HEAT PUMP SYSTEM

Abstract

A hybrid heat pump system including, as a compressor for a refrigerant circuit, an engine-driven compressor and an electric-motor-driven compressor to achieve a rational structure with redundancy. The hybrid heat pump system further includes an operation control unit and a power source unit. The operation control unit is comprised of an engine control unit controlling the operation of an engine and an electric-motor control unit controlling the operation of an electric motor, which are individually provided. The power source unit converts commercial electric power into operating electric power and supplies the operating electric power to the operation control unit. The power source unit is comprised of an engine-side power source unit supplying the operating electric power to the engine control unit and an electric-motor-side power source unit supplying the operating electric power to the electric-motor control unit, which are individually provided.

Description

TECHNICAL FIELD

The present invention relates to a heat pump system including: a compressor for a refrigerant circuit in which a refrigerant circulates, the compressor including an engine-driven compressor configured to be driven by an engine to compress the refrigerant and an electric-motor-driven compressor configured to be driven by an electric motor to compress the refrigerant; an operation control unit; and a power source unit configured to convert commercial electric power into operating electric power and supply the operating electric power to the operation control unit.

BACKGROUND ART

There has been a compression-type heat pump system including a refrigerant circuit (heat pump circuit) in which a refrigerant circulates and a compressor provided to the refrigerant circuit. Among this type of heat pump systems, an engine-driven heat pump system (hereinafter, referred to as “GHP” occasionally) and an electric-motor-driven heat pump system (hereinafter, referred to as “EHP” occasionally) have achieved widespread use. The engine-driven heat pump system includes an engine-driven compressor configured to be driven by an engine. Namely, the engine-driven heat pump system uses the engine as a driving source of the compressor. The electric-motor-driven heat pump system includes an electric-motor-driven compressor configured to be driven by an electric motor. Namely, the electric-motor-driven heat pump system uses the electric motor as a driving source of the compressor.

In addition to them, there has been proposed a so-called hybrid heat pump system including an engine-driven compressor and an electric-motor-driven compressor, wherein both of the engine-driven compressor and the electric-motor-driven compressor can be used as a driving source of the compressor (see, e.g., Patent Literature 1 (hereinafter, referred to as PTL 1)). The hybrid heat pump system controls an operation balance between the engine-driven compressor and the electric-motor-driven compressor to optimize factors such as the energy cost, the burden on the environment, and/or the convenience, for example. In this regard, the hybrid heat pump system attracts attention.

CITATION LIST

Patent Literature

PTL 1: Japanese Patent Application Laid-Open No. 2013-250004 A

SUMMARY OF INVENTION

Technical Problem

Conventional hybrid heat pump systems involve a problem as below. That is, if trouble such as an electrical leakage and/or a malfunction occurs in a power source unit of a hybrid heat pump system, this makes it impossible for an operation control unit to control operation of an engine and an electric motor, thereby leading to abnormal stop of both the engine and the electric motor. Consequently, the hybrid heat pump system cannot continue an air conditioning process in its refrigerant circuit.

In addition, the hybrid heat pump system has a structure more complex than those of GHP and EHP, and therefore is relatively expensive. In order to achieve more widespread use, the hybrid heat pump system has been desired to adopt a structure that is designed as rationally as possible to reduce the cost.

In view of the actual circumstances as described above, a main object of the present invention is to provide a technique for a so-called hybrid heat pump system including a compressor for a refrigerant circuit, the compressor including an engine-driven compressor configured to be driven by an engine and an electric-motor-driven compressor configured to be driven by an electric motor. Specifically, the technique allows the hybrid heat pump system to achieve a structure which is designed rationally to enable cost reduction and which has redundancy allowing continuation of operation in the refrigerant circuit even if either of the engine and the electric motor is abnormally stopped due to trouble such as an electrical leakage and/or a malfunction.

