JP6051401B2 - Heat pump air conditioning and hot water supply system - Google Patents

Description

  The present invention relates to a heat pump type air conditioning and hot water supply apparatus that performs air conditioning and hot water supply operations.

  Conventionally, a heat pump type air conditioning and hot water supply apparatus 90 as shown in FIG. 6 is disclosed as a heat pump type air conditioning and hot water supply apparatus that performs hot water supply operation using high-temperature exhaust heat generated during cooling operation (see, for example, Patent Document 1). .

  The heat pump type air conditioning and hot water supply apparatus 90 includes a first refrigerant circuit 110 that circulates a refrigerant for air conditioning operation and a second refrigerant circuit 120 for hot water operation. The first refrigerant circuit 110 includes a compressor 111, a four-way valve 112, a heat source side heat exchanger 113, a heat source side expansion means 114, a supercooler 115, a use side expansion means 116, a use side heat exchanger 117, a four way valve 112, The gas-liquid separator 118 is annularly connected by piping.

  The second refrigerant circuit 220 branches from the discharge-side piping of the compressor 111 and is connected to the heat source side expansion means 114 via an electromagnetic valve 119 that is an opening / closing means, a hot water heat exchanger 121, and a hot water expansion means 122. And the use side expansion valve 116 communicate with the first refrigerant circuit 110.

  In the heat pump type heating / cooling hot water supply apparatus 90, the refrigerant discharged from the compressor 111 by the first refrigerant circuit 110 and the second refrigerant circuit 220 is converted into the hot water heat exchanger 121, the hot water expansion means 122, and the use side expansion means. 116, a cycle returning to the compressor via the use side heat exchanger 117, the four-way valve 112, and the gas-liquid separator 118 is configured.

  As a result, energy can be saved by performing heating (hot water supply operation) in the hot water heat exchanger 121 and cooling (cooling operation) in the use-side heat exchanger 117 and performing hot water supply operation using cooling exhaust heat. It becomes.

  Moreover, the heat pump type air conditioning hot-water supply apparatus 100 as shown in FIG. 7 is disclosed (for example, refer patent document 2).

  Although this heat pump type air conditioning and hot water supply apparatus 100 includes a first refrigerant circuit 110 that circulates refrigerant for air conditioning operation and a second refrigerant circuit 120 for hot water operation, as in Patent Document 1, In the refrigerant circuit 110, a part of the refrigerant branched from between the subcooler 115 and the use side expansion means 116 is cooled under reduced pressure via the bypass expansion valve 119, and circulates through the first refrigerant circuit 110 in the subcooler 115. After the heat exchange with the refrigerant to be heated and evaporated, a bypass circuit 130 communicating with the outlet side pipe of the gas-liquid separator 118 is added.

  In the heat pump type air conditioning and hot water supply apparatus 100, the first refrigerant circuit 110 and the second refrigerant circuit 120 cause the high-temperature and high-pressure gas refrigerant discharged from the compressor 111 to branch until it enters the four-way valve 112. Part of the refrigerant is radiated to the atmosphere by the heat source side heat exchanger 113, and the refrigerant itself is cooled.

  Thereafter, the refrigerant is further cooled by the subcooler 115, and a part of the refrigerant branched from between the subcooler 115 and the use side expansion means 116 branches to the bypass circuit 130 side, and is cooled under reduced pressure via the bypass expansion valve 119. The supercooler 115 exchanges heat with the refrigerant circulating in the first refrigerant circuit 110 to heat and evaporate, and then communicates with the outlet side pipe of the gas-liquid separator 118.

  As a result, the refrigerant cooled by the heat source side heat exchanger 113 is further cooled by the low-pressure and low-temperature refrigerant branched to the first bypass circuit 130 in the subcooler 115, and the refrigerant subcooling degree is increased. The refrigerant enthalpy flowing into a certain indoor heat exchanger 117 is lowered.

