基于高效非灰辐射模型的碳氢燃料燃烧产物特性研究

Gas combution products and soot play an important role on the radiative heat transfer and nitrogen oxides(NOx).In this project, the method of the combination of theoretical modeling simulation and experimental validation will be adopted to model the properties of combution products of hydrocarbon fuel and valide the results.The main work includes four parts.(1)Based on the updated spectral database,the line by line method is used to compute the absorption coefficient (CO2,CO, H2O,NO and soot) and botain their databases.(2)Introduce the porper orthogonal decoposition, the POD-SLW(Porper Orthogonal Decoposition -Spectral Line based Weight-Sum-of-Gray-Gases) model is proposed to investigate the radative heat transfer process in combustion involved with high temperature participation medium. Using the DO method,this model can calculate effectively the radiative flux at arbitrary point and improve the analysis capability about radiative heat transfer process with high temperature particpation medium in the combustion.(3)The non gray radiation model combined with detailed chemical reaction will be used to simulate the methane/air and ethylene/air diffusion flame, and to gain the distribution in space of concentration,temperature and radiative properties.(4) The concentration, temperature and radiative properities distributions will be reconstructed by using emission CT method and the tunable diode laser absorption spectroscopy (TDLAS).The distribution of reconstruction can confirm the results of the numerical simulation.The achievements of the present project will be helpful for the better understant of the effectos of combustion processes and flame radiative heat transfer and for the developemt of cobustion technologies of advanced high efficiency and low pollution emission.

碳氢火焰中，气体燃烧产物和碳黑对辐射换热和NOx生成有很大影响。本项目采用理论模拟和实验验证相结合的研究方法，开展碳氢燃料燃烧产物特性的模拟和实验验证研究。主要内容包括：1）采用最新光谱数据库和逐线法预测CO2、CO、H2O、NO和碳黑的吸收系数，建立四种气体的吸收系数数据库；2）引入本征正交分解法，提出高效、高精度的POD-SLW模型，并结合离散坐标法求取参与性介质的辐射换热分布；(3）基于挥发份详细化学反应、简单双方程碳黑模型和气体非灰辐射模型（POD-SLW），深入研究甲烷/空气、乙烯/空气层流扩散火焰中燃烧产物的浓度、温度和辐射特性在空间上的分布；4）基于发射CT法和TDLAS检测技术，获得燃烧产物特性和温度分布，对模拟结果进行验证。预料本项目的研究成果可深化碳氢火焰燃烧产物对燃烧过程和辐射换热影响的认识，以及为先进高效低污染燃烧技术的研发提供理论依据。

为探究碳氢燃料燃烧气体燃烧产物和碳黑对燃烧过程的影响，本项目从理论模拟和实验两方面进行了基础性研究。主要内容包括：1) 研究了高压下气体辐射特性，发展了一维、二维高压逐线法、FSCK模型等多种气体辐射模型，揭示了压力对辐射换热的影响规律，建立了普朗克平均吸收系数求解方法，综合评估了灰气体加权和模型；2) 基于详细化学反应机理，开展了碳氢燃料燃烧模拟工作，研究了气体燃料添加同时添加二氧化碳和氢气对燃烧过程中碳烟生成、火焰结构、火焰温度的影响机理，辨析了二氧化碳和氢气化学效应和稀释效应；3) 搭建了碳氢燃料燃烧实验台、碳烟二维消光法测量平台和碳烟TEM采样系统，基于平台测量火焰温度分布，揭示了不同条件下的火焰结构及产物生成规律，分析了氧浓度、二氧化碳稀释对火焰温度和碳烟微观结构的影响规律。本项目的研究成果可深化碳氢火焰燃烧产物对燃烧过程和辐射换热影响的认识，以及为先进高效低污染燃烧技术的研发提供理论依据。