火电厂烟塔合一技术应用现状与现存问题分析

Application Status and Existing Problem Analysis of the Natural Draft Cooling Towers With Flue Gas Injection Technology in Thermal Power Plants

【目的】烟塔合一技术是火电厂提高能效的重要改造手段,但是实际运行对现有系统造成的不利影响也不容忽视。为此,对烟塔合一技术应用现状及其在运行中存在的问题进行分析,并提出处理对策。【方法】通过综合分析现有研究,探讨了烟塔合一技术改造后造成环境影响、冷却塔塔体腐蚀以及循环冷却水水质恶化的成因和形成机理。【结果】根据计算流体动力学(computational fluid dynamics,CFD)对烟气排放轨迹以及污染物落地浓度的模拟结果,可合理设置防护距离,并通过塔顶加装挡板预防极端天气下的烟气下洗现象;针对不同部位,可采用不同防腐涂料对冷却塔进行防腐改造,以延长其使用寿命;为控制和优化循环水质,需采用深度水处理方法优化药剂投加,并适当控制循环水排污量与补水量,以维持其运行可持续性。【结论】通过采取适当的应对措施,可以有效缓解烟塔合一技术改造所带来的负面影响,提高火电厂环境效益和经济效益。

[Objectives]The natural draft cooling towers with flue gas injection(NDCT-FGI)is a crucial retrofitting technique for enhancing the efficiency of thermal power plants.However,its operational impacts on existing systems are significant and cannot be overlooked.Therefore,the current status of NDCT-FGI technology and its problems in operation were analyzed,and the countermeasures were put forward.[Methods]Through comprehensive analysis of the existing research,the causes and formation mechanism of environmental impact,cooling tower corrosion,and deterioration of circulating cooling water quality caused by the technical transformation of NDCT-FGI were discussed.[Results]The protective distance can be reasonably set by the simulation results of flue gas emission trajectory and pollutant landing concentration by computational fluid dynamics(CFD).Installation of baffles at the tower top can prevent flue gas washdown during the extreme weather conditions.Different anticorrosive coatings are recommended for various parts of the cooling tower to extend its service life.To control and optimize cooling water quality,the advanced water treatment techniques are necessary for optimizing chemical dosing,and the management of effluent and makeup water must be carefully controlled to ensure operational sustainability.[Conclusions]By implementing appropriate and effective countermeasures,the negative impacts of NDCTFGI retrofitting can be mitigated,thereby enhancing both the environmental and economic benefits for thermal power plants.