Numerical Simulation Analysis Of Targeted Personalized Ventilation

Conventional office environment is usually based on the centralized air conditioning air supply mode with single air supply mode and fixed air supply angle.The conventional air conditioning system is under partial load most of the time,and the air supply temperature often deviates from the standard working conditions,which affects the comfort of the personnel in the office environment and also causes a certain amount of energy waste.Based on the current situation of office environment,this paper proposes a new targeted personalized air supply method to solve the shortcomings of conventional centralized air conditioning supply in the office environment.This paper established the numerical model of targeted personalized air supply,determined the simulation method suitable for the analysis of airflow environment in this room,and compared the experimental data in the literature.The reliability and correctness of the numerical model of targeted air supply mode in this paper was verified.The change law of office thermal environment under the targeted personalized air supply and conventional mixed air supply modes was compared and analyzed,the distribution of thermal environment and indoor airflow around human body under different air supply conditions(multiple groups of different air supply temperature speed)were studied,and the PMV as well as heat dissipation of human body were analyzed.It was shown that under the same air supply temperature speed,the PMV value of human body in targeted personalized air supply was smaller than that of conventional mixed air supply mode,and the heat dissipation of human body in office environment was larger than that of conventional mixed air supply mode in targeted personalized air supply mode.It was also shown that under the same air supply temperature condition,when the air supply speed increased,the difference between the PMV value of human body in targeted personalized air supply and that in conventional mixed air supply condition also increased.This indicates that the heat dissipation of human body in the target personalized air supply condition is larger,and when the target personalized air supply and the conventional mixed air supply human body reach the same human body thermal comfort,the target personalized air supply can achieve the effect of energy saving by increasing the air supply temperature or reducing the air supply volume.The influence of targeted personalized air supply on human thermal comfort under different air supply angles(30°,45°,60°)was explored to provide some basis for the selection of air supply angle for targeted personalized air supply.It was shown that when the air supply angle was 60°,effect of air supply was the best;when the air supply angle was 45°,effect of air supply was the second best;when the air supply angle was 30°,the air supply path was almost perpendicular to the ground,the airflow was obstructed,and most of the airflow was not sent to the vicinity of human body by gravity,resulting in poor effect of air supply.The change law of PMV and heat dissipation of human body under the same working condition when the human body was at different positions from the air outlet was studied,and the mathematical equation between the target air supply distance,air supply speed and air supply temperature was fitted with the best thermal comfort of human body as the target,which provides a theoretical reference for the optimization of air supply parameters of target personalized air supply.