摘要：In this paper,a correlation model between centrifugal compressor and its piping system is built based on plenum chamber model and throttle valve model.This model could be used to conduct numerical analysis of compressor systems from steady to surge operating points.Three dimensional unsteady numerical simulations were performed to predict the performance of a centrifugal compressor.The flow structures in blade passage and diffuser were plotted and analyzed.The fluctuations of pressure and mass flow rate over time at the outlet of diffuser are obtained at surge condition.The characteristic changes of compressor-pipe network under the surge condition were carried out,and the effects of model characteristics including valve coefficient and backpressure on surge were analyzed.