摘要
本文简述用光电光谱仪法测定轴对称火焰温度分布的基本原理。由直接检测的火焰射流弦向钠D线的光谱积分辐肘强度分布I_(λg)(x)、参考光源的光谱辐射强度I_(λs)和迭加参考光源透过的火焰光谱积分总辐射强度分布I_(λgs)(x),然后分别用积分方程变换加迭代计算法和等温阶跃串联火焰近似计算法,逐步算出光谱体积吸收系数径向分布K_λ(r)和光谱体积发射系数径向分布ε_λ(r)。最后假设存在局部热平衡条件,由基尔霍夫定律和普朗克定律来得火焰射流的径向温度分布T(r)。用串联火焰近似计算法求得的中心温度与用动态热电偶测得的中心温度基本相附。
This paper describes a spectroscopic method of determination ofthe temperature distribution of a flame jet. This method is used to measurethe lateral integrated spectral intensity profile of the flame jet Iλ_g(x), thespectral radiation intensity of a reference source behind the flame Iλ_s, and thecombined spectral radiation intensity profile Iλ_(gs) (x) of the flame superposedby the reference source observed through the flame. The integrated spetral transmission of flame can be evaluated by substracting the intensity of twoscans and dividing it by the intensity of the reference source. Thesemeasurements which can be realized by using of grating monochromatorwith photomultiplier detector, are sufficient to determine the radial distribu-tion of the volume absorption and emission coefficients. The volume absorptioncoefficient profile has been determined by Barr's method based of a numericaltechnique for performing an Abel inversion on the observed intensityprofile. Once the radial profile of the absorption coefficient has been obtainedan iterative procedure is used to find the radial profile of the volume emissioncoefficient. Finally the ratios of these two profiles are used to evaluate thetemperature radial profile of the flame jet using Kirchhoff's Law and plan-ck's Law with the assumption of local thermodynamc equilibrium. Compa-rison of flame core. temperature measured by this spectroscopic method withthat by the transient thermocouple method indicated that the results of thesetwo measurments are in quite good agreement with each other.
出处
《仪器仪表学报》
EI
CAS
1985年第3期286-291,共6页
Chinese Journal of Scientific Instrument
