Numerical Simulation And Experimental Study On Flow Field Characteristics Of Vertical Uniform Push-pull Ventilation Device

The occupational health,safety and environmental problems caused by indoor dust and toxic pollutants in industrial plants are becoming increasingly serious.The vertical uniform push-pull ventilation device can effectively control dust and toxic pollutants in industrial plants and improve indoor air quality.The flow field characteristics of the device have an important influence on the control effect of dust and toxic pollutants.Therefore,the flow field characteristics of the device need to be clarified in order to improve the application effect.Based on the theory of computational fluid dynamics,the physical models of the main components and devices of the vertical uniform push-pull ventilation device are built by three-dimensional modeling method.Fluent software,multi-channel wind velocity monitoring experiments and smoke generation experiments are carried out to study the flow field characteristics of the vertical uniform push-pull ventilation device.The research indicates that:(1)The results of numerical simulation analysis are consistent with the results of multi-channel wind velocity monitoring experiments and smoke generation experiments.It is accurate and feasible to use the numerical simulation method to study the flow field characteristics of the vertical uniform push-pull ventilation device.(2)With the increase of the radius of curvature R of the 90° rectangular elbow,the wind velocity non-uniformity is significantly reduced,the airflow uniformity is improved by 33.86%,and the wind pressure gradient is significantly reduced by 30.13%.In the engineering application of the vertical uniform push-pull ventilation device,the elbow with R = 2.5h can be used as the best design structure for the 90° rectangular elbow.(3)The parameter of the holey board,which is 45° arrangement,opening ratio ?=0.29,aperture d=2 mm,can guarantee the best effect on improving of the airflow uniformity.In the case of optimal parameters,the airflow uniformity of the vertical uniform push-pull ventilation device with the double-layer holey board is twice as high as that of the single-layer holey board.(4)When the wind velocity ratio k=1.75 of the air supply hood and exhaust hood of the vertical uniform push-pull ventilation device,the whole dust and toxic pollutants in the flow field can be captured.Under this working condition,it can effectively control the dust and toxic pollutants in the indoor working environment of industrial plants,and guarantee the occupational health,safety and work efficiency of the operators with lower energy consumption.