基于激光双吸收谱线的氨气温度测量研究

摘要

Selective catalytic reduction(SCR)is the most commonly used technology for reducing NOx emissions in coal-fired power generation.Ammonia gas(NH3 )temperature in chemical reduction reaction is one of the key param-eters for the closed-loop control of SCR process.A measurement method of ammonia gas temperature based on two-line tunable diode absorption spectroscopy is proposed.Real-time monitoring of chemical reaction temperature of SCR process was achieved.A pair of ammonia absorption lines(6605.1042 cm -1 and 6605.1901 cm -1 )was selected ac-cording to HITRAN08 database.The relationship between the intensity ratio and temperature of two absorption lines was theoretically derived.The experimental results show that linear error and the maximum fluctuation of temperature measurement are 0.89％(average)and 3.5％(RMS)in 80 ～160 ℃ temperature range.It lays the foundation for the temperature and concentration measurement of ammonia under high temperature.%选择性催化还原(SCR)是燃煤发电中降低NOx排放使用最多的技术,化学还原反应中氨气(NH3)温度是闭环控制SCR过程的关键参数之一.提出了一种基于激光双吸收谱线的氨气温度测量方法,实现SCR过程化学反应温度实时监测.利用HITRAN08数据库,选取一对氨气的吸收谱线6605.1042 cm-1和6605.1901 cm-1,理论推导了两条吸收谱线的强度比与温度的关系.实验结果显示,在80～160℃温度范围内,温度测量的线性误差为0.89％(平均值),最大波动为3.5％,为下一步高温测量氨气浓度和温度测量奠定了基础.