the compressor 1 and air. The heat pump system 100 includes a refrigeration system device 50, a blower 5, a condenser 2, and a room (not shown) having a limited space volume in which hot air from the condenser 2 circulates (inside or inside the room). The apparatus 6 is comprised.

The heating device 6 includes an indoor heating device 6 for heating with air heated by the air refrigerant heat exchanger 2. The fluid circulation device 5 includes a blower 5 that circulates the air heated by the air refrigerant heat exchanger so as to pass through the air refrigerant heat exchanger 2.

According to this, since the opening degree of the control valve is increased and the blower 5 is rotated during the defrosting operation, the heat held by the indoor heating device 6 that heats the air in the air refrigerant heat exchanger 2 is used as the refrigerant. The defrosting operation of the evaporator 7 can be performed by supplying. Thereby, the heat pump system 100 using a highly efficient refrigeration cycle can be provided by performing the defrosting operation in a short time while suppressing the power consumption or the power consumption during the defrosting operation.

Further, the control of the heat pump system 100 of the fifth embodiment can be performed by the method of FIG. 2 or the method of FIG. When the method of FIG. 2 is used, a fluid temperature detection unit 11 (blowing temperature sensor 11) that detects the temperature of the air that is the fluid heated by the fluid refrigerant heat exchanger 2 is used. A refrigerant temperature detector 12 (refrigerant discharge temperature sensor 12) that detects the temperature of the refrigerant compressed by the compressor 1 is used.

When the temperature obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit 12 is higher than the temperature detected by the fluid temperature detection unit 11, the control device 10 decreases the rotation speed of the compressor 1 by a predetermined amount. .

According to this, when the temperature obtained by subtracting the predetermined temperature from the temperature of the refrigerant is higher than the temperature of the fluid (air) detected by the fluid temperature detection unit 11, the rotation speed of the compressor 1 is decreased by a predetermined amount. The power or power of the machine 1 can be reduced. And since the temperature of a refrigerant | coolant falls by the fall of the rotation speed of the compressor 1, a refrigerant | coolant comes to be fully heated with air through the condenser 2. FIG.

When the control of the heat pump system 100 of the fifth embodiment is performed by the method of FIG. 6, the fluid temperature for detecting the temperature of the fluid composed of air heated by the fluid refrigerant heat exchanger 2 composed of the condenser 2. The detection unit 11 is used. A refrigerant temperature detector 12 that detects the temperature of the refrigerant compressed by the compressor 1 is used.

When the temperature obtained by subtracting the predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit 12 is higher than the temperature of the fluid detected by the fluid temperature detection unit 11, the control device 10 sets the opening degree of the control valve 9 in advance. A predetermined amount is further increased from the defrosting opening.

According to this, when the temperature obtained by subtracting the predetermined temperature from the temperature of the refrigerant is higher than the temperature of the fluid made of heated air detected by the fluid temperature detection unit 11, the opening degree of the control valve 9 is increased by a predetermined amount. Therefore, the pressure on the high pressure side of the compressor 1 can be reduced, and the power or power of the compressor 1 can be reduced. Furthermore, when the pressure on the high pressure side of the compressor 1 is reduced, the temperature of the refrigerant passing through the condenser 2 is lowered, and the refrigerant can sufficiently absorb heat.

On the other hand, during the defrosting period, in order to keep the blower 5 rotating, a room (not shown) having a limited space volume of the indoor heating device 6 in which the hot air from the condenser 2 circulates ( Hot air is circulating. Therefore, it is possible to cause the refrigerant to absorb heat (heat the refrigerant) via the condenser 2 by using the heat capacity of the air and the room (the room or the interior) where the temperature is rising.

(Sixth embodiment)
In the sixth embodiment, parts different from the above-described embodiment will be described. A heat pump system according to the sixth embodiment will be described with reference to FIG. In the sixth embodiment, hot water heated by the water-refrigerant heat exchanger 2 is used for the floor heating device 6, and the hot water storage tank 21 is connected to the hot water storage tank 21 via the hot water supply heat exchanger 22 for supplying high-temperature water. It is also used for the hot water supply device 60 for heating the water supply (hot water supply water).

The hot water from the water / refrigerant heat exchanger 2 can be switched to the floor heating panel 4 or the hot water supply heat exchanger 22 depending on whether the circulation pump 5 or the first hot water supply pump 23 is operated. A second hot water supply pump 24 is provided between the hot water supply heat exchanger 22 and the hot water storage tank 21.

In the sixth embodiment, during the defrosting period, the heat capacity of the hot water flowing through the second water refrigerant heat exchanger 2 is switched and controlled between the circulation pump 5 and the first hot water supply pump 23 to increase it. be able to. In other words, the

pumps

5 and 23 having the larger heat capacity can be operated.

