Numerical solution of MHD slip flow of a nanofluid past a radiating plate with Newtonian heating : a lie group approach

In this paper, we have examined the magnetohydrodynamic flow of a nanofluid past a radiating sheet. The Navier velocity slip, Newtonian heating and passively controlled wall boundary conditions are considered. The governing equations are reduced into similarity equations with the help of Lie group. A collocation method is used for simulation. The influence of emerging parameters on velocity, temperature, nanoparticle volumetric fraction profiles, as well as on local skin friction factor and local Nusselt number are illustrated in detail. It is found that the friction (heat transfer rate) is lower (higher) for passively controlled boundary conditions as compared to the case of an actively controlled boundary condition. The magnetic field decreases both the skin friction and the rate of heat transfer. The findings are validated with existing results and found an excellent agreement. The model explores new applications in solar collectors with direct solar radiative input using magnetic nanofluids

Performance amelioration of single basin solar still integrated with V- type concentrator: Energy, exergy, and economic analysis

© 2020, Springer-Verlag GmbH Germany, part of Springer Nature. Solar desalination is one of the most sustainable solutions to produce freshwater from brackish water. The present research work aims to experimentally investigate the effect of a V-shape concentrator integrated with solar still (SS). The V-shape concentrator integrated with the conventional solar still (CSS) is used to supply the saline water at elevated temperature to the basin of SS, which augments the freshwater yield compared to CSS. The experimental investigation was performed at different brackish water depths of 0.01, 0.02, and 0.03 m, respectively. The SS system was evaluated based on water yield, energy, exergy, concentrator efficiency, and economic analysis. The freshwater yield of the solar still integrated with V-shape concentrator (SSVC) was found to be 5.47, 5.10, and 4.89 L/m2.day, whereas the yield of the CSS was 3.73, 3.27, and 2.91 L/m2.day at the water depths of 0.01, 0.02, and 0.03 m, respectively. The daily energy and exergy efficiency of CSS were 38.5, 33.5, and 29.4% and 1.9, 1.5, and 0.97 % in the case of 0.01, 0.02, and 0.03m water depth , respectively. However, the integration of concentrator significantly augmented the energy efficiency to 57.4, 51.7, and 44.9% and exergy efficiency to 3.8, 3.3, and 2.8% for the respective water depths. Life cycle studies demonstrated that the freshwater cost per liter for CSS and SSVC were 0.0102 $and 0.0117$ respectively, at a water depth of 0.01 m. It was concluded that the addition of V-shape concentrator and minimum water depth is useful to augment the energy efficiency, exergy efficiency, and yield of the SS in the very economical way

Sea-water desalination using a desalting unit integrated with a parabolic trough collector and activated carbon pellets as energy storage medium

Solar energy is considered the most influential source for various sustainable applications and its utilization can effectively convert brackish water into freshwater. The present work explores a novel method of augmenting the water productivity of the desalination unit using sea-water as the feed water through integrating a parabolic trough collector (to preheat the water supplied to the still basin) and activated carbon pellet (a highly porous energy storage material) to improve the rates of evaporation and water production. Experimental results revealed that the full-day water yield was augmented by 50.21% for the modified desalination unit, as compared to the conventional unit. 24-Hours water yield of modified solar still was increased by 85.2% compared to the conventional unit, owing to the synergetic effect of the parabolic trough and porous carbon. However, the integration of the parabolic trough collector significantly reduced the energy and exergy efficiency of the modified unit. The economic analysis estimated that the cost of the produced clean water was 0.010 US $ per liter for the modified unit, with a payback period of 66 days. Moreover, it was found that the modified desalination unit configuration can reduce CO2 emissions by 18.74 tons during its lifespan