Simulation Research On Ventilation Optimization Of High-temperature Workshop Under Negative Pressure

Due to the requirements of production,some of industrial buildings are large space.there is a large amount of waste heat and aerosol generated in the process of production,so a semi-closed exhaust cover is set up on the upper part of the equipment.Local ventilation removes most of the heat and aerosols and maintains negative pressure,while the remaining heat in the plant and aerosols in the working area are discharged by general ventilation.The thermal environment and aerosol diffusion in the workshop can be controlled through the coupling action of overall ventilation and local exhaust.This paper takes hengyang local a nuclear industry building as the research object,using Fluent software to optimize and simulate the air distribution in the workshop.The conclusion can provide a reference for optimizing the environment in a tall space.The main contents of the research include the following aspects:(1)According to the characteristics of the heat source that needs to be controlled in the plant,the initial physical model of the local exhaust hood is established,and the three parameters of the distance between the intake of the exhaust hood and the control point,the length of the extended hood under the exhaust hood and the size of the exhaust hood opening are determined.Carry out structural optimization and determine the structural parameters of the local exhaust hood when meeting production requirements.(2)The influence of the air inlet temperature of the local exhaust hood,the temperature of the outer wall of the heat source and the temperature of the inner wall of the exhaust hood on the heat exhaust effect of the exhaust hood is studied,and the change of the air temperature distribution and the heat output in the exhaust hood is analyzed.(3)According to the structural characteristics of the plant and the layout of the heat source,determine the overall ventilation air organization plan,calculate the relevant parameters of the air organization,and provide a reference for the boundary conditions of the numerical simulation.Compare and analyze the influence of different air organization forms on the thermal environment in the factory building,and discuss the advantages and disadvantages of the thermal environment in the working area of the factory under different air distributions.(4)Compare the aerosol concentration change of the two kinds of air flow to determine whether setting a comprehensive exhaust outlet under the roof is beneficial to the control of aerosol in the workshop;The influence of "upper exhaust" ratio on aerosol control was studied.