湿法烟气脱硫系统出口净烟气的温湿度变化特性  

Temperature and humidity variation characteristics of desulfurated flue gas at outlet of wet flue gas desufurization system

作　　者：鲍静静[1] 毛琳[1] 李卓凡 朱婧瑶[1] 马凌 杨林军[2] 杨宏旻[1] 

机构地区：[1]江苏省能源系统过程转化与减排技术工程实验室南京师范大学能源与机械工程学院,南京210042 [2]东南大学能源热转换及其过程测控教育部重点实验室,南京210096

出　　处：《农业工程学报》2016年第8期231-237,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金项目(51506099);江苏省自然科学基金项目(BK20130906)

摘　　要：水汽相变技术与湿法烟气脱硫系统(wet flue gas desulfurization,WFGD)结合可有效控制细颗粒物排放,脱硫净烟气所能达到的过饱和度直接影响细颗粒物脱除效果,而烟气过饱和度取决于脱硫净烟气温湿度和水蒸气添加量。因而脱硫净烟气温湿度变化特性研究可为WFGD系统中应用水汽相变促进细颗粒物脱除提供依据,对于优化湿法脱硫操作条件、估算水蒸气添加量以及实现低能耗高效脱除细颗粒物具有重要意义。该文基于石灰石-石膏法脱硫工艺,试验考察了脱硫塔进口烟气温湿度、空塔气速、液气比、脱硫液温度等操作条件以及脱硫塔类型对脱硫净烟气温湿度的影响。结果表明,空塔气速由2.5 m/s提高至2.9 m/s可使脱硫净烟气相对湿度和绝对湿度分别由88%、82.2 g/kg先急剧降低至52%、57.3 g/kg,随后趋于相对平缓;液气比由5 L/m^3增至20 L/m^3有利于提高脱硫净烟气的相对湿度和绝对湿度,可分别由39%、46.4 g/kg提高至91%、84.3 g/kg,但相对湿度的增幅明显高于绝对湿度增幅;脱硫净烟气的相对湿度、绝对湿度及温度均随脱硫液温度升高而迅速提高,液气比为15 L/m3时,脱硫液温度由25℃升至60℃可使脱硫净烟气相对湿度、绝对湿度、温度分别由54%、25.9 g/kg、42℃提高至85%、98.5 g/kg、56℃,但脱硫液温度升至40℃后,脱硫净烟气的相对湿度趋于平缓;脱硫液温度保持不变时,提高塔进口烟气温度可使脱硫净烟气的绝对湿度和温度先明显增加,随后趋于平缓,而相对湿度随塔进口烟温提高稍有降低;并且不同的脱硫塔型对脱硫净烟气温湿度也有影响,液气比为5 L/m3时,经湍球塔、旋流板塔、喷淋塔脱硫后的净烟气相对湿度分别为90%、91%、44%。该研究结果为湿法烟气脱硫系统的应用提供参考。Emission of fine particles can be controlled effectively in the wet flue gas desufurization(WFGD) system by the combining vapor heterogeneous condensation technology. Fine particles removal efficiency is influenced directly by the supersaturation degree of desulfurated flue gas with water vapor added. The supersaturation degree of desulfurated flue gas depends on the temperature and humidity of desulfurated flue gas and the amount of water vapor added. Hence the research of variation characteristics of desulfurated flue gas temperature and humidity would provide a basis for fine particles removal in WFGD system combined with vapor heterogeneous condensation. The results are significant to the optimization of WFGD operating conditions, the estimation of the amount of water vapor added and the fine particle removal with high efficiency and low energy. Based on the limestone-based desulfuration process, the influences of the temperature and humidity of inlet flue gas, superficial gas velocity, liquid-to-gas ratio, desulfurization solution temperature etc. on the temperature and humidity(absolute humidity and relative humidity) of desulfurated flue gas were investigated in this paper. The results showed that the relative humidity and absolute humidity of desulfurated flue gas would first decrease sharply from 88%, 82.2 g/kg to 52%, 57.3 g/kg respectively, and then become flat when the superficial gas velocity increased from 2.5 to 2.9 m/s. An increase of liquid-to-gas ratio from 5 to 20 L/m^3 was beneficial to enhance the absolute humidity and relative humidity of desulfurated flue gas. They increased from 39%, 46.4 g/kg to 91%, 84.3 g/kg, respectively. The increase amplitude of relative humidity was much higher than that of absolute humidity. With the increasing of the temperature of desulfuration solution, the temperature, absolute humidity and relative humidity of desulfurated flue gas enhanced significantly. If the desulfurization liquid temperature rose from 25 to 60 ℃, the relative humidity, absolute humidity

关 键 词：温度 湿度 燃烧 湿法烟气脱硫 烟道气 

分 类 号：X701.3[环境科学与工程—环境工程]