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

Authors: Bilge Ozdogan Cumali; Semih Nemlioglu

Addresses: Department of Environmental Engineering, Faculty of Engineering, Istanbul University-Cerrahpasa, 34320, Avcilar, Istanbul, Turkey ' Department of Environmental Engineering, Faculty of Engineering, Istanbul University-Cerrahpasa, 34320, Avcilar, Istanbul, Turkey

Abstract: 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°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/m3. Nozzle downward inclination angles of thermal discharges and impact point dilution increment ratios were found as in the range between for 12°-13°: 0.3 and 1.2, for 13°-15°: 0.6 and 2.6, and for 14°-20°: 1.5 and 6.3 for nozzle diameters of 0.1 m, 0.2 m, and 0.5 m, respectively.

Keywords: greenhouse gas; inclined jet; positive buoyant jet; thermal discharge; visual plumes; water vapours.

DOI: 10.1504/IJGW.2022.10051029

International Journal of Global Warming, 2022 Vol.28 No.2, pp.170 - 184

Received: 12 Mar 2022
Accepted: 23 Mar 2022

Published online: 10 Oct 2022 *

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