OPTIMIZATION OF COMBINED-CYCLE POWER PLANT EFFICIENCY THROUGH ONLINE CONDITION MONITORING AND MODEL BASED PERFORMANCE PREDICTION

摘要

Over 40% of the total electrical energy in Malaysia are generated by Combined-Cycle Gas and Steam Turbines power plant. Combined-Cycle has the advantage of higher conversion efficiency as compared to single-cycle power plant. For a combined-cycle plant, the required total block power output can be obtained by running the individual gas turbines at different loads. However, the overall conversion efficiency will not be the same under all combinations. For a new plant with the same gas turbines efficiency curves, the maximum conversion efficiency will be achieved when both gas turbines are firing equal load. However, after many hours of operation, the efficiency of individual gas turbines will be different and hence the combination that gives maximum block efficiency will change. Under this condition, to achieve maximum block efficiency, the optimum combinations with the current health of the machine need to be found. This paper describes the development of a program that can find this optimum combination and its implementation at Paka power plant. The program is combined with an integrated condition monitoring system, TURBOWATCH, which stores the historical data on the component efficiencies of the plant. The verifications with field data from the power plant are also included.