Dynamic modeling of compressors illustrated by an oil-flooded twin helical screw compressor

Compressed air is a basic energy source in several industrial areas. The energy of pressurized air is used during manufacturing processes, commonly as driving force for actuating pneumatic cylinders and in power tools such as pneumatic screwdrivers. The widespread use of this energy source justifies efforts to reduce losses within the compressed air infrastructure. One of the main energy consumers in the network is the production of compressed air. Thus, one problem area is generation with compressors of different kinds and sizes. Another problem affects the transmission through piping networks with non-negligible leakage effects adding to energy losses within the pneumatic infrastructure. This paper focuses on the process of compressing air and describes a dynamic simulation model of an oil-flooded screw compressor. A single compressor block, part of an overall compressor station, is split into four subsystems which are presented as mathematical models. Simulation results are compared to physical measurements and studied with respect to energy losses. The presented model is detailed enough to account for dynamic effects in real machines. But it is also abstract enough to be integrated in further simulations with more components. Future work will be done on optimizing compressor station design with respect to the reduction of energy losses. (C) 2010 Elsevier Ltd. All rights reserved.