As a result, the dryness of the refrigerant flowing into the indoor heat exchanger 117 is reduced, that is, the gas-phase refrigerant component is reduced, so that the ratio of the refrigerant amount contributing to evaporation in the use-side heat exchanger 117 is increased, and the evaporator The performance is drawn out.

  Further, since the dryness of the refrigerant flowing into the indoor heat exchanger 117 is small (the liquid phase component is large), compared to the case where the refrigerant dryness is large (the gas phase component is large), a plurality of refrigerant flow paths are used. The phenomenon that the refrigerant flow rate becomes uneven on the inflow side of the configured use side heat exchanger 117 (evaporator) is avoided (refrigerant distribution performance is improved), and the heat transfer area of the use side heat exchanger 117 is effectively utilized. Is done.

  Further, the refrigerant that does not contribute to evaporation in the use side heat exchanger 117 returns to the compressor 111 via the first bypass circuit 130 without flowing into the use side heat exchanger 117, so that unnecessary refrigerant in the refrigerant pipe is removed. No pressure loss occurs.

  On the other hand, the high-temperature and high-pressure gas refrigerant discharged from the compressor 111 is divided into the remaining refrigerant until it enters the four-way valve 112. The hot water heat exchanger 121, the hot water expansion means 122, and the use side expansion means. 116, a cycle returning to the compressor via the use side heat exchanger 117, the four-way valve 112, and the gas-liquid separator 118 is configured.

  By these actions, when performing the cooling operation in the use side heat exchanger 117 while performing the atmospheric heat radiation operation in the heat source side heat exchanger 113 and the hot water heating operation in the hot water heat exchanger 121, the first bypass The circuit 130 can be used, and the refrigerant pressure loss on the low pressure side can be reduced while maintaining the evaporation heat exchange amount (cooling capacity) in the use side heat exchanger 117. As a result, the refrigerant density on the suction side of the compressor 1 increases, the refrigerant flow rate increases, and the amount of heat released in the heat source side heat exchanger 113 and the amount of heating in the hot water heat exchanger 121 can be increased. .

Registered Utility Model No. 1586330 JP 2010-196953 A

  However, in the conventional configuration, the bypass circuit 130 installed for improving the performance of the heat pump type air conditioning and hot water supply apparatus cannot be used in the hot water supply operation using cooling exhaust heat, and further energy saving is achieved. I can't.

  The present invention solves the above-described conventional problems, and an object of the present invention is to provide a heat pump type air conditioning and hot water supply apparatus that can effectively use a bypass circuit having a supercooler even in a cooling exhaust heat utilization hot water supply operation. And

In order to solve the above problems, a heat pump type air conditioning and hot water supply apparatus of the present invention includes a compressor, a four-way valve, a heat source side heat exchanger, a heat source side expansion means, a subcooler, a use side expansion means, and a use side heat exchanger. A first refrigerant circuit connected in a ring, and branching from the first refrigerant circuit between the heat source side expansion means and the subcooler or between the subcooler and the utilization side expansion means, and a bypass expansion means and Via the supercooler, the first bypass circuit connected to the first refrigerant circuit between the four-way valve and the compressor, and the heat for hot water branched from between the compressor and the four-way valve A second refrigerant circuit connected between the supercooler and the use side expansion means via an exchanger, a connection portion between the second refrigerant circuit and the first refrigerant circuit, and the use side expansion means; First opening and closing means provided between the heat source side expansion means and the A second bypass circuit branched from the cooler and connected between the first opening / closing means and the utilization side expansion means via the second opening / closing means, and a control device, the control device comprising: When the cooling operation is performed by the use side heat exchanger and the hot water generating operation is performed by the hot water heat exchanger, the first opening / closing means is closed, the second opening / closing means is opened, and the heat source The side expansion means is closed.

  As a result, the refrigerant cooled by causing the hot water heat exchanger to act as a condenser and exchanging heat with the hot water is divided into a part of the refrigerant between the subcooler and the outdoor expansion means, and thus the first bypass. The refrigerant is further cooled by the low-pressure and low-temperature refrigerant flowing in the circuit, the refrigerant supercooling degree is increased, and the refrigerant enthalpy flowing into the indoor heat exchanger as the evaporator is reduced.

