Parallel compressors unit capable of self-adaptively operating at low load and implementation method thereof

Abstract

The invention provides a parallel compressors unit capable of self-adaptively operating at low load. The parallel compressors unit comprises compressors, an oil separator, a condenser, a liquid storage device, a filter, a visual liquid lens, an expansion valve and an evaporator, which are connected in sequence in an end-to-end manner. The output end of the oil separator is connected with the input ends of the compressors through a hot gas bypass solenoid valve and a hot gas bypass valve and connected with the input end of the evaporator through an oil supply solenoid valve, and the output end of the filter is connected with the input ends of the compressors through a superheat-removing solenoid valve and a superheat-removing expansion valve. Meanwhile, the invention further provides an implementation method of the self-adaptive operation of the parallel compressors unit at low load. According to the parallel compressors unit and the implementation method thereof, by improving the structure of the parallel compressors unit, the frequent start and stop of one compressor is avoided when the cool storage load is reduced to be below the lowest regulation load, and the problems of temperature fluctuation and oil return of the evaporator are avoided. Meanwhile, a manual control mode is added, so that the parallel compressors unit is stable and saves energy.

Description

technical field [0001] The invention relates to a parallel unit, in particular to a parallel unit which can realize self-adaptive operation at low load and its realization method. Background technique [0002] When the load of the cold storage is lower than the cooling capacity produced by the last compressor in the parallel unit, the traditional parallel unit relies on the compressor's own energy to unload to match the cold storage load. [0003] The disadvantages of this approach are: [0004] 1. When the load of the cold storage is as low as the minimum unloading load of the last compressor in the parallel unit, the compressor will not be able to continue unloading, which will cause the low pressure to be too low, causing the compressor to start and stop frequently. [0005] Second, it will cause large temperature fluctuations in the cold storage. [0006] 3. It is difficult to return the refrigerated oil in the evaporator. Contents of the invention [0007] The tech...

AI Technical Summary

Problems solved by technology

[0004] 1. When the load of the cold storage is as low as the minimum unloading load of the last compressor in the parallel unit, the compressor will not be able to continue unloading, which will cause the low pressure to be too low, causing the compressor to start and stop frequently

[0005] Second, it will cause large temperature fluctuations in the cold storage

[0006] 3. It is difficult to return the refrigerated oil in the evaporator

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