Method for ascertaining surge pressure ratio in compressors for turbines

摘要

The surge pressure ratio of a compressor is determined by transiently reducing the inlet flow to the compressor to increase the compressor pressure ratio sufficiently to produce the surge pressure ratio. The reduction in flow of fluid is maintained for a time period insufficient to exceed the exhaust gas temperature limit for the turbine. The area of the first-stage nozzle of the turbine is reduced and the inlet flow to the compressor is reduced to a steady state to achieve pressure ratios, in close proximity to the surge line. By transiently further reducing the inlet flow to the compressor and then increasing the inlet flow back to the steady-state condition, the surge pressure ratio can be obtained without exceeding machine operational limits.