| The counter-rotating fan, which has the merits of compact structure, highefficiency, and good performance, is being more and more widely applied as theventilating equipment in mines. However, with the increase of excavation depth,higher requirements are put forward for the fan. Therefore, further researches ondesign theory and optimization method are still needed.This paper makes an overview about the overseas and domestic research statusof counter-rotating fan first, and then presents its relevant theoretical knowledge inbrief. On this basis, regarding the FBDCZ series fan as research object, mathematicalmethods to calculate the value of all performance parameters are introduced, specificsteps to derive the parametric equation of a given pipe network are listed, anddifferent curves to describe the operation conditions are obtained. When theventilation distance gets longer, the rear motor is often burnt down. According to theobtained values and curves, possible cause that gives rise to this phenomenon isanalyzed. At the same time, an appropriate way to solve this problem is offered, thatis, adjusting the working point of fan by altering the speed matching type.In order to prove the feasibility of this method, three-dimensional entity modelof the counter-rotating fan is established by using the software SolidWorks. Besides,analysis are made on the flow path and pressure distribution diagrams as well as thecharacteristic curves obtained by using the software FLUENT.At last, the winding type of the pole-changing motor is discussed. The conceptof balanced winding is proposed, the method of constructing it is explained indetail， and the general derivation process of its magnetomotive forces presented. Useful conclusions were obtained after analyzing the harmonic magnetomotive forceof the balanced winding with specified pitch through an example. |
PDF Full Text Request