Centrifugal fan volute profile design method

Abstract

The invention relates to a centrifugal fan volute profile design method. The method comprises the steps that three control points of A, B, and C are determined; coordinates on a theta angle distance d coordinate system of the three control points of A, B, and C are calculated and determined, three control points is drawn on the theta angle distance d coordinate system, and the three control points are fitted to a continuous curve; the coordinates of the three points of A, B, and C on the theta angle distance d coordinate system is converted into coordinates on a polar coordinate system; a volute profile is drawn. The centrifugal fan volute profile design method is simple, the volute profile drawn according to the method is capable of controlling volute sectional area distribution, and the volute sectional area increasing according to a designated law can be ensured; at the same time, by controlling the coordinate of A, centrifugal fan volute tongue position and volute tongue gap size can be controlled; the diffusion effect of the centrifugal fan volute can be effectively improved, fan outlet total pressure is increased in a certain range, the flow loss in the volute is reduced, and the fan overall efficiency is improved.

Description

technical field [0001] The invention relates to the technical field of centrifugal fluid machinery, in particular to a method for designing a spiral case profile of a centrifugal fan. Background technique [0002] The role of the centrifugal fan volute includes two points, one is to collect the fluid flowing out of the impeller, and the other is to convert the kinetic energy of the high-speed fluid flowing out of the impeller into the required potential energy. The volute profile is the boundary that constrains the fluid movement inside the volute, and it also determines the position of the volute tongue and the size of the volute tongue gap, which has a great impact on the diffusion performance of the volute. [0003] At present, most of the design of the outer profile of the volute is based on the assumption of equal circulation distribution or equal velocity distribution. However, there is a huge unsteady flow in the actual flow in the volute. The parameter distribution ...

AI Technical Summary

Problems solved by technology

[0003] At present, most of the design of the outer profile of the volute is based on the assumption of equal circulation distribution or equal velocity distribution. However, there is a huge unsteady flow in the actual flow in the volute. The parameter distribution is uneven, and the assumptions in the design process often do not correspond to the actual situation

Secondly, the current volute profile design method lacks the control of the distribution of the volute cross-sectional area on the circumference method and fails to determine the position of the volute tongue and the size of the volute tongue gap

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