介绍了使用氟塑料换热器回收大型火电厂烟气潜热和凝结水的试验研究.火电厂湿法脱硫系统出口温度为50~55℃的饱和或过饱和烟气,其烟气水蒸气浓度为12%~18%.烟气中的水蒸气携带大量潜热,降低了锅炉效率.拟在脱硫系统出口烟道中加装冷凝换热回水装置(换热器),以实现高水分烟气的深度凝结,回收大量水分,同时回收气化潜热.为此,在某褐煤电厂搭建中试试验系统,抽取实际烟气进行试验.结果显示:当烟气温度降低9~10℃,将结果折算到全烟气量(2500000 m3/h,标准状态,下同),可以回收凝结水92.25 t/h,回收热量226.97 GJ/h;该系统可实现褐煤机组湿法脱硫零耗水,这对干旱地区的水资源保护有重要意义.
Recovery of latent heat and condensate water from flue gas in a large coal-fired power plant using fluorine plastic heat exchanger was introduced.The flue gas temperature at outlet of the wet desulphuriza-tion system is about 50 ℃ to 55 ℃,and the flue gas is saturated or supersaturated.The water vapor con-centration in flue gas is about 12% to 15%.Water vapor in flue gas carries a large amount of latent heat, which reduces the boiler efficiency.If equipped with condensing heat exchanger at outlet of the flue desul-phurization system,the deep condensation of high moisture flue gas can be realized,which can recycle water of great quantities and recover the latent heat at the same time.Thus,a pilot test system was constructed in a coal power plant to extract the flue gas for field test.The experimental results show that,when the flue gas temperature was reduced by 10 ℃,the condensate of 92.25 t/h and latent heat of 226.97 GJ/h can be obtained,by translating the results to the whole flue gas volume (2 500 000 Nm3/h,standard state,the same as follows).This system can realize zero water consumption in wet desulphurization system,which has important significance in protection of water resources in arid regions.