烟气汞浓度监测吸附管离线采样方法的拓展应用  

Extended application of carbon sorbent traps method in mercury concentration measurement in coal-fired power plants

作　　者：钟犁[1] 肖平[1] 江建忠[1] 郭涛[1] 郭安[1] 

机构地区：[1]中国华能集团清洁能源技术研究院有限公司,北京100098

出　　处：《热力发电》2014年第6期17-22,31,共7页Thermal Power Generation

基　　金：华能集团科技项目(HNKJ11-H22)

摘　　要：将吸附管离线采样方法应用于美国EPA Method 30B标准允许外的高温、高灰条件下的汞浓度及形态监测试验研究,以拓展该方法的应用范围。试验结果表明:当采用吸附管采样法测量烟气总汞,且控制低流速采样并采用防尘罩时,该方法可以应用于湿法脱硫除尘前等粉尘浓度较高的场合,由粉尘引起的误差小于1%,但该方法不适用于高粉尘浓度的极端条件;在空气预热器前的高温位置,通过加设风冷套管并控制采样枪插入深度,可以保证吸附管温度处于合适的温度水平,从而保证测量的准确性;在烟囱入口等低粉尘浓度区域,测得的元素汞的比例与Hg-CEMS基本一致,尤其是湿法脱硫后的测试数据一致性良好,而干法脱硫后的采样测试结果略显偏低;但在高粉尘浓度区域,测得的元素汞比例则可能严重偏低。The carbon sorbent traps method was used to monitor the mercury content and speciation under high-temperature and high-ash content conditions that are beyond the allowable conditions of the EPA Method 30B,to extend its application range.The results show that,when measuring the total mercury concentration in flue gas,this method can be applied to the occasions of high dust concentration （e.g.before the WFGD system）,with the error caused by dust lower than 1％,if keeping the flow rate at a lower level and employing dustproof cover.But this method is not suitable to the conditions with extreme high dust content.By applying air-cooled casing and controlling the sampling gun＇s insert depth,the temperature of carbon traps can be kept within a suitable range.Thus,the measurement accuracy of mercury concentration before air preheater can be ensured.For the chimney inlet and other areas with low dust concentration,the proportion of Hg0 measured by the 30B method is in accordance with the Hg-CEMS after the WFGD system,while after the CFB-FGD system,the proportion of Hg0 measured by the 30B method is slightly lower than that by the Hg-CEMS method.For locations with high dust concentration,the proportion of Hg0 measured by the 30B method may be much lower than the true value.

关 键 词：燃煤电厂 吸附管采样法 汞形态监测 高温 高灰 

分 类 号：O657.99[理学—分析化学] X511[理学—化学]