Solution to Problem and Advantageous Effects of Invention

A first aspect of the present invention provides a heat pump system including:

a compressor for a refrigerant circuit in which a refrigerant circulates, the compressor including an engine-driven compressor configured to be driven by an engine to compress the refrigerant and an electric-motor-driven compressor configured to be driven by an electric motor to compress the refrigerant;

an operation control unit; and

a power source unit configured to convert commercial electric power into operating electric power and supply the operating electric power to the operation control unit, wherein

the operation control unit includes an engine control unit configured to control operation of the engine and an electric-motor control unit configured to control operation of the electric motor, and

the power source unit includes an engine-side power source unit configured to supply operating electric power to the engine control unit and an electric-motor-side power source unit configured to supply operating electric power to the electric-motor control unit, the engine-side power source unit and the electric-motor-side power source unit being arranged in parallel.

With this configuration, even in a case where trouble such as an electrical leakage and/or a malfunction occurs in the operation control unit or the power source unit related to one of the engine and the electric motor, the operation control unit and the power source unit related to the other of the engine and the electric motor can be kept normal. Thus, a structure with redundancy can be achieved. Specifically, with this configuration, even in a case where one of the engine and the electric motor is abnormally stopped due to trouble such as an electrical leakage and/or a malfunction, the other of the engine and the electric motor can operate to allow continuation of operation in the refrigerant circuit.

In addition, the engine control unit and the engine-side power source unit can be configured independently of the electric-motor-side configuration. Therefore, the engine control unit and the engine-side power source unit can be made of many components in common with a generally-used GHP. Meanwhile, the electric-motor control unit and the electric-motor-side power source unit can be configured independently of the engine-side configuration. Therefore, the electric-motor control unit and the electric-motor-side power source unit can be made of many components in common with a generally-used EHP. Thus, the first aspect of the present invention provides a rational structure, which enables cost reduction.

Thus, the first aspect of the present invention can provide a so-called hybrid heat pump system having a rational structure with redundancy.

According to a second aspect of the present invention, commercial electric power is distributedly supplied to the engine-side power source unit and the electric-motor-side power source unit through their respective electrical leakage breakers.

With this configuration, even in a case where the electrical leakage breaker connected to one of the engine-side power source unit and the electric-motor-side power source unit is actuated to interrupt the supply of the commercial electric power to the one of the engine-side power source unit and the electric-motor-side power source unit, it is possible to continuously supply the commercial electric power to the other of the engine-side power source unit and the electric-motor-side power source unit without affecting the other of the engine-side power source unit and the electric-motor-side power source unit. Consequently, even in a case where one of the engine and the electric motor is abnormally stopped as a result of actuation of its corresponding electrical leakage breaker, the compressor associated with the other of the engine and the electric motor can solely operate to compress the refrigerant so as to continue the operation in the refrigerant circuit.

According to a third aspect of the present invention, one of an engine-side circuit including the engine control unit and the engine-side power source unit and an electric-motor-side circuit including the electric-motor control unit and the electric-motor-side power source unit is detachably attachable to the other of the engine-side circuit and the electric-motor-side circuit.

With this configuration, the electric-motor-side circuit is detachably attachable to the engine-side circuit, or the engine-side circuit is detachably attachable to the electric-motor-side circuit. By attaching the engine-side circuit and the electric-motor-side circuit to each other, it is possible to provide an operation control unit and a power source unit for a hybrid heat pump system made of a combination of the engine-driven heat pump system and the electric-motor-driven heat pump system. Conversely, by detaching the electric-motor-side circuit from the operation control unit and the power source unit for the hybrid heat pump system, it is possible to provide an operation control unit and a power source unit for the engine-driven heat pump system. Also, by detaching the engine-side circuit from the operation control unit and the power source unit for the hybrid heat pump system, it is possible to provide an operation control unit and a power source unit for the electric-motor-driven heat pump system. Thus, an easy and rational mode change between the hybrid mode and the engine-driven mode or between the hybrid mode and the electric-motor-driven mode can be achieved. Also, since many common components can be used to achieve these modes, it is possible to further reduce the cost.

According to a fourth aspect of the present invention, the engine-driven compressor and the electric-motor-driven compressor are connected in parallel in the refrigerant circuit.