  As a result, the dryness of the refrigerant flowing into the indoor heat exchanger is reduced, that is, the gas-phase refrigerant component is reduced, so that the ratio of the refrigerant amount contributing to evaporation is increased in the use side heat exchanger, and the performance as an evaporator is increased. Drawn out.

  In addition, the refrigerant dryness flowing into the indoor heat exchanger is small (the liquid phase component is large), so that it is composed of a plurality of refrigerant channels compared to the case where the refrigerant dryness is large (the gas phase component is large). The phenomenon of non-uniform refrigerant flow on the inflow side of the use side heat exchanger (evaporator) is avoided (refrigerant distribution performance is improved), and the heat transfer area of the use side heat exchanger (evaporator) is effectively Be utilized.

  Furthermore, the refrigerant that does not contribute to evaporation in the use side heat exchanger returns to the compressor via the first bypass circuit without flowing into the use side heat exchanger, thereby generating unnecessary pressure loss in the refrigerant pipe. Disappears.

  ADVANTAGE OF THE INVENTION According to this invention, the heat pump type heating and cooling hot-water supply apparatus which can utilize a bypass circuit which has a supercooler effectively also in a cooling exhaust heat utilization hot-water supply operation can be provided.

1 is a schematic configuration diagram of a heat pump type air conditioning and hot water supply apparatus in a single cooling operation according to the first embodiment of the present invention. Mollier diagram (refrigerant pressure P-refrigerant enthalpy h diagram) of the heat pump air-conditioning and hot water supply system Explanatory drawing of the principle at the time of utilization of the 1st bypass circuit in the hot water supply operation using the cooling exhaust heat of the heat pump type air conditioning and hot water supply apparatus Flowchart of overall refrigeration cycle control of the heat pump type air conditioning and hot water supply system Flow chart for controlling the opening of a bypass expansion valve in the first bypass circuit of the heat pump type air conditioning and hot water supply apparatus according to the first embodiment of the present invention. Schematic configuration diagram of a conventional heat pump air conditioning and hot water supply system Schematic configuration diagram of another conventional heat pump type air conditioning and hot water supply system

The first invention includes a compressor, a four-way valve, a heat source side heat exchanger, a heat source side expansion means, a subcooler, a use side expansion means, a first refrigerant circuit in which a use side heat exchanger is connected in an annular shape, The four-way valve branches from the first refrigerant circuit between the heat source side expansion means and the subcooler or between the subcooler and the utilization side expansion means, and passes through the bypass expansion means and the subcooler. A first bypass circuit connected to the first refrigerant circuit between the compressor and the compressor, a branch from between the compressor and the four-way valve, and via a hot water heat exchanger, the supercooler and the A second refrigerant circuit connected between the use side expansion means, a first opening / closing means provided between the connection portion between the second refrigerant circuit and the first refrigerant circuit and the use side expansion means; Branching from between the heat source side expansion means and the supercooler, via the second opening and closing means, Second connecting between the opening-closing means and the usage-side expansion means
A bypass circuit; and a control device, wherein the control device performs the cooling operation in the use-side heat exchanger and the first opening and closing when performing the hot water generation operation in the hot water heat exchanger. The heat pump air-conditioning hot-water supply apparatus is characterized in that the means is closed, the second opening / closing means is opened, and the heat source side expansion means is closed.

  Accordingly, the refrigerant cooled by causing the hot water heat exchanger to act as a condenser (heater) and exchanging heat with the hot water is partially branched between the subcooler and the outdoor expansion means. The refrigerant is further cooled by the low-pressure and low-temperature refrigerant flowing through the first bypass circuit, the refrigerant supercooling degree is increased, and the refrigerant enthalpy flowing into the indoor heat exchanger that is an evaporator (cooler) is reduced.

  As a result, the dryness of the refrigerant flowing into the indoor heat exchanger is reduced, that is, the gas-phase refrigerant component is reduced, so that the ratio of the refrigerant amount contributing to evaporation is increased in the use side heat exchanger, and the performance as an evaporator is increased. Is pulled out.

