JP2008121982A - Refrigerating cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the reliability of a system and to make effective use of exhaust heat in a refrigerating cycle device carrying out hot water supply and air-conditioning. <P>SOLUTION: A heat pump device comprises a main refrigerant circuit formed by connecting a compressor 11, a parallel circuit with a hot water supply heat exchanger 12 and a heating heat exchanger 16 arranged through a refrigerant conduit, a restricting device 15 and an outdoor heat exchanger 14 annularly in sequence; and a flow control valve provided upstream of the heating heat exchanger 16 in the parallel circuit, wherein the hot water supply heat exchanger 12 and the heating heat exchanger 16 are constituted to be switched in series and in parallel. With this constitution, when high temperature water flows into the hot water supply heat exchanger 12, heat of a refrigerant at the outlet of the hot water supply heat exchanger 12 is effectively used for heating while suppressing the abnormal rise of high pressure, and operation can be comfortably performed without reducing the respective heating capacities of the hot water supply heat exchanger 12 and heating heat exchanger 16. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heat pump type hot water supply apparatus and a heat pump type hot water supply and heating apparatus using a refrigerant such as HFC or CO2.

  Conventionally, in a refrigeration cycle apparatus that performs hot water supply, cold water that flows out from the lower part of the hot water tank flows into the hot water heat exchanger of the refrigeration cycle apparatus, exchanges heat with the high-temperature refrigerant discharged from the compressor, and becomes hot water. The returning operation is performed until the temperature of the water in the hot water storage tank reaches a predetermined temperature (for example, 65 ° C. in the intermediate period and summer, and 90 ° C. in the winter). In the initial stage of the refrigeration cycle, hot water is stored in the upper part of the hot water tank and cold water is stored in the lower part, that is, a temperature stratification is formed, and cold water is always supplied to the heat exchanger for hot water supply from the lower part of the hot water tank. When the hot water storage tank begins to be filled with hot water at a later stage, the temperature of the cold water in the lower part of the hot water storage tank gradually increases, and the temperature of the water supplied to the hot water supply heat exchanger of the refrigeration cycle apparatus also increases. In addition, if the hot water in the hot water storage tank is used for heat dissipation such as floor heating, the temperature stratification in the hot water storage tank is destroyed by the medium hot water returned from the heat dissipation means such as floor heating, even when not at the end of boiling operation, The temperature of the water supplied to the hot water heat exchanger is also increased. Along with this, the refrigerant temperature at the outlet of the hot water supply heat exchanger also increased, and the high pressure increased, impairing the reliability of the refrigeration cycle apparatus.

  Therefore, in the heat pump hot water supply apparatus disclosed in Patent Document 1, if the temperature of the water entering the heat exchanger for hot water supply is higher than the standard temperature, the specified frequency of the compressor is decreased to suppress an increase in high pressure. 10 and 11 show a conventional heat pump apparatus described in Patent Document 1 and an operation flowchart thereof.

In FIG. 10, when the temperature sensors 20A, 20B, 20C, and 20D in the hot water storage tank 20 detect that the amount of hot water in the hot water storage tank 20 has become a predetermined value or less, the heat pump circuit 10 is operated to start the hot water storage operation. . In the heat pump circuit 10, the refrigerant compressed by the compressor 11 dissipates heat in the hot water supply heat exchanger 12, is depressurized by the main expansion valve 13A and the capillary tube 13B, then absorbs heat in the evaporator 14, and in a gas state. It is sucked into the compressor 11. On the other hand, by the operation of the circulation pump 23, the water in the hot water storage tank 20 is led to the water pipe 12A through the bottom pipe 22, and the hot water heated by the water pipe 12A takes the upper circulation pipe 24. It is returned to the hot water storage tank 20. The capacity control in the compressor 11 and the opening degree control in the expansion valve 13 are controlled such that the refrigerant discharge temperature detected by the temperature sensor 10A maintains a preset temperature. FIG. 11 is a block diagram of frequency determination control of the compressor 11. In the specified frequency setting means 41, a reference operating frequency is set in advance. In the incoming water load setting means, the temperature range is divided into a plurality of sections according to the incoming water temperature, and the frequency that increases or decreases in each of the sections is set. That is, the incoming water load setting means 42 is set to decrease the specified frequency if the incoming water temperature is higher than the standard temperature, and to increase the specified frequency if the incoming water temperature is lower than the standard temperature.
JP 2005-147542 A

  However, if the operating frequency of the compressor is reduced in order to suppress an increase in high pressure, the amount of refrigerant circulation decreases and the hot water heating capacity in the hot water heat exchanger decreases, so the desired hot water temperature and boiling time can be reduced. There were problems that it could not be achieved and that the heating and heating capacity of the heat exchanger for heating was reduced and the comfort was impaired.