With this configuration, the engine-driven compressor and the electric-motor-driven compressor are connected in parallel in the refrigerant circuit. Consequently, even in a case where one of the engine and the electric motor is abnormally stopped, the compressor associated with the other of the engine and the electric motor can solely operate to compress the refrigerant so as to continue the operation in the refrigerant circuit.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 A view illustrating a schematic configuration of a heat pump system according to an embodiment of the present invention.

DESCRIPTION OF EMBODIMENTS

The following will describe embodiments of the present invention with reference to the drawing.

The heat pump system illustrated in FIG. 1 includes a refrigerant circuit 10 in which a refrigerant circulates. The refrigerant circuit 10 is configured to enable a so-called compression type refrigerating cycle. In the compression type refrigerating cycle, a gas-phase refrigerant is compressed by a compressor 11, the compressed refrigerant is condensed by a condenser so that heat of condensation from the refrigerant is released to the air, a liquid-phase refrigerant resulting from the condensation is expanded by an expansion valve 15, and then the expanded refrigerant is evaporated by an evaporator so that heat of evaporation taken from the air is absorbed to the refrigerant.

The refrigerant circuit 10 is provided with an oil separator 12 and a four-way valve 13. The oil separator 12 separates the liquid-phase refrigerant from the gas-phase refrigerant having been compressed by the compressor 11, and supplies the separated liquid-phase refrigerant back to the compressor 11. The four-way valve 13 is configured to change the destination of the gas-phase refrigerant having passed through the oil separator 12. Specifically, the four-way valve 13 changes the destination from an outdoor-unit heat exchanger 14 provided to an outdoor unit to an interior-unit heat exchanger 16 provided to an interior unit, or vice versa. When the four-way valve 13 is set in the state illustrated in FIG. 1, the outdoor-unit heat exchanger 14 serves as a condenser and the interior-unit heat exchanger 16 serves as an evaporator, so that the interior-unit heat exchanger 16 can perform so-called cooling operation for cooling indoor air. Meanwhile, when the four-way valve 13 in the state illustrated in FIG. 1 is turned by 90 degrees, the outdoor-unit heat exchanger 14 serves as an evaporator and the interior-unit heat exchanger 16 serves as a condenser, so that the interior-unit heat exchanger 16 can perform so-called heating operation for heating indoor air.

The heat pump system of the present embodiment includes, as the compressor 11 for the refrigerant circuit 10, an engine-driven compressor 20 configured to be driven by an engine 21 to compress the refrigerant and an electric-motor-driven compressor 30 configured to be driven by an electric motor 31 to compress the refrigerant.

Namely, the heat pump system of the present embodiment is a hybrid heat pump system made of a combination of an engine-driven heat pump system (GHP) employing the engine 21 as a driving source of the compressor 11 and an electric-motor-driven heat pump system (EHP) employing the electric motor 31 as a driving source of the compressor 11. There is no particular limitation on the type, the fuel, and the like of the engine 21. Examples of the engine 21 encompass a reciprocating engine and a gas-turbine engine each using city gas as its fuel.

In the refrigerant circuit 10, the engine-driven compressor 20 and the electric-motor-driven compressor 30 are connected in parallel. Specifically, a refrigerant discharge port of the engine-driven compressor 20 and a refrigerant discharge port of the electric-motor-driven compressor 30 are merged with each other at a location upstream of the four-way valve 13, specifically, at a location upstream of the oil separator 12. Meanwhile, a refrigerant inflow port of the engine-driven compressor 20 and a refrigerant inflow port of the electric-motor-driven compressor 30 diverge from each other at a location downstream of the four-way valve 13, specifically, at a location downstream of a merged point of the liquid-phase refrigerant having been separated by the oil separator 12.

Namely, in the refrigerant circuit 10, both of the refrigerant compressed by the engine-driven compressor 20 and the refrigerant compressed by the electric-motor-driven compressor 30 flow through the oil separator 12 and the four-way valve 13, which are provided in common to the engine-side and the electric-side.

