Investigation of the effects of ambient temperature and dimensional parameters on the performance of solar chimney power plants

In this study, the influence of ambient temperature is investigated on the performance of solar chimney. Dimensional analysis is performed to find the dimensionless variables for the purpose of predicting the solar chimney performance. A mathematical model was developed and validated with the experimental data of an experimental pilot. By using this model, it is shown that the ambient temperature has an adverse effect on the SCPP output. For this purpose, a solar chimney with 7.4 m chimney height, 0.6 m chimney diameter, 8 m collector diameter, and 0.2 m mean collector height was built. By using the Buckingham Pi theory, a dimensionless variable was obtained, and its value was correlated using the experimental data. The investigation of the system performance using this dimensionless variable shows that the output power increases with a third-order polynomial relation through increasing the size of SCPP, and with a linear relation through increasing the solar insolation. In the other word, when the size of the system and solar insolation increase, the output power of the solar chimney rises. The variation of the air velocity versus daytime shows maximum area from 11:00 a.m. to 1:00 p.m.