Compressor unit and refrigeration apparatus

A compressor unit includes a first case, a compressor, a connecting port, and a shutoff valve. The connecting port includes a first connecting port and a second connecting port. The shutoff valve includes a first shutoff valve and a second shutoff valve. A heat source heat exchanger is accommodated in a second case. A utilization heat exchanger is accommodated in a third case. The compressor unit is disposed inside a building. The first connecting port is connected to the heat source heat exchanger via a first connection piping. The second connecting port is connected to the utilization heat exchanger via a second connection piping. The first shutoff valve shuts off flow of a refrigerant between the first connecting port and the heat source heat exchanger. The second shutoff valve shuts off flow of the refrigerant between the second connecting port and the utilization heat exchanger.

TECHNICAL FIELD

The present disclosure relates to a compressor unit and a refrigeration apparatus including the compressor unit.

BACKGROUND ART

Patent Literature 1 (Japanese Patent Application Laid-Open Publication No. 2018-511771) discloses an air conditioner including a compressor unit, a heat source heat exchanger unit, and a utilization unit.

SUMMARY

A compressor unit according to one aspect includes a first case, a compressor, a connecting port, and a shutoff valve. The compressor is accommodated in the first case. The connecting port includes a first connecting port and a second connecting port. The shutoff valve includes a first shutoff valve and a second shutoff valve. The compressor, a heat source heat exchanger, and a utilization heat exchanger constitute a refrigerant cycle. The refrigerant cycle adopts the heat source heat exchanger as a heat source and causes circulation of a refrigerant. The heat source heat exchanger is accommodated in a second case provided separately from the first case. The utilization heat exchanger is accommodated in a third case provided separately from the first case. The compressor unit is disposed inside a building. The first connecting port is connected to the heat source heat exchanger via a first connection pipe. The second connecting port is connected to the utilization heat exchanger via a second connection pipe. The first shutoff valve shuts off movement of the refrigerant between the first connecting port and the heat source heat exchanger. The second shutoff valve shuts off movement of the refrigerant between the second connecting port and the utilization heat exchanger.

With this configuration, the shutoff valve can shut off a connection pipe extending from the compressor unit. Therefore, when the compressor unit has internal refrigerant leakage, leaking refrigerant is restrained from reaching outside the compressor unit.

DESCRIPTION OF EMBODIMENTS

First Embodiment

(1) OVERALL CONFIGURATION

FIG.1is a circuit diagram of a refrigeration apparatus100according to the first embodiment. The refrigeration apparatus100is typically exemplified by an air conditioner, but is not limited thereto. For example, the refrigeration apparatus100may be a refrigerator, a freezer, and a hot water supplier. The refrigeration apparatus100includes a heat source heat exchanger unit10, a compressor unit20, a first connection piping30, utilization units501and502, and a second connection piping40. The refrigeration apparatus100handles a refrigerant R0. For example, the refrigerant R0may be R32or carbon dioxide.

(2-1) Heat Source Heat Exchanger Unit10

The heat source heat exchanger unit10is disposed outside a building B. The heat source heat exchanger unit10includes a case10a, a heat source heat exchanger11, a heat source fan12, a heat source heat exchanger unit expansion valve13, and a heat source heat exchanger unit control unit19.

The case10aaccommodates components constituting the heat source heat exchanger unit10. The case10ais made of a metal or the like.

(2-1-2) Heat Source Heat Exchanger11

The heat source heat exchanger11functions as a heat source. The heat source heat exchanger11exchanges heat between air outside the building B and the refrigerant R0. During cold heat utilization operation, the heat source heat exchanger11functions as a heat radiator (or a condenser) for the refrigerant R0. During hot heat utilization operation, the heat source heat exchanger11functions as a heat absorber (or an evaporator) for the refrigerant R0.

The heat source fan12generates an air flow to promote heat exchange in the heat source heat exchanger11.

(2-1-4) Heat Source Heat Exchanger Unit Expansion Valve13

The heat source heat exchanger unit expansion valve13decompresses the refrigerant R0. The heat source heat exchanger unit expansion valve13is configured to adjust its opening degree.

(2-1-5) Heat Source Heat Exchanger Unit Control Unit19

The heat source heat exchanger unit control unit19includes a microcomputer and a memory. The heat source heat exchanger unit control unit19controls the heat source fan12, the heat source heat exchanger unit expansion valve13, and the like. The memory stores software for control of these components.

