Capacity adjusting method for screw compressor

Abstract

The invention provides a capacity adjusting method for a screw compressor. The capacity adjusting method comprises the following steps of collecting current of the screw compressor, calculating the fluctuation value of the detected current, and judging whether the fluctuation value of the current exceeds a preset value; if the fluctuation value of the current exceeds the preset value, powering off a loading electromagnetic valve and an unloading electromagnetic valve of the screw compressor to enable the capacity of the screw compressor to be kept stable, and after the power-off time reaches preset time, carrying out capacity adjustment on the screw compressor; and continuing to collect the current of the screw compressor and calculate the fluctuation value of the detected current, and continuing to execute the step of judging the fluctuation value of the current. According to the capacity adjusting method for the screw compressor, the loading and unloading rates are controlled by adding current detection control, the reliability of capacity adjustment of the screw compressor is improved, and the problem that abnormal conditions and disorder control may be caused by excessively fast loading of the compressor is solved.

Description

technical field [0001] The invention relates to the technical field of refrigeration, in particular to a method for adjusting the capacity of a screw compressor. Background technique [0002] At present, the conventional stepless adjustment capacity adjustment method of screw compressors is to energize the corresponding loading and unloading solenoid valves (25%-100%) in the form of pulses to achieve the purpose of capacity adjustment, and adjust the pulse time (capacity adjustment solenoid valves open B seconds stop C seconds) has nothing to do with working conditions and current fluctuations. The problems of this method are as follows: 1) Under the condition of high pressure difference and low water temperature, since the adjusted pulse is the same as that of the general working condition, with the increase of the loading pressure difference, it may occur that the loading is too fast and the freezing water temperature is lower. 2) Once the capacity adjustment mechanism in...

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Problems solved by technology

[0003] In view of the status quo of the prior art, the purpose of the present invention is to provide a capacity adjustment method for screw compressors. By increasing the current detection control to control the loading and unloading rate, the reliability of capacity adjustment is improved, and the problem of over-loading of the compressor can be solved. Fast and abnormal and control disorder problems

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