| Natural ventilation is green, environmentally friendly, energy-efficiently. Through the effective use of solar chimneys,we can achieve the purposes of enhancing the natural ventilation. The paper presents the potential of the solar chimney enhancing the natural ventilation, the air volume calculation model and the solar energy’s contribution rate in enhancing natural ventilation.Firstly, the "solarenergy- hour" conception isput forward to measure the potential of the solar chimney enhancing natural ventilation in typical cities such as Lasa 、Zhengzhou、Guangzhou and Mianyang based on the analysis of solar radiation data. It is found that solarenergy-houris the biggest during autumn in Lasa、 Zhengzhou and Mianyang, while solarenergy- hour in Guangzhou is the biggest in winter.In addition, the formulae on natural ventilation rate are deduced and corrected of vertical roofsolar chimneywith a correction coefficient of 0.5~0.87. Furthermore, the "solar contribution rate" is posed to describe contribution of solar energy to enhancing natural ventilation. The solar contribution rate reaches the maximum of 15 % in vertical roof solar chimney by using theoretical analysis. Three different types of solar chimney’s contribution rate are discussed by using numerical simulation. The results show that the vertical roof-Trombe solar chimney has the highest solar contribution rate which is 33.2%, while that of the Trombe solar chimney is the lowest.Finally, the transient natural ventilation enhanced by the double inclined roof solar chimney is studied on a typical day in Mianyang. the airflow rate, indoor temperature and temperature in solar chimney were obtained. The asymmetry phenomenon in indoor flow field is observed That is because the differences between the southward solar radiation intensity and the northward. |
PDF Full Text Request