Experimental investigation and CFD simulation studies of a laboratory scale solar chimney for power generation

摘要

In this communication, thermal performance of the laboratory type solar chimney for power generation is studied for a warm and semi-arid climate of Kota, India. Mathematical and Computational Fluid Dynamics (CFD) modeling are used to calculate the specific parameters, energetic and exergetic efficiencies. The predicted results are validated through experimental studies and statistical assessment shows that predicted temperatures are observed very close to measured data. The temperature variation along the collector height is also examined. The maximum air temperature and velocity in the collector area are found to be 42.4 ℃ and 12.2 m/s respectively at 1400 h of the typical day. The maximum solar radiation is measured to be 820 W/m2 at 1200 h. The maximum ambient temperature is found to be 42 ℃ at 1400 h of the typical day. The temperature of the collector surface is approximately 4-6 ℃ higher than the hot air temperature at the peak hours of the typical day. The high energy efficiency is estimated to be 3.5% at 1200 h of the day and reduced by morning and evening hours. The exergy efficiency is also low and found to be 8% at the same time. The turbine installation location is decided by the maximum velocity point, which is estimated with the help of CFD simulation as to be 0.25-1 m inside the chimney pipe. The effect of chimney height, inlet temperature and the solar radiation is also evaluated and model equation for performance measurements is developed. The diameter of the chimney is very low as 0.2032 m and velocity generated at the entry of the chimney (exit of collector) is appropriate to produce small power and it can be used as a small power plant.