JPH10259959A - Heating device using refrigeration cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress condensation pressure low even when an outside area to be heated with a first outside heating heat exchanger is subjected to a high temperature condition and enhance operation efficiency. SOLUTION: This heating device is provided with a main circuit 41 of a refrigeration cycle which comprises a compressor 1, a first outside heating heat exchanger 2, a gas-liquid separator 9, a decompression device 3 and an evaporator which are all connected one after another by way of refrigerant piping, a supper cooling heat exchanger 10a which supper-cools the refrigerant fed from the gas-liquid separator 9 provided between the gas-liquid separator 9 and the decompression device 3, a second decompression device 16 which is bypassed between the outside of the evaporator 6 and the bottom of the gas liquid separator 9 and a first bypass circuit 42 having a first refrigerant flow rate control valve 7 and a refrigerant temperature detection means 71 which detects the refrigerant temperature on the discharge side of the compressor 1 where there is provided a first control device 38 which on/off controls the first refrigerant flow rate control valve 7 based on the detected refrigerant temperature.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating apparatus using a refrigeration cycle used for, for example, hot water supply equipment.

[0002]

2. Description of the Related Art FIG. 10 shows a conventional example of a heating device for hot water supply heating described in a Mitsubishi Electric Cooling and Heating Handbook (Air Conditioning Equipment Edition (1995, 1996 edition)). In the figure,
1 is a compressor, 2 is a first heat exchanger for external heating, 3 is a first heat exchanger.
6 is an evaporator, 6 is an evaporator, 14 is a four-way switching valve, 18 is an accumulator, 16, 68 and 69 are each a pressure reducing device composed of a capillary tube, etc., 62 to 65 are check valves, 66 is an on-off valve, and 61 is an on-off valve Shows a reservoir.

Here, the refrigerant circuit forming the refrigeration cycle is as follows:
The compressor 1, the four-way switching valve 14, the first heat exchanger for external heating 2, the liquid reservoir 61, the check valve 62, the first pressure reducing device 3, the check valve 65, the evaporator 6, and the accumulator 18 are connected to a refrigerant pipe. A bypass circuit 42B branched from the outlet pipe of the liquid reservoir 61 and connected to the outlet pipe of the evaporator 6 via the on-off valve 66 and the pressure reducing device 16, and a check valve. 62, a pressure reducing device 69 provided in parallel with the check valve 6,
A check valve 64 provided on a pipe branched from the second inlet pipe and connected to the outlet pipe of the first decompressor 3, and an inlet of the evaporator 6 branched from the inlet pipe of the first decompressor 3 A check valve 63 provided on a pipe connected to the pipe, a check valve 6
3 and a pressure reducing device 68 provided on a pipe connected in parallel.

[0004] During the hot water supply operation, the refrigerant flows in the solid arrow direction. The refrigerant exiting the compressor 1 passes through the four-way switching valve 14 to the first refrigerant.
Flows into the heat exchanger 2 for external heating. The refrigerant condensed in the first external heating heat exchanger 2 and further supercooled flows into the lower part of the liquid reservoir 61. Some of the refrigerant flowing out of the upper part of the liquid reservoir 61 passes through the check valve 62 and the first refrigerant.
The pressure in the evaporator 6 is reduced by the pressure reducing device 3 through the check valve 65.
Flows into. On the other hand, the remaining refrigerant is depressurized by the decompression device 16 through the bypass circuit 42B and flows into the evaporator 6. The refrigerant evaporated in the evaporator 6 is supplied to the four-way switching valve 1
4. After passing through the accumulator 18, it is sucked into the compressor 1.

[0005]

As described above, since the conventional heating device is constituted as described above, there are the following problems. In order to secure a stable operation state, it is necessary to supply a supercooled liquid refrigerant to the first pressure reducing device 3. For that purpose, the refrigerant must be supercooled in the first external heating heat exchanger 2. However, during the hot water supply operation under high water temperature conditions, the condensation pressure of the refrigerant in the first external heating heat exchanger 2 increases. Therefore, it is necessary to increase the pressure resistance of the components such as the compressor 1 and the first heat exchanger for external heating 2, resulting in a problem that the cost is increased. In addition, there is also a problem that the refrigeration efficiency is reduced due to an increase in the condensing pressure.

[0006] The present invention has been made in view of the above problems, and even if the outside to be heated by the first external heating heat exchanger 2 is under a high temperature condition, the condensing pressure is kept low and the operation efficiency is improved. An object is to provide a heating device using a good refrigeration cycle.

[0007]

In order to achieve the above object, a heating apparatus using a refrigeration cycle according to the present invention comprises a compressor, a first heat exchanger for external heating, a gas-liquid separator,
Heat exchange between a main circuit of a refrigeration cycle in which a first pressure reducing device and an evaporator are sequentially connected in a ring shape by a refrigerant pipe, and a low-temperature heat source provided between a gas-liquid separator of the main circuit and the first pressure reducing device. A supercooling heat exchanger for supercooling the refrigerant from the gas-liquid separator, and a second decompression device and a first refrigerant flow rate which are bypass-connected between the evaporator outlet side of the main circuit and the gas-liquid separator bottom. A first bypass circuit having a regulating valve; and a refrigerant temperature detecting means for detecting a refrigerant temperature on a compressor discharge side, wherein the first temperature is determined based on the refrigerant temperature on the compressor discharge side detected by the refrigerant temperature detecting means. The first control device for controlling the opening and closing of the refrigerant flow control valve is provided.

In the above-mentioned configuration, a third pressure reducing device is provided between the inlet side of the second pressure reducing device of the first bypass circuit and the outlet side of the first refrigerant flow control valve, and is bypass-connected. A second bypass circuit for circulating the refrigerant from the bottom of the gas-liquid separator is provided for a low-temperature heat source of the cooling heat exchanger.

In the above-mentioned configuration, air is used as a low-temperature heat source of the supercooling heat exchanger.

Further, in each of the above-described configurations, a third bypass circuit having a second refrigerant flow control valve, which is bypass-connected between the subcooling heat exchanger inlet side of the main circuit and the upper portion of the gas-liquid separator, Refrigerant pressure detecting means for detecting the refrigerant pressure on the compressor discharge side, and a second control device for controlling the opening and closing of the second refrigerant flow regulating valve based on the refrigerant pressure on the compressor discharge side detected by the refrigerant pressure detecting means Are provided.

A main circuit of a refrigeration cycle in which a compressor, a first heat exchanger for external heating, a gas-liquid separator, a first decompression device, and an evaporator are sequentially connected in a ring through a refrigerant pipe;
For supercooling, which is interposed between the first external heating heat exchanger of the main circuit and the first decompression device and supercools the refrigerant from the first external heating heat exchanger by heat exchange with a low-temperature heat source. A heat exchanger, a second external heating heat exchanger provided between the compressor of the main circuit and the first external heating heat exchanger, a water pump, and a first external heating heat exchanger. A water main circuit in which a heated side and a water flow rate regulating valve are sequentially connected in a ring by a water pipe; and a bypass connection is made between a first external heating heat exchanger outlet side of the water main circuit and a water pump suction side. A portion of the water heated by the first external heating heat exchanger is interposed between the heated side of the second external heating heat exchanger and the hot water storage tank, and a part of the water is heated by the first external heating heat exchanger. And a water temperature detecting means for detecting the water temperature at the outlet side of the second external heating heat exchanger of the water auxiliary circuit. Water supply before supply to the hot water storage tank is used as a low-temperature heat source of the supercooling heat exchanger, and a water flow control valve is provided based on the water temperature at the outlet of the second external heating heat exchanger detected by the water temperature detecting means. Open / close control
Is provided.