  In addition, the refrigerant dryness flowing into the indoor heat exchanger is small (the liquid phase component is large), so that it is composed of a plurality of refrigerant channels compared to the case where the refrigerant dryness is large (the gas phase component is large). The phenomenon that the refrigerant flow rate becomes uneven on the inflow side of the use side heat exchanger (evaporator) can be avoided (refrigerant distribution performance is improved), and the use side heat exchanger (evaporator) can be effectively used. .

  Furthermore, the refrigerant that does not contribute to evaporation in the use side heat exchanger returns to the compressor without flowing into the use side heat exchanger via the first bypass circuit, thereby reducing unnecessary pipe pressure loss in the refrigeration cycle. The rise can be avoided.

  Through these actions, the amount of heat exchanged in the heat exchanger (evaporation heat exchange) in the heat exchanger using the exhaust heat (cooling exhaust heat hot water supply operation in which the cooling operation in the heat exchanger on the use side and the hot water generation operation in the hot water heat exchanger are performed simultaneously ( Refrigerant pressure loss on the low pressure side can be reduced while maintaining the cooling capacity), increasing the refrigerant density on the compressor suction side, resulting in an increase in the refrigerant flow rate and an increase in the amount of heat in the hot water heat exchanger Is possible.

  The second aspect of the invention is particularly the heat pump type air conditioning and hot water supply apparatus of the first aspect of the invention, further comprising refrigerant superheat degree detecting means for detecting the degree of refrigerant superheat on the outlet side of the first bypass circuit, wherein the control device includes the refrigerant The opening degree of the bypass expansion means is controlled so that the refrigerant superheat degree by the superheat degree detection means falls within a predetermined range.

  Thereby, in addition to the effect of 1st invention, it becomes possible to keep the refrigerant | coolant superheat degree of the exit side of a 1st bypass circuit in a predetermined target range, and the bypass flow volume which passes a 1st bypass circuit for every driving | running condition is obtained. Optimized.

  In particular, by setting the upper limit value of the control target of the outlet side refrigerant superheat degree of the first bypass circuit to be within 1K, the refrigerant on the outlet side of the first bypass circuit is not excessively heated, and the degree of superheat is almost equal. Zero (refrigerant saturated state) can be achieved, the performance of the subcooler can be maximized, and the efficiency can be maximized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a heat pump air-conditioning / heating water heater 10 according to a first embodiment of the present invention. This heat pump type heating and cooling water heater 10 includes a first refrigerant circuit 20, a second refrigerant circuit 21, a first bypass circuit 30, a second bypass circuit 40, various actuators, various sensors, and a control device 50 that circulate refrigerant. It has.

  As the refrigerant, for example, a non-azeotropic refrigerant mixture such as R407C, a pseudo-azeotropic refrigerant mixture such as R410A, or a single refrigerant can be used.

  The first refrigerant circuit 20 includes a compressor 1, a four-way valve 2, a heat source side heat exchanger 3, a heat source side expansion valve 4, a supercooler 5, a first opening / closing means 41, a use side expansion valve 6, and a use side heat. The exchanger 7 is connected in a ring shape, and the second refrigerant circuit 21 branches from between the compressor 1 and the four-way valve 2 and is used with the supercooler 5 via the hot water heat exchanger 22 and the hot water expansion valve 23. It communicates with the first refrigerant circuit 20 between the side expansion valve 6.

  The hot water heat exchanger 22 is a refrigerant-to-water heat exchanger in which water flows in the outer flow path and refrigerant flows in the inner flow path, for example, a double-pipe heat exchanger, and the heat source side heat exchanger 3 The use side heat exchanger 6 is a finned tube heat exchanger.

  A first opening / closing means 41 is provided between the connection portion of the second refrigerant circuit 21 and the first refrigerant circuit 20 and the use side expansion valve 6.

