Soft-Sensor-Based Flow Rate and Specific Energy Estimation of Industrial Variable-Speed-Driven Twin Rotary Screw Compressor

Energy costs are typically the largest cost element in the life-cycle of a compressed-air system (CAS). Real-time usage information as well as historical data can help identify whether the CAS is functioning properly. To this end, modern variable-speed drives are able to provide this information as well as produce soft-sensor estimates of volume flow rate production and specific energy consumption of a CAS. In this paper, an identification (ID) run sequence for a twin rotary screw compressor-operated system is proposed to identify the total system volume, to improve the estimation accuracy of a volume flow rate soft sensor, and to create a specific energy consumption map for the CAS performance monitoring. Laboratory measurements are carried out to evaluate the feasibility of the proposed ID run and related estimations. Moreover, possible usage applications of the proposed methods are discussed.