The heat pump system of the present embodiment includes an operation control unit A configured to perform operation control and a power source unit B. The power source unit B converts commercial electric power into operating electric power, and supplies the operating electric power to the operation control unit A. More specifically, the power source unit B converts, with use of an alternating current (AC)-to-direct current (DC) converter and/or the like, alternating-current commercial electric power supplied from a commercial power source 42 into direct-current operating electric power, and supplies the direct-current operating electric power to the operation control unit A.

As the operation control unit A, an engine control unit 25 configured to control operation of the engine 21 and an electric-motor control unit 35 configured to control operation of the electric motor 31 are provided individually. As the power source unit B, an electric power converter 23 serving as an engine-side power source unit for supplying operating electric power to the engine control unit 25 and an electric power converter 33 serving as an electric-motor-side power source unit for supplying operating electric power to the electric-motor control unit 35, which are arranged in parallel, are provided.

Specifically, the engine control unit 25 and the electric power converter 23 are mounted on a GHP controller 22, which is an engine-side circuit. In addition to the engine control unit 25 and the electric power converter 23, a main control unit 24 configured to control operation of the refrigerant circuit 10 is mounted on the GHP controller 22. The electric power converter 23 supplies operating electric power to the engine control unit 25. The electric power converter 23 can supply operating electric power not only to the engine control unit 25 but also to other electric components. To the electric power converter 23 of the GHP controller 22, commercial electric power that has been branched at a terminal 40, which is connected to the commercial power source 42, and has passed through an electrical leakage breaker 28 is distributedly supplied.

Meanwhile, the electric-motor control unit 35 and the electric power converter 33 are mounted on an EHP controller 32, which is an electric-motor-side circuit provided separately from the GHP controller 22. The electric power converter 33 mounted on the EHP controller 32 can supply operating electric power not only to the electric-motor control unit 35 but also to other electric components. To the electric power converter 33 of the EHP controller 32, commercial electric power that has been branched at the terminal 40, which is connected to the commercial power source 42, and has passed through an electrical leakage breaker 38 is distributedly supplied.

Namely, the electric power converter 23 converts, into operating electric power, commercial electric power distributedly supplied from the commercial power source 42, and supplies the operating electric power to the engine control unit 25. Similarly, the electric power converter 33 converts, into operating electric power, commercial electric power distributedly supplied from the commercial power source 42, and supplies the operating electric power to the electric-motor control unit 35. As described above, the electric power converter 23, which is the engine-side power source unit, and the electric power converter 33, which is the electric-motor-side power source unit, are arranged in parallel.

With the operating electric power from the electric power converter 23, the engine control unit 25 controls operation of the engine 21 to actuate the refrigerant circuit 10 to perform an air-conditioning process or the like. Similarly, with the operating electric power from the electric power converter 33, the electric-motor control unit 35 controls operation of the electric motor 31 to actuate the refrigerant circuit 10 to perform an air-conditioning process or the like. Thus, either with the operating electric power from the electric power converter 23, which is the engine-side power source unit, or the operating electric power from the electric power converter 33, which is the electric-motor-side power source unit, it is possible to actuate the refrigerant circuit 10 to perform an air-conditioning process or the like.

The GHP controller 22 and the EHP controller 32 are communicable with each other via communication units 26 and 36. With this configuration, the engine control unit 25 and the electric-motor control unit 35 can control outputs of the engine 21 and the electric motor 31 in a coordinated manner so as to optimize the energy cost, the burden on the environment, and/or the like while performing a requested air-conditioning process in the refrigerant circuit 10, for example.

As described above, in the heat pump system of the present embodiment, the GHP controller 22 on which the engine control unit 25 and the electric power converter 23 are mounted and the EHP controller 32 on which the electric-motor control unit 35 and the electric power converter 33 are mounted are provided individually and arranged in parallel. With this configuration, even in a case where trouble such as an electrical leakage and/or a malfunction occurs in one of the GHP controller 22 and the EHP controller 32, the other of the GHP controller 22 and the EHP controller 32 is kept normal. Thus, a structure with redundancy can be achieved. Specifically, with the above configuration, even in a case where one of the engine 21 and the electric motor 31 is abnormally stopped due to the trouble as described above, the other of the engine 32 and the electric motor 31 can operate to allow continuation of an air-conditioning process or the like in the refrigerant circuit 10.

