Method and control system for controlling multiple throttled inlet rotary screw compressors

摘要

A more efficient compressor control system and a more efficient method of operating a multiple throttled inlet rotary screw compressor system includes the method and control system which are a function of both the actual system pressure and volumetric flow rate. Specifically, a throttled inlet rotary screw compressor is loaded or unloaded from the compressor system after sensing the actual system pressure and calculating the system's actual volumetric flow rate. The control system calculates the system's volumetric flow rate by sensing each loaded throttled inlet rotary screw compressor's inlet pressure and converting those inlet pressures to outlet volumetric flow rates. The aggregate of the loaded compressors' volumetric flow rates represents the actual system flow rate. Determining the system's volumetric flow rate by sensing the inlet pressures of the loaded throttled inlet rotary screw compressors omits the need for including a flow meter downstream of the compressors, and using that calculated flow rate, in conjunction with system's actual pressure to control the loading and unloading of the throttled inlet rotary screw compressors, produces a more efficient compressor control system.