Design and Implementation of a Reliable and Cost-Effective Surge and Choke Control System on Centrifugal Compressors

The proposed oral presentation will review the steps involved in the design and implementation of a reliable and cost-effective surge control system for centrifugal compressors.  Additionally, it will review the design requirements for a performance control and choke control system.  The paper will highlight the basics of surge control system design, instrumentation, and guidelines for a controls retrofit and field testing.  Surge and choke control as they pertain to the Cracked Gas Compressor, Propylene Compressor, and Ethylene Compressor will be addressed.  Special attention will be given to process upsets that can cause surge events in the compressors, and how a properly-designed control system can ameliorate the impacts caused by these upsets.  Events such as a furnace shut-down can cause the Crack Gas Compressor to shut-down if the surge and performance control system is not adequately designed.  A trip of the Propylene Compressor can cascade to the Ethylene Compressor and shut it down unless its Compressor Control System can use appropriate feed-forward signals to prevent that occurrence.

Actual design and implementation of surge control systems will be illustrated with two successful field installations: 1) A surge control system for a refrigeration application in a gas fractionation plant, and 2) A surge control and performance control system for two compressors in series.  Final mention will be made about choke control that was implemented for a pipeline compressor to illustrate the different means for preventing a compressor from choke.

This tutorial content is meant to target rotating equipment, reliability and instrumentation engineers, and process engineers working in ethylene plants as well as other industries that make use of centrifugal and axial compressors.  The material covered will be technical in nature, and it will be a good source of training material for new engineers, and a refresher for experienced engineers.