  Next, the first bypass circuit 30 branches from the first refrigerant circuit 20 between the supercooler 5 and the first opening / closing means 41, and the bypass expansion valve 9 and the low pressure side heat exchange part of the supercooler 5. The second refrigerant circuit 40 communicates again with the first refrigerant circuit between the gas-liquid separator 8 and the compressor 1 via the first refrigerant circuit between the heat source side expansion valve 4 and the subcooler 5. 20, and communicates again between the first opening / closing means 41 and the use side expansion valve 6 via the second opening / closing means 42.

  The refrigerant circuit 20 is provided with a four-way valve 2 for switching the flow direction of the refrigerant, such as cooling operation and heating operation in the use side heat exchanger 7, and hot water generation (hot water supply) operation in the hot water heat exchanger 22. Switching control is performed according to the operation mode.

  Further, the first bypass circuit 30 is provided with a temperature sensor Th for detecting the temperature Tr of the refrigerant flowing out of the subcooler 5 and a pressure Pr, and a pressure sensor PS.

  The control device 50 includes a temperature detection means 51, a pressure detection means 52, a refrigerant superheat degree detection means 53, an opening / closing means control means 54, and an expansion valve control means 55. The temperature detection means 51 is detected by a temperature sensor Th. The pressure detection means 52 takes in the detection values by the pressure sensor PS, inputs these detection values to the refrigerant superheat degree detection means 53, and detects the refrigerant superheat degree SH at the outlet side of the first bypass circuit 30.

  The operation of the heat pump air-conditioning and hot water supply apparatus 10 configured as described above during the cooling exhaust heat hot water supply operation will be described.

  In FIG. 1, the flow directions of the refrigerant and hot water during the cooling operation in the use side heat exchanger 6 and the hot water generation operation in the cooling waste heat use hot water operation in which the hot water generation operation in the hot water side heat exchanger 22 is performed are indicated by arrows. FIG. 2 shows a Mollier diagram (refrigerant pressure P-refrigerant enthalpy h diagram) of the heat pump type air conditioning and hot water supply system according to the first embodiment of the present invention.

  In the hot water supply operation using cooling exhaust heat, the hot water expansion valve 23: fully open, the four-way valve 2: cooling mode (communicating the compressor 1 and the heat source side heat exchanger 3), the heat source side expansion valve 4: fully closed, first opening / closing means : Closed, second opening / closing means: open, use side expansion valve 6: predetermined opening, bypass expansion valve 9: predetermined opening.

With this setting, the high-pressure high-temperature gas refrigerant discharged from the compressor 1 (point a in FIG. 2) does not flow to the heat source side heat exchanger 3 side because it is set to the heat source side expansion valve 4: fully closed, It flows into the heat exchanger 22 for hot water, functions as a radiator, heats the aqueous medium of the hot water utilization circuit communicating with the hot water terminal equipment, generates hot water, and the high-pressure high-temperature gas refrigerant itself is cooled and liquefied and condensed. Then, it becomes a saturated liquid state or a supercooled liquid state (point b in FIG. 2).

  The high-pressure liquid refrigerant that has flowed out of the hot water heat exchanger 22 passes through the hot water expansion valve 23 (fully open) and then flows to the subcooler 5 side because the first opening / closing means is set to be closed. A part of the high-pressure refrigerant branches to the first bypass circuit 30 side on the inlet side, and the remaining high-pressure refrigerant is further subcooled by the subcooler 5 (point c in FIG. 2), and then the heat source side expansion valve 4. Is fully closed and the second opening / closing means is set to open, so that it does not flow to the heat source side heat exchanger 3 side, and the first refrigerant circuit 20 is interposed between the heat source side expansion valve 4 and the subcooler 5. From the first opening / closing means 41 and the utilization side expansion valve 6 via the second opening / closing means 42 (open).

  After that, since the first opening / closing means is set to be closed, the high-pressure liquid refrigerant flows to the use side heat exchanger 7 side and is decompressed and expanded by the use side expansion valve 6 (point d in FIG. 2). It flows into the utilization side heat exchanger 7 which acts as an evaporator.

  The low-pressure two-phase refrigerant that has flowed into the use-side heat exchanger 7 evaporates here and absorbs heat from the air side, cools and dehumidifies the air, and the refrigerant itself is heated, as in the case of the single cooling operation. It will be in a state (g point in FIG. 2) and will return to the compressor 1. FIG.

  On the other hand, the high-pressure refrigerant branched to the first bypass circuit 30 side on the inlet side of the subcooler 5 is depressurized and expanded by the bypass expansion valve 9 (point e in FIG. 2), and then the secondary side of the subcooler 5. While the liquid refrigerant in the first refrigerant circuit 20 flowing through the primary heat exchange section is cooled in the heat exchange section, the liquid refrigerant is heated to become a two-phase refrigerant state or a saturated gas state (point f in FIG. 2), and the compressor 1 again joins the refrigerant flowing through the first refrigerant circuit 20 (point h in FIG. 2) and is sucked into the compressor 1 again.

  At that time, the opening degree control of the bypass expansion valve 9 is performed so that the outlet side refrigerant superheat degree SH of the first bypass circuit 30 falls within a predetermined target range, for example, ± 1K.

  With the above operation, the first bypass circuit 30 can be used in the operation of generating hot water through the heat exchanger 22 for hot water while performing the cooling operation in the use-side heat exchanger 7, and highly efficient operation can be performed. It becomes possible.

  Accordingly, even during the cooling exhaust heat utilization hot water supply operation, the operation using the first bypass circuit 30 reduces the refrigerant enthalpy flowing into the utilization side heat exchanger 7 as an evaporator, that is, the degree of supercooling on the high pressure side. While enlarging (arrow A in FIG. 2), a refrigerant gas component that does not contribute to evaporation can be bypassed to the suction side of the compressor 1 through the first bypass circuit 30 at the same time, so that a significant pressure loss increase in the evaporator In other words, the suction pressure of the compressor 1 can be increased (arrow B in FIG. 2), and the refrigerant flow rate can be increased and the condensation (heating) capacity can be increased.

  In addition, the hot water produced | generated in the hot water utilization circuit is conveyed, such as heat exchange units (not shown), such as a radiator, and a hot water storage tank (not shown), for example, and heating and hot water supply are performed.

  On the other hand, by changing the setting of various actuators and controlling the control device 50, the cooling operation in the use side heat exchanger 6 and the cooling exhaust heat to the atmosphere are performed in the heat source side heat exchanger 3 as shown in FIG. The cooling operation can be performed in the same manner as in the conventional cooling operation in which the operation of dissipating heat is performed. The operation in this case will be described below with reference to FIG.

  In cooling only operation, the hot water expansion valve 23: fully closed, four-way valve 2: cooling mode (compressor 1 and heat source side heat exchanger 3 are communicated), heat source side expansion valve 4: fully open, first opening / closing means: open, Second opening / closing means: closed, use side expansion valve 6: predetermined opening, bypass expansion valve 9: predetermined opening. In addition, the heat pump type air conditioning and hot water supply apparatus of the present invention forms a cooling cycle basically similar to that of the conventional example shown in FIG.

  With this setting, the high-pressure gas refrigerant discharged from the compressor 1 (point a in FIG. 2) flows into the heat source side heat exchanger 3, dissipates heat to the outdoor air, and the refrigerant itself is cooled and liquefied and condensed. Then, the supercooled liquid state (b point in FIG. 2) is obtained.

  The high-pressure liquid refrigerant (point b in FIG. 2) that has flowed out of the heat source side heat exchanger 3 is further subcooled (point c in FIG. The refrigerant branches to the first bypass circuit 30 side, and the remaining high-pressure refrigerant is decompressed and expanded by the use side expansion valve 6 (point d in FIG. 2), and then enters the use side heat exchanger 7 acting as an evaporator. Inflow.

  The low-pressure two-phase refrigerant that has flowed into the use-side heat exchanger 7 that is a finned-tube heat exchanger evaporates and absorbs heat from the air side, cools and dehumidifies the air, and the refrigerant itself is heated to be in a superheated gas state. (Point g in FIG. 2) flows out from the use side heat exchanger 7 and returns to the compressor 1.

