CFD optimization study on heat transfer enhancement of air-cooled condenser spray cooling system

Heat dissipation problems during the high-temperature period of thermal power units in summer are numerous, and the air-cooled condenser spray cooling system can effectively solve both the problem of reduced heat dissipation capacity and the problem of high fan back pressure. The size of the model involved spans several orders of magnitude, and the simulation difficulty is greatly increased. Therefore, the flow field is modelled and analysed in Fluent to obtain the boundary conditions, and at the same time, based on the DPM discrete-phase model coupled with heat and mass transfer, the critical diameter of the droplets is introduced to ensure the simulation accuracy and then simulated. The experimental results show that under the set conditions, when the spray water flow rate of the single nozzle is 400 L/min, the air reflux phenomenon gradually occurs around the air-cooled condenser, and the heat transfer of the finned tubes on both sides at 1200 L/min is seriously affected. The heat transfer enhancement of the air-cooled condenser is best at a flow rate of 1000 L/min. The average temperature drop in the core spray zone reached 9.46 °C and the relative humidity reached 43.75 %.