适合逃逸氨取样测量的新型样品池研究  

Study on the new Herriott cell for escaping ammonia detection in sampling measurement

作　　者：张增福[1] 李晨曦[1] 陈文亮[1] 赵会娟[1] 徐可欣[1] 

机构地区：[1]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《激光与红外》2014年第5期545-548,共4页Laser & Infrared

基　　金：国家863项目(No.2012AA022602);国家重大科学仪器专项(No.2012YQ 060165)资助

摘　　要：可调谐半导体激光吸收光谱技术(TDLAS)为逃逸氨的在线检测提供了可靠的技术手段,然而现场取样测量需要克服高温、高粉尘及测量滞后性的影响,使得NH3浓度控制在3×10-6左右。采用特殊设计的新型Herriott样品池,具有中空光路、气路带加热的设计结构,能够提高测量的实时性。为了评价样品池的测量精度,分别对浓度为1×10-6到10×10-6的NH3进行检测,采集得到其二次谐波光谱,通过分析吸收峰以及谷值,得到测量结果的拟合曲线,根据光谱曲线的标准偏差得到了样品池的最低检测限为0.22×10-6。结果表明,新型Herriott样品池测量精度高、实时性好,能够满足逃逸氨的取样测量要求,适合在线监测。Tunable diode laser absorption spectroscopy （TDLAS）provides a reliable means for on-line detection tech-nology of escaping ammonia.However,sampling measurement needs to overcome the effect of high temperature,dust and measuring hysteresis,and the NH3 concentration needs to be controlled at about 3 ＆#215; 1 0 -6 level.A new special Herriott cell was designed with the structure of the hollow path and the gas heating,and it can improve the measuring real-time.In order to evaluate the measuring accuracy of sample cell,the concentrations of 1 ＆#215; 1 0 -6 to 1 0 ＆#215;1 0 -6 NH3 were detected,and their second harmonic spectrum were collected.Through the analysis of absorption peak and valley value,the fitting curve was obtained.According to the standard deviation of spectral curves,the detection limit of NH3 concentration is 0.22 ＆#215;1 0 -6 in the Herriott cell.The results show that the Herriott cell with the high measur-ing accuracy and good real-time performance can meet the requirements of sampling measurement of trace detection of escaping ammonia,and it is suitable for online monitoring.

关 键 词：可调谐激光吸收光谱(TDLAS) 逃逸氨检测 Herriott样品池 取样测量 

分 类 号：TH74[机械工程—光学工程]