Numerical investigation of supercritical heat transfer of water flowing in vertical and horizontal tube with emphasis of gravity effect

Over a decade, coal-based thermal power plants are upgraded to operate at supercritical pressure conditions due its high efficiency and low emissions. Water wall panels of typical boiler structured spirally in the lower furnace vertically placed upper furnace. The spiral tubes inclined 19 22 degrees which fluid behaves as horizontal tubes. design water plays key role designing boiler. present work aims numerically investigate heat transfer behavior both vertical conditions. Since temperature distribution across cross-section tube is uniform, 2D axis symmetry has been considered for analyzing tube. Unlike tube, characteristics different Therefore, 3D modelled computation In order gain confidence, simulations validated with experiments results available literature. Ansys-Fluent used simulation. SST k-ω turbulence model this analysis. work, 10 mm diameter 4m length chosen simulated flux mass ratio 0.27 0.67 241 bar. effect (q) (G) responsible enhancement deterioration studied plotted along top bottom portion compared buoyancy vital horizontal
 Heat occurs direct linkage gravity. Three cases were studied, one full gravity (factor 1), half 0.5) zero 0). It observed that, sudden rise case factor 1.0, i.e, considering effect. For gravity, no peak local absence term Navier-Stokes equations. Some thermo-physical properties like velocity, turbulent kinetic energy, density, viscosity analyzed three cases.