An experimental study of the effect of 2.5% methane addition on self-ignition and flame propagation during high-pressure hydrogen release through a tube

Zeng, Qian; Duan, Qiangling; Li, Ping; Hong-ya, Zhu; Sun, Dongxu; Sun, Jinhua

doi:10.1016/j.ijhydene.2019.11.155

Cited by 32 publications

(6 citation statements)

References 37 publications

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“…The temperature contour illustrates that the ambient air in front of the fuel jet is heated to above 1000 K merely under the thermal effect of shock wave, but the expanded hydrogen temperature near the contact surface decreases to about 200 K. Obviously, the hot compressed air diffused into the mixing layer plays a role as the direct ignition source of the spontaneous ignition. Thus, the success of ignition in our 1D model suggested that the fuel release tube wall boundary layer effect and multidimensional shock waves interactions stressed in many prior experiments 6,16,18 are not essential for the spontaneous ignition. The future works could focus more on the spontaneous ignition characteristics of the hydrogen directly spouted from a small orifice.…”

Section: Resultsmentioning

confidence: 63%

“…In the prior experimental studies on the spontaneous ignition of H 2 -based binary fuel, the safety improvement was qualitatively attributed to two points. , On the one hand, the shock wave intensity decreases as the molecular weight of the fuel increases according to the Sod problem solution . On the other hand, the addition of CH 4 into H 2 reduces the overall chemical activity of the fuel.…”

Section: Resultsmentioning

confidence: 99%

“…Meanwhile, the strategies to reduce the risk of spontaneous ignition are rarely proposed in the literatures. Recently, the diffusion autoignition of high-pressure accidentally released H 2 /CH 4 binary fuels were discussed in the experiments of Duan et al, 16 Golovastov et al, 17 and Rudy et al 18 They all found that the minimum spontaneous ignition pressure is dramatically affected by the CH 4 addition. The results imply that adjusting the fuel properties by the little addition or dilution of other gases may be a promising method to control the high-pressure hydrogen autoignition risk in the case where the high purity of hydrogen is not strictly required.…”

Section: Introductionmentioning

confidence: 99%

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Inhibition Mechanism of CH₄ Addition on the Pressurized Hydrogen Spontaneous Ignition

Zhong

Gou

2021

Energy Fuels

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It is well known that the high spontaneous ignition risk of pressurized hydrogen poses a serious threat to hydrogen storage safety. Aiming to reveal the inhibition mechanism of the fuel-blending strategy on autoignition, the spontaneous ignition of the H 2 /CH 4 mixture suddenly released into a one-dimensional (1D) tube at high pressure is studied numerically with highresolution difference schemes and a detailed kinetics model. First, the basic spontaneous ignition features are obtained. It is observed that under the shock wave compression effect, the air in front of the high-pressure hydrogen jet is heated up to 1200 K when the bursting pressure is 90 atm. Thus, the onset of autoignition always occurs under a quite fuel-lean, high-pressure, and hightemperature condition. Moreover, after autoignition, multiflame regions are found in the mixing layer, which are two short-lived premixed flames and a diffusion flame. The 1D result suggests that the occurrence of the spontaneous ignition is not dependent on the wall boundary layer and the shock wave interactions. Subsequently, autoignition under different blending levels is examined. The comparison shows that a minor amount of CH 4 addition (3% by mole) results in a sixfold increase in the ignition delay. Through the simulations of the fuel with artificial property, reaction sensitivity analysis, and Damkoḧler number evaluation, it was found that the addition decreases the shocked air temperature, reduces the H radical accumulation rate, and increases the relative loss of free radicals on the reaction front. Our work demonstrates that the key to the fuel-blending strategy for diffusion autoignition inhibition is increasing the fuel molecular weight.