  The present invention has been made in view of the above problems, and when high-temperature water enters the hot water supply heat exchanger, the hot water supply heat exchanger and the heating heat exchanger are switched from parallel connection to series connection, The purpose is to effectively use the heat of the refrigerant at the outlet of the heat exchanger for heating and suppress an abnormal increase in high pressure, and to operate comfortably without reducing the heating capacity of each of the heat exchanger for hot water supply and the heat exchanger for heating. To do.

In order to solve the above problems, a refrigeration cycle apparatus according to the present invention includes a compressor, a parallel circuit in which a hot water supply heat exchanger and a heating heat exchanger are arranged in parallel via a refrigerant pipe, and a throttling device. A main refrigerant circuit in which the outdoor heat exchangers are sequentially connected in an annular shape,
A bypass path connecting the refrigerant outlet of the hot water heat exchanger and the inlet of the heating heat exchanger;
A first path through which the refrigerant that has passed through the hot water supply heat exchanger flows through the heating heat exchanger via the bypass path, and a second path toward the expansion device without passing through the bypass path; And switchable control means.

  With this configuration, when high-temperature water enters the hot water supply heat exchanger, the heat of the hot water supply heat exchanger outlet refrigerant is effectively used for heating and the rise in abnormal high pressure is suppressed. It is possible to operate comfortably without reducing the heating capacity of each exchanger.

  According to the heat pump device of the present invention, when high-temperature water enters the hot water supply heat exchanger, the heat of the hot water supply heat exchanger outlet refrigerant is effectively used for heating and high-pressure abnormal rise is suppressed, and heat exchange for hot water supply is performed. It is possible to operate comfortably without reducing the heating capacity of each of the heater and the heat exchanger for heating.

(Embodiment 1)
Hereinafter, Embodiment 1 of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same structure as background art.

  In FIG. 1, the refrigeration cycle apparatus of the present embodiment includes a compressor 11 that compresses a refrigerant to high temperature and high pressure, a high temperature and high pressure refrigerant discharged from the compressor 11 branched in two directions, and one of them is cold water in a hot water storage tank 20. The hot water supply heat exchanger 12 that cools the high-temperature and high-pressure refrigerant by exchanging heat with the other, the heating heat exchanger 16 that uses the other for indoor heating, floor heating, bathroom heating, and the like, and the heating heat exchanger in the parallel circuit The flow rate control valve 17 for adjusting the refrigerant circulation amount provided on the upstream side of 16 and the refrigerant flowing out of the hot water radiator 12 and the refrigerant flowing out of the heating heat exchanger 16 are mixed and then expanded under reduced pressure. It comprises an expansion mechanism 15 and an outdoor heat exchanger 14 that exchanges heat with air flowing from the outdoor fan 18 and absorbs heat from the atmosphere.

  In addition, the refrigeration cycle apparatus of the present embodiment includes a bypass path 61 that connects the refrigerant outlet of the hot water supply heat exchanger 12 and the inlet of the heating heat exchanger 16. A three-way valve 32 is provided at the refrigerant inlet of the bypass passage 61. By switching the three-way valve 32, the refrigerant that has passed through the hot water supply heat exchanger 12 passes through the bypass path 61 and the first path (series connection) through the heating heat exchanger 16 and the bypass path 61. It is possible to switch between the second path (parallel connection) toward the aperture device 15 without going through. Switching of the three-way valve 32 is performed by the control means 21.

  The control means 21 controls the three-way valve 32 and the flow control valve 17 based on detection information such as the refrigerant pressure detection means 39 and the refrigerant temperature detection means 38 provided in the refrigeration cycle.

  The refrigerant pressure detection means 39 is provided in the high-pressure side refrigerant pipe downstream of the hot water supply heat exchanger 12 in the second path (parallel connection) and upstream of the inlet side of the expansion device 15. Desirably, it is near the exit of the hot water supply heat exchanger 12.

  The refrigerant temperature detection means 38 is provided on the upstream side of the heating-side heat exchanger 16 in the parallel circuit and on the downstream side of the junction of the bypass path 61.

