Analysis of exergy in a dimple-roughened solar thermal collector using MATLAB simulation

Abstract

In the current study, the performance of a dimple-roughened solar thermal collector (DRSTC) is investigated within a (\({\text{Re}}_{\text{xx}}\)) range that spans from 3000 to 48,000. Under constant solar intensity (\({I}_{\text{sr}}\)=1000 \({\text{Wm}}^{-2}\)), relative roughness height (\({e}_{\text{d}}/{D}_{\text{h}}\)) varied from 0.021 to 0.036, relative roughness pitch (\(p/{e}_{\text{d}}\)) from 10 to 20, arc angle (\({\alpha }_{\text{a}}\)) from 45 to 60°, and temperature rise parameter from 0.003 to 0.02, and the proposed model predicts exergy efficiency of the SAH, and the results obtained can be used as reference for the design of new solar thermal systems. The assessment makes use of advanced MATLAB simulations in order to evaluate the exergetic efficiency \({(}\eta_{{{\text{ex}}}} )\) of a DRSTC. At lower \({\text{Re}}_{\text{xx}}\) values, \({(}\eta_{{{\text{ex}}}} )\) increases uniformly; however, stabilization and decline occur at higher \({\text{Re}}_{\text{xx}}\) values. The highest \({(}\eta_{{{\text{ex}}}} )\) for the DRSTC is 1.47% under a temperature rise parameter \((\Delta T/I_{{{\text{sr}}}} )\) of 0.0071 \({\text{Km}}^{2}{\text{W}}^{-1}\) for obtaining optimum values of \({e}_{\text{d}}/{D}_{\text{h}}\) = 0.036, \(p/{e}_{\text{d}}\) = 10, and \(\alpha_{a}\) = 60°. This research illustrates the usefulness of MATLAB for solar energy system analysis and optimization by integrating simulation and experimental data. This investigation further supports the feasibility of the proposed collector design.