Optimizing thermal performance of direct flow evacuated solar tubes

Abstract

With the increasing global adoption of renewable energies, including solar energy, direct-flow evacuated solar systems have emerged as highly efficient solutions for thermal energy conversion, maintaining 75% of their efficiency even on overcast days. This thesis aims to enhance the thermal design of these solar collectors and optimize their performance by processing various geometrical, physical, and meteorological data. It examines critical parameters such as solar incident energy (W·m?²), absorber length (L in m), mass flow rate (kg·s?¹), and their impact on the thermal performance of these systems, including efficiency (?), useful heat flux (W), dissipated heat flux (W), and outlet temperature (T? in K), displaying the results in graphical curves. Utilizing a combination of numerical methods, coding, and simulation, a model of non-linear equations based on heat transfer laws and correlations was developed and solved using the fixed-point method. The results were then compiled and transformed into Fortran code, processed, simulated, and analyzed in Chapter 3. This study provides valuable insights into improving the thermal characteristics and performance of direct-flow evacuated solar collectors, advancing their application in sustainable solar energy systems