In the refrigerant circuit 10, the engine-driven compressor 20 and the electric-motor-driven compressor 30 are connected in parallel. Consequently, even in a case where one of the engine 21 and the electric motor 31 is abnormally stopped, the compressor 11 associated with the other of the engine 21 and the electric motor 31 that is not abnormally stopped can solely operate to compress the refrigerant so as to continue the operation in the refrigerant circuit 10.

In addition, the electrical leakage breakers 28 and 38 are arranged at locations downstream of the terminal 40, where commercial electric power is branched. At locations downstream of the electrical leakage breakers 28 and 38, the electric power converter 23, which is the engine-side power source unit, and the electric power converter 33, which is the electric-motor-side power source unit, are respectively disposed. Thus, commercial electric power from the commercial power source 42 is branched at the terminal 40 so as to be supplied to the electric power converter 23 of the GHP controller 22 and to the electric power converter 33 of the EHP controller 32 through the electrical leakage breakers 28 and 38, which are provided individually. Consequently, even in a case where one of the electrical leakage breakers 28 and 38 is actuated due to trouble, the electric power converter 23 or 33 connected to the other of the electrical leakage breakers 28 and 38 is supplied with commercial electric power continuously without being affected by the trouble, so that the engine 21 or the electric motor 31 can operate continuously.

Here, noise filters (not illustrated) may be individually provided at locations downstream of the electrical leakage breakers 28 and 38. With this configuration, commercial electric power may be supplied to the electric power converter 23 of the GHP controller 22 and to the electric power converter 33 of the EHP controller 32 through the noise filters, which are provided individually. Alternatively, a common noise filter may be provided upstream of the location where commercial electric power is branched to be supplied to the electrical leakage breakers 28 and 38. With this configuration, commercial electric power may be distributedly supplied to the electric power converter 23 of the GHP controller 22 and to the electric power converter 33 of the EHP controller 32 through the common noise filter.

The GHP controller 22 and the EHP controller 32 are arranged in parallel. This configuration can prevent the structure related to the GHP controller 22 and the structure related to the EHP controller 32 from influencing each other. Thus, in a case where a generally-used GHP is modified into a hybrid heat pump system by applying the heat pump system of the present embodiment to the GHP, many components in common with the GHP can be used in the hybrid heat pump system. This enables reduction in cost. Meanwhile, in a case where a generally-used EHP is modified into a hybrid heat pump system by applying the heat pump system of the present embodiment to the EHP, many components in common with the EHP can be employed in the hybrid heat pump system. This enables reduction in cost.

In addition, the EHP controller 32, which is the electric-motor-side circuit including the electric-motor control unit 35 and the electric power converter 33 serving as the electric-motor-side power source unit, is detachably attachable to the GHP controller 22, which is the engine-side circuit including the engine control unit 25 and the electric power converter 23 serving as the engine-side power source unit. Namely, merely by attaching the EHP controller 32 to the GHP controller 22, the operation control unit A and the power source unit B for the hybrid heat pump system are provided. Conversely, detaching the EHP controller 32 therefrom yields an operation control unit A and a power source unit B for the engine-driven heat pump system made of the GHP controller 22 alone. Thus, an easy and rational mode change between the hybrid mode and the engine-driven mode can be achieved. Also, since many common components can be used to achieve these modes, it is possible to further reduce the cost.

In order to detach the EHP controller 32 from the GHP controller 22, a communication cable of the communication unit 36 of the EHP controller 32 is disconnected from the communication unit 26 of the GHP controller 22, and the electrical leakage breaker 38 of the EHP controller 32 is electrically disconnected from the terminal 40 connected to the commercial power source 42. In addition, in order to detach the EHP controller 32, other elements related to the EHP controller 32, such as the electrical leakage breaker 38, the electric motor 31, and/or the electric-motor-driven compressor 30, may also be detached.

