文章來源： 作者：羅茨機電 發布時間：2022-04-08 瀏覽次數：504
In daily life and industrial fields, fan is a very common and widely used mechanical equipment. Its main function is to provide ventilation and pneumatic pressure difference to realize dust removal, heat dissipation, ventilation and pneumatic conveying. Centrifugal fan is a typical turbine fluid machinery with dynamic and static components. Aerodynamic noise is generated with the work process of centrifugal fan. Ensuring that high-pressure centrifugal fan maintains good sound quality during the work process is one of the hot research directions of scholars in relevant fields at home and abroad. What are the local flow fields of high-pressure centrifugal fan?
1. Secondary flow high pressure
The secondary flow of centrifugal fan is a bad flow field state inside the fan. The flow channel between blades is composed of the suction area on the back of the front blade and the extrusion area in front of the rear blade. The disharmony between the blade clearance and speed design of the fan will lead to the mismatch between the extrusion of air flow and the filling of local vacuum and the rotation of blades, and the two air flows form secondary flow locally. Others are mainly due to the effect of the pressure zone in the blade clearance channel under the blade speed, resulting in high speed and high pressure at the front end of the blade. Therefore, reasonable blade design and speed matching are very important for the work of the fan. Therefore, reducing the generation of secondary flow is a better way to improve the efficiency of the fan.
2. Gap flow in air flow
When entering the impeller channel from the collector, due to a certain gap between the impeller and the volute boundary, part of the air flow enters the narrow gap, forming a local backflow between the impeller and the volute. The flow velocity of the fluid in the gap decreases rapidly and remains in the gap. The outlet meets with the main flow channel of the impeller volute to form a circulating reflux. The gap flow can be understood as the pressure loss caused by the diversion of the main channel to the narrow tributary, which is also an unhealthy state of the flow field in the fan. There is a large circle of circulating flow between the impeller and the volute. This irregular flow phenomenon further increases the pressure pulsation of the volute and blade, which has a certain impact on the aerodynamic noise of the fan.
In the field of vehicles, high-pressure centrifugal fans are mostly used in road sweepers, which is a new type of urban environmental protection and sanitation vehicle. Previously developed by foreign teams, this model integrates the functions of road garbage cleaning, collection and transportation, greatly improves the cleaning efficiency, saves labor costs, and can better control urban road pollution. After introduction, digestion, absorption and innovation, this type of vehicle has become the main equipment for environmental sanitation in some large and medium-sized cities.
The above is the detailed introduction of Shaanxi centrifugal fan manufacturers. I hope it will be helpful to you If you have any questions, please contact us We will provide you with professional service http://www.makemoore.com