In any one of the above configurations, the third refrigerant flow control valve, the liquid reservoir, and the fourth pressure reducing device are connected by bypass between the first pressure reducing device inlet side and the outlet side of the main circuit. A fourth bypass circuit, a refrigerant pressure detecting means for detecting a refrigerant pressure on the compressor discharge side, and a third refrigerant flow regulating valve based on the refrigerant pressure on the compressor discharge side detected by the refrigerant pressure detecting means. And a fourth control device for controlling opening and closing.

Further, a main circuit of a refrigeration cycle in which a compressor, a first heat exchanger for external heating, a gas-liquid separator, a first decompression device, and an evaporator are sequentially connected in a ring by a refrigerant pipe;
A supercooling heat exchanger provided between the gas-liquid separator of the main circuit and the first decompressor for supercooling the refrigerant from the gas-liquid separator by heat exchange with a low-temperature heat source; A four-way switching valve disposed between the heat exchanger for external heating and between the evaporator and the suction side of the compressor for inverting the refrigerant flow path of the main circuit, the evaporator outlet side of the main circuit and the bottom of the gas-liquid separator A first bypass circuit having a second depressurizing device and a first refrigerant flow regulating valve connected by a bypass between the first depressurizing device and the first refrigerant flow regulating valve; A second bypass circuit for bypassing a third decompression device between the two sides, and for circulating a refrigerant from the bottom of the gas-liquid separator for a low-temperature heat source of the supercooling heat exchanger; A plate type heat exchanger is used as the heat exchanger, and the evaporator inlet side of the main circuit is connected to the first heat exchanger. A fifth check valve having a first check valve and a fifth pressure reducing device, which is bypass-connected between the outlets of the heat exchangers for external heating and is arranged so that the flowing direction of the refrigerant is directed toward the heat exchanger for external heating; A bypass circuit and a plate heat exchanger outlet side of the main circuit or a plate heat exchanger inlet side of the second bypass circuit and a first external heating of the main circuit, which are arranged vertically below the plate heat exchanger; Bypass circuit having a second check valve which is bypass-connected between the outlets of the heat exchangers and has a second check valve arranged so that the refrigerant flowing direction is directed toward the first heat exchanger for external heating; A third check valve is provided on the outlet side of the first pressure reducing device, the third check valve being arranged with the flowing direction of the refrigerant toward the evaporator.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. Embodiment 1 of the Invention FIG. 1 is a refrigerant circuit configuration diagram showing a heating device using a refrigeration cycle according to Embodiment 1 of the present invention, and the same parts as those of the conventional device shown in FIG. 10 are denoted by the same reference numerals. In FIG. 1, the refrigerant circuit includes a compressor 1, a four-way switching valve 14, a first external heating heat exchanger 2, a gas-liquid separator 9, a supercooling heat exchanger 10a, a first decompression device 3, an evaporator. The main circuit 41 of the refrigeration cycle in which the accumulator 6 and the accumulator 18 are sequentially connected by a refrigerant pipe, and the bypass circuit is connected between the outlet of the accumulator 18 downstream of the evaporator 6 of the main circuit 41 and the bottom of the gas-liquid separator 9. A second high-pressure and low-pressure liquid refrigerant stored in the lower part of the gas-liquid separator 9 by the second pressure reducing device 16 having a second pressure reducing device 16 (for example, made of a capillary tube) and a first refrigerant flow control valve 7. And a first bypass circuit 42 that leads the refrigerant to the inlet of the compressor 1 via the first refrigerant flow control valve 7.

Further, the control circuit includes a refrigerant temperature detecting means 71 provided at an outlet pipe of the compressor 1 for detecting a refrigerant temperature on the discharge side, and a refrigerant temperature detected by the refrigerant temperature detecting means 71 and a preset temperature. And a first controller 38 that compares the temperature with the first refrigerant flow control valve 7 to control the opening and closing of the first refrigerant flow control valve 7.

Next, the flow of the refrigerant will be described. The refrigerant exiting the compressor 1 flows through the four-way switching valve 14 into the first external heating heat exchanger 2 and becomes a saturated liquid refrigerant or a two-phase refrigerant having a very low dryness, and becomes a gas-liquid separator 9. Flows into.
The refrigerant flowing out of the upper part of the gas-liquid separator 9 is supplied to the subcooling heat exchanger 1.
After being supercooled by Oa, the pressure is further reduced by the first pressure reducing device 3. The depressurized low-temperature low-pressure refrigerant flows into the evaporator 6 through the supercooling heat exchanger 10a as a cold / hot heat source. Next, the refrigerant evaporates in the evaporator 6, and the four-way switching valve 14
Then, it is sucked into the compressor 1 through the accumulator 18. Further, the first refrigerant flow control valve 7 is connected to the first control device 3.
When opened by 8, the liquid refrigerant separated by the gas-liquid separator 9 is depressurized by the second pressure reducing device 16, merges with the refrigerant from the accumulator 18, and is sucked into the compressor 1.

Next, the control will be described. The refrigerant temperature detected by the refrigerant temperature detecting means 71 is compared with a set temperature (for example, 120 ° C. which is near the upper limit of the operating temperature range of the four-way switching valve 14 and the like). The first refrigerant flow control valve 7 is opened by the control device 38, and the unevaporated liquid refrigerant is supplied to the suction side of the compressor 1 to prevent the refrigerant temperature from rising on the discharge side of the compressor 1.

Here, the structure of the gas-liquid separator will be described. FIGS. 2A and 2B show an example of the structure of the gas-liquid separator used in the present invention. In FIG. 2, the gas-liquid separator 9 is provided with a closed container 95 and a connection port provided at the center of the closed container 95, and the refrigerant that has exited the first external heating heat exchanger 2 is sent to the gas-liquid separator 9. Supply refrigerant pipe 91
And the supercooling heat exchanger 10a
A refrigerant pipe 92 whose connection port is provided at substantially the same height as that of the refrigerant pipe 91 so as to guide the liquid refrigerant stored in the lower portion of the closed vessel 95 to the second pressure reducing device 16 and the first refrigerant flow rate adjustment. Refrigerant pipe 93 leading to the suction pipe of the compressor 1 through the valve 7, and refrigerant pipes 92, 91 inside the closed vessel 95.
And a plate 94 which is provided at a position below the connection port and has several holes. The end of the refrigerant pipe 91 is bent inside the container, and the tip is cut so as to face the wall surface of the container. The plate 94 is for preventing the liquid refrigerant stored in the lower part of the closed container 95 from being stirred by the flow of the refrigerant. The refrigerant pipes 91 and 92 are connected to the main circuit 41 of the refrigeration cycle.
The refrigerant pipe 93 is connected to the first bypass circuit 42.