  In the operation of supplying hot water, the cold water flowing out from the lower part of the hot water storage tank 20 flows into the hot water supply heat exchanger 12 of the refrigeration cycle apparatus, exchanges heat with the high-temperature refrigerant discharged from the compressor 11, and becomes hot water. The operation of returning to is continued until the temperature of the water in the hot water storage tank 20 reaches a predetermined temperature (for example, 65 ° C. in the intermediate period, summer, and 90 ° C. in the winter). In the initial stage of the refrigeration cycle, hot water is stored in the upper part of the hot water storage tank 20 and cold water is stored in the lower part, that is, temperature stratification is formed by the density difference of the water, and cold water is always supplied from the lower part of the hot water storage tank 20 to the heat exchanger for hot water supply. However, at the later stage of operation, the temperature of the cold water in the lower part of the hot water storage tank 20 rises, the temperature of water entering the heat exchanger 12 for hot water supply of the refrigeration cycle apparatus rises, and an abnormal rise in high pressure is caused.

  Here, the reason why the high pressure rises when the incoming water temperature to the hot water supply heat exchanger 12 of the refrigeration cycle apparatus increases will be described with reference to FIG. FIG. 2 is a pressure-specific enthalpy diagram during normal operation and when the temperature of the water flowing into the hot water supply heat exchanger becomes high (for example, at the end of boiling). When heat is exchanged between the high-temperature refrigerant and low-temperature water, if the temperature of the low-temperature water flowing into the hot water supply heat exchanger rises, the temperature of the refrigerant flowing out of the hot water heat exchanger also rises. Enthalpy increases. When the expansion mechanism is, for example, an expansion valve, the refrigerant discharged from the hot water supply heat exchanger expands under reduced pressure along the isentropic line, so the refrigerant enthalpy at the evaporator inlet also increases. Therefore, the average density of the refrigerant held in the evaporator decreases, and the volume of the refrigerant held in the evaporator decreases because the volume of the evaporator is constant. Since the refrigerant weight in the refrigeration cycle is constant, the refrigerant that cannot be held by the evaporator due to the rise in the temperature of the water flowing into the hot water supply heat exchanger overflows to the high pressure side, so that the pressure rises. At the end of boiling, a pressure-specific enthalpy diagram in which the high pressure, the hot water supply heat exchange outlet refrigerant temperature, and the compressor discharge temperature are increased as shown by the dashed line.

  At the start, the hot water supply heat exchanger 12 and the heating heat exchanger 16 are connected in parallel (the three-way valve is a direction), the flow control valve is open, and the hot water supply heat exchanger 12 and the heating heat exchanger are open. 16 is operated simultaneously. Here, the reason for operating the hot water supply heat exchanger and the heating heat exchanger in parallel connection at the start is that the heating heat exchanger requires a large heating capacity at the time of start-up, so the circulation rate is large and the high-temperature refrigerant is heated. This is because it is necessary to flow into the exchanger. However, if a hot water supply heat exchanger and a heating heat exchanger are operated in series from the start, low-temperature refrigerant after heat exchange with water in the hot water heat exchanger flows into the heating heat exchanger. The desired heating capacity cannot be obtained. Therefore, at the start, it is necessary to operate the heat exchanger for hot water supply and the heat exchanger for heating in parallel connection. However, when medium and high temperature water enters the hot water supply heat exchanger, operation in parallel connection is disadvantageous compared to operation in series connection. The reason for this is that when medium-high temperature water enters the hot water supply heat exchanger, the refrigerant temperature at the hot water supply heat exchanger outlet also increases, and the enthalpy of the hot water supply heat exchanger outlet refrigerant increases. Therefore, the enthalpy of the evaporator inlet refrigerant also increases, and the hot water supply heating capacity decreases. Furthermore, as described above, the evaporator high pressure abnormally rises. However, if medium and high temperature water enters the hot water supply heat exchanger and the hot water supply heat exchanger and the heating heat exchanger are operated in series, the refrigerant temperature at the hot water supply heat exchanger outlet becomes medium to high. Therefore, not only can it be used for heating, but also the refrigerant temperature after passing through the heating heat exchanger can be lowered, so that an abnormal increase in high pressure can be suppressed, and further, the refrigerant enthalpy at the evaporator inlet can be lowered.

