A Design Method of Axial Flow Pump Impeller under All Working Conditions

Abstract

A method for designing the impeller of an axial flow pump under full working conditions, comprising the following steps: (1) Parametric modeling of the impeller of the axial flow pump: selecting k airfoil sections of the axial flow pump impeller, the cascade density and the total value of the airfoil placement angle 2k design parameters; (2) Optimal design for all working conditions: First, determine the conventional design parameters of the impeller; then perform numerical calculations on the design working conditions of the axial flow pump impeller, comprehensively analyze various losses in the pump, and minimize the total loss Preliminary design of a pair of axial flow pump impellers with better hydraulic performance under the design working conditions; second, design guide vanes, water guide cones and water inlet and outlet channels for the impeller; The optimal weighted average efficiency is the goal, and the head is the constraint condition. The sequential quadratic programming method of the gradient optimization algorithm is used to continuously change the design parameters of the axial flow pump impeller, and iterative numerical calculations are performed on the pump device. The invention adopts CFD numerical calculation, has high design precision and reliable optimization result.

Description

technical field [0001] The invention relates to a method for designing the impeller of an axial flow pump under all working conditions, and belongs to the technical field of water conservancy and power engineering. Background technique [0002] The traditional axial flow pump design method is a single design method only according to the design working conditions, that is, a certain set of design flow and design head values ​​are put forward according to the application occasions, and the design of the whole pump is carried out, but the so-called design working conditions are actually only the head. - A point on the flow (H-Q) performance curve. The design using the traditional design method only guarantees the performance of the design point under ideal fluid and idealized flow conditions. As for the performance under non-design conditions, it cannot be guaranteed in the design, or can only be obtained from experiments. . In most cases, the site where the axial flow pump i...

AI Technical Summary

Problems solved by technology

However, the traditional axial flow pump design method one-sidedly pursues higher efficiency requirements under design conditions, ignoring other hydraulic performance requirements

Therefore, the traditional design method of this design condition will be increasingly unable to meet the increasingly complex production requirements. The defects of the traditional design method of the axial flow pump impeller mainly include the following aspects:

[0003] 1. The theory of the method is the Euler equation, and the Euler equation only establishes the relationship between the external characteristic parameters and the speed of the impeller inlet and outlet of the axial flow pump, and does not analyze the flow field and pressure field inside the impeller, although some designs consider the liquid Viscous effects, corrected by empirical formula, but still too rough

[0004] 2. The design process is aimed at the impeller of the axial flow pump itself, without considering the influence of the guide vane, inlet and outlet water passages and other flow components on the internal flow of the axial flow pump and the performance of the axial flow pump

[0005] 3. The design process is oversimplified, with large human factors and large errors

[0006] 4. The performance of the axial flow pump under non-design conditions cannot be balanced, and the efficiency under design conditions can only reach the level of the statistical data, and it is difficult to further improve

[0007] 5. The design is carried out sequentially, without considering the interaction between upstream and downstream and various losses

Images