汽轮机排汽缸加强筋板的优化设计及影响

Optimized Design of a Plate Stiffener for Steam Turbine Exhaust Hood

采用拉丁立方试验设计、三阶响应面近似及Hooke-Jeeves直接搜索算法的组合优化策略对排汽缸下部的加强筋板进行了优化设计,并通过选取大量样本点,研究了加强筋板不同几何参数对排汽缸气动性能的影响,同时在变工况下对筋板优化后的排汽缸进行了校核计算.结果表明:筋板到排汽缸子午平面的距离X和筋板倾角θ对排汽缸气动性能影响较大,而筋板底边到排汽缸出口的距离Y和筋板长度L对排汽缸气动性能影响较小;合理布置筋板,可有效提高排汽缸的静压恢复能力,降低出口不均匀性,但也会增加一定的总压损失.

An optimization was conducted to the design of a plate stiffener located in the lower area of steam turbine exhaust hood using Latin hypercube experiment design, cubic response surface model and Hooke- Jeeves direct search technique. Based on numerical investigation of a large number of samples, the influ- ence of different geometric parameters of the stiffener was studied on the aerodynamic performance of the exhaust hood, which was examined under variable conditions after optimization. Results show that both the distance between the stiffener and the meridian plane X as well as the dip angle of the stiffener 0 have large influence on the aerodynamic performance of the exhaust hood, while the distance between the stiff- ener bottom and the hood outlet Y as well as the length of the stiffener L have little influence. The static pressure recovery coefficient can be improved effectively by arranging the stiffener appropriately, when the outlet non-uniformity would be reduced; however, this may lead to a certain loss of the total pressure.