A counter-rotating blower and a shaft power matching method of the counter-rotating blower

Abstract

The invention discloses a counter-rotating fan and a shaft work matching method of the counter-rotating fan. The method comprises the steps that in the design stage, according to performance indexes of shaft work, flow and air pressure of design conditions provided by a client, a motor meeting shaft work requirements is selected, the rotating speed, diameter and blade angle of a front-stage impeller are designed and determined, the rotating speed and blade angle of a rear-stage impeller are determined according to the rotating speed ratio S of the front-stage impeller to the rear-stage impeller and the ratio K of the tangent value of the air outlet angle of the front-stage impeller to the tangent value of the air outlet angle of the rear-stage impeller, the front-stage impeller and the rear-stage impeller are the same in hub diameter and equal in outer diameter, finally, the front-stage impeller and the rear-stage impeller meeting the requirements are assembled to manufacture the counter-rotating fan, the front-stage impeller and the rear-stage impeller achieve the largest shaft work output simultaneously at the design work condition point, and at the non-design work condition point, no matter whether the flow is too large or too small, the shaft work of the rear-stage impeller is always the same as that of the front-stage impeller and smaller than the largest shaft work.

Description

technical field [0001] The invention relates to the technical field of induced draft equipment, in particular to a counter-rotating fan and a shaft power matching method of the counter-rotating fan. Background technique [0002] Counter-rotating fans are widely used in tunnels, mines, aviation and other fields. In the design working condition, the counter-cyclone fan has the advantages of large flow rate, high pressure rise, and high efficiency, and the power and pressure rise characteristics of the two-stage impeller are roughly equal, and the efficiency is also high. However, when the working condition deviates from the design, the two-stage impeller The pressure rise, power and efficiency characteristics are quite different, especially the pressure rise, power and efficiency characteristics of the rear stage impeller change drastically with the flow rate, and are greatly affected by the change of flow rate. If the pressure rise and power rise too fast, it will easily lea...

AI Technical Summary

Problems solved by technology

In the design working condition, the counter-cyclone fan has the advantages of large flow, pressure rise, and high efficiency, and the power and pressure rise characteristics of the two-stage impeller are roughly equal, and the efficiency is also high. However, when the working condition deviates from the design, the two-stage impeller The pressure rise, power and efficiency characteristics are quite different, especially the pressure rise, power and efficiency characteristics of the rear stage impeller change drastically with the flow rate, and are greatly affected by the change of flow rate. If the pressure rise and power rise too fast, it will easily lead to the overload of the rear-stage motor; under the condition of large flow, the pressure rise and efficiency of the rear-stage impeller will drop too fast as the flow increases, and even the pressure rise will be zero.

When the flow rate changes, it is necessary to dynamically adjust the speed of the rear-stage impeller in real time according to the working conditions, which cannot automatically match the shaft work of the front-stage impeller and the rear-stage impeller of the counter-cyclone fan

Images