某MW级燃机低压离心压气机优化设计
Optimization design of a low pressure centrifugal compressor in a MW size gas turbine

为了优化离心压气机叶轮与扩压器的匹配特性, 该文开发了基于iSIGHT的1维优化设计系统。针对某MW级燃机低压级离心压气机, 对其几何参数及匹配特性进行了优化设计。计算结果表明:原始设计中扩压器与叶轮不相匹配, 无叶扩压器径比过大, 从而导致整级效率偏低。根据1维优化计算结果, 在3维上对扩压器进行了重新设计,减小了无叶扩压器径比, 并采用串列式有叶扩压器代替了原有单级有叶扩压器。与原始设计相比, 优化后的离心压气机整级性能有了明显改善, 压比提高了约4%, 效率提高了约2%。
Abstract：A one-dimensional optimization design system based on iSIGHT was used to optimize the matching of a diffuser with a centrifugal impeller. The system was then used to optimize the geometry and matching characteristics of a low pressure stage centrifugal compressor for a MW size gas turbine. The results show that the diffuser and impeller are not well matched in the original design. The diameter ratio of the vaneless diffuser is too large, resulting in low efficiencies throughout the entire stage. The one-dimensional optimization results are used to redefine the diffuser geometry to improve the performance. The vaneless diffuser outlet diameter is reduced and the original single stage diffuser is replaced by a tandem vane diffuser. The optimization significantly improves the performance of the entire stage. The pressure ratio is increased by about 4% and the efficiency is increased by about 2%.