CO2高温光谱参数测量系统设计与实验

Design and experiment of CO2 high temperature spectrum parameter measurement system

CO2 和 CO 被称为燃烧效率指示性气体燃烧流场中 CO2 的精确测量对工业燃烧过程的节能减排和发动机燃烧状态诊断等都具有重要意义.研究 CO2 气体的高温光谱参数包括:线强、自加宽系数、温度系数可提高燃烧过程中 CO2 浓度的测量精度和可靠性.为了获得可用于燃烧诊断的 CO2 吸收线的高温光谱参数基于可调谐半导体激光吸收光谱技术设计了一套最高温度可达2-0173 K 的精确控温控压气体光谱参数测量系统.采用该系统开展了CO2R(50e)吸收线(中心频率为5007.787cm )的高温光谱测量实验获得了温度范围1212~1873K内多个压强下的纯 CO2 气体的大量高温吸收光谱经热辐射背景扣除、基线拟合、时频转换、多线组合非线性最小二乘法拟合等数据处理过程得到温度范围1212~1873K内CO2R(50e)吸收线的线强、自加宽系数及温度系数其中线强不确定度<1.5%自加宽系数不确定度小于4.5%.这些参数是对现有数据库的补充和完善对燃烧诊断中的CO2浓度检测有很大帮助能够满足燃烧过程中 CO2 浓度精确反演的需求.

CO2 and CO are called the key indicators of combustion efficiency. Accurate measurement of CO2 in the combustion flow field is very important for energy conservation and emission reduction in industrial combustion process and engine combustion state diagnosis. Researching intensity,self-broadening full-width,temperature-dependence exponent and other parameters of CO2 in high temperature, may improve the accuracy and reliability of measurements for CO2 concentration. A precise temperature control and pressure control gas spectroscopic parameter measurement system with a design temperature up to 2073 K based on absorption spectroscopy has been developed for the measurement of spectroscopic parameters of the R( 50e) line at 5 007. 787cm - 1 of CO2 . Many high temperature survey spectra of the CO2 R ( 50e) line were recorded at 1 212 ~ 1 873 K and many pressures through the system. Through background subtraction,baseline fitting,time-frequency conversion,multi-line combination and nonlinear least squares fitting,and other data processing based on the CO2 R( 50e) survey spectra,intensity,self-broadening full-width and temperature-dependence exponent at 1 212-1 873 K were obtained. The uncertainty of line strength is less than 1. 5%,the uncertainty of self-broadening full-width is less than 4. 5%. These parameters are supplement and improvement to the existing database. They are helpful for the detection of CO2 concentration in combustion diagnosis to ensure the accurate inversion of CO2 concentration in the combustion process.