JP2011214750A - Heat pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a first refrigerating circuit generating hot water for hot water supply and/or floor heating and a second refrigerating circuit for indoor air conditioning, and enable switching between a single stage cycle and an injection cycle in accordance with outside air temperature.SOLUTION: A portion of refrigerant piping within a refrigerant circulation system of the second refrigerating circuit 20 for indoor air conditioning is used for a heat source, and is inserted to inside of a heat exchanger 17 between refrigerants of the first refrigerating circuit 10 generating hot water for hot water supply and floor heating. When outside air temperature is high, heat source supply from the second refrigerating circuit 20 to the heat exchanger 17 between refrigerants is stopped, and each refrigerating circuit 10, 20 is operated independently. When outside air temperature is low, the heat source is supplied from the second refrigerating circuit 20 to the heat exchanger 17 between refrigerants, and the injection cycle operation of the first refrigerating circuit 10 is performed.

Description

  The present invention relates to a heat pump device, and more specifically, relates to a heat pump device for low outside air having a first refrigeration circuit that generates hot water for hot water supply and / or floor heating and a second refrigeration circuit for indoor air conditioning. Is.

  For example, Patent Document 1 discloses an inter-refrigerant heat exchanger in a heat pump system-type heating device using a refrigerant, wherein the refrigerant after passing through the water-refrigerant heat exchanger and the refrigerant injected into the intermediate compression stage of the compressor. There is described an invention in which high-temperature hot water can be obtained while preventing an increase in the discharge temperature of the compressor by exchanging heat with the (internal heat exchanger).

  Since the above invention is an apparatus intended for heating operation, the temperature of the water flowing into the water-refrigerant heat exchanger, that is, the return temperature of the heating is relatively high. Therefore, when the refrigerant is injected at a geometric mean pressure √ (Pe · Pc) (hereinafter referred to as “intermediate pressure”) of the evaporation pressure Pe and the condensation pressure Pc at a low outside air temperature, the return temperature of water is high. The refrigerant inlet temperature of the intermediate heat exchanger is greater than the injection refrigerant temperature, and heat can be recovered.

  However, when using low-temperature water stored at the bottom of the tank, such as hot water storage hot water and floor heating, the refrigerant temperature after passing through the condenser is close to the injection refrigerant temperature unless some measures are taken. Since it becomes temperature, even if it installs the heat exchanger between refrigerant | coolants, there exists a problem that the heat recovery to the injection refrigerant | coolant side cannot be performed.

JP 2006-112708 A

  Accordingly, an object of the present invention is to provide a first refrigeration circuit that generates hot water for hot water supply and / or floor heating and a second refrigeration circuit for indoor air conditioning, and a single-stage cycle and an injection cycle according to the outside air temperature. Even if the water inlet temperature of the water-refrigerant heat exchanger is low, as in the hot water supply system using a hot water storage tank, heat recovery to the injection refrigerant side in the inter-refrigerant heat exchanger is possible. An object of the present invention is to provide a heat pump device that can be used.

  In order to solve the above-described problem, the present invention provides a heat pump apparatus having a first refrigeration circuit for generating hot water and a second refrigeration circuit for indoor air conditioning, wherein the first refrigeration circuit has a first compression having an injection port. A hot water generating water-refrigerant heat exchanger connected to the refrigerant discharge side of the first compressor, and a branch pipe branched from the refrigerant outflow side of the water-refrigerant heat exchanger to the injection port A refrigerant heat exchanger provided; a first expansion valve connected between the water-refrigerant heat exchanger and the refrigerant heat exchanger; a refrigerant outflow side of the water-refrigerant heat exchanger; A first outdoor heat exchanger connected to the refrigerant suction side of the first compressor, and a second expansion valve provided between the branch point of the branch pipe and the first outdoor heat exchanger. The second refrigeration circuit includes a second compressor and an indoor heat exchanger A refrigerant circulation system including a second outdoor heat exchanger and a third expansion valve connected between the indoor heat exchanger and the second outdoor heat exchanger, and the second refrigeration circuit A part of the refrigerant pipe in the refrigerant circulation system is inserted into the inter-refrigerant heat exchanger, and heat exchange is performed between the refrigerant injected into the first compressor and the refrigerant in the second refrigeration circuit. It is a feature.

