Sustainability and Cost Effectiveness Analysis of Staggered Jet Impingement on Solar Thermal Collector

The sustainability index, waste energy ratio and improvement potential of a staggered air jet impingement on the staggered spherical protrusions of a roughened absorber plate were derived for the present study to evaluate exergy losses and irreversibility in the system. The experimental analysis was carried out for selected parameters: relative streamwise pitch, relative spanwise pitch and relative jet diameter to hydraulic diameter ratio. The flow Reynolds number ranged from 4000–18,000. The augmentation in Nusselt number and friction factor compared to a smooth surface was 4.9 and 12.4 times, respectively. The statistical correlation developed determined the maximum thermohydraulic performance parameter and exergetic efficiency be 3.02 and 3.87%, respectively. The magnitude of the sustainability index, waste energy ratio and improvement potential was found to be 1.0347, 0.962 and 10.84, respectively, for the entire range of tested parameters. A cost analysis was also performed to evaluate the cost-effectiveness of the solar thermal system with and without turbulent promoters.