Changes the Governor Valve Operation Mode to Improve Efficiency HP Turbine

Abstract

AbstractIn the turbine governor valve (GV) operating system there are two modes, that is single mode and sequence mode. Single mode is GV operation with the same % valve opening between numbers one until four, while sequence mode is GV operation that varies between numbers one until four. In August 2020, the GV turbine unit 1 changed the operating mode, which previously used single mode since commissioning in 2014 and changed it to sequence mode. In this mode change, look for differences in values, especially on the efficiency of the high pressure (HP) turbine. The aim is to find out whether this change in operating mode has an impact on the performance of the unit 1 steam power plant. The data collected in this process are steam operating parameters which are used to calculate HP turbine efficiency with single mode and HP turbine efficiency with sequence mode. For data accuracy, these parameters are taken from DCS with the same load of 196 MW, the same coal source and calorific value. The method used to calculate the efficiency of the HP turbine is to use the first law of thermodynamics which is in accordance with the standard EPRI Heat Rate Improvement Reference Manual TR-109546. At a load of 196 MW, the efficiency of the HP turbine with single mode operating mode is 79.96%, and with sequence mode operating mode is 82.55%. From the change in operating mode, there is an increase in the efficiency of the HP turbine so that the performance of the generator is increasing.KeywordsGovernor valveHigh pressure turbineEfficiencySingle modeSequence mode