摘要
飞灰的介电性质是影响电收尘效率的重要因素。根据自行研制的直流高压试验系统,对不同燃煤飞灰的漏泄电流和比电阻进行了实测分析,获得了一系列伏安特性曲线。实验结果表明:施加在灰层上的电压、通过灰层的漏泄电流和飞灰的比电阻三者之间的关系不总是遵循经典的欧姆定律,即V/I≠常数;飞灰的伏安特性曲线在高、中、低3个电压段具有不同的形态特征;随着电压的提高,飞灰的比电阻呈下降趋势,下降幅度在1个数量级(101Ω.cm)以内。导致这一现象发生的原因是飞灰的高电阻特性,同时与燃前煤种和飞灰的物化性质密切相关。
The dielectric character of fly ash is a major factor having an impact on the efficiency of electrostatic precipitators.By employing a self-developed directcurrent high voltage test system the current leakage and specific resistance of the fly ash of various kinds of coal being fired were measured and analyzed,and a series of volt-ampere characteristic curves obtained.It has been found that the relation among the following three items,i.e.,the voltage applied to the ash layer,the current leakage through the ash layer and fly-ash specific resistance,does not always conform to the classic Ohm's law,namely,V/I ≠ constant.At the three segments of high,middle and low voltage the volt-ampere characteristic curves of the fly ash have different configuration features.With an increase in voltage the specific resistance of the fly ash assumes a descending tendency with the range of descending amount being within one order of magnitude(10~1Ω·cm).The cause leading to the occurrence of this phenomenon consists in the high-resistance feature of the fly ash.Meanwhile,this is also closely related with the physical-chemical properties of the coal rank and fly ash.
出处
《热能动力工程》
EI
CAS
CSCD
北大核心
2006年第1期58-61,共4页
Journal of Engineering for Thermal Energy and Power
关键词
燃煤飞灰
介电性质
比电阻
电除尘器
fly ash of coal fired,dielectric properties,specific resistance,electrostatic precipitator