  In order to enable switching from a single-stage cycle to an injection cycle according to the outside air temperature, or vice versa, assuming that the flow direction of the refrigerant in the refrigerant circulation system is during heating air conditioning, the refrigerant circulation system includes: From the refrigerant discharge side of the second compressor to the inter-refrigerant heat exchanger, drawn from the inter-refrigerant heat exchanger, a first pipe having a first on-off valve on the upstream side and a second on-off valve on the downstream side. A second pipe that reaches the second outdoor heat exchanger via the third expansion valve; and a third pipe that is bypassed to the first pipe and includes the indoor heat exchanger and a third on-off valve. The first and second expansion valves and the first to third on-off valves are controlled in accordance with the operation mode.

  According to a preferred aspect of the present invention, a fourth pipe having a fourth on-off valve for connecting a pipe portion between the confluence of the third pipe and the second on-off valve in the first pipe to the second pipe. And a control means for controlling the operation mode. The control means closes both the flow rate adjustment valve and the first and second on-off valves, and opens the third and fourth on-off valves. By controlling the first to third expansion valves to a predetermined opening degree, the first and second refrigeration circuits are independently operated.

  On the other hand, the first and second on-off valves are opened and the third and fourth on-off valves are closed by the control means, and the flow rate adjusting valve and the first to third expansion valves are opened to a predetermined degree. With this control, heat exchange is performed in the inter-refrigerant heat exchanger without performing indoor air conditioning by the second refrigeration circuit, and the first refrigeration circuit operates in an operation mode based on an injection cycle. It will be.

  The control means opens the second and third on-off valves, closes the first and fourth on-off valves, and controls the flow rate adjusting valve and the first to third expansion valves to a predetermined opening degree. Thus, indoor air conditioning is performed by the second refrigeration circuit, heat exchange is performed by the inter-refrigerant heat exchanger, and the first refrigeration circuit operates in an operation mode based on an injection cycle.

  According to the present invention, a part of the refrigerant pipe in the refrigerant circulation system of the second refrigeration circuit for indoor air conditioning is inserted into the inter-refrigerant heat exchanger of the first refrigeration circuit that generates hot water for hot water supply or floor heating. Since the heat exchange between the refrigerant injected into the first compressor of the first refrigeration circuit and the refrigerant of the second refrigeration circuit is possible, the first refrigeration is performed using two refrigeration circuits at a low outside temperature. The circuit is operated in the operation mode by the injection cycle, and at the time of high outside air temperature, the first refrigeration circuit and the second refrigeration circuit can be separated and operated individually, and it is not necessary to always operate the two refrigeration circuits simultaneously, An efficient heat pump device is provided.

The refrigerant circuit figure which shows the heat pump apparatus which concerns on embodiment of this invention.

  Next, an embodiment of the present invention will be described with reference to FIG. 1, but the present invention is not limited to this.

  Referring to FIG. 1, the heat pump device according to this embodiment has, as a basic configuration, a first refrigeration circuit 10 for generating hot water, a second refrigeration circuit 20 for indoor air conditioning, and hot water supply and floor heating. And a hot water storage tank 30.

  The first refrigeration circuit 10 includes, for example, a two-stage compression type first compressor 11 having an injection port 11a, a water-refrigerant heat exchanger 12 connected to the refrigerant discharge side of the first compressor 11, and a water-refrigerant. The first expansion valve 13 and the second expansion valve 14 connected in series to the refrigerant outflow side of the heat exchanger 12, and between the refrigerant outflow side of the second expansion valve 14 and the refrigerant intake side of the first compressor 11. And a first outdoor heat exchanger 15 connected thereto.

