湿烟羽治理中脱硫系统水平衡影响因素分析  

Analysis of influencing factors on water balance of desulfurization system in wet plume treatment

作　　者：杨爱勇 舒喜 韦飞 祝业青 YANG Aiyong;SHU Xi;WEI Fei;ZHU Yeqing(National Environmental Protection Research Institute for Electric Power,Nanjing 210031,China)

机构地区：[1]国电环境保护研究院有限公司,江苏南京210031

出　　处：《洁净煤技术》2020年第6期217-223,共7页Clean Coal Technology

基　　金：国家科技支撑计划资助项目(2015BAA05B01)。

摘　　要：目前各地政府对湿烟羽治理越来越重视,燃煤电厂、钢铁、焦化等行业陆续开展湿烟羽治理改造工作,但设计中对影响脱硫水平衡的因素缺少系统分析,导致脱硫水平衡难以控制或排烟温度超标等问题。通过对历史在线数据、理论分析与计算,对燃煤电厂脱硫水平衡的影响因素进行全面总结与量化分析。明确燃煤煤质、环境条件、脱硝等环保设施对脱硫水平衡的影响。燃煤煤质的全水和氢含量影响最大,几种典型煤种的脱硫排烟温度差异可达10℃以上。环境温度和湿度的影响明显,环境温度从0℃升到40℃时(假定环境相对湿度为60%),脱硫排烟温度差异达4.6℃。空气过剩系数(或氧量)也有较大影响,氧含量从4%增到8%时,排烟温度相差超过2.5℃。采用SNCR等工艺时,尿素溶液中含大量水,对脱硫排烟温度的影响可达1℃。脱硫入口烟温对脱硫排烟温度的影响明显,具体差异与脱硫入口烟温和煤质有关。此外,机组负荷等因素也会对脱硫水平衡产生较大影响。全厂废水零排放方案中,常将冷却塔排污水等高含盐废水用于脱硫除雾器冲洗等,决定了脱硫系统必须接受补给水的同时保证水平衡。不同湿烟羽治理技术方案对脱硫水平衡的影响存在差异,其中烟气冷凝工艺无影响,而浆液冷却技术影响较大。因此,在湿烟羽治理在方案选择和工艺参数设计时,要综合考虑各因素之间的匹配性,选取合适的方案和设计参数对降低投资运行费用、提高系统的可靠运行方面具有重要意义。At present,local governments pay more and more attention to the treatment of wet plume.Coal fired power plants,iron and steel,coking and other industries have carried out wet plume treatment reform.However,there is a lack of systematic analysis on the factors affecting the desulfurization water balance,which leads to the difficulty of controlling the desulfurization water balance or the flue gas temperature exceeding the standard.Based on the historical online data,theoretical analysis and calculation,in this paper,the influencing factors of desulfurization water balance in coal-fired power plants were comprehensively summarized and quantitatively analyzed.For the first time,the influence of coal quality,environmental conditions,denitrification and other environmental protection facilities on the water balance of desulfurization was clarified.The results show that the total water and hydrogen content of coal are the most important factors,and the difference of flue gas temperature of several typical coals is more than 10℃.The influence of environmental temperature and humidity is obvious.When the ambient temperature rises from 0℃to 40℃(assuming the relative humidity is 60%),the difference of flue gas temperature is 4.6℃.Air excess coefficient(or oxygen content)also has a great influence.When the oxygen content increases from 4%to 8%,the difference of exhaust gas temperature is more than 2.5℃.When SNCR and other processes are used,urea solution contains a lot of water,and the influence on flue gas temperature of desulfurization can reach 1℃.The influence of flue gas temperature at desulfurization inlet on flue gas temperature is obvious,and the specific difference is related to flue gas temperature and coal quality.In addition,the unit load and other factors will also have a greater impact on the desulfurization water balance.In the scheme of zero discharge of wastewater,high salinity wastewater from cooling tower wastewater is often used for demister flushing,which determines that the desulfurization

关 键 词：湿烟羽治理 脱硫 水平衡 影响因素 

分 类 号：TK16[动力工程及工程热物理—热能工程]