Article
Engineering, Environmental
Yue Wu, Xing Yu, Zongcheng Wang, Hao Jin, Yanqiu Zhao, Changjian Wang, Zhihe Shen, Yi Liu, Wei Wang
Summary: Hydrogen has gained attention worldwide for its zero pollution and recycling potential, but its flammability range and low ignition energy can pose safety problems such as hydrogen jet fire. To explore methods of preventing hydrogen jet fire, experiments were conducted to study flame behavior under the influence of nitrogen and carbon dioxide jets as fire extinguishing agents. Results showed that decreasing the installation height of the extinguishing agent nozzle led to an increase in the reduction ratio of vertical flame length, indicating the potential extinguishing effect when the agent is injected at the root of the hydrogen jet flame. Additionally, the thermal radiant flux and total heat flux received by the flame were analyzed, as well as the extinguishing limits of hydrogen jet flame under the effects of nitrogen and carbon dioxide jets.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2022)
Article
Energy & Fuels
Xing Yu, Wenjing Yan, Yi Liu, Penggang Zhou, Bing Li, Changjian Wang
Summary: The reliability and safety of hydrogen refueling stations are crucial for the acceptance of hydrogen energy by the public. This study used the FireFOAM solver and a modified combustion model to investigate the mitigation effect of barrier walls on jet flames and the changes in flame length and deflection angle. The simulation results showed that increasing the height difference between the barrier wall and hydrogen jet exit can decrease the visible flame length and reduce the dangerous area behind the wall. However, increasing the wall height also leads to a significant increase in flame radiation.
Article
Engineering, Environmental
Jianpeng Wang, Xiaoyang Luan, Jiali Huo, Mingju Jing, Mitchell Huffman, Qingsheng Wang, Bin Zhang
Summary: Hydrogen has the potential for emissions-free energy production, making it a strategic opportunity for renewable energy storage. Safety issues related to high-pressure hydrogen incidents are a key factor limiting its development. This study uses a CFD model to investigate the characteristics of high-pressure hydrogen jet flames under different forms of barrier walls and hydrogen pressure. Results show that complex barrier walls can effectively block flames compared to vertical barriers. A 60-degree plate is the preferred choice based on flame shape and temperature analysis.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Chemistry, Physical
Dinggen Li, Renlang Wang, Gang Yang, Jianlong Wan
Summary: This study investigates the effect of hydrogen addition on the structure and stabilization of micro-jet methane diffusion flame through numerical simulation. The results show that hydrogen addition can make the flame more circular, suppress the increase in flame height with inlet velocity, and improve flame stabilization. However, excessive hydrogen addition may have detrimental effects on flame stabilization.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Engineering, Environmental
Chen Wang, Long Ding, Huaxian Wan, Jie Ji, Yonglong Huang
Summary: The study investigates the complex process of a horizontal jet flame impinging a wall, exploring different stages of flame morphology and spread mechanisms. The results are significant for understanding the development of fires and improving safety management.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2021)
Article
Chemistry, Physical
Andrei Tchouvelev, William J. Buttner, Daniele Melideo, Daniele Baraldi, Benjamin Angers
Summary: The top research priority for hydrogen sensors identified at the 2018 HySafe Research Priority Workshop was guidance on sensor placement. This effort aims to develop optimal sensor placement guidance to enable earlier detection of leaks and reduce hazards. Validation of hydrogen dispersion modeling in mechanically ventilated enclosures was conducted, with plans to expand to larger facilities in Phase 2 and inform national and international standards.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Physical
Ho Lung Yip, Ales Srna, Guanxiong Zhai, Armin Wehrfritz, Sanghoon Kook, Evatt R. Hawkes, Qing Nian Chan
Summary: This study investigates the mechanisms governing H2 jet flame evolution and stabilization by controlling the jet ignition location using a laser-induced plasma. The experiments examine the flame evolution in a constant-volume combustion chamber under various ambient O2 concentrations and temperatures. The results show that a localized flame kernel forms at the laser-induced plasma and spreads to engulf the entire upstream and downstream jet volume. The flame lift-off is sensitive to ambient O2 and temperature changes, and the edge-flame deflagration into stratified premixed fuel-ambient reactant streams explains the lift-off response.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Environmental
Chunxiang Zhao, Xing Li, Xiaohan Wang, Min Li, Huahua Xiao
Summary: This paper experimentally studied the characteristics of H-2/CH4 jet flames at varied heat release rates (HRRs) with H-2 volume fraction (fv) ranging from 0% to 90%. The results showed that the flame height is affected by the increase in mixture molecular diffusivity, radicals pool, air entrainment, flame temperature, and jet velocity of fuel flow. A flame height model for H-2/CH4 flames was obtained through comparisons of different correlations.
