Study On Optimization Of Stratified Air-conditioning Airflow Distribution Design In A Large Space Building

The large space buildings have relatively large heat and cold loads,as well as a complex internal thermal environment.Without an appropriate airflow distribution system,the working area of the building will either be too hot or too cold.This means that suitable airflow distribution design in large space buildings can not only make people feel more comfortable but also reduce the air-conditioning energy consumption.Based on the RNG 6)-? model and a constant air supply volume,this paper uses CFD technology to numerically simulate the airflow distribution of stratified air-conditioning in a large space building under different working conditions in summer.The three conditions are as follows: set the air supply speed with 8.34m/s,4.53m/s and 10.04m/s,set the air supply temperature as 16°C,18°C and 20°C and set the air supply angle as horizontal air supply,downward inclination of 15° and 30° and air supply height as 7.7m,6.7m and 5.7m.Then calculate and analyze thermal comfort in the working area and air-conditioning energy consumption under these conditions;Under winter conditions,using CFD technology to numerically simulate the airflow distribution under different heating modes,they are: the air supply angle is three conditions of horizontal air supply and downward inclination of 15° and 30°,using different conditions of hot air + floor radiation combined heating and single floor radiant heating,then calculate and analyze thermal comfort in the working area and air-conditioning energy consumption under these conditions.Research indicates:Under summer conditions,the preliminary design scheme(Air supply speed of 8.34m/s,air supply temperature of 16?,horizontal air supply and air supply height of 7.7m)is named as working condition 1,compared with:(1)When the air supply speed increases to 10.04m/s,compared with the working condition 1,the average temperature of the personnel activity area decreases by 0.2 ?,and the air-conditioning energy consumption decreases by 6.18%.(2)When the air supply temperature is reduced to 16 ?,the average temperature of the personnel activity area is also lower,the thermal comfort meets the design requirements,but the airconditioning energy consumption increases by 30.49% compared with the working condition 1;(3)When the air supply angle increases to 15°,the temperature and velocity distribution in the personnel activity area is ideal,the comfort is higher.Compared with the working condition 1,the average temperature is reduced by 0.3 ? and the air-conditioning energy consumption decreases by 7.74%.(4)When the air supply height is reduced to 5.7 m,compared with the working condition 1,the average temperature of the work area is reduced by 0.5 ° C,and the air-conditioning energy consumption is reduced by 13.23%.(5)In the design scheme of summer airflow organization optimization,the average wind speed of the personnel activity area is 0.256m/s,the average temperature is 25.5?,the ADPI is 78.3%,the optimized airflow organization effect is better,and the air-conditioning energy consumption is reduced by 17.04% compared with the working Condition 1,which is more energy saving.Under the winter conditions:(1)With the increase of the air supply angle of the nozzle,the average temperature of the working area increases gradually,and the phenomenon of "hot and cold" in space has been alleviated to a certain extent.However,with the increase of the angle of air supply,the thermal load of air conditioner increases gradually.When the air supply angle is 15?,compared with the horizontal air supply,the average temperature of the working area increases by 0.5?,and the heat load increases by 3.35%.(2)When using a single floor radiant heating,compared with hot air + floor radiant heating,the average temperature of the working area increases by 1.2 ?,the energy consumption is also reduced by 11.04%,and the heating effect is better.