基于烟气余热梯级利用的燃煤电厂脱硫废水零排放工艺及CFD模拟研究OA

To achieve zero discharge of desulphurisation wastewater and efficient utilisation of waste heat in coal-fired power stations,an integrated process comprising a'concentration tower+high-temperature flue gas drying tower evaporation'system,utilising waste heat from the flue gas tail stream,has been proposed and implemented.This process extracts a mixture of high-and low-temperature flue gas from the upstream and downstream of the low-temperature economiser to serve as a heat source.The desulphurisation wastewater is first pre-concentrated and reduced in volume within the concentration tower,after which the concentrated solution is sent to the drying tower for final evaporation and solidification.For the key equipment of the drying tower,computational fluid dynamics(CFD)was employed,utilising the Euler-discrete phase model,to conduct numerical simulations of the flow field,temperature distribution and droplet trajectories within the tower under two typical operating conditions:100%BMCR and 60%BMCR.The results indicate that,under varying loads,the flow field within the tower remains stable,droplets evaporate effectively and no wall adhesion occurs,thereby validating the reliability of the process.Compared with conventional direct drying processes,this integrated technology offers advantages such as strong adaptability to water quality,stable operation,and lower energy consumption and operating costs,providing an efficient,economical and scalable solution for zero-discharge of desulphurisation wastewater from coal-fired power plants.