Study On Flow Field Characteristics Of The Task Air Conditioning In High Temperature Industrial Workshop Location Area

Dust,harmful gas and waste heat will be emitted due to the process of industrial production. Local ventilation is an energy savingway of the ventilation. Because industrial buildings are usually taller, workers operating position are fixed, setting local post air supply deviceto control the key areacan eliminate heat and harmful gas effect to human body and improve the local micro-environment of work areaeffectively, it also can reduce the energy consumption.At present the study of local task ventilation is mostly in the, and the environmental temperature of the civil constructionis higher than thecivil buildings. Besides,some industrial buildings, workers operating equipment or the workpieces may emit a lot of heat and then, forming high strength heat sources beside the workers. Some of these heat sources are distributed on the vicinity of the workers, directly affect the air environment of the station area, and another scattered in the workshop, affected the indoor air environment.The research of the high temperature and high strength heat source for industrial buildings of the location area is less, so it restricted the application of the local workshop air supply system.in order to play the advantage of the local post air supply system, provide design data for designers and promote the further popularization and application of local workshop air supply system, this paper adopts the method of numerical simulation and experiment, studies the main factors which influence the local micro-environment of work area. And the reliability of the numerical simulation is verified by the experiment.The main research content is as follows:First of all, we simulate the task air conditioning system at the top of the workshop and without the heat source. Then, we analysis the various design parameters(such as supply air velocity, air temperature, the size of outlet,etc) which are influence the flow field characteristics of the workshop task air conditioning system. Finally, we obtain some conclusions:at the top location,when the supply air temperature is 293 K and blowing distance is 1.1 m, the size of outlet is 0.3m×0.3m, the best air supply velocity is 0.8 m/s. When the supply air velocity increased from 0.4 m/s to 1.0 m/s, for every 0.2 m/s, increasing speed for location of supply air velocity is not uniform, the biggest increase of supply air velocity is from 0.4 m/s to 0.6 m/s. When the supply air velocity of 0.4 m/s, supply air velocity can reach 1.8 times, and the supply air velocity of 0.8 m/s, the speed increase of 1.1 times. When the supply air velocity of 0.6 m/s, if continue to increase the supply air velocity, the increase of the supply air velocity is small. Because of the supply air is cooled jet, it has a longer acceleration way after ejection from the outlet, so for the top location of task air conditioning, the larger size of the air supply outlet is preferred.Secondly, for the task air conditioning system which heat source at the top of the workshop,we simulate and analysis the different supply air speed, air supply temperature, distance of heat source and heat source intensity under the top for the flow field of air conditioning. When the distance of the heat source and the body is 0.8 m or more, the heat source have less effect on the flow field. When the distance is less than 0.8 m, the heat source will cause great influence to the field. The differences of the intensity of heat source have less effect on the field, when the difference of the heat source temperature is 100 ℃, their fields is nearly consistent.Finally, we simulate the lateral flow field. Compared to the top air supply system, side air supply system is less for the control part in the work place.And in the horizontal direction and vertical direction, particularly in the upper and lower section and the sides of bodies,will forms a larger temperature, speed, the concentration difference. The lateral size of the outlet make a decision to the scope of the control environment, bigger outlet and smaller velocity will be the best choice.