Dilution of Single Port Submerged Diffuser Clogged by a Free Rotating Propeller

Abstract

Thermal pollution raises the water source temperature and thus causes a change in the physical, chemical, and biochemical properties of water. That makes limitations for designing cooling systems, which increase its cost. Single port submerged diffuser is used for the disposal of hot water. It is a form of once-through cooling systems, and it is between the surface discharge and the multi-port submerged diffuser in comparison with cost and dilution of temperature. A new method was used to increase the dilution of Single-port submerged diffuser discharging hot water in ambient temperature. The diffuser was clogged by a free rotating propeller, to study its effect on temperature distributions experimentally, a model with 18 m long and 2 m was constructed. The results were confirmed using numerical simulations. An experimental test was carried on for three different Reynolds number Ratios Re_r (0.4, 0.21, and 0.13). Adding propeller at (L = 0.1), the plume centre temperature ratios were decreased by 22.62%, 46.23% and 48.57%. There was an agreement between experimental and numerical results for temperature distributions through the model. Clogging single port submerged diffuser increase dilution of the thermal plume.