海水淡化能量回收透平水力模型优化设计

Optimization design of hydraulic model for seawater desalination energy recovery turbine

为提高反渗透海水淡化系统中能量回收透平的回收效率,对透平叶轮的水力模型进行优化设计,分析透平叶轮几何参数交互作用对叶轮性能的影响规律,得到透平叶轮性能最佳时的几何参数.以叶片进口角、叶片出口角和叶片数为试验因素,透平水头和水力效率为试验指标,基于BBD试验设计方法对透平进行多参数组合的数值计算,并采用响应面分析法对试验数据进行处理和分析,建立试验因素对试验指标的回归方程.结果表明:当透平叶片进口角为28.8°,出口角为23.3°,叶片数为7时,透平的水力性能最优,在设计工况下,优化透平的扬程比原型高6 m,优化透平的效率比原型提高0.8%;叶片数对透平性能的影响最大,叶片出口角对透平水头的贡献率比叶片进口角大,而叶片进口角对透平效率的贡献率比叶片出口角大.

In order to improve the recovery efficiency of the seawater desalination energy recovery turbine in the reverse osmosis seawater desalination system.The hydraulic model of turbine impeller was optimized,and the influence law of the interaction between turbine impeller geometric parameters on its performance was analyzed,and the geometric parameters of turbine impeller with best performance were obtained.The inlet angle,outlet angle and number of blades were taken as test factors,turbine head and hydraulic efficiency were taken as test indexes.The multiple parameter combination numerical calculation of turbine was carried out based on the BBD test design method,and the response surface analysis method was used to process and analyze the test data.The regression equation between test factors and test indexes was established.The results show that when the inlet angle of turbine blade is 28.8°,the outlet angle is 23.3°,and the number of blades is 7,the hydraulic perfor-mance of the turbine is the best.Under design condition,the head of the optimized turbine is 6 m higher than that of the prototype,and the efficiency of the optimized turbine is 0.8%higher than that of the prototype.The number of blades has a great influence on the turbine head and efficiency.The blade number has significant effect on the turbine performance.The contribution rate of blade outlet angle to turbine head is larger than that of blade inlet angle,and the contribution rate of blade inlet angle to turbine efficiency is greater than that of blade outlet angle.