The Optimization Of New Ventilation Window Operation Scheme

Indoor environment is the outside environment that most closely contact with people.With the improvement of people’s living standard, the requirements of people for indoor thermal environment and air quality are more and more higher, the good or bad indoor environment directly affects the study and work efficiency and healthy, so how to improve the indoor environment is particularly important. The ventilated window without the window open to achieve that the outdoor fresh air into indoor after being purified, which can improve the indoor air quality. It has considerable application prospects.In this paper, a new type of ventilation window operation scheme was studied, by optimizing the operation scheme could improve the effect of ventilation window on indoor air quality. Optimization plan of operation scheme need comprehensively consider influence factors, according to the operating principle of the ventilation window and the related literature on indoor air quality, the indoor air quality impact factors were analyzed and summarized, and the basis for selection experiments and simulation impact factors were provided. Simulation results of the ventilation window verified each other, provide experimental basis for establishing operation scheme. Simulation study based on the experimental and theoretical basis to establish mathematical model, increasing the conditions of high and middle filtration efficiency and outdoor temperature as the influence factors. Working conditions of each group in determining the ventilator filtering efficiency,outdoor air quality, outdoor temperature adjusting the volume of ventilation air, analysed of the indoor temperature field, velocity field and PM2.5 concentration field under different working conditions. By simulation study, the influence of a ventilator on indoor PM2.5concentration field and thermal comfort under different conditions was obtained,and the basis for ventilation window operation scheme was provided. According to the simulation and experiment results, the ventilation window operation scheme was developed, and according to different indoor and outdoor environment conditions, the mode of the ventilator was adjusted, and the indoor air quality was improved at the same time to guarantee the indoor thermal environment is good.Experiment and simulation results showed that the Selection of operation scheme need comprehensively consider outdoor air pollution, outdoor temperature and filtration efficiency of the ventilator. When outdoor temperature is less than-10℃ at the cold case,and outdoor air quality levels is more than the level 6, the effect on improving indoor air quality of ventilation window is not obvious, indoor thermal comfort will reduce, and the predicted percent dissatisfied is high, at the moment, the ventilation window should shut down or maintain the high filtration efficiency; When the outdoor temperature increases to-3 to 6℃ at the cold situation, the PMV value maintains between-0.5~0.5 mainly by using low supply air volume, and the predicted percent dissatisfied is less than 10%; While the outdoor air quality level is less than 5, the low filtration efficiency of ventilator could take small air volume to supply, and improving the air supply volume to reduce the effect of indoor PM2.5 concentration is not significant, while the ventilator filtration efficiency is90%, that the air volume could be improved relatively; And when the outdoor air quality level is less than level 4, operating the ventilation window could exhaust indoor pollutants effectively, while the ventilation window filtration efficiency and concentration is low, the larger air supply volume is essential; On the premise of meeting the requirements of the indoor thermal comfort, ventilation window could operate high-grade for a short time at first to reduce the indoor air quality index to level 2; Then remaining the low-grade to supply air to reduce the influence of operating ventilation window on indoor thermal comfort and exhaust indoor pollutants effectively, which may maintain indoor high temperature at the same time, and reduce the conditioning load for supplying outdoor air.