Compressor oil return structure, refrigerating unit and air conditioning system

The invention discloses a compressor oil return structure, a refrigeration unit and an air conditioning system. The compressor oil return structure comprises a compressor, an oil separator, an oil return pipeline, a bypass branch and a control assembly, wherein the oil return pipeline is provided with a first throttling device, one end of the oil return pipeline is connected to an air suction portof the compressor, and the other end of the oil return pipeline is connected to an oil return port of the oil separator; and the bypass branch is provided with a bypass valve in parallel connection with the first throttling device, the control assembly is connected with the bypass valve, and the bypass valve is opened for unloading when the compressor is overloaded. The compressor oil return structure, the refrigeration unit and the air conditioning system can effectively improve the operation reliability of the compressor. 本发明公开了种压缩机回油结构、制冷机组及空调系统，其中，压缩机回油结构包括：压缩机、油分离器、回油管路、旁通支路和控制组件，回油管路设有第节流装置，回油管路的端连接至压缩机的吸气口、另端连