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Section: Resultsmentioning

confidence: 63%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Inhibition Mechanism of CH₄ Addition on the Pressurized Hydrogen Spontaneous Ignition

Zhong

Gou

2021

Energy Fuels

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“…N2, the initial pressures required for spontaneous ignition were increased by a factor of 2.12 and 2.85, respectively. Qian Zeng [52][53][54] studied the effect of impurity gases (N2, CO, CH4) to discuss the effect of nitrogen on the spontaneous ignition of high-pressure leaking hydrogen. Their results showed that the order of reducing the possibility of self-ignition was the same as that of reducing the intensity of the excitation, i.e.…”

Section: Effect Of Mixing With Other Gasesmentioning

confidence: 99%

Safe use of hydrogen energy: review on hydrogen self- ignition and generated hydrogen jet fire

Zhi,

Li,

Zhou

et al. 2024

Preprint

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In the fight against climate change, hydrogen is seen as a promising sustainable energy alternative to fossil fuels. However, its wider adoption has raised safety issues, particularly regarding spontaneous combustion without an external spark. To ensure safe and sustainable hydrogen use, researchers have developed a thorough research approach targeting hydrogen's potential for spontaneous combustion. Progress has been made in understanding this phenomenon within transparent extension tubes, examining various factors like tube dimensions, curvature, shape, and rupture disc properties. These studies have revealed consistent trends. Simulations have helped explain how hydrogen auto-ignites, often starting at the tube wall, especially in high-pressure situations where it interacts with hot air and expands cold fuel. Researchers have also created mathematical models related to ignition dynamics. Yet, there's limited experimental data on hydrogen jet self-ignition in open spaces. Some simulations suggest that high-pressure hydrogen can ignite spontaneously even without a confinement, but the ignition event is so brief that it's difficult to capture experimentally. Moreover, scholars are creating more accurate empirical formulas based on extensive experimental statistics that connect internal tube ignition to external jet flames. The accuracy of these empirical estimates improves as more experimental data becomes available.

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“…The results showed that after adding 18% The H 2 -CH 4 ignition delay time increases l6 times. Zeng et al [5] conducted an experimental study on the propagation characteristics of autoignition flame of high-pressure H 2 -CH 4 mixed gas through pipelines. The ratio of CH 4 to H 2 is 2.5% by volume.…”

Section: Introductionmentioning

confidence: 99%

The influence of methane blending ratio on the spontaneous combustion characteristics of high-pressure hydrogen leakage

Luo,

Luo

2024

E3S Web Conf.

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Adding CH4 to high-pressure H2 is considered one of the effective and convenient measures to reduce high-pressure H2 leakage and spontaneous combustion, which is conducive to improving the safety of H2 energy storage. Based on the independently built high-pressure hydrogen leakage and self ignition experimental platform, the influence of CH4 on the critical self ignition pressure and flame of high-pressure H2 leakage and self ignition was tested. The results indicate that the addition of methane can effectively increase the critical spontaneous combustion pressure. When 20% CH4 is added, the critical self ignition pressure can be increased by 151.58%. Under similar discharge pressure conditions, the flame velocity in the pipeline decreases from 1224.64m/s for pure H2 to 1024.07m/s for 10% CH4. In addition, after mixing CH4, the dispersion time of the jet flame is advanced, the flame duration is shortened, and the flame brightness is reduced. There are two main reasons for the mixed inhibition of spontaneous combustion by CH4. On the one hand, it reduces the Mach number of shock wave propagation, thereby lowering the ignition temperature. On the other hand, the activity of the fuel system decreases, and the heat required for self ignition increases.

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An experimental study of the effect of 2.5% methane addition on self-ignition and flame propagation during high-pressure hydrogen release through a tube

Cited by 32 publications

References 37 publications

Inhibition Mechanism of CH₄ Addition on the Pressurized Hydrogen Spontaneous Ignition

Inhibition Mechanism of CH₄ Addition on the Pressurized Hydrogen Spontaneous Ignition

Safe use of hydrogen energy: review on hydrogen self- ignition and generated hydrogen jet fire

The influence of methane blending ratio on the spontaneous combustion characteristics of high-pressure hydrogen leakage

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An experimental study of the effect of 2.5% methane addition on self-ignition and flame propagation during high-pressure hydrogen release through a tube

Cited by 32 publications

References 37 publications

Inhibition Mechanism of CH4 Addition on the Pressurized Hydrogen Spontaneous Ignition

Inhibition Mechanism of CH4 Addition on the Pressurized Hydrogen Spontaneous Ignition

Safe use of hydrogen energy: review on hydrogen self- ignition and generated hydrogen jet fire

The influence of methane blending ratio on the spontaneous combustion characteristics of high-pressure hydrogen leakage

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Product

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Inhibition Mechanism of CH₄ Addition on the Pressurized Hydrogen Spontaneous Ignition

Inhibition Mechanism of CH₄ Addition on the Pressurized Hydrogen Spontaneous Ignition