The heat source heat exchanger unit control unit19transmits and receives data and a command, via a communication line (not depicted), to and from each of a compressor unit control unit29and a utilization unit control unit59, which will be described later.

The compressor unit20has external appearance depicted inFIG.2. As depicted inFIG.1, the compressor unit20is disposed inside the building B. The compressor unit20includes a case20a, a compressor21, a four-way switching valve22, a connecting port60, a leakage detection sensor61, the compressor unit control unit29, and a fan69.

The case20aaccommodates components constituting the compressor unit20. The case20ais made of a metal or the like.

The compressor21compresses the refrigerant R0that is sucked and is in a low-pressure gas state to obtain the refrigerant R0in a high-pressure gas state. The compressor21includes a compressor motor21a. The compressor motor21agenerates motive power necessary for compression.

The compressor21is a vibration source and may thus cause refrigerant leakage from the compressor21and a component adjacent thereto.

The four-way switching valve22switches connection of a refrigerant circuit. During cold heat utilization operation, the four-way switching valve22achieves connection depicted by solid lines inFIG.1. During hot heat utilization operation, the four-way switching valve22achieves connection depicted by broken lines inFIG.1.

The connecting port60is provided for connection of a connection pipe. The connecting port60includes a first connecting port23and a second connecting port28.

The first connecting port23is connected with the first connection piping30to be described later. The first connecting port23is provided with a first liquid side shutoff valve23aand a first gas side shutoff valve23b.

The second connecting port28is connected with the second connection piping40to be described later. The second connecting port28is provided with a second liquid side shutoff valve28aand a second gas side shutoff valve28b.

The first liquid side shutoff valve23a, the first gas side shutoff valve23b, the second liquid side shutoff valve28a, and the second gas side shutoff valve28bshut off a refrigerant flow path in response to a received command. The first liquid side shutoff valve23a, the first gas side shutoff valve23b, the second liquid side shutoff valve28a, and the second gas side shutoff valve28bmay be collectively called a shutoff valve67in the present description.

The leakage detection sensor61detects leakage of the refrigerant R0. The leakage detection sensor61is a refrigerant detection sensor61aconfigured to detect presence of the refrigerant R0.

The compressor unit control unit29includes a circuit board, a microcomputer, a memory, an electrical component74, and a heat sink75, which are mounted on the circuit board. The electrical component74generates heat. The heat sink75effectively releases, into air, the heat generated by the electrical component74.

The compressor unit control unit29controls the compressor motor21a, the four-way switching valve22, the first liquid side shutoff valve23a, the first gas side shutoff valve23b, the second liquid side shutoff valve28a, the second gas side shutoff valve28b, the fan69, and the like. The compressor unit control unit29receives a signal from the leakage detection sensor61. The memory stores software for control of these components.

The compressor unit control unit29transmits and receives data and a command, via a communication line (not depicted), to and from each of the heat source heat exchanger unit control unit19and the utilization unit control unit59to be described later.

The fan69is configured to form a circulation air flow. The circulation air flow hits the circuit board to cool the microcomputer, the memory, the electrical component74, and the heat sink75constituting the compressor unit control unit29.

The first connection piping30connects the heat source heat exchanger unit10and the compressor unit20. The first connection piping30includes a first liquid connection pipe31and a first gas connection pipe32.

(2-3-1) First Liquid Connection Pipe31

The first liquid connection pipe31connects the heat source heat exchanger unit10and the first liquid side shutoff valve23a. The first liquid connection pipe31guides the refrigerant R0principally in a high-pressure liquid state or in a low-pressure gas-liquid two-phase state.

(2-3-2) First Gas Connection Pipe32

The first gas connection pipe32connects the heat source heat exchanger unit10and the first gas side shutoff valve23b. The first gas connection pipe32guides the refrigerant R0principally in the high-pressure gas state or in the low-pressure gas state.

The utilization units501and502each have external appearance depicted inFIG.3. As depicted inFIG.1, the utilization units501and502are disposed inside the building B. The utilization unit501and the utilization unit502are configured identically to each other.

The following description will thus be made to only the utilization unit501without repetitively describing the utilization unit502. The utilization unit501includes a case50a, a utilization unit expansion valve51, a utilization heat exchanger52, a utilization fan53, and the utilization unit control unit59.

