Transient Study (Annual) of the Heat Transfer of a Two-Channel Solar Air Collector

In this paper, a numerical heat transfer study of a solar air collector with two channels (SAC-2C) was carried out. Energy global balances in two dimension (2D) and unsteady state were considered, as well as bio-climatic conditions of Toluca city in Mexico (sub-humid temperate climate). Six mass flowrates (0.01, 0.05, 0.1, 0.2, 0.4, and 0.5 kg/s) were considered during the numerical simulation, for the coldest and the warmest day of each month during a complete year (2019). Among the results, it was found that thermal efficiency of the system increases up to $35%$ when the mass flowrate changes from 0.01 to 0.2 kg/s, meanwhile, maximum efficiency of $84%$ were obtained for a mass flowrate of 0.5 kg/s. Finally, based on a cost-benefit analysis, it was determined that the SAC-2C has a recovery time of the initial investment ($ 250 USD) of three and a half years. So that the SAC-2C has the capacity to produce 1, 654, 451 kW h/m² of clean energy annually, which is equivalent to ceasing to produce 871, 895 kg CO₂ per square meter of installation.