The hot water heat exchanger 22 may be provided in the hot water storage tank 21. The hot water supply heat exchanger 22 is a heat exchanger so that the hot water in the hot water storage tank 21 and the hot water in the floor heating device 6 are not mixed. This type of heat exchanger may be provided on the floor heating device 6 side.

In the sixth embodiment, as shown in FIG. 8, the heat pump system 100 includes a refrigeration cycle apparatus 50, a floor heating apparatus 6, and a hot water supply apparatus 60. The water refrigerant heat exchanger 2 in FIG. 8 constitutes the fluid refrigerant heat exchanger 2, and the floor heating device 6 and the hot water supply device 60 constitute the

heating devices

6 and 60. Further, the circulation pump 5 and the first hot water supply pump 23 constitute

fluid circulation devices

5 and 23, and the control valve 9 can adjust the opening degree from fully closed to fully opened by the control device 10.

The heat pump system 100 includes a compressor 1 that compresses a refrigerant, and a fluid refrigerant heat exchanger 2 that performs heat exchange between the refrigerant compressed by the compressor 1 and a fluid. Furthermore, circulation pumps serving as

fluid circulation devices

5 and 23 for circulating the fluid through the fluid refrigerant heat exchanger 2 to the

heating devices

6 and 60 through which the hot water as the fluid heated by the fluid refrigerant heat exchanger 2 flows. 5 and a first hot water supply pump 23 are provided.

Furthermore, the control valve 9 that controls the flow of the refrigerant that has passed through the fluid refrigerant heat exchanger 2, the evaporator 7 in which the refrigerant that has passed through the control valve 9 flows and absorbs heat from the outside air, and at least the

fluid circulation devices

5 and 23 are controlled. A control device 10 for controlling the valve 9 is provided. The control device 10 makes the opening degree of the control valve 9 larger during the defrosting operation of the evaporator 7 than during the non-defrosting operation, and at least of the circulation pump 5 and the first hot water supply pump 23 serving as the fluid circulation device 5. Either of them is operated and hot water as a fluid continues to flow through the fluid refrigerant heat exchanger 2.

According to this, the heat which the

heating apparatuses

6 and 60 with which the fluid heated with the fluid refrigerant | coolant heat exchanger 2 is filled is supplied to a refrigerant | coolant, and the defrosting operation of the evaporator 7 can be performed. it can. Thereby, a heat pump system using a highly efficient refrigeration cycle can be provided by performing the defrosting operation in a short time while suppressing power consumption or power consumption during the defrosting operation.

Thus, the

heating devices

6 and 60 include either the floor heating device 6 that heats the floor or the hot water supply device 60 that includes the hot water supply device 60 that supplies hot water to the tank. Therefore, the defrosting of the evaporator can be quickly completed using the heat held by the floor heating device 6 or the hot water supply device 60.

(Other embodiments)
In the above-described embodiment, the preferred embodiment of the present disclosure has been described. However, the present disclosure is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present disclosure. It is. The structure of the said embodiment is an illustration to the last, Comprising: The range of this indication is not limited to the range of these description. The scope of the present disclosure is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

For example, the room heated by the air passing through the condenser does not have to be a room in a house, but may be in an in-vehicle storage or the like that becomes a closed space. Further, when the flow rate is adjusted by the control valve, the flow rate is controlled by controlling the duty ratio of the ON-OFF valve, not limited to fine adjustment of the opening degree of the valve. In addition to the electromagnetic valve, it is of course possible to use a control valve whose valve operation is controlled by a control signal such as an electric valve using a step motor.

Further, the compressor is not limited to an electric compressor, and may be a compressor driven by an internal combustion engine. The heating device can be composed of various devices through which hot water flows. For example, the heating device may be a device that supplies hot water to a hot water pool or a hot water tank serving as a tank. Furthermore, the fluid circulating in the pump is not limited to water, but may be other fluids such as oil.

Also, as shown in FIG. 6, when the opening of the control valve is increased by a predetermined amount to reduce the pressure on the high pressure side and the power or power of the compressor is reduced, the opening for defrosting is not fully opened but is further opened. Start defrosting in a state where the degree can be increased. However, when the rotational speed of the compressor is controlled as shown in FIG. 2, the control valve 9 is fully opened during defrosting. In this case, a simple solenoid valve having a structure for switching between fully closed and fully open can be used.