  In the refrigerant main piping system of the first refrigeration circuit 10, a branch pipe 18 is branched from between the first expansion valve 13 and the second expansion valve 14 to the injection port 11 a, and the flow rate adjusting valve 16 is placed in the branch pipe 18. And an inter-refrigerant heat exchanger 17 are provided. The branch pipe 18 is connected to the injection port 11a via a check valve 19.

  The second refrigeration circuit 20 includes a second compressor 21, a four-way valve 22, an indoor heat exchanger 23, a second outdoor heat exchanger 24, an indoor heat exchanger 23, and a second outdoor heat exchanger 24. A refrigerant circulation system including a third expansion valve 25 connected therebetween is provided.

  When the four-way valve 22 is in the illustrated solid line state, the refrigerant flow direction in the refrigerant circulation system is during heating air conditioning, and the refrigerant circulation system of the second refrigeration circuit 20 is connected to the refrigerant discharge side of the second compressor 21. A first pipe 26 leading to the inter-refrigerant heat exchanger 17, a second pipe 27 drawn from the inter-refrigerant heat exchanger 17 and reaching the second outdoor heat exchanger 24 via the third expansion valve 25, and an indoor heat exchanger Between the first pipe 26 on the refrigerant inflow side and the second pipe 27 on the refrigerant outflow side with respect to the inter-refrigerant heat exchanger 17. A fourth pipe 29 to be connected is included.

  The first pipe 26 is provided with a first on-off valve 26a on the upstream side (second compressor 21 side), and a second on-off valve 26b on the downstream side (inter-refrigerant heat exchanger 17 side).

  The third pipe 28 is provided with a third on-off valve 28 a, and the third pipe 28 is connected between the upstream side and the downstream side of the first on-off valve 26 a in the first pipe 26. The joining point of the first pipe 26 and the third pipe 28 is 28b, and the second on-off valve 26b of the first pipe 26 is disposed between the joining point 28b and the inter-refrigerant heat exchanger 17.

  The fourth pipe 29 connects a pipe portion between the junction 28b of the third pipe 28 and the second on-off valve 26b in the first pipe 26 to the second pipe 27. A fourth on-off valve 29a is provided.

  The hot water storage tank 30 has a water circulation circuit 31 including a first pump 31 a that circulates water at the bottom of the tank to the upper part of the tank and a part of which is passed through the water-refrigerant heat exchanger 12.

  The hot water storage tank 30 is provided with a hot water circulation circuit 33 including a second pump 33a that is inserted into the tank and circulates hot water through the indoor floor heating panel 32.

  A water supply pipe 34 a is connected to the lower part of the hot water storage tank 30, and a hot water tap 35 is connected to the upper part of the hot water storage tank 30. Hot water from the hot water tap 35 is mixed with water whose flow rate is adjusted by the water tap 36 from the water pipe 34 b and supplied to the hot water from the third pump 37.

  The heat pump device includes a control unit 40 that controls an operation mode and the like. The control means 40 is composed of a CPU (Central Processing Unit), a micro computer, etc., and according to the outside air temperature or the discharge temperature of the first compressor 11, the flow rate adjusting valve 16 in the first refrigeration circuit 10, the first one. 1, the second expansion valves 13 and 14, the third expansion valve 25 in the second refrigeration circuit 20, the first to fourth on-off valves 26a, 26b, 28a, 29a and the like are controlled.

  Next, each operation mode will be described. The control means 40 basically performs the first refrigeration when the outside air temperature (Td) is a high outside air temperature (for example, Td> −2 ° C.) and when the outside air temperature (for example, Td ≦ −2 ° C.). It is selected whether the circuit 10 and the second refrigeration circuit 20 are independently operated or combined operation.

