燃煤电厂烟气汞监测技术的采样方法研究

Research on Sampling Method of Mercury for Monitoring in Flue Gas of Goal-fired Power Plant

烟气汞监测技术是实现燃煤电厂汞污染控制的有力保障。为探讨不同采样条件对监测结果的影响,以重庆某燃煤电厂为例,研究了方法适用范围、采样装置气密性及抗负压等问题,分析了采样管材质、还原性气体等因素对监测结果的影响。结果显示,对于燃煤电厂出口烟气汞监测,HJ 543-2009法检出限偏高,采样时应适当延长采样时间以降低检出限;选择加热的teflon材质采样管,监测结果最准确;增加串联吸收瓶数量,可降低高浓度还原物质对汞吸收的干扰;采样时应保证采样管路气密性良好及采样流量平稳。

Flue gas mercury monitoring technology- play-s an important role in mercury control for Coal-fired Power Plants, To explore the ilffluenee of different sampling conditions on the monitoring results of this method, field experiments were conducted at one Coal-fired Power Plants in Chongqing, and the application scope, sampling devices tightness and anti-vacuum were discussed, the impact of sampling tube material, reducing gas and other factors on monitoring resultwere analyzed. The results indicated that the detection linfit of mercury in HJ 543-2009 is relatively high in practice, so the sampling time should be extend in order to lower the detection linfit. Compared with stainless steel and titanium alloy sampling tube, the heated teflon sampling tube can make the monitoring results more accurate. Interference of reducing substances can be reduced by connecting absorption bottles, we showld guarantee good gas tightness and sampling flow smoothly while sampling.