The case50aaccommodates components constituting the utilization unit501.

The utilization unit expansion valve51decompresses the refrigerant R0. The utilization unit expansion valve51controls a flow rate of the refrigerant R0. The utilization unit expansion valve51is configured to adjust its opening degree.

The utilization heat exchanger52provides a user with low temperature heat or high temperature heat. The utilization heat exchanger52exchanges heat between air inside the building B and the refrigerant R0. During cold heat utilization operation, the utilization heat exchanger52functions as a heat absorber (or an evaporator) for the refrigerant R0. During hot heat utilization operation, the utilization heat exchanger52functions as heat radiator (or a condenser) for the refrigerant R0.

The utilization fan53generates an air flow to promote heat exchange in the utilization heat exchanger52.

The utilization unit control unit59includes a microcomputer and a memory. The utilization unit control unit59controls the utilization unit expansion valve51, the utilization fan53, and the like. The memory stores software for control of these components.

The utilization unit control unit59transmits and receives data and a command, via a communication line (not depicted), to and from each of the heat source heat exchanger unit control unit19and the compressor unit control unit29.

The second connection piping40connects the compressor unit20and the utilization units501and502. The second connection piping40includes a second liquid connection pipe41and a second gas connection pipe42.

(2-5-1) Second Liquid Connection Pipe41

The second liquid connection pipe41connects the second liquid side shutoff valve28aand the utilization units501and502. The second liquid connection pipe41guides the refrigerant R0principally in the high-pressure liquid state or in the low-pressure gas-liquid two-phase state.

(2-5-2) Second Gas Connection Pipe42

The second gas connection pipe42connects the second gas side shutoff valve28band the utilization units501and502. The second gas connection pipe42guides the refrigerant R0principally in the high-pressure gas state or in the low-pressure gas state.

(3) CONFIGURATION OF REFRIGERANT CIRCUIT

The refrigeration apparatus100entirely constitutes a single refrigerant cycle C0. The refrigerant cycle C0causes circulation of the refrigerant R0. The refrigerant cycle C0adopts the heat source heat exchanger11as a heat source. The refrigerant cycle C0is constituted by components such as the compressor21, the four-way switching valve22, the first gas side shutoff valve23b, the heat source heat exchanger11, the heat source heat exchanger unit expansion valve13, the first liquid side shutoff valve23a, the second liquid side shutoff valve28a, the utilization unit expansion valve51, the utilization heat exchanger52, and the second gas side shutoff valve28b.

(4) OPERATION OF REFRIGERATION APPARATUS100

Hereinafter, assume that the refrigerant R0has reaction accompanied with phase transition (condensation or evaporation) during heat exchange. The refrigerant R0is not limited to these in terms of its state, and may have reaction accompanied with no phase transition.

(4-1) Cold Heat Utilization Operation

The compressor21discharges the refrigerant R0in the high-pressure gas state. The refrigerant R0in the high-pressure gas state passes through the four-way switching valve22and the first gas side shutoff valve23bto reach the heat source heat exchanger11. The refrigerant R0condenses to come into the high-pressure liquid state in the heat source heat exchanger11. The refrigerant R0in the high-pressure liquid state reaches the heat source heat exchanger unit expansion valve13. At the heat source heat exchanger unit expansion valve13, the refrigerant R0is decompressed to come into the low-pressure gas-liquid two-phase state. The refrigerant R0in the low-pressure gas-liquid two-phase state passes through the first liquid side shutoff valve23aand the second liquid side shutoff valve28ato reach the utilization unit expansion valve51. The refrigerant R0is further decompressed at the utilization unit expansion valve51. The refrigerant R0reaches the utilization heat exchanger52. The refrigerant R0evaporates to come into the low-pressure gas state at the utilization heat exchanger52. The refrigerant R0provides the user with low temperature heat in this process.

The refrigerant R0in the low-pressure gas state passes through the second gas side shutoff valve28band the four-way switching valve22to reach the compressor21. The compressor21sucks the refrigerant R0in the low-pressure gas state.

