Oil returning system for multi-compressor parallel-connection unit

Abstract

The invention provides an oil returning system for a multi-compressor parallel-connection unit. Under the working condition that two compressors are in parallel connection, oil tanks of each compressor (1) are connected through an oil balance pipe (3); the axis (OO') of each oil balance pipe (3) is lower than the lowest oil level line (PP') in an oil mirror (4); the upper portions of oil surfaces of the oil tanks of each compressor (1) are connected with each other through an air balance pipe (2); under the working condition that three compressors are in parallel connection, an air outlet (16) of each compressor (1) is connected with an oil separator (7), the upper end of each oil separator (7) is connected with a condenser, the lower end of each oil separator (7) is connected with an oil storing device (8), and each oil storing device (8) is connected with a ball cock type oil level controller (6); a pressure adjusting valve (10) is connected between the corresponding oil storing device (8) and a low-pressure pipe of the parallel-connection unit; and according to the high-pressure oil returning system for the parallel-connection unit, the air outlet (16) of each compressor (1) is connected with an oil separating and storing device (20), the upper end of each oil separating and storing device (20) is connected with the corresponding condenser, and the lower end of each oil separating and storing device (20) is connected with an electronic type oil level controller (19).

Description

technical field [0001] The invention relates to variable volume fluid machinery technology, in particular to the oil return technology of multi-compressor parallel units. Background technique [0002] Compressor parallel units have been widely used in food refrigeration, shopping malls, island cabinets, display cabinets, cold drink processing, and ice making. The key technology of the parallel unit is that each parallel compressor can return oil smoothly and evenly to ensure the normal lubrication and operation of each compressor. [0003] The multiple compressors connected in parallel in parallel units do not start and stop at the same time, and the running time of each compressor cannot be the same, and the pipeline path of each compressor is also different. When the number of compressors is different, the flow rate of the refrigerant in the system pipeline is also different, the positions of the evaporator and condenser are different, the oil return conditions are also d...

AI Technical Summary

Problems solved by technology

However, for multiple parallel compressor units, if they run continuously for a long time, the lubricating oil of the compressor will be unbalanced or even the compressor unit will be burned out due to too little lubricating oil.

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