无过载双流道排污泵性能预测研究

Research on the Performance Forecasting of a Non-overload Double-channel Sewage Pump

在进行无过载双流道排污泵设计时,利用公式预测的性能和试验结果有较大误差。对此,通过流动分析指出,普通离心泵相对液流角与叶片出口安放角相差不大,而在双流道叶轮出口速度三角形中,相对液流角与叶片出口安放角相差较大,因此,用叶片出口安放角进行性能预测是造成误差的主要原因。提出了双流道泵无过载性能预测的计算方法:!2应取叶片背面出口安放角;计算叶片排挤系数时,叶片厚度应取内流道出口处叶片厚度。试验表明,该计算方法能大大提高性能预测的准确性,预估最大轴功率值及其位置较普通计算方法误差大幅度减小。

In the design on a non-overload double-channel sewage pump, compared to the test results, the performances forecasted by the formula have greater error. Flow analysis indicated that the relative flow angle of an ordinary channel impeller vel centrifugal pump impeller almost equaled to the blade outlet angle, and in the doubleocity triangle, the relative flow angle is quite different from the blade outlet angle, so using the blade outlet angle to forecast performance was the mair, reason of causing errors. In this thesis a non-overload performance forecasting method of the double-channel pump was provided： B2 is the blade back outlet angle; when calculating the blade expelling coefficient, blade thickness should be the inner channel one. The testing shows that the method can greatly increase the accuracy of performance forecasting, and the error of the estimated maximum axis power value and its place is much more less than the ordinary method.