无电晕式阴极放电对SNCR脱除NO影响

Influence of electron emission by no-corona electrode on NO removal by SNCR

将无电晕式阴极放电技术应用于NH3选择性非催化还原（SNCR）脱硝系统中,分析反应机理。在热输入为0.17 MW循环流化床燃煤锅炉上,研究烟气温度（800~900℃）、阴极电压（0~12 k V）、电子密度（0~0.995 8 m A/cm2）、氨与氮物质的量比（0.75~2.00）和停留时间（0.25~2.00 s）等因素对发射电子催化NH3选择性非催化还原烟气中NO的影响。研究结果表明：随着阴极电压、电子密度、氨与氮物质的量比及停留时间的增加,NO脱除率可达到50.00%~71.30%;电压大于9 k V、温度高于850℃后,电子密度显著增大,NO脱除率迅速增加;随着发射电子增加,NO脱除率增加幅度降低;氨与氮的物质的量比在1.0~1.5区间时脱硝效果较好且NH3逃逸量在允许范围内。

Technique of electron emission by no-corona electrode was introduced into the process of NO removal by ammonia-based selective no-catalytic reduction （SNCR）, and the reaction mechanism was analyzed. The influence of temperature（800-900 ℃）, voltage （0-12 kV）, electron density （0--0.995 8 mA/cm2）, mole ratio of ammonia to nitrogen （0.75-2.00）, resident time （0.25-2.00 s） on the reaction that electron catalyzes the NO removal by NH3 in process of SNCR in a 0.17 MW CFB coal-fired boiler was investigated. The results show that with the increase of voltage, electron density, NSR and residence time, the efficiency of NO removal reaches 50%-71.3%. When the voltage is larger than 9 kV and the temperature over 850 ℃, electron density and NO removal intensely increase; with the increase of electron density, the increase rate of NO removal decreases; when the range of NSR is 1-1.5, the quantity of NO removal and the amount of NH3 escapement ranks among the range of permission.