H_(2)/NF_(3)燃烧火焰荧光光谱分析及温度分布测量  

Fluorescence Spectra Analysis and Temperature Profile Measurement of H_(2)/NF_(3)Combustion Flames

作　　者：李留成[1] 王元虎[1] 唐书凯[1] 王增强[1] 多丽萍[1] 李刚[1] 金玉奇[1] Li Liucheng;Wang Yuanhu;Tang Shukai;Wang Zengqiang;Duo Liping;Li Gang;Jin Yuqi(Key Laboratory of Chemical Lasers,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,Dalian 116023,Liaoning,China)

机构地区：[1]中国科学院大连化学物理研究所化学激光重点实验室,辽宁大连116023

出　　处：《中国激光》2023年第10期233-239,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(21590803);中国科学院化学激光重点实验室创新基金(KLCL-2020S06,KLCL-2021S02)。

摘　　要：为了研究燃烧驱动DF/HF化学激光器燃烧室内H_(2)/NF_(3)(或D_(2)/NF_(3))的混合燃烧特性,搭建了小型燃烧室平台。采用火焰荧光光谱法对燃烧室内H_(2)/NF_(3)燃烧火焰的形状和温度分布进行了测量和分析,光谱测量结果表明:在紫外可见光谱区域,H2/NF3燃烧火焰的自发光主要由N_(2)(B)、NF(b)、NH(A)等电子激发态分子的辐射跃迁产生,其中N_(2)(B)和NH(A)是燃烧过程中的关键物质成分,其发光强度可以很好地表征火焰燃烧的剧烈程度,可以用于定量测定燃烧火焰的长度;在近红外光谱区域,H_(2)/NF_(3)燃烧火焰自发光的光谱主要由HF(v)振动激发态分子的第一泛频振动转动跃迁谱带组成。利用HF(v=2→v=0)谱带的转动结构强度分布,结合电动平移台,给出了火焰温度沿气流方向的分布情况。考察了气体配比系数(NF_(3)与H_(2)的流量之比)对燃烧火焰温度分布的影响,结果显示:当气体配比系数较小时,燃烧室内气体温度沿气流方向下降得较为平缓;随着气体配比系数逐渐增大,气体温度沿气流方向下降得越来越快。燃烧火焰长度和火焰温度分布测量结果表明,燃烧室内的化学反应可能分为两个过程:一个是H_(2)/NF_(3)剧烈快速燃烧过程,此过程非常快,几乎一混合便立刻燃烧;另一个是过量NF_(3)在高温下的热解离过程,此过程相对较慢,并且温度越低NF_(3)的热解离越慢。因此,当NF3的占比较大时,需要较长的燃烧室滞留时间才能使过量的NF_(3)充分解离为氟原子。Objective For combustion-driven deuterium fluoride/hydrogen fluoride(DF/HF)chemical lasers,fluorine atoms produced in the combustion chamber are the source of the laser energy.The production efficiency of fluorine atoms in the combustion chamber directly determines the upper limit of the chemical efficiency of combustion-driven DF/HF chemical lasers.The atomic fluorine production efficiency limits several characteristic parameters of combustion-driven DF/HF chemical lasers,such as the amplification scale,volume efficiency,and weight efficiency.Therefore,it is necessary to investigate the combustion process of combustion-driven DF/HF chemical lasers thoroughly.In the past,most studies on HF/DF laser combustors were conducted theoretically using thermodynamic equilibrium methods rather than experimentally because of the extremely high temperature of the combustion production gases and the strong corrosivity of the combustion products F,F2,etc.To date,only a few indirect experimental studies have been conducted on HF/DF laser combustors.These experimental studies considered the laser output power as the research object to investigate the working performance of the combustion chamber indirectly without direct observation of the combustion process.In this study,a small combustion chamber platform was built.The ultraviolet–visible and near-infrared spectra of the H_(2)/NF_(3)combustion flame were directly observed by flame fluorescence spectroscopy.The combustion process of the H_(2)/NF_(3)mixture in the combustion chamber was analyzed using spontaneous emission spectroscopy.The gas temperature in the combustion chamber was measured using the rotational structure strength distribution of the HF(v=2→v=0)band.The flame temperature distribution along the gas flow direction is provided in combination with an electric translation platform.The influence of flow ratio of oxidant NF3 to fuel H2 on the flame gas temperature distribution was examined.Methods In this study,a small combustion chamber test platform was built(Fi

关 键 词：光谱学 荧光光谱 化学激光 燃烧室 温度分布 燃烧火焰 

分 类 号：O436[机械工程—光学工程]