TRANSIENT PHENOMENA IN COMPRESSOR STATIONS DURING SURGE

Transient phenomena are generally inherent in the operation of compres sor stations: These are either fast or slow transients. A model descri bing the governing equation for the gas dynamics, control system, comp ressor and turbine shaft inertias has been developed. The effect of th ese inertias is manifested by an example of a compressor station opera ting near the surge control line. Another example deals with a station that has a cooler placed in the recycle path. This alters the rate at which the compresser shaft decelerates upon shutdown and may cause ba ckward spinning depending on the relative magnitude of the shaft inert ia with respect to the cooler volume. Backward spinning of compressor shaft has detrimental effects on dry seals and is undesirable. It was found that by keeping the recycle value closed upon shutdown, the rare of shaft deceleration will be reduced.