离心泵关死点扬程的计算一直是一个难题。该文详细总结了目前各种离心泵关死点扬程的计算方法并给出了各种计算方法准确的数学表达式。通过对34台离心泵的实际计算与比较,分析了各种计算方法的精度和适用范围。分析结果表明,Euler方法计算的是离心泵关死点扬程的理论值,计算偏差大于60%;Throne计算方法的计算精度最高,平均偏差为4.29%;Stirling计算方法的精度最低,平均偏差为11.30%。以比转数作为自变量,采用非线性回归分析法对离心泵关死点扬程的7种计算方法分别进行了修正并给出了修正系数数学表达式和置信度。实例计算表明:修正后的各关死点扬程计算公式精度明显提高,适用范围更广,都能够为工程实际所应用。
How to calculate head of the centrifugal pump at shut off condition has been a difficult problem.The existing methods to compute head of centrifugal pump at shut off condition and their detail formula were introduced.Based on the practical calculation of 34 centrifugal pumps,the precision and application range of all methods were analyzed.The analysis indicates that the result of Euler method is theoretical head of centrifugal pump at shut off condition and its deviation is more than 60%.The precision of Throne method is the highest and its average deviation is 4.29%.The precision of Stirling method is the lowest and its average deviation is 11.3%.The specific speed was chosen as independent variable and non-linearity regression analysis was used to amend the seven methods.The revision formula and confidence parameters were presented.At last,5 centrifugal pumps were chosen to check up the regression analysis results and the practical application indicates that the precision of the modified formula is improved obviously and can meet the engineering requirement.