Numerical Analysis Of Solar Chimneys For Ventilation In Building

Ventilation of buildings is required to ameliorate the indoor environment and comfort levels of thermal conditions. Technical ventilation is mainly practised in structures today using equipment like air conditioning and ventilation. This equipment however consumes a lot of electricity, and electricity is generated by the burning of fossil fuels that causes green house emissions that in turn cause climate change. Hence it is necessary to convert to natural ventilation systems with Renewable Resource Energy systems. Natural ventilation systems such as the solar chimney which can be mounted or walled up in buildings are such systems. The investigation was undertaken in order to derive an analytical modelling tool that assesses the thermal effectiveness of solar chimneys while mounted in inclined or wall type fashion. The model has been validated using CFD digital simulations and also (and also). To do this CFD has design and modeled various configurations of solar chimney in order to compare their results with regards to the ventilation rate expressed in ACH; air changes per hour. From literature, numerical climatology of Jodhpur city, Rajasthan, India, is presented here and these comprised global and diffuse solar radiation as horizontal, wind speed and ambient temperatures. This was employed in the simulation of solar chimneys using CFD. The current outcome compromises the research of the inclination angles, air gap, chimney height and view factor and its impact on the thermal performance of the solar chimneys. It could be seen that the data obtained from this theoretical model has reasonably good correlation with the experimentally obtained values reported in the literature. The rmse were respectively 13 & 20 % for models with and those without the view factor. Also, it was discovered that the maximum ventilation rate was obtained at a tilting angle of 60° as this was considered the best tilting angle. Besides, the specific ventilation rate was raised, with the air gap being raised. With the extension of chimney height, the ACH has similarly been raised up. There was also the observation that when tailored to provide the more practical rate of ventilation, the view factor was one to behold. Also, due to the incorporation of view factor into the overall assessment, ACH has been revealed to be enhanced. In general the inclined solar chimney with roof integrated to the building exhibits better thermal performance than the vertical solar chimney fixed on the building wall. In addition, the addition of the viewing factor improves the accuracy of the modelling of a solar chimney.