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
(2023)
Article
Thermodynamics
Xing Yu, Yue Wu, Yanqiu Zhao, Changjian Wang
Summary: In this work, the characteristics of cryogenic hydrogen fires were investigated experimentally, including flame size, radiative power, and flame temperature. The results showed that flame size was influenced by nozzle diameter, stagnation pressure, and temperature. A correlation model was proposed for predicting flame size at different temperatures.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Haiou Wang, Guo Chen, Kun Luo, Evatt R. Hawkes, Jacqueline H. Chen, Jianren Fan
Summary: In this study, three-dimensional turbulent non-premixed oblique slot-jet flames impinging at a wall were investigated using direct numerical simulation (DNS). The flame extinction and reignition behavior were found to differ between cases with different Damköhler numbers, while flame/wall interactions and chemical reactions had impacts on flow topologies.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2021)
Article
Energy & Fuels
Changchun Liu, Linyuan Huang, Tiandiao Deng, Hua Jiang, Pengzhi Wu, Bo Liu, Jun Deng, Zhenmin Luo
Summary: This study investigated the influence of different rear bottom wall lengths on jet diffusion flames under cross-wind conditions. The experimental results showed that the bottom wall had a significant effect on flame blow-out limit, shape, length, and tilt angle. Exceeding a certain length, the rear bottom wall caused the flames to lift-off easily, and the flames adhered to the bottom wall due to the Coanda effect. The empirical formula of flame tilt angle was obtained by analogy analysis and exhibited good correlation with experimental data.
Article
Energy & Fuels
Zehua Zhang, Abouelmagd Abdelsamie, Cheng Chi, Dominique Thevenin, Kai H. Luo
Summary: This study numerically investigated the flame anchoring of a hydrogen-rich jet injecting perpendicularly into hot vitiated crossflow. The flame was found to be anchored around the jet exit and downstream only on the windward side. Diffusion flame was dominant, though some premixed or partially premixed regions were found on the leeward side due to turbulent mixing.
Article
Energy & Fuels
Zhirong Wang, Hui Xu, Yawei Lu, Zhenhua Tang, Rujia Fan
Summary: This study investigates the suppression effect of water mist containing DMMP on H2 jet flame. Results show that the suppression effect of water mist containing DMMP is better than pure water mist. Analysis of burning velocity, heat production, and free radicals indicate that suppressant can reduce the burning velocity by scavenging free radicals in a wide range of equivalence ratios. In comparison with lean CH4 flame, the combustion parameters of lean H2 flame decrease with DMMP addition and there is no combustion enhancement effect. Analysis of DMMP decomposition path demonstrates that the rates of phosphorus reactions in H2 flame are higher than in CH4 flame.
Article
Energy & Fuels
Yongliang Xie, Na Lv, Xujiang Wang, Dejian Wu, Shimao Wang
Summary: This study conducted a numerical research on the effects of longitudinal ventilation strategies on hydrogen jet flames in tunnels, showing that ventilation greatly influences the flame characteristics. Critical ventilation velocity increases with hydrogen leakage rates and the predicted theoretical model can accurately predict critical ventilation velocity for hydrogen jet fires. Increasing longitudinal ventilation velocity significantly reduces maximum ceiling temperatures and impacts flame bending characteristics.
Article
Energy & Fuels
Xing Li, Shengrong Xie, Jing Zhang, Daiqing Zhao, Xiaohan Wang
Summary: The effect of wall thickness on the combustion characteristics of nonpremixed hydrogen micro-jet flames was studied. It was found that wall thickness affects the temperature distribution, flame shape, and heat recirculation, which in turn affect the combustion efficiency.
FRONTIERS IN ENERGY RESEARCH
(2022)