scholarly journals Experimental Study on the Thermal Effect according to the Distance around a Hydrogen Jet Flame

2021 ◽  
Vol 35 (6) ◽  
pp. 15-20
Author(s):  
Ohseung Kwon ◽  
Keonho Cho ◽  
Kyung-Hwan Park
Keyword(s):  
Vertical Direction ◽  
Hydrogen Gas ◽  
Fire Fighting ◽  
Gas Jet ◽  
Safe Distance ◽  
Storage Container ◽  
Jet Flame ◽  
Thermally Activated ◽  
Device Operation ◽  
Resistant Structure

In this study, the safe distance in the case of a hydrogen vehicle fire was analyzed according to the temperature distribution around a hydrogen gas jet flame formed by the thermally activated pressure relief device operation of a hydrogen storage container. The experiment was conducted while 70 MPa hydrogen gas was released from a 1.8-mm-diameter nozzle to a 1.8- × 1.8 m fire-resistant structure wall for distances of 2 and 4 m between the nozzle output and the wall. To analyze the temperature around the hydrogen gas jet flame, five fire-fighting heat-protective hood test samples, certified by the Korea Fire Institute, and temperature sensors were installed every 1 m from the center of the jet flame in the vertical direction to the direction of the flame. In the experiment, the temperature around the jet flame was measured to observe the safe distance for firefighters. The results show that the safe distances at 70°C or less, which is harmless to firefighters, were 5 m without a heat-protective hood and 3 m with a heat-protective hood. In addition, it was confirmed that the direction of the jet flame and blocking by obstacles affect the safe distance during fire-fighting and rescue activities by firefighters.

A Thermodynamic Analysis of Compressing Hydrogen for Storage

2006 ◽  
Author(s):  
Clinten D. Lingel
Keyword(s):  
Energy Source ◽  
Internal Combustion Engines ◽  
Hydrogen Gas ◽  
Methane Reforming ