Energy-exergy and enviro-economic survey of solar air heaters with various air channel modifications

Solar air heaters (SAHs) are generally used in different applications because of their simple structure, low setup cost, and also their higher energy conversion efficiency. In this study, a v-groove type SAH (VTPSAH) has been developed, manufactured and compared with parallel-pass SAH (PPSAH) and double-pass SAH (DPSAH) under same climatic conditions. In addition to the experimental analysis, CFD simulation of SAHs has been done to investigate heat and flow behavior inside the systems. The experiments have been performed in 0.015 kg/s, 0.013 kg/s and 0.011 kg/s mass flow rates on February and June to evaluate the performance of SAHs at various climatic conditions. According to the obtained results, annual average thermal efficiency for PPSAH, DPSAH and VTPSAH were obtained as 54–60.29%, 61.86–66.95% and 70.91–78.18%. The maximum instantaneous thermal efficiency was achieved in all tests as 90.65% in highest mass flow rate in VTPSAH in February. Exergy efficiency values for VTPSAH, DPSAH and PPSAH were obtained in the range of 14.62–18.95%, 12.28–15.68% and 6.68–9.74%, respectively. Moreover, Enviro-economic costs were found between 4.22 and 7.66 $/year. Also, the highest deviation between numerical and experimental results is 10%.