Here, the inside of the closed vessel 95 and the refrigerant pipe 9
The state of the refrigerant inside 1, 92, 93 will be described. From the amount of refrigerant distributed on the low pressure side determined by the evaporation pressure and the total amount of refrigerant (filled refrigerant amount), the refrigerant on the high pressure side such as the first external heating heat exchanger 2 or the gas-liquid separator 9 which is a condenser Is determined. The refrigerant that has flowed into the closed vessel 95 from the refrigerant pipe 91 in a two-phase state or a saturated state flows through the refrigerant pipe 91 as it is when the first refrigerant flow regulating valve 7 is closed by the first control device 38. The refrigerant in the substantially same state as the flowing refrigerant flows out from the refrigerant pipe 92. On the other hand, the first
When the first refrigerant flow control valve 7 is in the open state by the control device 38, the liquid refrigerant flows out from the lower portion of the closed vessel 95, and the refrigerant having a smaller dryness than the dryness in the refrigerant pipe 91 flows from the refrigerant pipe 92. Will be leaked.

The main purpose of the gas-liquid separator is to obtain a liquid refrigerant for preventing the refrigerant temperature from rising at the discharge side of the compressor 1. Therefore, the gas-liquid separator having the structure shown in FIG. 9
a. This gas-liquid separator 9a is
5, a refrigerant pipe 97 connected so as to penetrate through the interior of the closed vessel 95, and a plate 94 provided below the refrigerant pipe 97 inside the closed vessel 95 and having several holes formed therein. I have. Further, the refrigerant pipe 9 is provided inside the container.
In the upper part of 7, there are provided holes at a constant interval which are equal to or less than 1/3 of the inner diameter of the pipe. Further, the liquid refrigerant stored in the lower portion of the closed container 95 due to the presence of the plate 94 is not stirred by the flow of the blown refrigerant.

The present embodiment is configured as described above. Since the refrigerant state at the outlet of the first external heating heat exchanger 2 is in a two-phase state or a saturated state, hot water supply under high-temperature water conditions Even during operation, the condensation pressure can be kept low, and efficient operation can be performed.

Embodiment 2 of the Invention FIG. 4 is a refrigerant circuit configuration diagram illustrating a heating device according to Embodiment 2 of the present invention,
Parts similar to those of the conventional device are denoted by the same reference numerals. In the figure, the refrigerant circuit includes a compressor 1, a four-way switching valve 14, a first external heating heat exchanger 2, a gas-liquid separator 9, a supercooling heat exchanger 10a, a first decompression device 3, an evaporator. 6. The main circuit 41 of the refrigeration cycle in which the accumulators 18 are sequentially connected by refrigerant pipes, and the high-temperature and high-pressure liquid refrigerant stored in the lower part of the gas-liquid separator 9 are decompressed by the second decompression device 16 to be the first. The first guide to the inlet of the compressor 1 through the refrigerant flow control valve 7
And a bypass circuit 42. In addition, the first bypass circuit 42 has a third pressure reducing device 15 (made of a capillary tube) between the inlet side of the second pressure reducing device 16 and the outlet side of the first refrigerant flow regulating valve 7 and is connected in a bypass manner. A second bypass circuit 43 for flowing a liquid refrigerant from the bottom of the gas-liquid separator 9 is provided for a low-temperature heat source of the supercooling heat exchanger 10a. The second bypass circuit 43 depressurizes the liquid refrigerant from the lower part of the gas-liquid separator 9 by the third decompression device 15 and circulates it as a low-temperature heat source of the supercooling heat exchanger 10a. And is guided to the inlet of the compressor 1.

Further, the control circuit compares the refrigerant temperature detected by the refrigerant temperature detecting means 71 provided in the outlet pipe of the compressor 1 with the refrigerant temperature detected by the refrigerant temperature detecting means 71 and sets a predetermined temperature. And a first controller 38 for controlling the opening and closing of the first refrigerant flow regulating valve 7.

Next, the flow of the refrigerant will be described. The refrigerant exiting the compressor 1 flows through the four-way switching valve 14 into the first external heating heat exchanger 2 and becomes a saturated liquid refrigerant or a two-phase refrigerant having a very low dryness, and becomes a gas-liquid separator 9. Flows into.
A part of the refrigerant exits from the upper part of the gas-liquid separator 9 in a two-phase state or a saturated state, is supercooled by the supercooling heat exchanger 10a, and is further decompressed by the first decompression device 3.
The depressurized low-temperature low-pressure refrigerant flows into the evaporator 6. Next, the refrigerant evaporates in the evaporator 6 and is sucked into the compressor 1 through the four-way switching valve 14 and the accumulator 18. On the other hand, the remaining refrigerant flows out of the lower part of the gas-liquid separator 9 to the first bypass circuit 42 in a liquid state, and a part thereof is depressurized by the third decompression device 15 of the second bypass circuit 43. The supercooling heat exchanger 10a flows as a low-temperature heat source. When the first refrigerant flow control valve 7 is opened by the first control device 38, the remaining portion is decompressed by the second decompression device 16 of the first bypass circuit 42, and
After flowing through the refrigerant flow control valve 7, the supercooling heat exchanger 1
The refrigerant flows through the second bypass circuit 43 from Oa and merges with the refrigerant flowing through the main circuit 41 from the accumulator 18 and is sucked into the compressor 1.

Next, the control will be described. The refrigerant temperature detected by the refrigerant temperature detecting means 71 is compared with a set temperature (for example, 120 ° C., which is near the upper limit of the operating temperature range of the four-way switching valve 14 or the like), and if the detected temperature is higher than the set temperature, The first controller 38 opens the first refrigerant flow control valve 7 and supplies the unevaporated liquid refrigerant to the suction side of the compressor 1 to prevent the refrigerant discharge temperature of the compressor 1 from rising.

The present embodiment is configured as described above. The refrigerant from the bottom of the gas-liquid separator 9 is used as the low-temperature heat source of the supercooling heat exchanger 10a by reducing the pressure in the second bypass circuit 43. Therefore, the refrigerant state at the outlet of the first external heating heat exchanger 2 can be set to a two-phase state or a saturated state. Therefore, even during the hot water supply operation under high-temperature water conditions, the condensing pressure can be kept low, and efficient operation can be performed.

