甲烷掺氢燃料反应动力学特性分析及机理验证

Kinetic Characteristics Analysis and Mechanism Verification of Hydrogen-doped Methane Fuel

燃气轮机燃用天然气-氢气混合燃料可以大幅降低碳排放。为了研究天然气在不同掺氢比时的燃烧特性,利用Cantera开源程序对其基本反应动力学特性开展研究,计算常压和典型F级燃气轮机运行条件下不同掺氢比时混合燃料的层流火焰速度、点火延迟时间等基本反应动力学参数。分析8种反应机理计算获得的火焰位置、温度场分布、主要燃烧产物(CO_(2)和H_(2)O)、中间燃烧产物(OH基和CO)和微量燃烧产物NO的浓度分布,并与悉尼大学天然气-氢气混合燃料(体积分数50%H_(2)+50%CH_(4))模型燃烧室实验数据进行比较。结果表明,采用DRM22、USC2、Kee以及Miller-Bowman机理计算获得的混合气体燃烧特性与实验结果吻合,耦合加州大学单独的氮氧化物机理后所获得的NO_(x)排放值也具有较高的计算精度。结果可为氢燃料燃气轮机燃烧室性能的后续研究提供理论依据,为氢燃料燃气轮机的安全运行奠定基础。

Traditional gas turbines burning natural gas when switch to hydrogen mixed fuel can greatly reduce carbon emissions.In order to study the combustion characteristics of natural gas at different hydrogen doping ratios,Cantera open-source code is used to calculate its basic reaction kinetics parameters.Adiabatic flame temperature,Laminar flame velocity,ignition delay time of hydrogen mixed fuel at different hydrogen mixing ratios in normal pressure and typical F-class gas turbine operating conditions are calculated.The flame positions,temperature field distributions,concentration distributions of major combustion products(CO2 and H2O),intermediate combustion products(OH radicals and CO)and trace combustion products NO calculated from 8 reaction mechanisms are analyzed and compared with experimental data from a model combustion chamber with a natural gas-hydrogen fuel mixture(50%H2+50%CH4 by volume fraction)at the University of Sydney.The results show that the combustion characteristics of the gas mixture obtained by using DRM22,USC2,Kee,and Miller-Bowman mechanisms agree well with the experimental results,and the NOx emission values obtained by coupling the separate NOx mechanism of UCSD also have a high calculation accuracy.Conclusions of this paper can provide a theoretical basis for the follow-up research on the performance of the combustor of hydrogen-fueled gas turbines,and lay a foundation for the safe operation of hydrogen-fueled gas turbines.