  On the other hand, the high-pressure refrigerant branched to the first bypass circuit 30 side on the outlet side of the subcooler 5 is depressurized and expanded by the bypass expansion valve 9 (point e in FIG. 2), and then the secondary side of the subcooler 5. While the liquid refrigerant in the first refrigerant circuit 20 flowing through the primary heat exchange section is cooled in the heat exchange section, the liquid refrigerant is heated to become a two-phase refrigerant state or a saturated gas state (point f in FIG. 2), and the compressor 1 again joins the refrigerant flowing through the first refrigerant circuit 20 (point h in FIG. 2) and is sucked into the compressor 1 again.

  At that time, the opening degree control of the bypass expansion valve 9 is performed so that the outlet side refrigerant superheat degree SH of the first bypass circuit 30 falls within a predetermined target range, for example, ± 1K.

  With the above operation, the cooling operation in the use side heat exchanger 6 and the cooling single operation in which the heat source side heat exchanger 3 performs the operation of dissipating the cooling exhaust heat to the atmosphere become possible.

  The refrigeration cycle control algorithm in the cooling exhaust heat utilization hot water supply operation related to the heat pump type air conditioning and hot water supply apparatus 10 of the present invention performing the above operation is shown in the flowchart of the entire refrigeration cycle control shown in FIG. 4 and FIG. A detailed description will be given below with reference to a flowchart of opening degree control of the bypass expansion valve 9 in the first bypass circuit 30.

  First, in step S1 shown in FIG. 4, as the setting of each actuator for the cooling exhaust heat utilization hot water supply operation, the hot water expansion valve 23: fully open, four-way valve 2: cooling mode (compressor 1 and heat source side heat exchanger 3), heat source side expansion valve 4: fully closed, first opening / closing means: closed, second opening / closing means: open, use side expansion valve 6: predetermined opening, bypass expansion valve 9: predetermined opening.

  Next, the operation frequency Fq of the compressor 1 is set in step S2, the opening degree control of the use side expansion valve 6 is performed in step S3, and then the operation of the compressor 1 is started in step S4.

  Thereafter, when a predetermined condition is satisfied, the process proceeds to opening degree control of the bypass expansion valve 9 of the first bypass circuit 30 in step S5.

As the opening degree control of the bypass expansion valve 9, the refrigerant temperature Tr and the refrigerant pressure Pr flowing out from the subcooler 5 are detected by the temperature sensor Th and the pressure sensor PS in step S6 shown in FIG. In S7, the detected value of the refrigerant pressure Pr is changed to the refrigerant superheat degree detecting means 53.
To calculate the saturation temperature Tsat of the refrigerant.

  In step S8, the refrigerant superheat degree SH on the outlet side of the first bypass circuit 30 is calculated.

  Thereafter, in step S9, it is determined whether or not the detected refrigerant superheat degree SH is between a preset lower limit value SH1 and upper limit value SH2, and if it is within the range of SH1 to SH2 (in step S9). In the case of Yes), the process returns to step S6 while the opening of the bypass expansion valve 9 is maintained.

  On the other hand, when the refrigerant superheat degree SH is not between the lower limit value SH1 and the upper limit value SH2 (No in step S9), the controller 50 should compare the magnitude relationship between the refrigerant superheat degree SH and the lower limit value SH1. The process proceeds to step S10.

  In Step S10, when it is determined that the refrigerant superheat degree SH is equal to or lower than the lower limit value SH1 (Yes in Step S10), the process proceeds to Step S11, and the opening degree of the bypass expansion valve 9 is set to a predetermined amount by the control device 50. The operation of reducing the flow rate of the refrigerant flowing down is performed.

  Conversely, when it is determined in step S11 that the refrigerant superheat degree SH is equal to or higher than the upper limit value SH2 (No in step S10), the process proceeds to step S12, and the opening degree of the bypass expansion valve 9 is determined by the control device 50. After performing the operation of increasing the flow rate of the refrigerant flowing by increasing the fixed amount, the process returns to step S6 and the operations of steps S6 to S12 are repeated.

