METHOD OF MONITORING EXTRACTION STEAM TEMPERATURE OF EXTRACTION TURBINE

摘要

PURPOSE:To prevent abrupt temperature change of turbine metals due to water induction to thereby prevent the metals from damaging by monitoring the changing rate of the extraction steam temperature to thereby rapidly and exactly detecting the water induction. CONSTITUTION:A detector 21 detects extraction steam pressure, and a function generator 24 produces, for example, 20% for saturated steam temperature in excess of set steam temperature limit value in response to the steam pressure to a comparator 28. A detector 22 detects the extraction steam temperature, and a calculator 25 calculates estimated extraction steam temparature value and produces it to the comparator 28. The steam temperature is also applied to a calculator 26, which thereupon calculates an extraction steam temperature change rate to a subtractor 29. A load change rate calculated by a calculator 27 from the output of a turbine load detector 23 is also applied to the subtractor 29, which thereupon calculates the extraction steam temperature change rate to the basis of water induction. This change rate is compared by a comparator 31 with the limited value of a potentiometer 30 to thereby ring an alarm unit 32.