Co <sub> 2 </ Sub> Component Measurement The Open Ambient Temperature Absorption Spectroscopy-based Online Measurement And Turn Pressure

Tunable diode laser absorption spectroscopy(TDLAS) technique on gas measurement has little impact by environment, fast response speed, high reliability and the simultaneous measurement of gas temperature and concentration etc., which become the fastest growing gas in situ measurement technique.First of all, in this dissertation the basic principles of TDLAS gas concentration and temperature, relevant spectral parameters and HITRAN database are described in detail. The relevant equipments of TDLAS experimental system are introduced, the tuning characteristics of distributed feed back model of tunable diode laser are studied by experimental analysis.Lines selection principles of TDLAS technology are described detailedly. The variation rule of spectral line intensity with temperature is calculated theoretically, and the characters of three kinds absorption spectroscopy profiles on different pressure and temperature are researched. Noise signal in the measurement system influence on the measurement of spectroscopy absorption is analyzed. Temperature field model with temperature gradient is established and the boundary effect on concentration and temperature measurement of central invariable temperature area is researched by using of multiple lines measurement methods.Temperature in situ measuring system of semiconductor laser is set up. According to the temperature measurements of pipe type furnace center invariable temperature zone, the effects of temperature on the four spectral line intensities and linewidths are studied, and the contrast and analysis of temperature measurement results of mutiple spectral lines pairs are achieved. Using time division multiplexing technology by means of scanning multiple characteristic lines, the temperature in situ measurements of pipe type furnace center invariable temperature zone in an open environment are performed, and non-linear equations are built. By using least-squares algorithm, the temperature results of invariable temperature zone on different conditions are obtained, comparisons of which and thermocouple measurements are analyzed, the maximum measurement error is 52.4K.Aimed at gas measurement in high pressure environment, CO2 concentration measurement experimental system is designed and built, and CO2 in situ measurement experiment in the pressure range of 1-4atm is actualized. The effects of pressure variations on spectral linewidth and spectral lines mutual superposition are experimentally researched, and the results are basically consistent with the theoretical calculation results. Using the multiple lines Lorentz fitting methods to finish CO2 concentration measurement under different conditions, error analysis under different pressure conditions is carried on.