마이크로 가스터빈의 탈설계 운전 성능특성

초록

Most micro gas turbines are designed with low turbine inlet temperature and pressure ratio, thus simple cycle efficiency is very low. To overcome the efficiency defect, the regenerative cycle is an inevitable choice. The efficiencies of commercial micro gas turbines are around 30% which is much supported by the recuperator. We should also pay attention to the off-design performance of gas turbines since they usually operate at part-load conditions for a considerable amount of the time. This study aims at analyzing off-design performance characteristics of micro gas turbines and addressing the importance of the recuperator in the part load operation. Comparative analyses have been performed to evaluate the part load performance differences among various possible design and operating options : simple vs recuperative cycles, single vs two shaft configurations, various operating strategies for the single shaft configuration (fuel only control, variable speed operation, variable inlet guide vane control), and current vs advanced engines. Major finding is that maintaining turbine at high level is crucial in efficient operation of micro gas turbines.