[At high outside temperature]
First, at a high outside air temperature, the flow rate adjustment valve 16 of the inter-refrigerant heat exchanger 17 is “fully closed”, the first on-off valve 26a and the second on-off valve 26b are both “closed”, the third on-off valve 28a and the fourth on-off valve. Both valves 29a are set to “open”.

  In the first refrigeration circuit 10, the low-temperature and low-pressure gas refrigerant is compressed to a predetermined pressure by the first compressor 11, and then stored in the lower part of the storage tank 30 by the water-refrigerant heat exchanger 12. Exchange and condense. Thereafter, the refrigerant passes through the first expansion valve 13 and the second expansion valve 14, expands to the evaporation pressure, evaporates by exchanging heat with the outside air in the first outdoor heat exchanger 15, and then the first compressor. 11 is returned. Thereby, warm water is stored in the hot water storage tank 30, and the warm water is used for hot water supply or floor heating.

  On the second refrigeration circuit 20 side, if it is heating air conditioning, the four-way valve 22 is switched to the state shown in the figure, and the low-temperature and low-pressure gas refrigerant is compressed to a predetermined pressure by the second compressor 21, and then It passes through the valve 22 and the third on-off valve 28a, and is condensed by exchanging heat with indoor air in the indoor heat exchanger 23. Thereafter, the refrigerant passes through the third on-off valve 29a to reach the third expansion valve 25, expands to the evaporation pressure at the third expansion valve 25, and then exchanges heat with the outside air at the second outdoor heat exchanger 24. It evaporates and returns to the second compressor 21 through the four-way valve 22.

  In the case of cooling air conditioning, the four-way valve 22 is switched to the state shown in the chain line, and the low-temperature and low-pressure gas refrigerant is compressed to a predetermined pressure by the second compressor 21, and then passes through the four-way valve 22. The second outdoor heat exchanger 24 condenses by exchanging heat with the outside air. Thereafter, the refrigerant expands to the evaporation pressure by the third expansion valve 25, then reaches the indoor heat exchanger 23 through the fourth on-off valve 29 a, evaporates by exchanging heat with the room air, and passes through the four-way valve 22 to evaporate. 2 Returned to the compressor 21.

  Thus, since the first refrigeration circuit 10 and the second refrigeration circuit 20 are independently operated at a high outside air temperature, the user can select one of hot water supply, floor heating, heating air conditioning, and cooling air conditioning. One or a combination thereof (“hot water + heating air conditioning”, “hot water + cooling air conditioning”, “floor heating + heating air conditioning”, “hot water + floor heating + heating air conditioning”, “hot water + floor heating”) can be selected it can.

[When indoor air conditioning is not required at low outside temperatures]
When indoor air conditioning (heating air conditioning) is unnecessary at low outside air temperature, both the first on-off valve 26a and the second on-off valve 26b are “open”, and the third on-off valve 28a and the fourth on-off valve 29a are Both are closed and the valve opening degree of the flow rate adjustment valve 16 and the first to third expansion valves 13, 14, 25 of the inter-refrigerant heat exchanger 17 are controlled to a predetermined opening degree, and the inter-refrigerant heat exchanger 17 is controlled. The refrigerant of the second refrigeration circuit 20 is supplied to the first refrigeration circuit 10 in an injection cycle.

  That is, a part of the refrigerant expanded to the intermediate pressure by the first expansion valve 13 exchanges heat with the refrigerant on the high-pressure side of the second refrigeration circuit 20 by the refrigerant heat exchanger 17, and then the intermediate pressure by the first compressor 11. It merges with the compressed refrigerant. The combined refrigerant is further compressed to a predetermined pressure, and is condensed by exchanging heat with water stored in the lower part of the hot water storage tank 30 by the water-refrigerant heat exchanger 12.

