Inducer designing method based on centrifugal pump

Abstract

The invention relates to an inducer designing method based on a centrifugal pump, which belongs to the technical field of pumps. The method is characterized in that an inducer is designed based on a given centrifugal pump device. According to the inducer designing method based on the centrifugal pump, the inducer is designed by determining the flow, the pump lift, necessary net positive suction head and other experimental data at a point of the centrifugal pump with the highest efficiency, based on an external characteristic experiment according to the conditions of an existing water pump device. Consequently, the inducer acquires higher cavitation specific speed under the conditions of an outer diameter of a rim, inlet hub ratio and optimal inlet flow coefficient. Not only can the inducer be enabled to have good cavitation performance, but also the inducer has good energy matching relationship with a pump impeller, the performance of the inducer is improved, the operation stability of a system is enhanced, assembly difficulties caused by size difference between the pump and the inducer due to an original designing method can be prevented, the inducer designing efficiency is improved, and popularization value is realized.

Description

technical field [0001] The invention relates to a design method of main parts of a centrifugal pump, in particular to a design method of an inducer of a centrifugal pump. Background technique [0002] The inducer technology is currently known as one of the most effective ways to improve the cavitation performance of centrifugal pumps and is widely used. The inducer belongs to the axial flow impeller, which is used to improve the cavitation performance of the centrifugal pump, and it can also work in a certain degree of cavitation state. In the actual design situation, the design of the inducer is often carried out in order to improve its cavitation performance after the pump device has been determined. In this case, there are some deficiencies in the existing design method of the inducer: in the existing design method, the design of the pump and the inducer is often completed independently, which will cause the diameter of the inducer outlet to be larger than the diameter o...

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Problems solved by technology

In this case, there are some deficiencies in the existing design method of the inducer: in the existing design method, the design of the pump and the inducer is often completed independently, which will cause the diameter of the inducer outlet to be larger than the diameter of the pump inlet. The outlet diameter of the inducer will reduce the head of the inducer and affect its efficiency; if the outer diameter of the inducer remains unchanged, it will cause difficulty in assembly, and it is necessary to adjust the pipeline at the pump inlet and install connecting devices such as conical guide sleeves , increased the cost of production and testing, and brought unnecessary troubles to production testing

[0003] After searching, there is no patent publication related to the present invention, but it is only mentioned in some documents, "Study on the Matching Relationship between Inducer and Pump Main Impeller" (Water Pump Technology, 1999, 9: 7~9, 13), It is proposed to increase the diameter of the pump inlet to achieve the optimal cooperation between the pump and the inducer, but this method cannot be applied to the design of the inducer when the pump device has been determined; "Design Analysis of High-speed Pump Variable Pitch Inducer" ( Journal of Agricultural Mechanics, 1997, 28 (4): 102~106), proposed a variable-pitch inducer design method, the design structure is that the outer diameter of the inducer is larger than the inlet diameter of the pump impeller, this structure needs to be placed between the inducer and the impeller Installing a conical guide device between them and changing the shape of the impeller rear cover plate has brought unnecessary troubles to the production test, and because the radial dimension of the inducer is too large, it will make the inducer not run smoothly. increased stability

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