燃煤电厂飞灰试验室比电阻测试方法及其分布特征

Laboratory Specific Resistance Measurement Method and Its Distribution Characteristics of Fly Ash for Coal-Fired Power Plants

全面分析了燃煤电厂飞灰试验室比电阻的测试方法,并基于最常用的圆盘法(DR-2型高压粉尘比电阻试验台),首次对国内290组燃煤电厂飞灰样品进行试验室比电阻测定,结果表明:90℃、120℃、150℃、180℃、210℃时燃煤飞灰样品的试验室比电阻分别多集中在10^(6)~10^(10)Ω·cm、10^(6)~10^(11)Ω·cm、10^(7)~10^(12)Ω·cm、10^(8)~10^(12)Ω·cm、10^(9)~10^(12)Ω·cm;90℃、120℃温度条件下,中比电阻(104~10^(11)Ω·cm)所占比例分别达97.76%、93.36%,该温度区间内,国内绝大多数的燃煤飞灰都适用于电除尘器收集;90℃与120℃相比,试验室比电阻差了1~3个数量级,因此,降低电除尘器入口烟气温度,有利于电除尘提效。对国内燃煤电厂的飞灰试验室比电阻进行科学全面表征,为后续电除尘技术优化提供数据参考。

Laboratory specific resistance test method of coal fly ash was analysied comprehensively,and based on the most commonly used method of disc(DR-2type high pressure dust specific resistance test bench),laboratory specific resistance of 290groups of coal fly ash samples were tested for the first time.The results show that,laboratory specific resistance of coal fly ash samples were concentrated in 10^(6)~10^(10)Ω·cm,10^(6)~10^(11)Ω·cm,10^(7)~10^(12)Ω·cm,10^(8)~10^(12)Ω·cm,10^(9)~10^(12)Ω·cm,as the temperature were at 90℃,120℃,150℃,180℃,210℃.Under the condition of temperature of 90℃,120℃,laboratory specific resistance(104~10^(11)Ω·cm)accounted for 97.76%,93.36%,respectively,and in this temperature range,the vast majority of domestic coal fly ash was suitable for electric dust collection.Compared with 120℃,the laboratory specific resistance of 90℃was 1~3 orders of magnitude lower.Therefore,lowering the temperature of the flue gas at the entrance of the electrostatic precipitator was conducive to improving the efficiency of electric dust removal.The purpose of this paper is to scientifically and comprehensively characterize the laboratory specific resistance of fly ash in domestic coal-fired power plants and provide data reference for subsequent optimization of electric dust removal technology.