Embodiment 3 of the Invention FIG. 5 is a refrigerant circuit configuration diagram illustrating a heating device according to Embodiment 3 of the present invention,
Parts similar to those of the conventional device are denoted by the same reference numerals. In the figure, the refrigerant circuit includes a compressor 1, a four-way switching valve 14, a first external heating heat exchanger 2, a gas-liquid separator 9, a supercooling heat exchanger 10a, a first decompression device 3, an evaporator. 6. A main circuit 41 in which the accumulators 18 are sequentially connected by refrigerant pipes
A first high-pressure and high-pressure liquid refrigerant stored in the lower part of the gas-liquid separator 9 is depressurized by the second decompression device 16 and guided to the inlet of the compressor 1 through the first refrigerant flow control valve 7. And a bypass circuit 42. In this case, the gas-liquid separator 9
Supercooling heat exchanger 1 for supercooling the refrigerant flowing out from the upper part
Ob is an air-cooled type using air as a low-temperature heat source. Further, the control circuit includes a refrigerant temperature detecting means 71 provided at an outlet pipe of the compressor 1 and a refrigerant temperature detecting means 7.
1 and a first control device 38 that controls the opening and closing of the first refrigerant flow control valve 7 based on the comparison result between the refrigerant temperature detected by Step 1 and the set temperature.

Next, the flow of the refrigerant will be described. The refrigerant that has exited the compressor 1 flows into the first external heating heat exchanger 2 via the four-way switching valve 14, and becomes a saturated liquid refrigerant or a two-phase refrigerant having a very low dryness, and is sent to the gas-liquid separator 9. Inflow. The refrigerant flowing out of the upper part of the machine liquid separator 9 is supplied to the subcooling heat exchanger 10.
After being supercooled by heat exchange with the outside air at b, the pressure is further reduced by the first pressure reducing device 3. The depressurized low-temperature and low-pressure refrigerant flows into the evaporator 6 through the supercooling heat exchanger 10b.
Next, after the refrigerant evaporates in the evaporator 6, the four-way switching valve 14
Then, it is sucked into the compressor 1 through the accumulator 18. On the other hand, the first refrigerant flow control valve 7 is
8, the liquid refrigerant below the gas-liquid separator 9 flows through the first bypass circuit 42 and is decompressed by the second decompression device 16, and further, the accumulator 18
And is sucked into the compressor 1.

Next, the control will be described. The refrigerant temperature detected by the refrigerant temperature detecting means 71 is compared with a set temperature (for example, 120 ° C., which is near the upper limit of the operating temperature range of the four-way switching valve 14 and the like), and if the detected temperature is higher than the set temperature, The first refrigerant flow control valve 7 is opened by the first control device 38, and the unevaporated liquid refrigerant is supplied to the compressor 1 suction side. This prevents the refrigerant temperature on the discharge side of the compressor 1 from rising.

The present embodiment is configured as described above, and since outside air is used as the low-temperature heat source of the supercooling heat exchanger 10b, the configuration for supplying the low-temperature heat source can be simplified. Further, the refrigerant state at the outlet of the first external heating heat exchanger 2 can be set to a two-phase state or a saturated state. Therefore, even during the hot water supply operation under high-temperature water conditions, the condensing pressure can be kept low, and efficient operation can be performed.

Embodiment 4 of the Invention FIG. 6 is a refrigerant circuit configuration diagram illustrating a heating device according to Embodiment 4 of the present invention,
Parts similar to those of the conventional device are denoted by the same reference numerals. In the figure, the refrigerant circuit includes a compressor 1, a four-way switching valve 14, a first external heating heat exchanger 2, a gas-liquid separator 9, a supercooling heat exchanger 10a, a first decompression device 3, an evaporator. 6. The main circuit 41 of the refrigeration cycle in which the accumulators 18 are sequentially connected by refrigerant pipes, and the high-temperature and high-pressure liquid refrigerant stored in the lower part of the gas-liquid separator 9 are decompressed by the second decompression device 16 to be the first. The first guide to the inlet of the compressor 1 through the refrigerant flow control valve 7
And the second bypass circuit 42 of the first bypass circuit 42
A third decompression device 15 is provided between the input side of the decompression device 16 and the output side of the first refrigerant flow control valve 7, and the second decompression device 15 is bypass-connected.
A bypass circuit 43, and a bypass connection between the inlet of the supercooling heat exchanger 10a of the main circuit 41 and the upper part of the gas-liquid separator 9 and a second refrigerant flow regulating valve 35, A high-temperature and high-pressure gas refrigerant is supplied to the gas-liquid separator 9 and the supercooling heat exchanger 10 through the second refrigerant flow regulating valve 35 from above.
and a third bypass circuit 45 that joins the refrigerant pipe of the main circuit 41 between the first and second circuits a.

The control circuit includes a refrigerant pressure detecting means 72 provided at the outlet pipe of the compressor 1 for detecting a refrigerant pressure on the discharge side, a refrigerant temperature detecting means 71 provided at the outlet pipe of the compressor 1, The second refrigerant flow control valve 35 is opened and closed based on the refrigerant pressure detected by the refrigerant pressure detection means 72, and the first refrigerant flow control valve 7 is controlled based on the refrigerant temperature detected by the refrigerant temperature detection means 71. And a second control device 38A that controls the opening and closing of

Next, the flow of the refrigerant will be described. The refrigerant exiting the compressor 1 flows through the four-way switching valve 14 into the first external heating heat exchanger 2 and becomes a saturated liquid refrigerant or a two-phase refrigerant having a very low dryness, and becomes a gas-liquid separator 9. Flows into.
A part of the refrigerant exits from the upper part of the gas-liquid separator 9 in a two-phase state or a saturated state, is supercooled by the supercooling heat exchanger 10a, and is further decompressed by the first decompression device 3.
The depressurized low-temperature low-pressure refrigerant flows into the evaporator 6. Next, the refrigerant evaporates in the evaporator 6 and is sucked into the compressor 1 through the four-way switching valve 14 and the accumulator 18. On the other hand, the remaining refrigerant flows out of the lower part of the gas-liquid separator 9 to the first bypass circuit 42 in a liquid state, and a part thereof is depressurized by the third decompression device 15 of the second bypass circuit 43. The supercooling heat exchanger 10a flows as a low-temperature heat source. When the first refrigerant flow control valve 7 is opened by the second control device 38A, the remaining portion is depressurized by the second decompression device 16 of the first bypass circuit 42 and the first refrigerant flow control is performed. After flowing through the valve 7, the refrigerant flows from the subcooling heat exchanger 10 a and merges with the refrigerant flowing through the second bypass circuit 43, and further merges with the refrigerant flowing through the main circuit 41 from the accumulator 18 to the compressor 1. Inhaled.

Next, the control will be described. The refrigerant temperature detected by the refrigerant temperature detecting means 71 is compared with a preset set temperature (for example, 120 ° C., which is near the upper limit of the operating temperature range of the four-way switching valve 14 or the like), and the detected temperature is higher than the set temperature. In this case, the first refrigerant flow control valve 7 is opened by the second control device 38A, and the unevaporated liquid refrigerant is supplied to the suction side of the compressor 1 so that the refrigerant temperature on the discharge side of the compressor 1 is increased. Prevent rise. Further, the second control device 38A performs the second control in proportion to the difference between the refrigerant pressure detected by the refrigerant pressure detecting means 72 and a preset set pressure.
The degree of opening of the refrigerant flow control valve 35 is increased to facilitate the flow of the refrigerant to the supercooling heat exchanger 10a. Thereby, the condensation pressure of the refrigerant is reduced.

