Minimum wetted perimeter volute section numerical value solving method based on speed moment conservation principle

Abstract

The invention discloses a minimum wetted perimeter volute section numerical value solving method based on a speed moment conservation principle. When all section of a volute are solved through the speed moment conservation principle, the target of reducing the wetted perimeter, namely the friction area, of the sections is persisted, and thus the hydraulic efficiency of the volute can be easily improved. Two symmetrical straight lines are still used on the lower portions of the sections of the volute on the axis face to form an axis face stream line without a turn, compared with a traditional trapezoid section, the difference that a circular arc in tangent to the two straight lines replaces the structure of two transition circular arcs exists, and the perimeter of the volute is obviously reduced than that of the traditional structure. By means of the two-straight-line type waist at the lower portion of the section mode, water flow entering the volute from an impeller can be prevented from disengaging, the arch formed by the upper single circular arc reduces the section wetted perimeter, and the friction loss of the water flow along the pass is reduced. The numerical value solving method and process for calculating and acquiring all geometric dimensions of the novel section are provided, meanwhile, the stress distribution in the volute becomes more even through the structure, and a possibility is provided for reducing the wall thickness of the volute.

Description

technical field [0001] The invention relates to a section design method of a volute of a centrifugal pump, in particular to a method for numerically solving the section of the volute with a minimum wetted circumference based on the principle of conservation of velocity moment. Background technique [0002] Centrifugal pumps account for most of the millions of domestic pump products each year. Improving the efficiency indicators of such pumps has social and economic value that cannot be underestimated for achieving the macro goal of energy saving and emission reduction. The spiral volute is the basic pressurized water chamber form of the centrifugal pump. The main body of the spiral volute is a spiral tube with a gradually increasing cross-sectional area arranged around the impeller, such as figure 1 . When the water flow enters the volute from the impeller, since there is no external force to do work on the water flow, the mechanical energy of the water cannot be increased....

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Problems solved by technology

It can also be seen that these two methods have a common deficiency: neither of the two methods takes the pursuit of the minimum friction loss in the flow of the volute as the goal, and neither of them includes ensuring that the volute can minimize the cross-sectional wetness under the condition that the volute realizes its basic functions. week length intent

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