Oil equalizing circuit compression mechanisms, heat source unit for freezing device, and freezing device having the same

摘要

The present invention provides an oil equalizing circuit that can improve the reliability of the oil supply to the compression mechanisms in a refrigeration system provided with a plurality of compression mechanisms. The compressor group (11) of the air conditioning system (1) is equipped chiefly with first, second, and third compressors (21a to 21c) and an oil equalizing circuit (42). The oil equalizing circuit (42) is equipped with the following: first, second, and third oil separators (24a to 24c) provided on the discharge side of the compressors (21a to 21c); first, second, and third oil return pipes (25a to 25c) connecting the oil separators (24a to 24c) to the intake sides of the compressors (21a to 21c); a communication pipe (26) for allowing the oil return pipes (25a to 25c) to communicate with one another; first, second, and third oil ON-OFF switching means (27a to 27c) provided downstream of the parts where the oil return pipes (25a to 25c) connect to the communication pipe (26); and first, second, and third pressure reducing means (28a to 28c) provided upstream of the parts where the oil return pipes (25a to 25c) connect to the communication pipe (26).