基于多工况数值试验的水轮机改造优化设计技术

Optimization Design Technique for Retrofit of Hydro Turbines Based on Multi-Condition Numerical Test

传统的水轮机改造方法是针对水电站水轮机中拟改造的过流部件和实际运行条件,采用类似新电站设计的多方案设计和模型试验进行性能对比来论证改造方案和验证设计。在水轮机改造过程中,因受到了已有流道的限制,其过流部件与新建电站的设计思路有很大的差异。我们根据水轮机改造中过流部件设计的特点,基于数字化设计与试验的思想,对整个流道进行联合的三维粘性流动数值模拟。在数值模拟的基础上进行性能预测,以数值试验取代模型性能试验,提出一套基于数值试验的水轮机改造技术,并简介在水电站水轮机改造中的应用情况。

The traditional way for retrofit of hydro turbines is a trial and error method by using the model tests with several design schemes based on modification of existing hydraulic passageway and operation condition.However,there exist big differences in methodology of research and development between the retrofit of turbine in old hydro power plant and design of turbine in new power plant,because there are many constraints and limitations in design of turbine passage parts to be retrofitted.In order to meet the requirement of the design for turbine passage to be retrofitted,numerical simulations of 3D viscous flow inside the integral hydro turbine passage at many operation conditions are carried out by means of digital design and numerical test.The performance of the retrofitted hydro turbine can be estimated based on numerical simulation so that the numerical tests can substitute for the model tests in the retrofit of a hydro turbine.Therefore,a new approach for retrofit of hydro turbines is presented,and some illustrations are also briefly introduced in this paper.