  A control method for switching from a parallel connection of a hot water supply heat exchanger and a heating heat exchanger to a serial connection when medium-high temperature water enters the hot water supply heat exchanger will be described with reference to the flowchart of FIG. First, in S1, the refrigerant pressure at the outlet of the hot water supply heat exchanger 12 is detected by the refrigerant pressure detecting means 39, and it is determined whether or not the set value Pa (for example, 13 MPa) or more. The set value Pa is determined in advance through experiments and analysis from the safety and reliability of the system and each device. Next, the process proceeds to S2, and if the detected value is equal to or less than the set value Pa, the three-way valve 32 is in the a direction and the flow control valve 17 is left open (the hot water supply heat exchanger 12 and the heating heat exchanger 16 are connected in parallel ) To return to S1 and perform the same operation again. If the detected value is greater than or equal to the set value Pa, the three-way valve 32 is switched in the b direction, and the flow control valve 17 is closed. (The hot water supply heat exchanger 12 and the heating heat exchanger 16 are connected in series) Next, the process proceeds to S3, where the refrigerant pressure is detected again by the refrigerant pressure detecting means 39, and it is determined whether or not the set value Pa is exceeded. Moving to S4, if the detected value P is equal to or greater than the set value Pa, the compressor frequency is lowered so as to be equal to or less than the set value. Alternatively, the expander rotational speed may be increased. If the detected value P is less than or equal to the set value Pa, the refrigerant temperature detecting means 38 detects the inlet refrigerant temperature of the heating heat exchanger 16 and determines whether the detected value T is greater than or equal to the set value Ta. As the set value Ta, a refrigerant temperature capable of arbitrarily adjusting the amount and temperature of warm air blown into the room is determined in advance through experiments and analysis. Moving to S5, if the detected value T is less than or equal to the set value Ta, the flow control valve 17 is opened, the compressor frequency is increased, and the process is repeated until the detected value T is greater than or equal to the set value Ta. If the detected value T is equal to or greater than the set value Ta, the operation returns to S3 while continuing the operation and the flowchart is repeated.

  By performing the above-described control, it is possible to avoid an abnormal increase in high pressure during medium-to-high-temperature water entry (for example, at the end of boiling) into the hot water supply heat exchanger.

  The series / parallel switching means for the hot water supply heat exchanger 12 and the heating heat exchanger 16 is not limited to a three-way valve, and for example, as shown in FIG. 4, a first switching valve 47 and a second switching valve 48 are provided. These may be controlled. For example, when it is desired to connect the hot water heat exchanger 12 and the heating heat exchanger 16 in parallel, the first flow path switching valve 47 is opened and the second flow path switching valve 48 is closed. When it is desired to connect the hot water heat exchanger 12 and the heating heat exchanger 16 in series, the first switching valve 47 is closed and the second switching valve 48 is opened.

  Note that the means for detecting an increase in high pressure is not limited to the refrigerant pressure detection means, and may be predicted from, for example, the incoming water temperature and the compressor frequency flowing into the hot water supply heat exchanger as shown in FIG. good. In other words, the relationship between the hot water supply heat exchanger inlet temperature, the compressor frequency, and the high pressure as shown in FIG. 6 is derived in advance by experiments or the like to estimate whether the high pressure is 13 MPa or more. Since the high pressure rises as the compressor frequency and the incoming water temperature to the hot water supply heat exchanger increase, the relationship shown in FIG. 6 can be derived. In the condition of the compressor frequency and the incoming water temperature at which the high pressure shown in FIG. 6 is 13 MPa or higher (above the dotted line shown in the figure), it is determined that the high pressure is 13 MPa or higher, and the control after S2 in the flowchart shown in FIG. . Although the method of measuring the refrigerant pressure with a pressure sensor is accurate, it is desirable to estimate the refrigerant pressure using a temperature sensor such as a thermistor from the viewpoint of cost.

  Further, as another alternative means, the refrigerant temperature on the high pressure side (for example, the outlet refrigerant temperature of the hot water supply heat exchanger 12) as shown in FIG. 7 may be detected. That is, when the temperature of the water flowing into the hot water supply heat exchanger 12 rises, the hot water supply heat exchanger 12 outlet refrigerant temperature also rises, and the high pressure also rises, so the high pressure becomes 13 MPa or higher, and the hot water supply heat exchanger 12 outlet refrigerant. Is derived in advance, and when the high pressure reaches an estimated temperature of 13 MPa or more, the control after S2 in the flowchart shown in FIG. 3 is performed.

