Performance Analysis of Solar Water Heater Using Al2O3 NanoParticle with Plain-Dimple Tube Design

In the present investigation the authors have presented a numerical and experimental analysis of a parabolic plate solar water heater using tube in tube type heat exchanger, with dimple inner tube having a different P/D ratio of 3. Also, the authors have used nanoparticles of Al2O3 of size 10-15 nm at volume concentrations of 0-3 % in steps of 1 % to analyzed the fluid flow pattern in the dimple texture tube, and heat transfer efficiency. The concentration of nanoparticles on the solar water heater performance was also analyzed by using Computational Fluid Dynamics (CFD) and validated through experimental analysis. Based on the study outcomes, the performance of the parabolic plate solar collector was increased to 32.3 % for 3 % Al2O3 concentration. The thermal efficiency of the solar water heater was improved gradually with the increase in the mass flow rate of water. At maximum mass flow rate of 2.5 kg/min the thermal efficiency was increased by about 4.5 % compared to mass flow rate of 2.0 kg/min. With addition of Al2O3, dimple P/D ratio of 3, dimples of 6 numbers with mass flow rate of 2.5 kg/min, the Nusselt number increased by about 29 % in comparison to flow rate of 2.0 kg/min. Dimple tube with nanoparticles of Al2O3 gives improvement in friction factor of about 45.5 % in comparisons to plan tube without nanoparticles at flow rate of 2.5 kg/min. The experimental results were compared with the simulation results and it is in the acceptable range with over all deviation of 3.1 %.

Automated summary

The authors conducted a study on the performance of a parabolic plate solar water heater using a tube in tube heat exchanger, finding that adding Al2O3 nanoparticles can enhance performance. Thermal efficiency improves with an increase in water flow rate. Experimental results were in good agreement with simulation results.