Modeling and analysis of the compressor for the closed cycle system on anti-surge process

Abstract

In order to study the interaction mechanism of the pipe network, the compressor and the control system in the process of the anti-surge regulation, the simulation model of the overall Closed Cycle System (CCS) is established in this paper. By comparing the simulation results with the target values at the Design Operation and the Maximum Mach Operation, the calculation deviation is less than 1%, which verifies the accuracy of the model. At the Maximum Mach Operation, the analysis of the CCS during the quasi steady process and the dynamic process is carried out respectively. According to the result of quasi steady state analysis, the effectiveness of the designed anti-surge circuit during the normal operating process of the CCS is verified. By opening the Anti-Surge Valve, additional 38.5% surge margin is provided. And the surge margin at the simulation process would be slightly higher than the design value for the variation of the inlet condition from the different operations. Through the dynamic analysis, the changes of the different performance parameters are studied in the process of sudden blockage in the pipe network, and during this process the compressor surge could be induced easily due to the sharp decline of the inlet pressure. To ensure the safety of the compressor during the acceleration and deceleration process, the moving trajectory of the operation point on the Compressor Characteristic Map should be studied by considering the effect of the resistance characteristics of the CCS pipe network. In addition, the anti-surge system should have a high response frequency to deal with the sudden blockage.