The Research On Prediction Model Of Buoyant Jet In Industrial Building And Optimization Of Ventilation System

At present, a large number of dusts, which is diffused disorganized in steel metallurgy,coking and other heavy industries, have caused critical pollution of indoor environmentand big hazards of worker’s healthy. In addition, under the hot press action, the dustexhausts to the outside and make environmental pollution.The dust produced in industry production is influenced by thermal effect to formdusty buoyant jet, it is the main form of dust movement. The local exhaust system is themajor way to control dusty buoyant jet, its parameter designing is importantly base onthe flowing law of buoyant jet. So the study of flowing law of buoyant jet is importantto improve the capture efficiency of this kind of dust and reduce the pollution to theenvironment.This article summarizes the buoyant jet research status at home and abroad, on thebasis of combining relevant test data and deviation analysis to determine the accurateboundary conditions, to select the reasonable turbulence model, gas-solid two phaseflow model and species transport equations. The results showed that at the beginningsection the axis velocity growth rate of the buoyant jet increased as the Archimedesnumber (Ar) increased and at the fully developed section the axis velocity decreased asthe section height increased. Based on the analyses of the section flow rate and the axisvelocity of the buoyant jet influenced by temperature, velocity and outlet size, theirformulas were obtained. These results complemented the design basis of the exhausthood over the buoyant jet.Using species transport model to analyses the flow flied of buoyant jet undermechanical ventilation systems and to study the law of thermal stratification in the roomwhich exists general ventilation system and local ventilation system. Do some research on the law of the velocity field of buoyant jet under side suction hood and the law ofcapturing velocity at capture point under different capture efficiency. Using DPM modelto compute the buoyant jet dust particles under air curtain, it’s got how velocity andangle of air curtain and exhaust air rate to influence buoyant jet controls. We will get thebest air curtain design method through comparative analysis. Finally the conclusions wesummarized of buoyant jet can provide a reference for the design of the associatedproject.