Aparato de refrigeración

摘要

A refrigerant circuit (11) of an air conditioner (10) includes a compressor (20) and an expander (30). In the compressor ( 20), refrigerator oil is supplied from an oil reservoir (27) t o a compression mechanism (21 ). In the expander (30) , the refrigerator oil is supplied from an oil reservoir (37) t o an expansion mechanism (31). The inner pressures of the compressor casing (24) and the expander casing (34) are the high pressure and the low pressure of the refrigeration cycle, respectively. An oil adjusting valve (52) is provided in an oil pipe (42) connecting the compressor casing (24) and the expander casing (34) . The oil amount adjusting valve (52) is operated on the basis of an output signal of an oil level sensor (51) . When the oil amount adjusting valve (52) is opened, the refrigerator oil flows from the oil reservoir (27) in the compressor casing (24) toward the oil reservoir (37 ) in the expander casing (34) through the oil pipe (42).