  The refrigerant expanded to the intermediate pressure by the first expansion valve 13 of the first refrigeration circuit 10 is divided into the refrigerant injected into the intermediate stage of the first compressor 11 and the refrigerant flowing into the second expansion valve 14. As described above, the refrigerant injected into the intermediate stage of the first compressor 11 is heat-exchanged with the heat source refrigerant of the second refrigeration circuit 20 in the inter-refrigerant heat exchanger 17, but flows into the second expansion valve 14. The refrigerant further expands to a predetermined evaporation pressure, evaporates by exchanging heat with the outside air in the first outdoor heat exchanger 15, and then returned to the first compressor 11.

  In the other second refrigeration circuit 20, the low-temperature and low-pressure gas refrigerant is compressed to a predetermined pressure by the second compressor 21, and then passes through the four-way valve 22, the first on-off valve 26a, and the second on-off valve 26b. Then, the refrigerant reaches the inter-refrigerant heat exchanger 17 and exchanges heat with the injection refrigerant of the first refrigeration circuit 10, and then expands to the evaporation pressure by the third expansion valve 25, and exchanges heat with the outside air by the second outdoor heat exchanger 24. Then, it evaporates and returns to the second compressor 21 through the four-way valve 22.

[When indoor air conditioning is required at low outside temperatures]
When indoor air conditioning (heating air conditioning) is required at low outside air temperature, both the second on-off valve 26b and the third on-off valve 28a are “open”, and the first on-off valve 26a and the fourth on-off valve 29a are Both are closed and the valve opening degree of the flow rate adjustment valve 16 and the first to third expansion valves 13, 14, 25 of the inter-refrigerant heat exchanger 17 are controlled to a predetermined opening degree, and the inter-refrigerant heat exchanger 17 is controlled. The refrigerant of the second refrigeration circuit 20 is supplied to the first refrigeration circuit 10 in an injection cycle.

  In this case, the first refrigeration circuit 10 is operated in the injection cycle as described above, and in the second refrigeration circuit 20, the low-temperature and low-pressure gas refrigerant is compressed to a predetermined pressure by the second compressor 21. After that, it passes through the four-way valve 22 and the third on-off valve 28a, reaches the indoor heat exchanger 23, and exchanges heat with the indoor air to condense. Thereafter, the refrigerant enters the inter-refrigerant heat exchanger 17 through the second on-off valve 26b, exchanges heat with the injection refrigerant of the first refrigeration circuit 10, and expands to the evaporation pressure at the third expansion valve 25. Thereafter, the second outdoor heat exchanger 24 evaporates by exchanging heat with the outside air, and returns to the second compressor 21 through the four-way valve 22.

  At low outside temperatures, the user can select one or a combination of hot water supply, floor heating, and heating air conditioning ("hot water + heating air conditioning", "floor heating + heating air conditioning", "hot water + floor heating + heating air conditioning"). ) Can be selected.

  In the operation at the low outside air temperature, when the temperature of the water flowing from the hot water storage tank 30 to the water-refrigerant heat exchanger 12 is low, the outlet side refrigerant of the water-refrigerant heat exchanger 12 and the inlet side of the inter-refrigerant heat exchanger 17 Although the temperature of the refrigerant becomes comparable and heat cannot be given to the refrigerant of the injection port 11a, according to the present invention, the heat is exchanged with the refrigerant of the second refrigeration circuit 20 by the inter-refrigerant heat exchanger 17, thereby Since heat can be applied to the refrigerant in the port 11a, the amount of injection refrigerant can be increased. Thereby, since the refrigerant | coolant amount to the low pressure side of the 1st compressor 11 falls, the improvement of the operating efficiency of a compressor and by extension, cycle efficiency improve.