Further, the high pressure may be estimated based on the tank temperature below the hot water storage tank and the frequency of the compressor 11 as shown in FIG. This is the temperature of the water flowing into the hot water supply heat exchanger 12 in the means for predicting the high pressure from the temperature of the water flowing into the hot water supply heat exchanger 12 and the frequency of the compressor 11 described with reference to FIGS. Is replaced with the lower temperature of the hot water storage tank 20, and the same control is performed.

  Further, the increase in high pressure may be estimated from the operation time from the start of operation. The time required to boil the water in the hot water storage tank 20 is obtained by experiment / analysis, etc., and it is determined that the high pressure has become 13 MPa or more after the time obtained from the start of operation has elapsed. I do. However, since the time required for boiling from the start of operation depends on the initial temperature of the water in the hot water tank and the operating condition, a temperature sensor is installed on the outer wall of the hot water tank to determine the temperature distribution of the water in the hot water tank. It is necessary to grasp.

  Note that the heating heat exchanger 16 is not limited to indoor heating, and as shown in FIG. 9, a heat radiating means 37 may be provided via a secondary refrigerant circuit 50 for circulating brine or the like to be used for floor heating or the like. good.

(Embodiment 2)
Hereinafter, Embodiment 2 of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the same structure as background art.

  FIG. 10 shows a configuration in which the room temperature detecting means 40 is provided in the configuration of the first embodiment. With this configuration, considering the case where a hot water supply operation is performed in the hot water supply heat exchanger 12 and a heating start-up operation is performed in the heating heat exchanger 16, the room temperature and the remote controller 49 are controlled by the heating heat exchanger 16. When there is a large difference between the set temperature and the heating capacity is required, operation is performed in parallel connection. When the room temperature approaches the set temperature of the remote controller 49 to some extent and the heating capacity is no longer required, control is performed to switch to serial connection. be able to. For example, consider a case where a heating / hot water supply parallel operation is performed in winter. Assuming that the outside air temperature is 10 ° C., the room temperature is 15 ° C., and the set temperature is 20 ° C., the amount of heat for raising the room temperature 15 ° C. to the set temperature 20 ° C. and the amount of heat radiated from the room to the outside at the start of heating. Are output, and since a large heating capacity is required, the refrigeration cycle is operated in a parallel circuit. By operating in a parallel circuit, a high temperature refrigerant flows into the heating heat exchanger 16 and a difference in entrance and exit enthalpies in the heating heat exchanger can be secured, so that a large heating capacity can be achieved. When the room temperature reaches the set temperature 20 ° C, the room temperature is maintained at 20 ° C by outputting the amount of heat radiated from the room to the outside. Therefore, the refrigeration cycle is operated by switching to a serial connection. When operated in a series circuit, the medium temperature refrigerant after heat exchange in the heat exchanger 12 for hot water flows into the heat exchanger 16 for heating. Since the temperature of the refrigerant flowing into the heating heat exchanger 16 is not higher than that in the parallel circuit, the heating capacity is not output so much. If the room temperature can be kept constant with this heating capacity, the operation is continued as it is, and if the heating capacity is insufficient, the flow control valve 17 is opened and the refrigerant flowing into the heating heat exchanger is opened. Heating capacity can be adjusted by increasing the temperature and circulation rate. A detailed control flowchart is shown in FIG.

  First, the room temperature is detected by the room temperature detecting means 40, and the detected value T is compared with the set value Ta of the remote controller 49. If T2 is less than Ta in S2, the three-way valve 32 is kept in the a direction and the flow control valve 17 is left open. If T is equal to or greater than Ta, the three-way valve 32 is switched from a to b and the flow rate control valve 17 is closed. In S3, the room temperature is detected again by the room temperature detecting means 40. If T is less than Ta, the flow control valve is opened, the compressor frequency is increased, and if T is Ta or more, the operation is continued.

  By performing the above control, when the heating load becomes small, the heat of the hot water supply heat exchanger outlet refrigerant can be effectively used.

  Although the embodiments of the present invention have been described above, the refrigerant used in the present invention is preferably a refrigerant that operates on the high-pressure side such as CO2 with supercriticality. This is because, in a system having a hot water supply function as in the present invention, a refrigerant operating with a high pressure side such as CO2 being supercritical is more advantageous for high-temperature heating than a refrigerant having a condensation region such as a chlorofluorocarbon refrigerant.

  The refrigeration cycle apparatus according to the present invention can be used as a refrigeration cycle apparatus such as a water heater, a refrigeration / air-conditioning apparatus, and a drying apparatus.

Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Pressure-specific enthalpy diagram at the end of boiling in Embodiment 1 of the present invention Control flowchart of refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 1 of the present invention Configuration diagram of a refrigeration cycle apparatus in Embodiment 2 of the present invention Control flowchart of refrigeration cycle apparatus in Embodiment 2 of the present invention Conventional refrigeration cycle diagram Control flowchart of conventional refrigeration cycle apparatus

Explanation of symbols

10 heat pump circuit 10A temperature sensor (discharge temperature detection means)
10B Pressure sensor (Discharge pressure detection means)
10C temperature sensor (outside air temperature detection means)
DESCRIPTION OF SYMBOLS 11 Compressor 12 Hot water supply heat exchanger 12A Water pipe 13A 1st on-off valve 13B Capillary tube 14 Evaporator 15 Expansion mechanism 16 Heating heat exchanger 17 Flow control valve 18 Outdoor fan 19 Use terminal 20 Hot water storage tank 20A, 20B, 20C, 20D, 20E, 20F Temperature sensor 21 Control means 22 Bottom pipe 23 First circulation pump 24 Upper circulation pipe 25 Second circulation pump 26 Secondary refrigerant pipe 27 First heat release means 28 Second heat release means 29 Circulating pump 30A Flow rate sensor 30B Temperature sensor 31 Indoor fan 32 Three-way valve 33 Hot water outlet pipe 34 Mixing valve 35 Water outlet pipe 36 Hot water supply faucet 37 Heat radiating means 38 Refrigerant temperature detecting means 39 Refrigerant pressure detecting means 40 Indoor temperature detecting means 41 Specified frequency Setting means 42 Incoming load setting means 43 Outside air load setting means 44 Incoming load determination Stage 45 outside air load determining means 46 target frequency determining means 47 first switching valve 48 second switching valve 49 remote controller 50 the secondary refrigerant circuit 51 tank temperature detecting means 52 water temperature detecting means 61 bypass path

Claims (8)

A main refrigerant in which a compressor, a hot water supply heat exchanger, and a heating heat exchanger are arranged in parallel via a refrigerant pipe, a throttling device, and an outdoor heat exchanger are sequentially connected in an annular shape. Circuit,
A bypass path connecting the refrigerant outlet of the hot water heat exchanger and the inlet of the heating heat exchanger;
A first path through which the refrigerant that has passed through the hot water supply heat exchanger flows through the heating heat exchanger via the bypass path, and a second path toward the expansion device without passing through the bypass path; A refrigeration cycle apparatus having switchable control means. The switching between the first path and the second path by the control means is performed by switching a three-way valve provided at the inlet of the bypass path at the outlet of the hot water heat exchanger. The refrigeration cycle apparatus described. 3. The refrigeration cycle apparatus according to claim 1, further comprising a flow rate control valve on an upstream side of the refrigerant flowing in the heating heat exchanger of the parallel circuit and on an upstream side of a confluence of the bypass path. . Further comprising a refrigerant pressure detection means in a high-pressure side refrigerant pipe downstream of the hot water supply heat exchanger in the second path and upstream of the inlet side of the expansion device;
The control means switches the refrigerant path that has passed through the hot water supply heat exchanger from the second path to the first path when the detection value of the refrigerant pressure detection means becomes a predetermined value or more. Refrigeration cycle apparatus in any one of -3. A refrigerant temperature detection means is further provided at the refrigerant inlet of the heat exchanger for heating,
The operating method of the refrigeration cycle apparatus according to claim 3, wherein the control means increases the opening of the flow control valve when the detection value of the refrigerant temperature detection means becomes less than a predetermined value. Water temperature detection means at the water inlet of the hot water supply heat exchanger, and further provided with means for measuring the frequency of the previous compressor,
The control means predicts the high pressure of the main refrigerant circuit from the detection value of the water temperature detection means and the frequency of the compressor, and when the high pressure exceeds a predetermined value, the refrigerant that has passed through the hot water supply heat exchanger The operation method of the refrigeration cycle apparatus according to any one of claims 1 to 3, wherein the route is switched from the second route to the first route. An indoor temperature detecting means is further provided in a heated room heated by the heating heat exchanger,
The control means switches the path of the refrigerant that has passed through the hot water supply heat exchanger from the second path to the first path based on the room temperature and the heating set temperature detected by the room temperature detecting means. The refrigeration cycle apparatus according to any one of claims 1 to 3. The refrigeration cycle apparatus according to any one of claims 1 to 7, wherein a refrigerant that enables operation with a high-pressure side pressure in a supercritical state is used.

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