Multi-module Parallel Oil Evening System and Control Method

Abstract

The invention discloses a multi-module parallel-connection oil balancing system which comprises more than two modules, an oil balancing pipe and an air suction main pipe. Each module comprises more than one high-pressure cavity compressor, oil separators arranged on the high-pressure cavity compressor and air-liquid separators arranged on the high-pressure cavity compressor, air outlets of the oil separators are connected with an outdoor heat exchanger or the air suction main pipe, and oil balancing ports of the oil separators are connected with the oil balancing pipe; an air suction port of each compressor is connected with an outlet of the air-liquid separator of the compressor, and the air suction port of the compressor is further connected with an oil retuning port of the oil separator of the compressor through an oil returning capillary pipe; an inlet of the air-liquid separator of each compressor is communicated with the air suction main pipe; a decompression valve is further connected between the air-liquid separator of each compressor and the oil balancing pipe, and an opening pressure value of the decompression valve is preset. The invention further relates to a control method. According to the multi-module parallel-connection oil balancing system and the control method, the oil balancing pipe is effectively prevented from bursting, and reliable operation of a unit is guaranteed.

Description

technical field [0001] The invention relates to the field of refrigeration, in particular to a multi-module parallel oil equalization system and a control method. Background technique [0002] In the mainstream multi-connected systems currently on the market, one outdoor unit module uses one or more compressors in parallel, and then multiple outdoor unit modules are combined together, which can not only obtain greater cooling capacity, but also meet the requirements of more places. use. In a multi-compressor parallel multi-connection system, since the oil discharge rate of each compressor is different and the refrigerant circulation volume is different, there will be deviations in the oil volume after long-term operation. How to reasonably distribute the returned oil to ensure the balance of the oil level of each compressor is the key Problems that must be solved in multi-line systems. At present, there are two main oil equalization methods used to balance the oil level of...

AI Technical Summary

Problems solved by technology

At present, there are two main oil equalization methods used to balance the oil level of each compressor in the multi-unit: the first is the multi-unit system using a low-pressure chamber compressor, in which the motor is on the return air side (the return air pressure is inside the housing), The oil pool is low pressure, and a pressure difference is formed by stopping part of the compressor during the oil equalization process. The oil return effect is poor when the pressure difference is small, and part of the compressor needs to be stopped during the oil return process to affect the cooling capacity output; the second is The multi-line system of the high-pressure chamber compressor is selected, in which the motor is on the exhaust side (the exhaust pressure inside the shell), the oil pool is high pressure, and there are two oil equalization methods, one is high pressure to high pressure, this oil equalization method During the oil equalization process, the compressor needs to be stopped to affect the capacity output; second, from high pressure to low pressure, the pressure difference is controlled by opening the solenoid valve during the oil equalization process. The oil return effect is good when the pressure difference is large, but the electromagnetic Valves and check valves are used to control the switch and direction. When the solenoid valves are closed, the oil equalizing pipe will form a closed space. When the ambient temperature rises, the volume of lubricating oil expands and the oil equalizing pipe rises. When the pressure exceeds a certain pressure, it will burst

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