Method for determining centrifugal pump full-condition theoretical lifts based on internal flow measurement

Abstract

The invention discloses a method for determining centrifugal pump full-condition theoretical lifts based on internal flow measurement. The process of the method includes using internal unsteady flow dynamic rules under different working conditions of a performance intercross valuation (PIV) experiment measurement centrifugal pump; calculating theoretical lifts of the centrifugal pump under different working conditions; using an overall optimization algorithm or combination to solve flow angle coefficients under the different working conditions, performing PIV measurement on internal flows of centrifugal pumps at different specific speeds and obtaining different flow angle coefficients k alpha 1, k alpha 2 and k alpha 3 at the different specific speeds and under the different working conditions, and utilizing a unitary linear regression method to build a relation between the flow angle coefficients and the specific speeds under the different working conditions and further build a centrifugal pump full-condition theoretical lift formula. According to the method, the centrifugal pump full condition theoretical lifts under the different working conditions can be calculated accurately, and a centrifugal pump full condition energy performance calculation model is built on the basis to optimally design a prior pump.

Description

technical field [0001] The invention belongs to the field of energy performance calculation of a centrifugal pump, and in particular relates to a method for determining the theoretical head of a centrifugal pump under full working conditions based on internal flow measurement. Background technique [0002] At present, the calculation of the theoretical head of a centrifugal pump is generally based on the premise that the circumferential component of the absolute velocity of the liquid at the impeller inlet is equal to zero. Under design conditions, the absolute liquid flow angle at the impeller inlet is close to 90°, so the circumferential component of the absolute liquid velocity at the impeller inlet of the centrifugal pump is small and can be assumed to be zero. For non-design conditions, especially small flow conditions, the absolute liquid flow angle at the impeller inlet is much smaller than 90°, but if it is assumed that the circumferential component velocity at the i...

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Problems solved by technology

[0003] So far, there has been no literature report on the method of determining the theoretical head of the centrifugal pump under all working conditions. Only some scholars have done research on the calculation or correction of the theoretical head of the centrifugal pump under the design working condition, and the influence of the peripheral speed at the impeller inlet is basically not considered.

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