Article
Energy & Fuels
R. Rabello de Castro, P. Brequigny, J. P. Dufitumukiza, C. Mounaim-Rousselle
Summary: Syngas, a gaseous biofuel, requires operation mode adaptation when used for stationary electricity generation in Internal Combustion engines. Research indicates that combustion parameters of different syngas compositions from various gasifiers affect flame speeds, with Updraft and Downdraft compositions showing higher speeds. Kinetic modeling results show good overall agreement with experimental data, with CRECK mechanism deviating by only 5-10%.
Article
Chemistry, Physical
Pinkun Guo, Songjie Liu, Xinyue Chang, Zhirong Wang, Chuanqing Xu, Lin Hu, Junchen Lu
Summary: The laminar flame speed of syngas/air premixed gas is influenced by the initial temperature and equivalence ratio. The laminar flame speed increases exponentially with the increase of initial temperature and reaches a maximum at an equivalence ratio of 2. The effect of initial temperature on the laminar flame speed depends on the equivalence ratio. A new correlation is proposed to predict the laminar flame speed of syngas/air premixed gas considering the synergistic effect of equivalence ratio and initial temperature.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Energy & Fuels
Saeid Shahpouri, Armin Norouzi, Christopher Hayduk, Alexander Fandakov, Reza Rezaei, Charles Robert Koch, Mahdi Shahbakhti
Summary: Artificial Neural Network (ANN) and Support Vector Machine (SVM) methods are used to predict the laminar flame speed (LFS) of ammonia, hydrogen, and methanol. These machine learning methods have significantly reduced computation time compared to traditional methods while maintaining similar accuracy. ANN outperforms SVM for single fuels, while SVM performs better for fuel blends.
Article
Chemistry, Physical
Berk Can Duva, Elisa Toulson
Summary: The fundamental combustion characteristics of H-2/air flames with the addition of actual H-2/air combustion residuals were examined experimentally and numerically. The results showed that the flame speed and adiabatic flame temperature decreased linearly with increasing diluent level, while the change in burned gas Markstein length was more complex.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Guo-Peng Zhang, Guo-Xiu Li, Hong-Meng Li, Jia-Cheng Lv
Summary: This study experimentally investigated the combustion characteristics of a hydrogen-rich syngas premixed flame with different diluents. The results showed that the flame propagation speed was lower under CO2 dilution but had a higher flame acceleration effect, and as the dilution increased, the rate of pressure rise and the maximum combustion explosion pressure gradually decreased.
Article
Thermodynamics
Nikolaos Papafilippou, Muhammad Aqib Chishty, Richard Bart Gebart
Summary: This paper investigates differences in combustion behavior by comparing numerical solutions with methane and various syngas compositions. The study shows that syngas combustion experiences lower swirl intensity and higher laminar flame speed compared to methane, resulting in differences in flame shape and position. The strong correlation between laminar flame speed and flame shape could be used as a guideline for evaluating combustion system performance.
FLOW TURBULENCE AND COMBUSTION
(2022)
Article
Thermodynamics
Xue Gong, Xiao Wang, Hua Zhou, Zhuyin Ren
Summary: This study numerically investigates the effects of hydrogen addition on laminar flame speeds, autoignition, and the coupling of autoignition and flame propagation for surrogate jet fuel n-dodecane at representative engine conditions. The results reveal the challenges for flame stabilization and the autoignition risks in combustor design due to the nonlinear increase in flame speed with hydrogen addition for fuel-rich conditions. The study also demonstrates the potential coupling of autoignition and flame propagation, showing that hydrogen addition can alleviate or eliminate the two-stage ignition characteristics for pure n-dodecane/air flames.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Thermodynamics
Luming Fan, Bo Tian, Cheng Tung Chong, Mohammad Nazri Mohd Jaafar, Kenji Tanno, Dante McGrath, Pedro M. de Oliveira, Bernd Rogg, Simone Hochgreb
Summary: In this study, the impact of fuel droplets on stretched laminar flame speeds was investigated by adding small acetone droplets to methane/air mixtures. It was found that the presence of droplets altered the relationship between flame speed and strain rate, especially under rich conditions. Unlike fully vaporized flames, a two-stage reaction flame structure was observed with droplets, indicating a change in flame behavior.
COMBUSTION AND FLAME
(2021)
Article
Chemistry, Physical
Minggao Yu, Fuer Zhai, Haitao Li, Shixin Han, Shanshan Li, Kai Zheng, Yingying Yu
Summary: This study investigates the effects of water addition on the laminar flame speed (Su) of heavily carbonaceous syngas under different conditions. Results show that Su is more sensitive to humidity variation for syngas with higher carbon content. The third-body effect of water in key reactions and two primary paths to generating OH radicals in heavily carbonaceous syngas are identified.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Shangkun Zhou, Wenjun Yang, Houzhang Tan, Qiwei An, Jinhua Wang, Hongchao Dai, Xiaoxiao Wang, Xuebin Wang, Shuanghui Deng
Summary: Ammonia (NH3) plays a crucial role in large-scale storage and long-distance transportation of renewable energy. Co-firing with syngas and bio-syngas, along with increasing the initial temperature of reactants, are effective methods to enhance the reactivity of NH3 flames. However, current kinetic models lack accuracy in temperature dependence, indicating a need for further research in this area.
COMBUSTION AND FLAME
(2021)
Article
Chemistry, Physical
Hui-Sheng Peng, Bei-Jing Zhong
Summary: Experiments were conducted to determine the effects of composition distribution on the laminar flame speeds of various pyrolysis products. It was found that the compositions of pyrolysis gases were similar, while the compositions of pyrolysis liquids varied significantly under different cracking conditions. The laminar flame speeds of different pyrolysis products showed significant differences, which were related to both the pyrolysis gas content and the properties of the pyrolysis liquids.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Energy & Fuels
Shixin Han, Minggao Yu, Xufeng Yang, Haitao Li, Zimao Ma
Summary: This study experimentally investigated the flame propagation of premixed syngas-air and identified three modes of flame propagation, analyzing the impact of hydrogen volume fraction (phi) on the flame propagation.
Article
Chemistry, Physical
V. Pessina, F. Berni, S. Fontanesi, A. Stagni, M. Mehl
Summary: This study provides laminar flame speed correlations for ammonia/hydrogen/air mixtures under high pressure and high temperature conditions, and proposes a formula that adapts to the hydrogen content. It is of great importance for the development of suitable numerical tools for ammonia/hydrogen mixtures.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Thermodynamics
Yiqing Wang, Wang Han, Antonio Attili, Zheng Chen
Summary: This study investigates the impact of soot formation on flame speed measurements under fuel-rich conditions by simulating one-dimensional outwardly propagating spherical flames. The results show that soot dynamics and morphology are highly sensitive to changes in equivalence ratio and flame radius.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Krishna Prasad Shrestha, Charles Lhuillier, Amanda Alves Barbosa, Pierre Brequigny, Francesco Contino, Christine Mounaim-Rousselle, Lars Seidel, Fabian Mauss
Summary: This study experimentally investigated the laminar flame speeds of ammonia and ammonia-hydrogen blends under different temperature, pressure, and oxygen content conditions, and developed a new kinetic model for predicting the oxidation mechanisms, considering the formation and reduction of nitrogen oxides. The results showed that the laminar flame speed increases with increasing initial temperature, fuel hydrogen content, or oxidizer oxygen content, but decreases with increasing initial pressure. The proposed kinetic model predicts the same trends as experiments and highlights the importance of N2H2 formation under rich conditions.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
