基于正交试验的炉水循环泵导叶优化设计

Optimization analysis of vaned-diffuser of boiler water circulating pump based on orthogonal experiment

利用正交试验法对导叶进行优化设计,选取导叶进口安放角、扩散角、喉部面积为因素,根据正交表选取9组作为试验组,采用计算流体动力学(CFD)方法对各试验组进行数值计算分析,与原导叶性能对比并对结果进行极差分析.结果表明:不同的导叶参数对炉水泵性能影响程度不同,3个因素影响的主次顺序为进口安放角、喉部面积、扩散角,其中进口安放角对炉水泵扬程与效率影响程度不同,对扬程影响较大,其余对炉水泵扬程和效率影响程度相同;根据正交法所选取的最优试验组合为α_3=16.2°,θ=8°,F_3=37×50 mm^2.最后通过原导叶的模拟结果与真机试验数据的对比可知,数值计算方法是可行的.由此可知,正交法可用于炉水泵的优化设计,通过调整主次因素来提高炉水泵的性能,更好地为火电厂水循环提供保障.

Orthogonal experiments were used to optimize the vaned diffuser of a boiler water circulating pump. The inlet vane angle, diffusion angle, and throat area were selected as three factors in orthogonal experimental design. Each factor was subject to three levels, resulting in nine experimental designs. Fluid dynamics in every experimental design were calculated and analyzed by using CFD me- thod . The performances of nine experimental designs were compared with each other and a range analysis was conducted on the performances of nine experimental designs. The results show that selected design factors play different roles in determining the characteristics of the pump.The three factors are in a rank such as inlet blade angel〉throat area〉diffusion angle to influence the pump characteristics from the most important to the least important.Specially, the inlet blade angle has a greater influence on the head than on the efficiency, however, the rest have an equal influence on the head and efficiency. According to the results of orthogonal experimental designs, the optimal design should be 16.2° inlet blade angle, 8° diffusion angle and 37×50 mm^2 throat area.Since the predicted performance of the pump with original diffuser is in agreement with the measurement, the simulation data of nine experimental designs are accurate.It can be concluded that orthogonal experimental design method is applicable in the design of vaned-diffuser of boiler water circulating pump. By adjusting the primary and se- condary important factors, the pump performance can be improved to provide a reliable support to boi- ler water circulation in thermal power plants.