Circulating temperature rise of compressor station caused by opening of anti-surge valve and its solution

Abstract

During the operation of the compressor station where the centralized air after-cooling mode is adopted, the uncooled hightemperature natural gas from the discharge of compressor enters the suction of compressor through the anti-surge pipeline after the anti-surge valve is opened, and then the natural gas is subjected to the repeated cyclic pressurization in the compressor, resulting in obvious temperature rise. During the operation of the unmanned station, there are problems of untimely handling of such phenomenon, which affects the normal operation of the compressor and shortens the life of the pipeline coating. Herein, the causes and effects of circulating temperature rise were analyzed, and it was proposed to open the circulation valve in the station by control to an appropriate opening, further to close the anti-surge valve of the compressor and solve the problem of circulating temperature rise. Therefore, the PI control with dead band was proposed to control the opening of the circulation valve in the station, and the conditions for opening the circulation valve in the station, the target value of PI control and the relevant control parameters were also set. It is verified through operation that the circulating temperature rise after the opening of anti-surge valve of the compressor under the condition of centralized air after-cooling process is effectively controlled, capable of ensuring the safe operation of the compressor station. Generally, the research results could provide guidance for the automatic control of the circulation valve in the compressor station in the centralized air after-cooling mode, laying a foundation for the construction of the unmanned station.

Keywords

• anti-surge valve
• internal station circulation
• centralized air cooling
• temperature rise
• dead band