The Application Research Of Stratified Air Conditioning In Precision Machining Plant

Stratified air conditioning applied to high ceiling building is a technique with quite distinct benefits for both energy and economy. The application research of stratified air conditioning, charactered with large space building in precision machining plant requires temperature-controlled in some field. At present,the application research at home and abroad is rare. In this paper, we do research on load characteristics of air conditioning as well as the airflow distribution of stratified air conditioning by the building environmental simulation and CFD analysis software. Finally, we summerised the load characteristics, calculation characteristics, influencing factors as well as the airflow distribution in different conditions of prcision machining plant's stratified air conditioning.In this paper, on the base of the precision machining in Chongqing, we analyze the calculation method of load,all-year dynamic load,influencing factors of load as well as energy consumption etc.by DeST. According to the actual buliding geometry, through reasonable assumptions, we establish computational models that can solve the airflow distribution of large size buliding, and then verify the accuracy and reliability of the model. We do research on the three-dimensional numerical simulation of stratified air conditioning' airflow distribution in summer,winter by CFD analysis software. Navier-Stokes equation is the governing equation of the computation and RNG k-εturbulent model is employed. The finite volume method is used to discretize the computed area. When dealing with the boundary condition in the area near the wall, the wall function is adopted. In addition,the upwind differencing scheme is used in the computation. And the SIMPLE algorithm is adopted to couple the velocity and pressure.In allusion to the process requirements of precision machining plant, we simulate and calculate the indoor airflow distribution of stratified air conditioning in summer,winter, and then use the temperature uniformity index,velocity uniformity index and energy utilization factor to focus on the framework of a certain range around equipments. Then, for summer and winter conditions, we discusse the influencing of equipment parameters, airflow parameters, tuyere parameters on environments of technological requirement-region. In accordance with the research results, we make some practical suggestions on plant layout and airflow distribution designment. The results show that: In case of precision machining plant, the energy could be saved for 37.9% using stratified air conditioning technology in summer; In the summer and winter design conditions,the uniformity air distribution around equipments is good, Stratified air-conditioning design can meet the process requirements of precision machining plant; In winter condition, using warm air-curtain to heating has a certain energy efficiency.