(4-2) Hot Heat Utilization Operation

The compressor21discharges the refrigerant R0in the high-pressure gas state. The refrigerant R0in the high-pressure gas state passes through the four-way switching valve22and the second gas side shutoff valve28bto reach the utilization heat exchanger52. The refrigerant R0condenses to come into the high-pressure liquid state at the utilization heat exchanger52. The refrigerant R0provides the user with high temperature heat in this process. The refrigerant R0in the high-pressure liquid state reaches the utilization unit expansion valve51. At the utilization unit expansion valve51, the refrigerant R0is decompressed to come into the low-pressure gas-liquid two-phase state. The refrigerant R0in the low-pressure gas-liquid two-phase state passes through the second liquid side shutoff valve28aand the first liquid side shutoff valve23ato reach the heat source heat exchanger unit expansion valve13. The refrigerant R0is further decompressed at the heat source heat exchanger unit expansion valve13. The refrigerant R0reaches the heat source heat exchanger11. The refrigerant R0evaporates to come into the low-pressure gas state in the heat source heat exchanger11. The refrigerant R0in the low-pressure gas state passes through the first gas side shutoff valve23band the four-way switching valve22to reach the compressor21. The compressor21sucks the refrigerant R0in the low-pressure gas state.

(4-3) Operation Upon Refrigerant Leakage

When refrigerant leakage occurs in the compressor unit20, the refrigerant detection sensor61adetects the refrigerant R0. The refrigerant detection sensor61aoutputs an output signal, which is then received by a microcomputer of the compressor unit20. The microcomputer transmits, to the shutoff valve67, a command (or a control signal) for shutoff. The shutoff valve67having received the command closes the refrigerant flow path.

The shutoff valve67can shut off the first connection piping30and the second connection piping40extending from the compressor unit20. When the refrigerant R0leaks in the compressor unit20, this configuration can thus inhibit the leaking refrigerant R0from reaching outside the compressor unit20.

The compressor unit20and the heat source heat exchanger unit10are constituted as separate units in the present configuration. The refrigeration apparatus100accordingly includes the first connection piping30(the first liquid connection pipe31and the first gas connection pipe32) connecting the compressor unit20and the heat source heat exchanger unit10. The refrigeration apparatus100including the first connection piping30having a large length uses a more refrigerant in comparison to a refrigeration apparatus including the compressor21and the heat source heat exchanger11belonging to an identical unit. Also in this case, the shutoff valve67thus provided can inhibit spread of refrigerant leakage.

The leakage detection sensor61detects leakage of the refrigerant R0. The shutoff valve67can thus be shut off in accordance with an output signal from the leakage detection sensor61.

The leakage detection sensor61is the refrigerant detection sensor61a. This configuration accordingly achieves direct detection of the leaking refrigerant R0.

The compressor unit control unit29automatically closes the shutoff valve67when leakage of the refrigerant R0is detected. This enables quick inhibition of refrigerant leakage. This configuration can also contain the refrigerant R0in the first connection piping30or the heat source heat exchanger unit10to inhibit spread of refrigerant leakage.

The compressor unit control unit29is cooled by the circulation air flow formed by the fan69. This enables effective release of heat generated by the electrical component74with the circulation air flow.

(6) MODIFICATION EXAMPLES

FIG.4depicts the refrigeration apparatus100according to the modification example 1A of the first embodiment. Unlike the above embodiment, the compressor unit control unit29in the refrigeration apparatus100is disposed outside the case20a.

This configuration enables effective release of heat generated by the circuit board constituting the compressor unit control unit29.

The heat source heat exchanger unit10according to the above embodiment is disposed outside the building B. The heat source heat exchanger unit10may alternatively be disposed inside the building B and be fluid connected to an outside of the building B. As exemplarily depicted inFIG.5, the heat source heat exchanger unit10may be disposed at a duct provided to the building B. The duct is fluid connected to the outside of the building B, and sends and receives air to and from outside the building B.

This configuration does not affect quality in outer appearance of the building B.

The above embodiment provides two utilization units, namely, the utilization units501and502. The number of the utilization units may alternatively be other than two. For example, the number of the utilization units may be one, three, or four.

Second Embodiment

FIG.6is a circuit diagram of a refrigeration apparatus100according to the second embodiment. Unlike the first embodiment, the refrigeration apparatus100includes a cascade heat exchanger24and entirely constitutes two refrigerant cycles.