The present embodiment is configured as described above. When the refrigerant pressure detected on the discharge side of the compressor 1 is high, the third bypass circuit 45 is opened to allow the refrigerant on the gas-liquid separator 9 to flow therethrough. Since the refrigerant is guided to the cooling heat exchanger 10a, the refrigerant state at the outlet of the first external heating heat exchanger 2 can be in a two-phase state or a saturated state even when the discharged refrigerant pressure is high. This makes it possible to keep the condensing pressure low even during hot water supply operation under high temperature water conditions,
Efficient operation can be performed.

Embodiment 5 of the Invention FIG. 7 is a configuration diagram of a refrigerant circuit and a water circuit showing a heating device according to Embodiment 5 of the present invention, and portions similar to those of the conventional device are denoted by the same reference numerals. In the figure, the refrigerant circuit includes a compressor 1, a second external heating heat exchanger 2a, a four-way switching valve 14, a first external heating heat exchanger 2, a supercooling heat exchanger 10a, and a first decompression. It is constituted by a main circuit 41 of a refrigeration cycle in which the device 3, the evaporator 6, and the accumulator 18 are sequentially connected by a refrigerant pipe.

On the other hand, the water circuit is a water main circuit 51 which is formed by sequentially connecting the water pump 22 and the heated side of the first external heating heat exchanger 2 with the water flow control valve 23 in an annular manner with a water pipe. The bypass connection is made between the outlet side of the first external heating heat exchanger 2 of the water main circuit 51 and the suction side of the water pump 22 and the heated side of the second external heating heat exchanger 2a and the hot water storage tank 25 are connected. A water auxiliary circuit 52 interposed in the middle, a water auxiliary circuit 53 that connects the hot water storage tank 25 and the water auxiliary circuit 52, and a water supply valve 26.
And a water supply circuit 54 connected to the inlet of the water pump 22 via the supercooling heat exchanger 10a. The water auxiliary circuit 52 is a circuit for further heating a part of the water heated by the first external heating heat exchanger 2 by the second external heating heat exchanger 2a and leading it to the hot water storage tank 25. The water auxiliary circuit 53 is a circuit for guiding hot water from the hot water storage tank 25 to the inlet of the water pump 22.

Here, as the low-temperature heat source of the supercooling heat exchanger 10a, relatively low-temperature water supply before supply to the hot water storage tank 25 is used. Further, the control circuit includes a water temperature detecting means 24 provided on the exit side of the second external heating heat exchanger 2a of the water auxiliary circuit 52 for detecting the water temperature of the part,
And a third control device 38B for controlling the opening of the water flow regulating valve 23 based on a comparison result between the water temperature detected by the control unit 4 and a preset water temperature.

Next, the flow of the refrigerant will be described. The high-temperature and high-pressure gas-phase refrigerant that has exited the compressor 1 is passed through the second external heating heat exchanger 2a to a saturated gas refrigerant or a gas-phase refrigerant having a smaller enthalpy than the gas-phase refrigerant that has exited the compressor 1. Become
It flows into the first external heating heat exchanger 2 via the four-way switching valve 14. The refrigerant condensed in the first external heating heat exchanger 2 exchanges heat with low-temperature feedwater in the supercooling heat exchanger 10a to be in a supercooled state. Next, the refrigerant is depressurized by the first decompression device 3, becomes a low-temperature low-pressure refrigerant, and flows into the evaporator 6.
The refrigerant evaporated by the evaporator 6 returns to the compressor 1 via the four-way switching valve 14 and the accumulator 18.

Next, the flow of water will be described. Water flowing out of the hot water storage tank 25 flows into the first external heating heat exchanger 2 via the water pump 22 of the water main circuit 51 and is heated, and then a part of water flows into the water auxiliary circuit 52. Then, it flows through the second external heating heat exchanger 2a. The remaining water is sucked into the water pump 22 via the water flow control valve 23 of the water main circuit 51. The water heated by the second external heating heat exchanger 2a is guided to the hot water storage tank 25. Further, the supply water is supplied to the hot water storage tank 25 after being heated by the supercooling heat exchanger 10a through the supply water valve 26, and is further sucked into the water pump 22.

Next, the control will be described. If the water temperature at the water outlet pipe of the second external heating heat exchanger 2a detected by the first temperature detecting means 24 is higher than the set water temperature, the third control device 38B controls the water flow control valve 23. When the opening is reduced and the detected water temperature is lower than the set water temperature, the opening of the water flow regulating valve 23 is increased. Thereby, the hot and cold water in the water circuit is maintained at a constant high temperature.

The present embodiment is configured as described above, and the refrigerant is cooled by the first external heating heat exchanger 2 and the second external heating heat exchanger 2a. Since the superheated water is supercooled in the exchanger 10a, the refrigerant at the outlet of the first external heating heat exchanger 2 is in a two-phase state or a saturated state. Therefore, even during the hot water supply operation under high-temperature water conditions, the condensation pressure can be kept low, and efficient operation can be performed. On the other hand, the second
When the water temperature on the exit side of the external heating heat exchanger 2a is low, the amount of water circulation in the water main circuit 51 is increased to increase the amount of heating, and the water main circuit 51 and the water auxiliary circuits 52, 5
3 is preheated by the supercooling heat exchanger 10a, so that a high water supply capacity can be obtained extremely efficiently. The water replenishment circuit 54 is directly connected to the hot water storage tank 25 without passing through the supercooling heat exchanger 10a. A refrigerant, outside air, or the like may be used. Also,
The opening of the water flow regulating valve 23 is set to the first external heating heat exchanger 2.
Alternatively, the same effect can be obtained by providing a refrigerant pressure detecting means in the refrigerant outlet pipe or the refrigerant inlet pipe of the second external heating heat exchanger 2a and controlling the pressure by the detected pressure of the pressure detecting means.

Embodiment 6 of the Invention FIG. 8 is a refrigerant circuit configuration diagram illustrating a heating device according to Embodiment 6 of the present invention,
Parts similar to those of the conventional device are denoted by the same reference numerals. In the figure, the refrigerant circuit includes a compressor 1, a four-way switching valve 14, a first heat exchanger for external heating 2, a gas-liquid separator 9, an air-cooled supercooling heat exchanger 10b, and a first pressure reducing device 3. , The evaporator 6 and the accumulator 18 are connected in order by a refrigerant pipe, and the high-temperature and high-pressure liquid refrigerant stored in the lower part of the gas-liquid separator 9 is depressurized by the second decompression device 16 to the first. A first bypass circuit 42 leading to the inlet of the compressor 1 via the refrigerant flow control valve 7 and a bypass connection between the inlet side and the outlet side of the first pressure reducing device 3 of the main circuit 41 are provided. It comprises a refrigerant flow regulating valve 13, a liquid reservoir 12, and a fourth bypass circuit 44 having a fourth pressure reducing device 17 (made of a capillary tube).

