Effect of geometric/operating parameters on thermal performance of a flat-plate solar collector

This work presents a parametric investigation of steady-state two-dimensional heat transfer in the absorbing plate of a flat-plate solar collector. The effects of key parameters, including absorbing plate material, mass flow rate, solar irradiation, absorbing plate thickness, and number of glass covers on the temperature profiles of the absorbing plate and the working fluid are analyzed in detail. A point-to-point Gauss–Seidel iterative algorithm is employed to solve the governing heat conduction equation, incorporating insulated and convective boundary conditions. The results reveal that the use of high thermal conductivity and low emissivity materials such as copper increases the collector efficiency approximately up to 26% compared to conventional materials. Increasing the absorbing plate thickness from δp=0.1mm to 10 mm leads to an increase of approximately 24% in the collector efficiency. Similarly, reducing the mass flow rate from m˙=0.01 to 0.0001 kg/s results in a higher efficiency, with an increase of about 25%, while the addition of glass covers significantly reduces thermal losses, increasing the collector efficiency slightly by 6%. Overall, the study demonstrates that an optimal combination of high thermal conductivity and low emissivity materials, thicker absorbing plates, lower mass flow rates, and multiple glass covers can substantially enhance the thermal performance of flat-plate solar collectors. These findings provide practical design guidelines for improving collector performance under various operating conditions.