발전용 가스터빈의 성능 해석 모델에 따른 부분부하 운전 모사 정확도 비교

초록

Predicted partial load performance of gas turbines varies depending on the off-design analysis method of the turbine or the cooling air extraction modeling. This study aimed at investigating which analysis model can analyze partial load performance more accurately. In many previous studies, the turbine was assumed to be choked. In addition, a simplified extraction model was used in which cooling air was extracted only at the end stage of the compressor. These simplified models are indeed effective in high load ranges, where the compressor pressure ratio is high enough. However, they might not be feasible to use in the low load ranges. Therefore, in this study, partial load simulations were performed using two turbine models and accuracies were comparatively analyzed using filed operation data of an F-class gas turbine. In addition, the two cooling air extraction models were compared and the impacts of the cooling air property were analyzed. As a result, assuming choking, the mean error of the performance parameters was up to 14.7%, but the error was reduced to around 1% when using the turbine performance map. Also, by using the detailed extraction model, the mean error of the performance parameters was reduced by up to 0.7%p compared to the simplified extraction model, which enabled a more accurate analysis of actual operations.

키워드