The control circuit is provided at the outlet pipe of the compressor 1 and detects the refrigerant pressure at the discharge side, and the control circuit is provided at the outlet pipe of the compressor 1 and detects the refrigerant temperature at the discharge side. The third refrigerant flow control valve 13 is opened and closed according to the comparison result between the refrigerant pressure detected by the refrigerant temperature detecting means 71 and the preset pressure and the refrigerant temperature detecting means. A fourth control for opening and closing the first refrigerant flow regulating valve 7 in accordance with a result of comparison between the refrigerant temperature detected by the controller 71 and a preset temperature.
And a control device 38C.

Next, the flow of the refrigerant will be described. The refrigerant that has exited the compressor 1 flows into the first external heating heat exchanger 2 via the four-way switching valve 14 and becomes a saturated liquid refrigerant or a two-phase refrigerant having a very low dryness. Inflow.
The refrigerant flowing out of the upper part of the gas-liquid separator 9 is supplied to the subcooling heat exchanger 1.
0b, superheated by exchanging heat with the outside air,
The pressure is reduced by the pressure reducing device 3. The depressurized low-temperature low-pressure refrigerant flows into the evaporator 6. Next, the refrigerant evaporates in the evaporator 6 and is sucked into the compressor 1 through the four-way switching valve 14 and the accumulator 18. On the other hand, when the first refrigerant flow control valve 7 is opened by the fourth control device 38C, the liquid refrigerant from the lower portion of the gas-liquid separator 9 is supplied to the second pressure reducing device 16 of the first bypass circuit 42. , And is combined with the refrigerant from the accumulator 18 and sucked into the compressor 1. On the other hand, when the third refrigerant flow control valve 13 is opened by the fourth control device 38C, a part of the refrigerant that has been supercooled by the supercooling heat exchanger 10b passes through the fourth bypass. The refrigerant flows into the liquid reservoir 12 via the third refrigerant flow control valve 13 of the circuit 44, and further passes through the fourth pressure reducing device 17 and joins the refrigerant flowing through the main circuit 41 at the inlet of the evaporator 6. At this time, the refrigerant is temporarily stored in the liquid reservoir 12.

Next, the control will be described. The refrigerant temperature detected by the refrigerant temperature detecting means 71 is compared with a set temperature (for example, 120 ° C., which is near the upper limit of the operating temperature range of the four-way switching valve 14 or the like), and if the detected temperature is higher than the set temperature, The first refrigerant flow control valve 7 is opened by the control device 38C of the compressor 4, and the unevaporated liquid refrigerant is removed from the compressor 1
To prevent the refrigerant discharge temperature of the compressor 1 from rising. Further, the refrigerant pressure detected by the refrigerant pressure detecting means 72 is equal to the set pressure (for example, 28 kg / cm, which is a pressure that does not significantly shorten the life of the compressor 1).
^{When the} pressure is larger than ² G), the fourth controller 38C opens the third refrigerant flow regulating valve 13 so that the refrigerant is stored in the liquid reservoir 12 and flows through the main circuit 41. And prevent the condensation pressure from rising.

The present embodiment is configured as described above. When the refrigerant pressure on the discharge side of the compressor 1 is high, the fourth bypass circuit 44 is opened, and the refrigerant from the supercooling heat exchanger 10b is discharged to the first Is temporarily stored in the liquid reservoir 12 by bypassing the decompression device 3, so that the refrigerant state at the outlet of the first external heating heat exchanger 2 is set to a two-phase state or a saturated state even when the discharge refrigerant pressure is high. can do. Therefore, even during the hot water supply operation under high-temperature water conditions, the condensing pressure can be kept low, and efficient operation can be performed.

Embodiment 7 of the Invention FIG. 9 is a configuration diagram of a refrigerant circuit according to Embodiment 7 of the present invention, and the same parts as those of the conventional device are denoted by the same reference numerals. In the figure, the refrigerant circuit
Compressor 1, four-way switching valve 14, first heat exchanger for external heating 2, gas-liquid separator 9, plate heat exchanger 10c as heat exchanger for supercooling, first decompressor 3, third Check valve 3
3, a main circuit 41 of the refrigeration cycle in which the evaporator 6 and the accumulator 18 are sequentially connected by a refrigerant pipe, and a second circuit connected by bypass between the evaporator 6 outlet side of the main circuit 41 and the bottom of the gas-liquid separator 9. A first bypass circuit 42 having a pressure reducing device 16 and a first refrigerant flow control valve 7, and a portion between the inlet side of the second pressure reducing device 16 and the output side of the first refrigerant flow control valve 7 of the first bypass circuit 42. Is connected by bypass with a third decompression device 15, the pressure of the liquid refrigerant from the lower part of the gas-liquid separator 10 is reduced by the third decompression device 15, and the evaporator 6 exits via the plate heat exchanger 10 c. Leading second bypass circuit 43
Is connected by bypass between the inlet of the evaporator 6 of the main circuit 41 and the outlet of the first external heating heat exchanger 2 so that the refrigerant flowing direction is the first direction.
And a fifth bypass circuit 47 having a first check valve 32 and a fifth pressure reducing device 34 (made of a capillary tube) disposed toward the heat exchanger 2 for external heating, and a plate-type heat exchanger 10c. It is a vertical lower device. Main circuit 41
Is bypass-connected between both the exit side of the plate heat exchanger 10c and the entrance side of the plate heat exchanger 10c of the second bypass circuit 43 and the exit side of the first external heating heat exchanger 2 of the main circuit 41. The refrigerant flowing direction is the first external heating heat exchanger 2
And a sixth bypass circuit 46 having a second check valve 31 disposed toward the second valve.

The sixth bypass circuit 46 joins the refrigerant from the two refrigerant pipes connected to the lower portion of the plate heat exchanger 10c, and then joins the first through the second check valve 31 to the first check valve 31. It joins with the main circuit 41 between the heat exchanger for external heating 2 and the gas-liquid separator 9. Here, in particular, a plate heat exchanger 10c is used as the supercooling heat exchanger. The four-way switching valve 14 is provided between the discharge side of the compressor 1 and the first external heating heat exchanger 2 and the evaporator 6.
And the suction side of the compressor 1 is arranged to reverse the refrigerant flow path of the main circuit 41. And the main circuit 41
A third check valve 33 is disposed on the outlet side of the first pressure reducing device 3 with the refrigerant flowing direction directed to the evaporator 6.

Further, the control circuit is provided with a refrigerant temperature detecting means 71 provided at the outlet pipe of the compressor 1 and a control circuit for controlling the refrigerant temperature detected by the refrigerant temperature detecting means 71 in accordance with a result of comparison between the refrigerant temperature and a preset temperature. And a first control device 38 for controlling the opening and closing of the first refrigerant flow control valve 7.

