Hitec熔盐传蓄热过程中NOx瞬态排放监测

摘要

The NO,NO2 and NOx transient emissions of Hitec molten salt,contacting with SS304,SS310 and SS316L were monitored respectively,in the temperature range of 200～600 ℃ by using the integrated flue gas analyzer with constant potential electrolytic gas sensor.The influence of stainless steel on the NOx transient emission of Hitec molten salt was assessed.The results showed that the NOx transient emission of Hitec molten salt in the temperature range of 300～600 ℃ have gone through 3 stages,including the initial stage,the rising stage and the acceleration stage.The molten salt was unstable due to the drastic increase of NOx transient emission,when the temperature of molten salt was above 553 ℃.The catalytic effect of stainless steel on the NOx transient emission of Hitec molten salt was 310＞304＞316L.SS310 was more likely to be corroded to generate NOx owing to higher chromium content.SS316L can prevent the catalysis of NOx emission of Hitec molten salt due to good corrosion resistance.It was proposed that SS316L could be used as the high temperature tank material of Hitec molten salt during heat storage and transfer.%利用带有定电位电解式气体传感器的综合烟气分析仪,分别对与不锈钢304、310及316L接触的Hitec熔盐在200～600℃的NO、NO2及NOx瞬态排放量进行监测,探讨了不锈钢对Hitec熔盐NOx瞬态排放量的影响.结果表明:Hitec熔盐在300～600℃的NOx瞬态排放量随熔盐温度的升高经历了初始阶段、上升阶段和加速阶段3个阶段,当温度大于553℃时熔盐因NOx瞬态排放量急剧增加而热稳定性失效;不锈钢对Hitec熔盐NOx瞬态排放催化效果由大到小顺序为310、304、316L,不锈钢310具有更高的含铬量更容易被腐蚀反应生成NOx,不锈钢316L因具有良好的抗蚀性对Hitec熔盐NOx催化作用趋近惰性,可以作为Hitec熔盐在传蓄热过程中的高温罐体材质使用.