The first refrigerant cycle C1causes circulation of the first refrigerant R1. The first refrigerant R1preferably has a low global warming potential (GWP) value. Examples of the first refrigerant R1include R32and carbon dioxide. The first refrigerant cycle C1adopts the heat source heat exchanger11as a heat source. The first refrigerant cycle C1is constituted by components such as the first compressor21, the first four-way switching valve22, the first gas side shutoff valve23b, the heat source heat exchanger11, the heat source heat exchanger unit expansion valve13, the first liquid side shutoff valve23a, and the cascade heat exchanger24.

The second refrigerant cycle C2causes circulation of the second refrigerant R2. The second refrigerant R2preferably has a low GWP value. Examples of the second refrigerant R2include R410A, R32, and carbon dioxide. The second refrigerant cycle C2adopts the cascade heat exchanger24as a heat source. The second refrigerant cycle C2is constituted by components such as a second compressor25, a second four-way switching valve26, the cascade heat exchanger24, a compressor unit expansion valve27, the utilization unit expansion valve51, the utilization heat exchanger52, and the first gas side shutoff valve23b.

Also in this configuration, the shutoff valve67can shut off the first connection piping30and the second connection piping40extending from the compressor unit20. When the refrigerant R0leaks in the compressor unit20, this configuration can thus inhibit the leaking refrigerant R0from reaching outside the compressor unit20.

(3) MODIFICATION EXAMPLES

FIG.7depicts the refrigeration apparatus100according to the modification example 2A of the second embodiment. Unlike the above embodiment, the refrigeration apparatus100includes compressor unit control units291and292that are cooled by cooling refrigerant pipes641and642via refrigerant jackets651and652, respectively. Furthermore, the case20aof the compressor unit20has airtightness. The leakage detection sensor61is the pressure sensor61b. The case20ais provided with a rupture disk66. The rupture disk66is destroyed by pressure exceeding a predetermined value.

In this configuration, the case20aof the compressor unit20has airtightness, so that the case20ais likely to contain heat generated by a circuit board. However, the cooling refrigerant pipes641and642can achieve effective release of heat generated by circuit boards constituting the compressor unit control units291and292, respectively. Alternatively, cooling of the circuit boards may be achieved by disposing the compressor unit control unit29outside the case20a, instead of the cooling refrigerant pipes641and642. Still alternatively, cooling of the circuit boards may be achieved when a fan configured to generate a circulation air flow is adopted instead of the cooling refrigerant pipes641and642.

Furthermore, the case20ahas airtightness to inhibit the refrigerant R0leaking in the compressor unit20from reaching outside the compressor unit20.

Furthermore, the leakage detection sensor61is the pressure sensor61bto detect leakage of the refrigerant R0in accordance with pressure change.

Furthermore, the case20aincludes the rupture disk66, so that the case20ahaving high airtightness can be inhibited from being ruptured by high internal pressure.

Moreover, the case20ahaving airtightness can inhibit noise of the compressor unit20.

The case20aachieves a higher electromagnetic noise cutoff effect when the case20ais made of a metal.

Any one of the modification examples of the first embodiment may be applied to the second embodiment.

Third Embodiment

FIG.8is a circuit diagram of a refrigeration apparatus100according to the third embodiment. Unlike the first embodiment, the refrigeration apparatus100includes a heat source71, a fluid-refrigerant heat exchanger72, and a pump73. The heat source71is disposed outside the building B. The fluid-refrigerant heat exchanger72and the pump73are provided at the compressor unit20.

The heat source71, the fluid-refrigerant heat exchanger72, and the pump73constitute a circuit configured to circulate fluid F such as water or brine.

The refrigerant cycle C0causes circulation of the refrigerant R0. The refrigerant cycle C0adopts the fluid-refrigerant heat exchanger72as a heat source. The fluid-refrigerant heat exchanger72exchanges heat between the fluid F and the refrigerant R0.

The compressor unit20includes the second liquid side shutoff valve28aand the second gas side shutoff valve28bdisposed at the second connecting port28.

In this configuration, the second connection piping40extending from the compressor unit20can be shut off by the second liquid side shutoff valve28aand the second gas side shutoff valve28b. When the refrigerant R0leaks in the compressor unit20, this configuration can thus inhibit the leaking refrigerant R0from reaching outside the compressor unit20.

(3) MODIFICATION EXAMPLES

Any one of the modification examples of the first or second embodiment may be applied to the third embodiment.

CONCLUSION

The embodiments of the present disclosure have been described above. Various modifications to modes and details should be available without departing from the object and the scope of the present disclosure recited in the claims.

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