Engineering the integration of a steam turbine into an existing process air compressor train

摘要

A major project to increase the throughput and improve variable cost on a large polyester intermediates plant identified the opportunity for heat recovery which would generate surplus extra low pressure steam. This led to an investigation into the feasibility of installing a steam turbine on the plant. A conventional turbo-generator did not meet the project payback requirements. An alternative solution of integrating a turbine into the existing 24MW air compressor train was developed. This paper describes the engineering solutions to the many issues encountered during the whole project from concept through to execution. The challenge was to produce a layout that met the space constraints and could be constructed within the shutdown timescale. Meeting these requirements led to further challenges with rotor design to avoid both lateral and torsional critical speed problems and with overspeed protection of the rotor.