Experimental Study On Solar Ventilating Technology

With the development of China's energy-saving and environmental protection work, people pay more and more attention to the use of natural ventilation to improve indoor environment. Natural ventilation is used more in green buildings to improve the thermal environment of constructions, reduce energy consumption of air conditionings, and at the same time be able to create sustainable development. Building natural ventilation in the normal sense refers to that air flow through the purposeful opening under the pressure of wind and heat. Solar ventilation is one of the measures that forced by heat pressure. It uses solar radiation to increase the air temperature difference between import and export, provide the buoyancy of air flow, to increase the ventilation of indoor air flow and lower room temperature. This paper studied the solar ventilation through experiments.The subject mainly studied ventilation application characteristics of Trombe Wall, solar chimney and solar ventilation roof on experiments, and analyzed the comprehensive benefits of application, and provided a theoretical basis for promoting the application of solar ventilation technologies in China's green buildings.First of all, this paper analyzed the experimental models theoretically on the basis of the research of Trombe wall, solar chimney and solar ventilation roof at home and abroad. The results show that when the room temperature is constant, the higher air temperature of the export is, the greater amount of ventilation gained; when export air temperature is constant, the more water added, the smaller amount of ventilation gained. When no water added, the ventilation gains the maximum. Therefore, humidification on the export paragraph can not increase the amount of ventilation of the system.And then set up a platform for experiments. Experiments based on weather conditions in Chongqing, under the different solar radiation and operation mode of summer and transition season, tested the thermal performance, the temperature distribution, ventilation capacity and the solar energy efficiency of the solar ventilation system, and analyzed the results.In addition, the subject presented a new type of solar heat storage ventilation system, which combines solar ventilation with phase-change heat storage materials to make full use of solar energy. The system can be integrated with the building structure, and can provide heat and ventilation effectively. Experiments studied the operation status and ventilation of the system of solar ventilation roof combined with different phase-change materials in the intermittent mode of ventilation and daytime ventilation, and analyzed the temperature field of the solar ventilation roof in this paper.The results show that: the greater area of the inlet of the Trombe wall is, the greater amount of the ventilation gained; when ventilation is during the day, the ventilation per unit collector area of Trombe wall is 185 m3/h, solar chimney is 204 m3/h, Trombe wall combined with solar chimney is 83m3/h, and the reason is that the resistance of the junction of Trombe wall and solar chimney is large, so it limits the increasing the ventilation. The solar ventilation roof combined with the phase-change materials, when ventilation is in the day, the ventilation per unit collector area is 132 m3/h, when ventilation is in the intermittent mode for 10 hours, the ventilation per unit collector area is 60 ~ 80 m3/h. ventilation is lager when the intake is closed in the day, when the phase-change temperature is 60℃than that is 40℃, and when the outdoor wind has speed.