Claims

A compressor (1) for compressing the refrigerant;
A fluid refrigerant heat exchanger (2) for exchanging heat between the refrigerant compressed by the compressor (1) and a fluid;
A heating device (6, 60) through which a heating fluid composed of the fluid heated by the fluid refrigerant heat exchanger (2) flows;
A fluid circulation device (5, 23) for circulating the heating fluid so as to pass through the heating device (6, 60) and the fluid refrigerant heat exchanger (2);
A control valve (9) for controlling the flow of the refrigerant that has passed through the fluid refrigerant heat exchanger (2);
An evaporator (7) in which the refrigerant that has passed through the control valve (9) flows and absorbs heat from outside air;
A control device (10) for controlling at least the fluid circulation device (5, 23) and the control valve (9),
The control device (10) increases the opening of the control valve (9) at the start of the defrosting operation of the evaporator (7) than in the non-defrosting operation, and the fluid circulation device (5, 23). ) To flow the fluid to the fluid refrigerant heat exchanger (2).
The fluid refrigerant heat exchanger (2) comprises a liquid refrigerant heat exchanger that performs heat exchange between the refrigerant compressed by the compressor (1) and the liquid constituting the heating fluid.
The heating device (6, 60) includes a hot water device that radiates heat from the liquid heated by the liquid refrigerant heat exchanger,
The heat pump system according to claim 1, wherein the fluid circulation device (5, 23) comprises a pump for circulating the liquid through the hot water device and the liquid refrigerant heat exchanger.
Furthermore, it has an internal heat exchanger (15),
The internal heat exchanger (15)
A high pressure side heat exchange section (15a) provided between the heat exchanger (2) and the expansion valve (16);
A low pressure side heat exchange section (15b) provided between the evaporator (7) and the compressor (1) and exchanging heat with the high pressure side heat exchange section (15a);
The heat pump system according to claim 1 or 2, wherein the defrosting control valve (9) is provided between a refrigerant outflow side of the fluid refrigerant heat exchanger (2) and a refrigerant inflow side of the evaporator (7). .
A fluid temperature detector (11) for detecting the temperature of the heated fluid;
A refrigerant temperature detector (12) for detecting the temperature of the refrigerant compressed by the compressor (1),
The control device (10) is configured such that a value obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit (12) is greater than the temperature of the heating fluid detected by the fluid temperature detection unit (11). When it is high, the control for reducing the rotational speed of the compressor (1) by a predetermined amount from the rotational speed of the compressor (1) at the start of the defrosting operation is repeatedly executed at predetermined time intervals. 4. The heat pump system according to any one of 3.
A fluid temperature detector (11) for detecting the temperature of the heated fluid;
A refrigerant temperature detector (12) for detecting the temperature of the refrigerant compressed by the compressor (1),
The control device (10) is configured such that a value obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit (12) is greater than the temperature of the heating fluid detected by the fluid temperature detection unit (11). When it is higher, the control for increasing the opening of the control valve (9) by a predetermined amount than the opening of the control valve (9) at the start of the defrosting operation is repeatedly executed at predetermined time intervals. The heat pump system according to any one of 4.
The fluid refrigerant heat exchanger (2) includes an air refrigerant heat exchanger that performs heat exchange between the refrigerant compressed by the compressor (1) and air,
The heating device (6, 60) includes an indoor heating device that heats with heated air that forms the heating fluid heated by the air refrigerant heat exchanger,
The heat pump system according to claim 1, wherein the fluid circulation device (5) includes a blower that circulates the heated air so as to pass through the air refrigerant heat exchanger.
A fluid temperature detector (11) for detecting the temperature of the heated fluid;
A refrigerant temperature detector (12) for detecting the temperature of the refrigerant compressed by the compressor (1),
The control device (10) is configured such that a value obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit (12) is greater than the temperature of the heating fluid detected by the fluid temperature detection unit (11). The heat pump system according to claim 6, wherein when it is high, the rotational speed of the compressor (1) is reduced by a predetermined amount from the rotational speed of the compressor (1) at the start of the defrosting operation.
A fluid temperature detector (11) for detecting the temperature of the heated fluid;
A refrigerant temperature detector (12) for detecting the temperature of the refrigerant compressed by the compressor (1),
The control device (10) is configured such that a value obtained by subtracting a predetermined temperature from the temperature of the refrigerant detected by the refrigerant temperature detection unit (12) is greater than the temperature of the heating fluid detected by the fluid temperature detection unit (11). The heat pump system according to claim 6, wherein the opening degree of the control valve (9) is made larger by a predetermined amount than the opening degree of the control valve (9) at the start of the defrosting operation when it is high.
The said heating device (6, 60) includes any one of a floor heating device (6) for heating the floor and a hot water supply device (60) for supplying hot water to the tank. The heat pump system as described in.
The control device (10) starts the defrosting operation when the difference between the outside air temperature and the refrigerant temperature downstream of the evaporator (7) becomes equal to or higher than a predetermined temperature (TA).
The heat pump according to any one of claims 1 to 9, wherein the control device (10) ends the defrosting operation when a refrigerant temperature downstream of the evaporator (7) becomes equal to or higher than a predetermined temperature (TB). system.