Numerical Study on the Application of Pressure-swirl Atomizing Nozzle in a Direct Air Cooling Condenser of the Power Plant

Abstract In this paper, a pressure-swirl atomizing nozzle was proposed to improve the atomization characteristics and enhance the heat transfer characteristics. By modifying the structural parameters of the nozzle, the effect of angles of inclined holes on the swirl plate on the heat transfer characteristics was studied and the structure of nozzle was optimized based on Fluent software. The corresponding relationship between the pressure difference between the inlet and outlet of the nozzle and the flow rate was obtained, which provides a basis for the parameter setting of the DPM. The nozzle was then applied to a spray humidification system of a direct air cooling unit in the power plant. The influences of nozzles arrangement and spray directions on the vacuum degree of the system were studied. The results of numerical study show that the nozzles with inclined holes with an angle of 45° not only have the highest heat transfer efficiency but also have the highest heat transfer uniformity among all the simulated cases. In the air cooling unit of the power plant, when the nozzles are arranged in staggered rows and the angle between the spray direction and the positive direction along the height is kept at 15°, the heat transfer performance of spray humidification is the best; the vacuum degree of the condenser is the highest.