Study On Characteristics Of Hybrid Ventilation With Machinery Supply In Large Industrial Buildings

Natural ventilation is one of the main ventilation mode of industrial architecture,in actual industrial buildings,however,because of the limit of auxiliary shelter and technology will be reduced the area of natural ventilation,exist within the industrial buildings often intensity bigger heat source at the same time,these can lead to the development of industrial buildings natural ventilation system can't satisfy the requirements of indoor thermal environment.In order to improve the internal thermal environment of industrial buildings,mechanical air inlet is added to the original natural ventilation system to form a hybrid ventilation system assisted by mechanical air inlet.In this paper,the ventilation characteristics of the hybrid ventilation system in large industrial buildings were studied numerically under the condition of summer meteorological parameters summer in Xi 'an.In this paper,the ventilation effect of natural ventilation system in industrial buildings is studied numerically under the conditions of insufficient natural air intake area and large indoor heat source intensity.It is found that the reduction of natural air intake area has different effects on the natural ventilation effect of industrial buildings with different type of heat sources.For the industrial buildings with an area ratio of heat source f=0.01,when the area of natural air inlet on one side decreases,the flow field will form a vortex moving along the direction of reduced air inlet area.When the vortex moves near the location of heat source,the vortex will strengthen the upward movement of thermal plume and increase the natural ventilation volume.For industrial buildings with heat source area ratio f=0.17,under the simulation condition of this project,when there is no natural air inlet on one side wall,the temperature efficiency will be reduced by more than 60%.In the working condition of Xi 'an in summer,when the heat source intensity is more than 140W/m3,the maximum temperature of the industrial building work area will exceed 35?,which is very harmful to the health of the staff.In view of the shortage of natural air inlet area in industrial buildings,a hybrid ventilation system with mechanical air inlet to assist the unilateral natural air inlet was studied by numerical simulation.Machinery blower are analyzed in three different positions on the non-uniform flow field characteristic and the effects of the hybrid ventilation machinery blower is decorated in the absence of natural air inlet side of the flow field is uniform,and the ventilation effect is best,under the condition of simulation in this paper,compared with unilateral natural ventilation system of natural ventilation,ventilation efficiency can be increased by 18.42%.In view of the high intensity of indoor heat source in industrial buildings,the characteristics of the hybrid ventilation system with mechanical air inlet and auxiliary natural air inlet on both sides were studied by numerical simulation,and the influence of the position of mechanical air feeder on the compound ventilation effect was analyzed.The symmetrical arrangement of mechanical blower in the direction of building length or width is helpful to the uniform distribution of airflow and achieves better ventilation effect.In this paper,it is concluded that compared with the natural ventilation system with bilateral natural air inlet,the temperature efficiency of mechanical blower with bilateral symmetrical arrangement can be increased by more than 20%.The results of this study can be used as a reference for hybrid ventilation design of large industrial buildings assisted by mechanical air inlet.