Optimisation of the thermodynamic and environmental performances of a flat plate solar collector with multiple turbulators: An integrated experimental, numerical, and machine learning investigation

Flat plate solar collectors (FPSCs) offer an economically attractive renewable energy solution, but their widespread adoption has been limited by suboptimal thermal performance. This study introduces an innovative strategy to boost FPSC efficiency through the optimisation of a multiple turbulator design. A thorough analysis of thermodynamic and heat transfer characteristics demonstrates the significant potential for reducing greenhouse gas emissions by replacing conventional gas-fired domestic heaters with thermally enhanced FPSCs. The study involves a series of numerical simulations and experimental measurements used for validation purposes. Machine learning techniques are employed to build a surrogate optimisation model, determining optimal values for key parameters such as blade count, blade rotation angle, turbulator length, blade diameter, and the working fluid's mass flow rate. The results show that the optimised FPSC configuration achieves substantial CO2 reductions, with annual savings of 2,387 kg to 3,520 kg compared to conventional gas-fired water heaters. This significantly outperforms conventional FPSCs, which only achieve a 1,715 kg reduction. Overall, the optimised FPSC delivers a 65.6 % decrease in CO2 emissions and enhances thermodynamic performance by reducing exergy destruction by 39.1 %. These findings show the substantial potential of optimised flow turbulators in improving both the thermal and environmental performance of FPSCs.