Heat source unit and refrigeration system

摘要

An outdoor unit (20) including a compressor (21) and an outdoor heat exchanger (22) and an indoor unit (30) including an indoor heat exchanger (31) are provided. The outdoor unit (20) and the indoor unit (30) constitute a main circuit (43) of a refrigerant circuit (40). A sub-circuit (70) whose one end is connected to a liquid line (4a) of the main circuit (43) and another end is connected to a low-pressure gas line (4b) of the main circuit (43), and which stores refrigerant in the main circuit (43) is also provided. The sub-circuit (70) is located on a sub-passageway (71), and includes: a refrigerant regulator (72) for storing refrigerant in the main circuit (43); and a switch mechanism (73) for establishing and blocking communication between the refrigerant regulator (72) and each of the liquid line (4a) and the low-pressure gas line (4b). When the amount of refrigerant in the main circuit (43) is excessive, redundant refrigerant in the main circuit (43) is stored in the refrigerant regulator (72).