Photothermal analysis of novel nanoparticles-laden fluid-based solar thermal receiver: A proof-of-concept experimental study

• Experimental study on a novel spiral-shaped miniaturized solar collector. • Various mass fractions of nanoparticles have been analyzed. • Clear optimum values of mass fraction are observed. • The novelty of variation in channel height has been presented in this study. • Volumetric flow rate effect has also been observed. Excessive extraction of fossil fuels leads to air pollution, water pollution, destruction of habitat, etc., which are some of the severe environmental consequences. Directing towards renewable energy sources like solar and wind energy helps to attenuate these impacts and promote a purified, healthier environment for future generations. Solar energy is infinitely available and used for present and future energy needs. Thus, by utilizing this power, we can mitigate the carbon footprint, greenhouse gas (GHG) emissions, etc., which helps to build a secure, clean energy future. This experimental study compared the photo-thermal effects of surface absorption and nanoparticle-laden systems on the moving flow characteristics of the nanoparticle-laden fluid in a novel spiral solar collector. The influence of channel depth (10 and 20 mm) and volume flow rate on temperature rise has been investigated in this experimental investigation, and it has been discovered that the nanoparticle mass fraction (optimum mass fraction of the nanoparticles) relies on channel depth. Experimental results show that for optical depth of 10 mm, a temperature rise of 11.4 °C is obtained at the optimum mass fraction of 40 mg/L, and compared to this, at the optical depth of 20 mm, a temperature rise of 6.7 °C has been achieved at the optimum mass fraction of 10 mg/L. After evaluating the influence of volume flow rate (25–200 mL/hr), a maximum temperature rise of 11.2 °C was obtained at 25 mL/hr. In all cases, the temperature rise in the N-VAS (Nanoparticle-laden volumetric absorption-based system) is more significant than S-BAS (Surface-based absorption system), indicating that the presence of nanoparticles results in a higher heat transfer rate by absorbing more radiation from the heat source.