Study On Thermal Comfort Of Wall-mounted Airc-onditioning Room Under Perforated Windshield

In the process of social development,indoor has become one of the most common places for people to live and work,and indoor environment has become one of the main environments for human survival.In order to meet the requirements of indoor comfort,this paper proposes a perforated plate jet air supply method with perforated windshield adjustment.The characteristics of the orifice plate jet air supply are short air supply distance,good jet diffusion and mixing,fast wind speed and temperature drop,relatively uniform and stable temperature and velocity field in the working area,and small temperature difference,which makes it suitable for the air conditioning space with strict requirements on the temperature difference and wind speed in the working area.Firstly,the research status of orifice jet and traditional jet air supply air conditioning system is briefly introduced,and the problems of complex process and poor indoor airflow organization at the end of tuyere in traditional jet air supply system are explained.Furthermore,a perforated windshield model suitable for traditional jet air supply system is designed.In order to verify whether the perforated windshield can meet the thermal comfort requirements of air-conditioned rooms,CFD numerical simulation and experimental verification are used to study the basic law of perforated windshield jet flow.Through the curve fitting method,the peak velocity attenuation rate curve formula and the temperature peak attenuation rate curve formula of the orifice jet under different mesh numbers are obtained.On this basis,an air-conditioned room model with perforated baffles is established,and the air distribution of the air-conditioned room with perforated baffles under summer and winter conditions is studied by changing the air supply parameters.In the summer and winter operation of wall-mounted air conditioning,the effects of different air supply speeds and different orifice plate forms on indoor air flow organization are studied.By comparing the temperature field,velocity field and air distribution characteristic index(ADPI),it is found that the average ADPI in summer under the five orifice plate forms is 89.24%,and the average ADPI in winter is 77.16%,indicating that the perforated windshield has a greater effect on improving the performance of summer airflow organization than winter.In the range of the number of orifice plates studied,the optimal number of orifice plates in summer and winter conditions is 2 mesh.Through the study of the temperature difference in the horizontal and vertical directions of the room,the maximum temperature difference in the horizontal direction of the working area in summer is 0.8℃,and the maximum temperature difference in the vertical direction is 1.6℃.In winter,the maximum temperature difference in the horizontal direction of the working area is 0.6℃,and the maximum temperature difference in the vertical direction is 1.9℃.Finally,based on the optimal number of orifice plates,the air-conditioned rooms under different orifice plate parameters are modeled and numerically simulated by changing the orifice radius and orifice plate inclination.The ADPI index is used as the evaluation standard of air distribution and thermal comfort.The optimal orifice radius in summer is 2mm-3mm,and the optimal orifice plate inclination angle is 85°.In winter,the optimal orifice radius is 4mm and the optimal orifice angle is 75°.By improving the perforated plate model,the problem of poor air distribution in summer and winter can be better solved,which provides reference and suggestions for the practical application of perforated windshield in air conditioning system.