Heat source unit of refrigeration system and refrigeration system

Abstract

A heat source circuit (12) includes: a first gas port (31) constantly communicating with a discharge side of a compressor (14); a second gas port (32) constantly communicating with a suction side of the compressor (14); a third gas port (33) selectively communicating with one of a first gas line (25) and a second gas line (26); a liquid port (34) constantly communicating with a liquid inlet / outlet end of a heat-source heat exchanger (15); a first switching mechanism (17) which switches a state of communication of a gas inlet / outlet end of the heat-source heat exchanger (15); and a second switching mechanism (18) which switches a state of communication of a third gas line (27).

Description

TECHNICAL FIELD[0001]The present disclosure relates to a heat source unit of a refrigeration system connected to a heat using unit through a connecting pipe, and a refrigeration system including the heat source unit.BACKGROUND ART[0002]Conventionally, heat source units of refrigeration systems including a compressor and a heat-source heat exchanger have been known. The heat source unit constitutes a refrigeration system, together with a heat using unit connected to the heat source unit through a connecting pipe. The heat source unit of this kind has been described in Patent Documents 1 and 2.[0003]Specifically, as a heat source unit of this kind, Patent Document 1 discloses an outdoor unit of an air conditioner. The outdoor unit includes a single gas port and a single liquid port. The gas port is connected to a four-way switching valve connected to a discharge side and a suction side of a compressor. The liquid port is connected to a liquid inlet / outlet end of an outdoor heat exchan...

AI Technical Summary

Benefits of technology

[0023]According to the present invention, in the heat source unit (10), which is applicable to both the refrigeration system (5) in which the operation state of the heat using unit (7) is switched by the switching mechanism (17) provided in the heat source unit (10), and the refrigeration system (5) in which the operation states of the heat using units (7) are switched by the switching mechanisms (63, 64) included in the switching units (60) corresponding to the heat using units (7), respectively, the first gas port (31) constantly communicating with the discharge side of the compressor (14) is provided. In this heat source unit (10), when the second switching mechanism (18) allows the third gas port (33) to communicate with the first gas line (25), the third gas port (33) functions as a port through which the compressed refrigerant discharged from the compressor (14) flows out, the liquid port (34) functions as a port through which the condensed liquid refrigerant to be evaporated in the heat-source heat exchanger (15) flows in, and the second gas port (32) functions as a port through which the evaporated refrigerant to be sucked into the compressor (14) flows in. On the other hand, when the second switching mechanism (18) allows the third gas port (33) to communicate with the second gas line (26), the liquid port (34) functions as a port through which the liquid refrigerant condensed in the heat-source heat exchanger (15) flows out, the second gas port (32) functions as a port through which the evaporated refrigerant to be sucked into the compressor (14) flows in, and the first gas port (31) functions as a port through which the compressed refrigerant discharged from the compressor (14) flows out.

[0024]For example, as shown in FIG. 5, in the state where the second switching mechanism (18) allows the third gas port (33) to communicate with the first gas line (25), with the gas inlet / outlet end of the heat-using circuit (8) connected to the third gas port (33), the liquid inlet / outlet end of the heat-using circuit (8) connected to the liquid port (34), the liquid inlet / outlet end of the auxiliary heat exchanger (52) of the auxiliary unit (50) connected to the liquid port (34), and the gas inlet / outlet end of the auxiliary heat exchanger (52) selectively connected to the first gas port (31) or the second gas port (32), the heating operation is performed in which the heat-using heat exchanger (40), to which a high pressure refrigerant discharged from the compressor (14) is supplied through the third gas port (33), functions as a condenser. In the heating operation, when the refrigerant condensed in the heat-using heat exchanger (40) is supplied to the auxiliary heat exchanger (52), the supplied refrigerant evaporates in the auxiliary heat exchanger (52), flows into the heat source circuit (12) through the second gas port (32), and is sucked into the compressor (14). Further, in the state where the second switching mechanism (18) allows the third gas port (33) to communicate with the second gas line (26), the cooling operation is performed in which the heat-using heat exchanger (40), to which a liquid refrigerant condensed in the heat-source heat exchanger (15) is supplied through the liquid port (34), functions as an evaporator. In the cooling operation, when the refrigerant discharged from the compressor (14) is supplied to the auxiliary heat exchanger (52) through the first gas port (31), the supplied refrigerant condenses in the auxiliary heat exchanger (52), and is supplied to the heat-using heat exchanger (40) together with the liquid refrigerant condensed in the heat-source heat exchanger (15). The refrigerant supplied to the heat-using heat exchanger (40) evaporates in the heat-using heat exchanger (40), and the evaporated low-pressure refrigerant flows into the heat source circuit (12) through the third gas port (33), and is sucked into the compressor (14).

[0025]In this way, by selectively connecting the gas inlet / outlet end of the auxiliary heat exchanger (52) of the auxiliary unit (50) to the first gas port (31) or the second gas port (32), the low-pressure gaseous refrigerant from the auxiliary heat exchanger (52) serving as an evaporator in the heating operation can be supplied to the compressor (14) through the second gas port (32), and the high-pressure gaseous refrigerant can be supplied to the auxiliary heat exchanger (52) serving as a condenser in the cooling operation through the first gas port (31). Therefore, the auxiliary unit (50) can be used for both of the cooling operation and the heating operation. The outdoor unit (10) of the present invention makes it possible to connect the auxiliary unit (50) to the outdoor unit (10) so that the auxiliary unit (50) can be used for both of the cooling operation and the heating operation.

[0026]According to the third aspect of the invention, the gas inlet / outlet end of the auxiliary heat exchanger (52) is selectively connected to the first gas port (31) or the second gas port (32). Therefore, as described above, the low-pressure gaseous refrigerant from the auxiliary heat exchanger (52) serving as an evaporator in the heating operation can be supplied to the compressor (14) through the second gas port (32), and the high-pressure gaseous refrigerant can be supplied to the auxiliary heat exchanger (52) serving as a condenser in the cooling operation through the first gas port (31). The auxiliary unit (50) according to the third aspect of the invention can be connected to the refrigeration system (5) so as to make up the lack of the amount of heat exchange in the heat-source heat exchanger (15) both in the cooling operation and the heating operation.

Problems solved by technology

Since the heat source unit of Patent Document 1 has only a single gas port, it cannot be applied to the latter refrigeration system.

Further, as the heat source unit of Patent Document 2 does not have the switching mechanism for changing the operation state of the heat using unit in the heat-source circuit, it cannot be applied to the former refrigeration system.

In a refrigeration system using this heat source unit, when a relatively high cooling or heating capacity is required by the heat using unit, e.g., when a large number of the indoor units are connected, the amount of heat exchange required by the heat-using heat exchanger of the heat using unit cannot be supplied by only the heat-source heat exchanger of the heat source unit.

In this case, an appropriate refrigeration cycle cannot be performed, and a coefficient of performance (COP) becomes relatively low.

Images