Basic Study On Using Solar Chimney To Enhance Natural Ventilation In Buildings

Natural ventilation plays an important role in building energy efficiency, because it is no energy consumption and no-pollution. But, because the wind pressure of natural ventilation is very small, so the natural ventilation rate it can bring is also very low, which is very difficult to satisfy people's normal needs. Solar chimney, as a technique that can use solar energy to enhance pressure and air rate of natural ventilation, is getting more and more attention. It is an equipment of natural ventilation under the action of heat pressure. It turns heat energy into kinetic energy and bring the new air to the room, in the mean while increasing ventilation rate.So far, there are so many methods to simulate natural ventilation. Most common method is the brine-water modeling, but it also has some disadvantages: need a large reservoir and supplement brine-water continuously. In order to simplify the experiment model, we establish a small-scale solar chimney model using a fine-bubble technique, which means using the fine bubbles that are generated electrolytically in salt solution to simulate the buoyancy effect in solar chimney. It can simulate two conditions: point source and line source. But it can not simulate the thermal characteristics. It is real, visible, low price and easy to control. Using this model, we can study that how the structure parameters of solar chimney (such as source strength, inlet area, chimney width and height) affect the ventilation rate.In this experiment, our main work is to study two kinds of solar chimney: vertical roof solar chimney and Trombe wall solar chimney. After experiment, we hope to get some useful conclusion that can optimize solar chimney.