Next, the flow of the refrigerant will be described. During the hot water supply operation, the refrigerant flowing out of the compressor 1 is supplied to the four-way switching valve 14.
Through the first heat exchanger 2 for external heating, and flows into the gas-liquid separator 9 as a saturated liquid refrigerant or a two-phase refrigerant having a very low dryness. A part of the refrigerant exits from the upper part of the gas-liquid separator 9 in a two-phase state or a saturated state, is supercooled by the plate heat exchanger 10c, and is further decompressed by the first decompression device 3. The depressurized low-temperature low-pressure refrigerant flows into the evaporator 6 via the third check valve 33. Then
The refrigerant evaporates in the evaporator 6 and is sucked into the compressor 1 via the four-way switching valve 14 and the accumulator 18. on the other hand,
The remaining refrigerant flows out of the lower part of the gas-liquid separator 9 in a liquid state, and a part of the refrigerant is decompressed by the third decompression device 15 of the second bypass circuit 43, and then the plate heat exchanger 10c is used as a low temperature heat source. Distribute. When the first refrigerant flow control valve 7 is opened by the first control device 38, the remaining portion is depressurized by the second decompression device 16 of the first bypass circuit 42 and the first refrigerant flow control is performed. After flowing through the valve 7, the refrigerant flows from the plate heat exchanger 10 c and merges with the refrigerant flowing through the second bypass circuit 43, and further merges with the refrigerant flowing through the main circuit 41 from the accumulator 18 and is sucked into the compressor 1. Is done.

On the other hand, during the defrost operation, the four-way switching valve 14
, The refrigerant flow direction is reversed. That is,
The refrigerant discharged from the compressor 1 flows into the evaporator 6 through the four-way switching valve 14, and is condensed by the evaporator 6 to perform defrost.
The condensed refrigerant is reduced in pressure by the fifth pressure reducing device 34 of the fifth bypass circuit 47, flows into the first external heating heat exchanger 2 via the check valve 32, and evaporates. Next, the refrigerant is sucked into the compressor 1 through the four-way switching valve 14 and the accumulator 18. In addition, the refrigerant that has accumulated in the lower portion of the plate heat exchanger 10c is recovered to the main circuit 41 via the check valve 31 during the defrost operation, so that there is no problem of refrigerant depletion.

Next, the control will be described. The refrigerant temperature detected by the refrigerant temperature detecting means 71 is compared with a set temperature (for example, 120 ° C., which is near the upper limit of the operating temperature range of the four-way switching valve 14 or the like), and if the detected temperature is higher than the set temperature, The first controller 38 opens the first refrigerant flow regulating valve 7 to supply the unevaporated liquid refrigerant to the suction side of the compressor 1, thereby preventing the refrigerant temperature on the discharge side of the compressor 1 from rising. .

The present embodiment is configured as described above. In the defrost operation, the liquid refrigerant stored in the lower part of the plate heat exchanger 10c is passed through the fifth bypass circuit 47 and the sixth bypass circuit 46. Since it is recovered to the main circuit 41 side, the defrost capacity is not reduced. Further, the refrigerant state at the outlet of the first external heating heat exchanger 2 also becomes a two-phase state or a saturated state,
Even during a hot water supply operation under high-temperature water conditions, the condensation pressure can be kept low, and efficient operation can be performed.

[0055]

As described above, the heating device using the refrigeration cycle according to the first invention is configured so that the refrigerant is supercooled by the low-temperature heat source by the supercooling heat exchanger, When the refrigerant temperature on the machine discharge side is high, the first bypass circuit is opened to bypass the liquid refrigerant at the bottom of the gas-liquid separator and supply unevaporated refrigerant to the compressor suction side. Even in a hot water supply operation under high-temperature water conditions, an efficient operation in which the refrigerant condensing pressure in the first external heating heat exchanger and the refrigerant temperature on the compressor discharge side can be suppressed can be performed. The range can be expanded.

In the second invention, the refrigerant from the bottom of the gas-liquid separator is decompressed and used in the second bypass circuit as the low-temperature heat source of the supercooling heat exchanger. Both the supercooling operation and the low-dryness refrigerant feeding operation in the heat exchanger can be performed. Therefore, the operation efficiency is good, and the use-side temperature range such as high-temperature hot water or high-temperature blowing can be expanded.

In the third invention, since air (outside air) is used as the low-temperature heat source of the supercooling heat exchanger, the structure for supplying the low-temperature heat source is simple, and the refrigerant is supercooled by air cooling. Thus, the use-side temperature range can be expanded.

Further, in the fourth aspect of the present invention, when the refrigerant pressure on the compressor discharge side is high, the third bypass circuit is opened so that the refrigerant above the gas-liquid separator can be easily guided to the supercooling heat exchanger. Therefore, even when the refrigerant pressure on the compressor discharge side is high, the use-side temperature range can be expanded.

In the fifth aspect of the present invention, when the water temperature on the outlet side of the second external heating heat exchanger is low, the amount of circulation of the water main circuit is increased to increase the amount of heating. Since the water supply to the main circuit and the water auxiliary circuit is preheated by the supercooling heat exchanger, a high oil supply capacity can be obtained very efficiently. On the other hand, the refrigerant is cooled in the first heat exchanger for external heating and the second heat exchanger for external heating, and the refrigerant is supercooled by the water supply in the supercooling heat exchanger. It is also possible to perform a suppressed refrigeration cycle operation.
That is, the use-side temperature range can be expanded.

In the sixth aspect of the present invention, when the refrigerant pressure on the compressor discharge side is high, the fourth bypass circuit is opened to allow the refrigerant from the supercooling heat exchanger to bypass the first decompression device and to supply the refrigerant. Since the refrigerant is temporarily stored in the reservoir, the use-side temperature range can be expanded even when the evaporation pressure of the refrigerant is high.

Further, when a plate heat exchanger is used as the subcooling heat exchanger, the liquid refrigerant is stored in the lower part of the plate heat exchanger during the heating operation. Since the refrigerant is recovered to the main circuit side through the fifth bypass circuit and the sixth bypass circuit during the defrost operation, the defrost capacity is not reduced, and the use-side temperature range is also expanded. You can do it.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit configuration diagram showing a heating device using a refrigeration cycle according to Embodiment 1 of the present invention.

FIG. 2 shows an example of a gas-liquid separator used in the present invention, wherein (a) is a plan view and (b) is a perspective view.

FIG. 3 is a perspective view showing another example of the gas-liquid separator used in the present invention.

FIG. 4 is a refrigerant circuit configuration diagram showing a heating device using a refrigeration cycle according to Embodiment 2 of the present invention.

FIG. 5 is a refrigerant circuit configuration diagram showing a heating device using a refrigeration cycle according to Embodiment 3 of the present invention.

FIG. 6 is a refrigerant circuit configuration diagram showing a heating device using a refrigeration cycle according to Embodiment 4 of the present invention.

FIG. 7 is a configuration diagram of a refrigerant circuit and a water circuit showing a heating device using a refrigeration cycle according to Embodiment 5 of the present invention.

FIG. 8 is a refrigerant circuit configuration diagram showing a heating device using a refrigeration cycle according to Embodiment 6 of the present invention.

FIG. 9 is a refrigerant circuit configuration diagram illustrating a heating device using a refrigeration cycle according to Embodiment 7 of the present invention.

