Study of thermal efficiency of a double pass solar air collector

Abstract

This thesis presents a numerical study on the efficiency of a DPSAH. The research aims to enhance the collector's performance by studying factors influencing its efficiency. Numerical studies were conducted to measure the outlet air temperature of the collector, as well as the temperatures of the glass cover, absorber, and insulation in the DPSAC system. A model for energy balance equations was used and solved using matrix inversion method via Matlab software. The model's accuracy was verified by comparing numerical results with experimental data from previous research, showing consistency. The collector length was tested at three different lengths (0.5 m, 1 m, 2 m), with results indicating that a length of 2 m was most effective. Similarly, mass flow rates were tested at different rates, with results showing increased collector efficiency at lower flow rates. A comparison was made between single-pass and DPSAH at the same heat transfer length, indicating that single-pass was superior. Comparisons were also made at the same collector length, confirming that double-pass was the better choice. The study also provides valuable guidance for selecting the most efficient design standards for DPSAH.