多级轴流式膨胀机的多学科优化设计

Multidisciplinary Optimization Design of Axial Flow Expander

膨胀机是有机朗肯循环系统中的核心动力部件,本文通过建立基于多目标优化算法MOGA的多学科优化平台,对5MW有机朗肯循环中的两级轴流膨胀机的流通部件参数化建模,应用叶片空间切向积叠规则进行叶片倾和弯造型,在动叶和静叶栅耦合上寻求最优解。原型膨胀机经优化后,工况1下的总-静效率提高1.23%,输出功率提高1.1%,轴向推力减小4.5%,两级动叶的最大等效应力均小于材料屈服极限。动叶片预应力处理下的前六阶模态计算结果表明,工作转速频率激励和静叶通过频率激励判定合格。

Expander is the key power component of Organic Rankine Cycle system.This paper establishes a multidisciplinary optimization platform based on multi-objective optimization algorithm MOGA.Through the parametric modeling of the flow components of two-stage axial-flow expander in 5 MW organic Rankine cycle,the blade inclination and bending modeling are carried out by using the blade space tangential stacking rule,and the optimal solution is sought on the coupling of dynamic and static cascades.In case 1,the total static isentropic efficiency increase 1.23%,the power increase 1.1%,the axial thrust reduce 4.5%after optimization.The maximum equivalent stress of the two stages of the rotor blade is not more than the yield strength of the material.In the study,the top six modes of the dynamic blade under the pre-stress treatment are analyzed.The frequency excitation of the dynamic speed and the frequency excitation of the stationary blade are determined,and the results are qualified.