Surge Avoidance in Gas Compression Systems

Abstract

The phenomenon of compressor surge and its prevention have drawn significant attention in the literature. An important aspect of surge avoidance lies in the design of the compressor station and, in particular, the piping upstream and downstream of the compressor. Most anti-surge systems are perfectly capable of avoiding surge during normal operating conditions. However, unplanned emergency shutdowns present a significant challenge, and surge avoidance in these cases depends to a large degree on the station layout. In this paper, data from a compressor that surged during an emergency shutdown are presented. The data are analyzed to determine the effects of surge and the rate of deceleration. A model to simulate shutdown events is developed and used to develop simpler rules that help with proper sizing of upstream and downstream piping systems, as well as the necessary control elements. The compression system is analyzed, thus verifying the model and the simplifications.