Methods and systems for antisurge control of turbo compressors with side stream

摘要

A method is described for providing antisurge control in a system comprising a compressor having at least an upstream compressor stage (51), a downstream compressor stage (52) and a side stream (59) bringing flow into a flow passage between the upstream compressor stage and the downstream compressor stage. The method provides for estimating a temperature of a flow delivered by the upstream compressor stage (51) using a non-dimensional performance map of the upstream compressor stage and further estimating a temperature of a flow entering the downstream compressor stage (52) based on the mass flow and flow temperature of the flow delivered by the downstream compressor stage and the mass flow and the flow temperature of the side stream. The method further provides for performing antisurge control of the downstream compressor stage (52) based on the temperature of the flow entering the downstream compressor stage.