Automotive air-conditioner having sub-compressor driven by electric motor

摘要

An air-conditioner for use in an automotive vehicle, an engine of which is stopped every time the vehicle stops at an intersection, includes a usual refrigeration cycle having a main compressor driven by the engine and a sub-circuit having a sub-compressor driven by an electric motor. The sub-compressor is connected in parallel to the main compressor, and both compressors are alternately driven. Refrigerant mixed with lubricant circulating in the main refrigeration cycle is prevented from entering into the sub-circuit while the sub-compressor is not in operation by means of a piping structure of the sub-circuit. When the refrigerant enters into the sub-circuit, it is efficiently returned to the main refrigeration cycle by intermittently operating the sub-compressor while the main compressor is operating.