大转差对转涡轮一体化过渡段多目标优化与分析

Multi-objective Optimization and Analysis of Integrated Inter-Turbine Duct in a Counter-rotating Turbine With Large Rotation Speed Ratio

针对某大转差对转涡轮性能提升需求,首先,分析了原燃气涡轮性能的不足,确定优化一体化过渡段(IITD)作为性能提升的手段;其次,基于iSIGHT2020,集成Numeca13、CFX19及自编程序,搭建了三维气动优化平台,其所需的计算机存储空间仅为原优化系统的9.42%,极大地降低对存储空间的要求;最后,考虑上游级出口气流参数、涡轮进口流量、对转涡轮级间、级内功分配,并兼顾与下游低压涡轮动叶适配性这5个约束条件,基于该优化平台,对IITD进行多目标气动优化。结果表明:满足上述5个约束条件,IITD总压恢复系数提高1.27%,IITD进口至叶片前缘,叶片最大厚度至IITD出口这两个区域的损失占总损失的比例达66.0%以上;低压涡轮功率提高0.78%,效率提高0.28%;燃气涡轮功率提高0.23%,效率提高0.17%。非设计点工况,IITD总压恢复系数及低压涡轮性能也均得到提升。

For improving the performance of a counter-rotating turbine with large rotation speed ratio,firstly,the shortcoming of the original gas turbine performance is analyzed, it is determined to optimize the integrated inter-turbine duct(IITD) as a means to improve the performance;Secondly,based on optimization platform iSIGHT2020, a 3D integrated aerodynamic optimization system is developed with Numeca13, CFX19 and self-program, only 9.42% of the computer storage space is required compare with the original optimization system;At last, considering five constraint condition which are the distribution of upstream stage outlet flow, inlet mass flow of turbine, internal stage and inter stage power distribution of the counter-rotating turbine, and the matching of downstream low pressure turbine(LPT) rotor, the IITD has been optimized base on the optimization system.The results show that under these five constraints, total pressure recovery coefficient of IITD is improved 1.27%, the losses between IITD inlet and the leading edge of the blade, the losses between maximum thickness of the blade and the IITD outlet, accounted for above 66.0% of the total losses;the power of LPT is improved 0.78% and the efficiency is improved 0.028%, also the gas turbine power is improved 0.28% and efficiency is improved 0.17%. Under the off design conditions, total pressure recovery coefficient of IITD and the efficiency of LPT are also improved.