OIL RETURN METHOD FOR MULTIPLE AIR CONDITIONING UNIT IN HEATING

摘要

An oil return method for multiple air conditioning unit in heating, comprising the steps of: S1, adjusting the operation frequency f0 of a compressor (11) to a first predetermined oil return frequency f1, and at the same time adjusting the open degree of all the indoor throttling elements (22) to the predetermined oil return open degree; S2, detecting the operation parameters of the system; S3, judging whether the system operation is abnormal, turning to the step S4 if so or turning to the step S5 if not; S4, quitting the oil return operation, adjusting the operation frequency f0 of the compressor (11) to a second predetermined oil return frequency f1, judging whether the system operation is abnormal, quitting the oil return operation if so or turning to the step S5 if not; S5, ending the oil return operation when the oil return time reaches the oil return time t2.