DESCRIPTION OF SYMBOLS 10 1st freezing circuit 11 1st compressor 12 Water-refrigerant heat exchanger 13 1st expansion valve 14 2nd expansion valve 15 1st outdoor heat exchanger 16 Flow control valve 17 Heat exchanger between refrigerants 18 Branch pipe 20 2nd Refrigeration circuit 21 Second compressor 22 Four-way valve 23 Indoor heat exchanger 24 Second outdoor heat exchanger 25 Third expansion valve 26 First pipe 26a First on-off valve 26b Second on-off valve 27 Second pipe 28 Third pipe 28a 3rd on-off valve 29 4th piping 29a 4th on-off valve 30 Hot water storage tank 31 Water circulation circuit 32 Floor heating panel 33 Hot water circulation circuit 35 Hot-water tap

Claims (5)

In a heat pump device having a first refrigeration circuit for generating hot water and a second refrigeration circuit for indoor air conditioning,
The first refrigeration circuit includes: a first compressor having an injection port; a water-refrigerant heat exchanger for generating hot water connected to a refrigerant discharge side of the first compressor; and the water-refrigerant heat exchanger. A refrigerant-to-refrigerant heat exchanger that is branched from the refrigerant outflow side and that is provided in a branch pipe leading to the injection port; and a first expansion valve that is connected between the water-refrigerant heat exchanger and the refrigerant-to-refrigerant heat exchanger. A first outdoor heat exchanger connected between a refrigerant outflow side of the water-refrigerant heat exchanger and a refrigerant suction side of the first compressor, a branch point of the branch pipe, and the first outdoor heat exchange. A second expansion valve provided between the container and
The second refrigeration circuit includes a second compressor, an indoor heat exchanger, a second outdoor heat exchanger, and a third expansion connected between the indoor heat exchanger and the second outdoor heat exchanger. A refrigerant circulation system including a valve,
A part of the refrigerant pipe in the refrigerant circulation system of the second refrigeration circuit is inserted into the inter-refrigerant heat exchanger, and between the refrigerant injected into the first compressor and the refrigerant of the second refrigeration circuit. A heat pump device characterized in that heat exchange is performed. Assuming that the flow direction of the refrigerant in the refrigerant circulation system is during heating and air conditioning, the refrigerant circulation system reaches the inter-refrigerant heat exchanger from the refrigerant discharge side of the second compressor, and the first opening and closing on the upstream side. A valve, a first pipe having a second on-off valve on the downstream side, a second pipe drawn from the inter-refrigerant heat exchanger and reaching the second outdoor heat exchanger via the third expansion valve, and the indoor heat A third pipe including a exchanger and a third on-off valve and connected to the first pipe in a bypass manner,
2. The heat pump device according to claim 1, wherein the first and second expansion valves and the first to third on-off valves are controlled in accordance with an operation mode.   A fourth pipe having a fourth on-off valve for connecting a pipe portion between the confluence of the third pipe and the second on-off valve in the first pipe to the second pipe, and a control for controlling the operation mode; And the flow control valve and the first and second on-off valves are both closed, the third and fourth on-off valves are opened, and the first to third expansion valves are predetermined. The heat pump apparatus according to claim 2, wherein the first and second refrigeration circuits are independently operated by being controlled by the opening degree.   A fourth pipe having a fourth on-off valve for connecting a pipe portion between the confluence of the third pipe and the second on-off valve in the first pipe to the second pipe, and a control for controlling the operation mode; And the control means closes the first and second on-off valves, closes the third and fourth on-off valves, and opens the flow rate adjusting valve and the first to third expansion valves to a predetermined degree. The heat pump device according to claim 2, wherein the first refrigeration circuit operates in an operation mode based on an injection cycle by being controlled each time.   A fourth pipe having a fourth on-off valve for connecting a pipe portion between the confluence of the third pipe and the second on-off valve in the first pipe to the second pipe, and a control for controlling the operation mode; And the control means closes the second and third on-off valves, closes the first and fourth on-off valves, and opens the flow rate adjusting valve and the first to third expansion valves to a predetermined degree. The heat pump device according to claim 2, wherein the first refrigeration circuit operates in an operation mode based on an injection cycle by being controlled each time.

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