  As described above, the refrigerant enthalpy flowing into the use-side heat exchanger 7 that is the evaporator is also obtained by repeating the operations of Step S1 to Step S12 using the first bypass circuit 30 even during the cooling exhaust heat utilization hot water supply operation. The refrigerant gas component that does not contribute to evaporation at the same time can be bypassed to the suction side of the compressor 1 through the first bypass circuit 30 while increasing the degree of supercooling on the high-pressure side. Therefore, it is possible to suppress an increase in pressure loss, that is, increase the suction pressure of the compressor 1 and increase the refrigerant flow rate and the condensation (heating) capacity.

  Furthermore, the opening degree control of the bypass expansion valve 9 makes it possible to keep the outlet side refrigerant superheat degree SH of the first bypass circuit 30 within a predetermined target range, and the bypass that passes through the first bypass circuit 30 for each operating condition. The flow rate is optimized.

  In particular, the refrigerant on the outlet side of the first bypass circuit 30 is excessively overheated by performing control so that the control target range of the outlet side refrigerant superheat degree SH of the first bypass circuit 30 is, for example, within 0K to 1K. Therefore, the degree of superheat can be made almost zero (refrigerant saturation state), the performance of the supercooler 5 can be maximized, and the efficiency can be maximized.

  As described above, the present invention is particularly useful for the cooling, heating, and heat pump type air conditioning and hot water supply apparatus that heats water and uses the water for heating and hot water supply by the heat pump apparatus.

DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Heat source side heat exchanger 4 Heat source side expansion valve (heat source side expansion means)
5 Subcooler 6 User side expansion valve (User side expansion means)
7 Use side heat exchanger 9 Bypass expansion valve (Bypass expansion means)
DESCRIPTION OF SYMBOLS 10 Heat pump type air conditioning hot-water supply apparatus 20 1st refrigerant circuit 21 2nd refrigerant circuit 22 Heat exchanger for hot water 23 Hot water expansion valve (expansion means for hot water)
DESCRIPTION OF SYMBOLS 30 1st bypass circuit 40 2nd bypass circuit 41 1st opening / closing means 42 2nd opening / closing means 50 Control apparatus 51 Temperature detection means 52 Pressure detection means 53 Refrigerant superheat degree detection means 54 Opening / closing means control means 55 Expansion valve control means (expansion means) Control means)

Claims (2)

A compressor, a four-way valve, a heat source side heat exchanger, a heat source side expansion means, a supercooler, a use side expansion means, a first refrigerant circuit in which a use side heat exchanger is connected in an annular shape, the heat source side expansion means and the Branching from the first refrigerant circuit between the subcoolers or between the subcooler and the utilization side expansion means, and via the bypass expansion means and the subcooler, the four-way valve and the compressor A first bypass circuit connected to the first refrigerant circuit, and between the compressor and the four-way valve, and via a hot water heat exchanger, the supercooler and the utilization side expansion means A second refrigerant circuit connected between the first refrigerant circuit, a first opening / closing means provided between a connecting portion of the second refrigerant circuit and the first refrigerant circuit, and the use side expansion means, and the heat source side expansion means Branching from between the subcooler and the first opening and closing means via the second opening and closing means; A second bypass circuit connected between the serial usage-side expansion means, and a control unit, said control unit performs a cooling operation in the use side heat exchanger and the hot water heat exchanger When the hot water generating operation is performed, the first opening / closing means is closed, the second opening / closing means is opened, and the heat source side expansion means is closed. A refrigerant superheat degree detecting means for detecting a refrigerant superheat degree at the outlet side of the first bypass circuit is provided, and the control device is configured to perform the bypass expansion so that the refrigerant superheat degree by the refrigerant superheat degree detecting means falls within a predetermined range. The heat pump air-conditioning / hot water supply apparatus according to claim 1, wherein the opening degree of the means is controlled.