HL638-WJ-84型水轮机增容改造及数值预测

Capacity enhancing remodelment and numerical prediction of HL638-WJ-84 hydraulic turbine

在无合适的新型转轮替代老转轮的情况下,可以采用减少叶片数以及切割叶片出水边的方法得到易于实施的改型转轮,从而达到增容改造目的.运用三维建模软件Pro/E进行建模,ICEM进行网格划分(非结构化网格),选用标准k-ω流模型以及SIMPLEC算法,Fluent 14.5进行水轮机全流道定常模拟计算,可以得到比较准确的水轮机外特性预测结果.水轮机全流动数值模拟计算可以为增容改造方案的可行性提供依据.以HL638-WJ-84型水轮机为研究对象,以减少转轮叶片数且切割出水边为改型方案,数值模拟了不同工况下改型前后水轮机的内部流动.外特性结果表明:改造后水轮机的最优效率区向大流量区域偏移,当转轮运行在限制工况时,改型后转轮出力比改造前增加16.35%.据此方案改造转轮,机组实际增容23%.

In the case of absence of suitable new-type runner to substitute outdated one,an easy-implemented modified runner will be achieved by means of reducing the number of blades and cutting the blade outlet edge,so that the goal of capacity enhancing remodelment will be achieved.Three-dimensional modeling software Pro/E is used to conduct modeling,ICEM is used to mesh dividing(unstructured grid),standard turbulence mode and SIMPLEC algorithm are selected to perform simulation and computation stationary flow in full flow-passage of turbine with Fluent 14.5,so that more accurate result of turbine external characteristics prediction can be obtained.This numerical simulative computation of full flow through turbine can provide a feasibility basis of capacity enhancing remodelment plan.An HL638-WJ-84 turbine is taken as research object,the reduction of number of blade together with cutoff of blade outlet edge is taken as modification plan,and then the interior flow of the turbine before and after modification is numerically simulated under different operational conditions.It is shown by the result of the external characteristics that the turbine optimal efficiency area will shift toward large flow area after modification and when the runner runs in limiting conditions,its output will increase by 16.35%after modification,According to this plan of runner remodelment,the actual capacity enhancement of the turbine unit will be 23%.