FIG. 10 is a refrigerant circuit configuration diagram showing a heating device using a conventional refrigeration cycle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Compressor, 2 1st heat exchanger for external heating, 2a 2nd heat exchanger for external heating, 3 First decompression device, 6 Evaporator, 7 First refrigerant flow control valve, 9 Gas-liquid separation Bowl, 9
a gas-liquid separator, 10a supercooling heat exchanger, 10b
Subcooling heat exchanger, 10c Plate heat exchanger, 12
Liquid reservoir, 13 third refrigerant flow control valve, 14 four-way switching valve, 15 third pressure reducing device, 16 second pressure reducing device, 1
7 Fourth decompression device, 22 water pump, 23 water flow regulating valve, 24 water temperature detecting means, 25 hot water storage tank, 31 second rotator valve, 32 first rotator valve, 33 third rotator valve, 34 fifth Pressure reducing device, 35 second refrigerant flow regulating valve, 38 first control device, 38A second control device,
38B third control device, 38C fourth control device, 4
1 main circuit, 42 first bypass circuit, 43 second bypass circuit, 44 fourth bypass circuit, 45 third bypass circuit, 46 sixth bypass circuit, 47 fifth bypass circuit
Bypass circuit, 51 water main circuit, 52 water auxiliary circuit,
53 water auxiliary circuit, 54 water supply circuit, 71 refrigerant temperature detecting means, 72 refrigerant pressure detecting means.

Claims (7)

[Claims] 1. A main circuit of a refrigeration cycle comprising a compressor, a first heat exchanger for external heating, a gas-liquid separator, a first decompression device, and an evaporator, which are sequentially connected in a ring by a refrigerant pipe; A subcooling heat exchanger that is provided between the gas-liquid separator and the first decompression device in the main circuit and supercools a refrigerant from the gas-liquid separator by heat exchange with a low-temperature heat source; A first bypass circuit, which is bypass-connected between the evaporator outlet side and the bottom of the gas-liquid separator and has a second decompression device and a first refrigerant flow regulating valve, and a refrigerant temperature on the compressor discharge side. And a first controller that controls the opening and closing of the first refrigerant flow regulating valve based on the refrigerant temperature on the compressor discharge side detected by the refrigerant temperature detecting unit. A heating device using a refrigeration cycle. 2. A subcooling heat exchanger having a third pressure reducing device between a second pressure reducing device inlet side of the first bypass circuit and a first refrigerant flow regulating valve outlet side. The heating device using a refrigeration cycle according to claim 1, further comprising a second bypass circuit for circulating a refrigerant from the bottom of the gas-liquid separator for the low-temperature heat source. 3. The heating device using a refrigeration cycle according to claim 1, wherein air is used as a low-temperature heat source of the subcooling heat exchanger. A third bypass circuit having a main circuit bypass-connected to the supercooling heat exchanger between the inlet side and the upper portion of the gas-liquid separator and having a second refrigerant flow control valve; A refrigerant pressure detecting means for detecting pressure; and a second control device for controlling the opening and closing of the second refrigerant flow regulating valve based on the refrigerant pressure on the compressor discharge side detected by the refrigerant pressure detecting means. A heating device using the refrigeration cycle according to claim 2 or 3. 5. A main circuit of a refrigeration cycle in which a compressor, a first heat exchanger for external heating, a gas-liquid separator, a first decompression device, and an evaporator are sequentially connected in a ring shape by a refrigerant pipe; The first circuit is interposed between the first external heating heat exchanger of the main circuit and the first decompression device and exchanges heat with a low-temperature heat source.
A supercooling heat exchanger for supercooling the refrigerant from the external heating heat exchanger, and a second external heat exchanger provided between the compressor and the first external heating heat exchanger in the main circuit. A water main circuit in which a heating heat exchanger, a water pump, a heated side of the first external heating heat exchanger, and a water flow control valve are sequentially connected in a ring by a water pipe; The first external heating heat exchanger is bypass-connected between the outlet side and the water pump suction side, and the heated side and the hot water storage tank of the second external heating heat exchanger are interposed in the middle. A water auxiliary circuit for further heating a part of the water heated by the first external heating heat exchanger by the second external heating heat exchanger; and a second external heating of the water auxiliary circuit. Water temperature detection means for detecting the water temperature of the heat exchanger outlet side, as a low-temperature heat source of the supercooling heat exchanger A third control that uses the water supply before the supply to the hot water storage tank and controls the opening and closing of the water flow control valve based on the water temperature at the outlet side of the second external heating heat exchanger detected by the water temperature detection means. A heating device using a refrigeration cycle, comprising a device. 6. A fourth bypass circuit, which is bypass-connected between the first pressure reducing device inlet side and the outlet side of the main circuit and has a third refrigerant flow regulating valve, a liquid reservoir, and a fourth pressure reducing device. A refrigerant pressure detecting means for detecting a refrigerant pressure on the compressor discharge side,
4. A control device for controlling the opening and closing of said third refrigerant flow regulating valve based on refrigerant pressure on the compressor discharge side detected by said refrigerant pressure detecting means. Item 6. A heating device using the refrigeration cycle according to any one of Items 5 to 5. 7. A main circuit of a refrigeration cycle in which a compressor, a first heat exchanger for external heating, a gas-liquid separator, a first decompression device, and an evaporator are sequentially connected in a ring by a refrigerant pipe; A supercooling heat exchanger provided between the gas-liquid separator of the main circuit and the first decompressor to supercool a refrigerant from the gas-liquid separator by heat exchange with a low-temperature heat source; A four-way switching valve disposed between a discharge side and the first external heating heat exchanger and between the evaporator and the compressor suction side for inverting a refrigerant flow path of the main circuit; The bypass connection is made between the outlet side of the evaporator and the bottom of the gas-liquid separator.
A first bypass circuit having a pressure reducing device and a first refrigerant flow control valve; and a first bypass circuit between the second pressure reducing device inlet side and the first refrigerant flow control valve outlet side of the first bypass circuit. A bypass circuit having a decompression device of No. 3, and a second bypass circuit for flowing a refrigerant from the bottom of the gas-liquid separator for a low-temperature heat source of the supercooling heat exchanger, A plate type heat exchanger is used as the exchanger, and a bypass is connected between the evaporator inlet side of the main circuit and the first external heating heat exchanger outlet side to change the refrigerant flowing direction to the first external heating. A fifth bypass circuit having a first check valve and a fifth pressure reducing device arranged toward a heat exchanger for use in the main heat exchanger, and a fifth lower circuit arranged vertically below the plate heat exchanger. Plate heat exchanger outlet or said second A bypass is connected between the plate-type heat exchanger inlet side of the main circuit and the first external heating heat exchanger outlet side of the main circuit, and the refrigerant flowing direction is directed toward the first external heating heat exchanger. A sixth bypass circuit having a second check valve arranged in a vertical direction, and a third check arranged in a direction in which the refrigerant flows toward the evaporator on the outlet side of the first pressure reducing device of the main circuit. A heating device using a refrigeration cycle, comprising a valve.