Patent ID: 7025558

Claim:
A process for the reliable operation of turbocompressors with surge limit control and a surge limit control valve, wherein the compressor delivers gases with different compositions and the composition of the gas (molecular weight) affects the performance characteristic of the turbocompressor and consequently the position of the surge limit in the performance characteristic, the process comprising: compensating the effect on the position of the surge limit and hence also on the position of the surge limit control line based on different compositions of the gases by using predetermined design values for the gas constant R, the isentropic exponent k and the compressibility number z within the surge limit control for determining the delivery head Δh and the volume flow V and plotted in the form of a predetermined surge limit within the surge limit control; and determining the set point and the actual value for the surge limit control from the graph plotted in the form of a predetermined surge limit; and operating the compressor with the determined set points and actual values for the surge limit control with a minimally necessary distance from the surge limit.