Initial dilution improvement of thermal wastewater outfall singular jets by nozzle inclination for decrement of sea water evaporation

Open-cycle cooling water systems and their discharges 'thermal wastewater outfalls' can be commonly used by seaside-located thermal power plants. Lower dilution performance having thermal wastewater outfalls may be one of the sources of greenhouse gas water vapour evaporation. Thermal wastewater jets of outfalls are positively buoyant, and they are commonly discharged from horizontally located nozzles on multi-port diffusers. In this study, impact point dilution increments of thermal wastewater singular jets (+10 degrees C heated) were investigated under the conditions of originally horizontally located, then downward inclined nozzle conditions using US Environmental Protection Agency-Visual Plumes model system for receiving water densities between 1,015-1,035 kg/m(3). Nozzle downward inclination angles of thermal discharges and impact point dilution increment ratios were found as in the range between for 12 degrees-13 degrees: 0.3 and 1.2, for 13 degrees-15 degrees: 0.6 and 2.6, and for 14 degrees-20 degrees: 1.5 and 6.3 for nozzle diameters of 0.1 m, 0.2 m, and 0.5 m, respectively.