Other Embodiments

(1) The embodiment described above is configured such that the engine-driven compressor 20 and the electric-motor-driven compressor 30 are connected in parallel in the refrigerant circuit 10. However, the present invention is not limited to this configuration. Alternatively, for example, an engine-driven compressor and an electric-motor-driven compressor may be connected in series in a refrigerant circuit. Further alternatively, an engine-driven compressor and an electric-motor-driven compressor may be provided as a single common compressor, and a shaft output from an engine and a shaft output from an electric motor may be combined together and inputted to the common compressor.

(2) The embodiment described above is configured such that the EHP controller 32, which is the electric-motor-side circuit, is detachably attachable to the GHP controller 22, which is the engine-side circuit, to enable an easy and rational mode change between the hybrid mode and the engine-driven mode. However, the present invention is not limited to this configuration. Alternatively, for example, a GHP controller 22, which is an engine-side circuit, may be detachably attachable to an EHP controller 32, which is an electric-motor-side circuit, to enable an easy and rational mode change between the hybrid mode and the electric-motor-driven mode.

(3) The embodiment described above is configured such that, in the refrigerant circuit 10, the refrigerant discharge port of the engine-driven compressor 20 and the refrigerant discharge port of the electric-motor-driven compressor 30 are merged at the location upstream of the four-way valve 13 to allow both of the refrigerant compressed by the engine-driven compressor 20 and the refrigerant compressed by the electric-motor-driven compressor 30 to flow through the common four-way valve 13. However, the present invention is not limited to this configuration. Alternatively, for example, four-way valves may be provided respectively for an engine-driven compressor and an electric-motor-driven compressor, and a refrigerant discharge port of the engine-driven compressor 20 and a refrigerant discharge port of the electric-motor-driven compressor 30 may be merged with each other at a location upstream of a condenser. Further alternatively, a refrigerant circuit in which a refrigerant compressed by an engine-driven compressor circulates and a refrigerant circuit in which a refrigerant compressed by an electric-motor-driven compressor circulates may be provided individually.

INDUSTRIAL APPLICABILITY

The present invention is applicable to a so-called hybrid heat pump system including, as a compressor for a refrigerant circuit, an engine-driven compressor and an electric-motor-driven compressor.

REFERENCE SIGNS LIST

• • 10 refrigerant circuit
  • 11 compressor
  • 20 engine-driven compressor
  • 21 engine
  • 22 GHP controller (engine-side circuit)
  • 23 electric power converter (engine-side power source unit)
  • 25 engine control unit
  • 30 electric-motor-driven compressor
  • 31 electric motor
  • 32 EHP controller (electric-motor-side circuit)
  • 33 electric power converter (electric-motor-side power source unit)
  • 35 electric-motor control unit
  • A operation control unit
  • B power source unit

Claims

1. A heat pump system comprising:

a compressor for a refrigerant circuit in which a refrigerant circulates, the compressor including an engine-driven compressor configured to be driven by an engine to compress the refrigerant and an electric-motor-driven compressor configured to be driven by an electric motor to compress the refrigerant;

an operation control unit; and

a power source unit configured to convert commercial electric power into operating electric power and supply the operating electric power to the operation control unit, wherein:

the operation control unit includes an engine control unit configured to control operation of the engine and an electric-motor control unit configured to control operation of the electric motor, and

the power source unit includes an engine-side power source unit configured to supply operating electric power to the engine control unit and an electric-motor-side power source unit configured to supply operating electric power to the electric-motor control unit, the engine-side power source unit and the electric-motor-side power source unit being arranged in parallel.

2. The heat pump system according to claim 1, wherein the commercial electric power is distributedly supplied to the engine-side power source unit and the electric-motor-side power source unit through their respective electrical leakage breakers.

3. The heat pump system according to claim 1, wherein one of an engine-side circuit including the engine control unit and the engine-side power source unit and an electric-motor-side circuit including the electric-motor control unit and the electric-motor-side power source unit is detachably attachable to another one of the engine-side circuit and the electric-motor-side circuit.

4. The heat pump system according to claim 1, wherein the engine-driven compressor and the electric-motor-driven compressor are connected in parallel in the refrigerant circuit.