Development of Performance Deterioration Diagnosis Method for Gas Turbine Combined Cycle Power Plants

Abstract

It is necessary to maintain or improve the thermal efficiency of actual thermal power generation plants from the viewpoint of environmental problems. When the thermal efficiency decreases, it is crucial to identify the performance deterioration factors by appropriate energy management. However, it is difficult to understand the internal state of such plants sufficiently and to determine performance deterioration factors only from operation data. In particular, investigating the performance deterioration factors is very difficult in gas turbine combined cycle (GTCC) power plants because the performance changes markedly depending on atmospheric conditions. Therefore, we develop a method based on heat and mass balance analysis to calculate the immeasurable quantity of state and the component performance values in GTCC power plants, and to correct them to the values under standard conditions using the performance function obtained from long-term operation data. From the results, we can identify the main factors affecting the thermal efficiency deterioration of GTCC power plants using this method.