A review of laminar flame speeds of hydrogen and syngas measured from propagating spherical flames

Han，Wang1; Dai，Peng2; Gou，Xiaolong3; Chen，Zheng4

2020-12-01

10.1016/j.jaecs.2020.100008

Applications in Energy and Combustion Science   影响因子和分区

2666-352X

As promising alternatives to fossil fuels, hydrogen (H) and syngas are playing important roles in the development and control of high-efficiency, low-emission engines. Achieving accurate prediction of H-fueled combustion requires a reliable chemical mechanism which, however, still exists considerable uncertainty. The laminar flame speed (LFS) has been widely employed to validate and optimize chemical mechanisms and to model turbulent premixed combustion. While in the literature there are extensive LFS data measured using the outwardly propagating spherical flame (OPF) method for hydrogen/air and syngas/air mixtures at normal temperature and pressure (NTP), the accuracy of the LFS data is not fully explored. This work aims to (i) review the uncertainty in the LFSs measured by different groups for hydrogen/air and syngas/air mixtures at NTP using the OPF method, and (ii) identify underlying sources of the uncertainty. It is found that there are considerable discrepancies in the LFS measurements, leading to these experimental data being unreliable for restraining the uncertainty of chemical models. The underlying sources of uncertainty are discussed in different flame propagation regimes and their contributions to the discrepancies are assessed individually using 1-D simulations. The results show that the contribution of ignition effects to the uncertainty depends strongly on the equivalence ratio and that the ignition effects could be one of the main sources of uncertainty for the LFSs of fuel-rich mixtures. Furthermore, it is found that the accuracy of measured LFSs is strongly affected by the choice of extrapolation model and flame radius range for extrapolation. The nonlinear extrapolation is less sensitive to the flame radius range than linear extrapolation, implying that using nonlinear extrapolation models can reduce the impact of the flame radius range selected on the uncertainty, especially for fuel-rich and/or fuel-lean mixtures. Nevertheless, strong nonlinear behavior between stretched flame speed and stretch rate still makes a major contribution to the very large discrepancies even when the nonlinear extrapolation models are used. To address the nonlinear stretch behavior, a new nonlinear extrapolation model NQH is proposed and it is shown to be more accurate than other models as pressure increases. Moreover, the recommendations on Hand syngas LFS measurements using the OPF method are provided.

Hydrogen Laminar flame speed Propagating spherical flame Syngas Uncertainty

英语

其他

National Natural Science Foundation of China[51861135309];National Natural Science Foundation of China[91741126];

2-s2.0-85107070353

Scopus

1.Institute for Multiscale Thermofluids,School of Engineering,The University of Edinburgh,Edinburgh,EH8 3JL,United Kingdom
2.Department of Mechanics and Aerospace Engineering,Southern University of Science and Technology,Shenzhen,518055,China
3.Key Laboratory of Low-grade Energy Utilization Technologies and Systems,School of Power Engineering,Chongqing University,Chongqing,400044,China
4.SKLTCS,CAPT,BIC-ESAT,College of Engineering,Peking University,Beijing,100871,China

Han，Wang,Dai，Peng,Gou，Xiaolong,et al. A review of laminar flame speeds of hydrogen and syngas measured from propagating spherical flames[J]. Applications in Energy and Combustion Science,2020,1-4.

Han，Wang,Dai，Peng,Gou，Xiaolong,&Chen，Zheng.(2020).A review of laminar flame speeds of hydrogen and syngas measured from propagating spherical flames.Applications in Energy and Combustion Science,1-4.

Han，Wang,et al."A review of laminar flame speeds of hydrogen and syngas measured from propagating spherical flames".Applications in Energy and Combustion Science 1-4(2020).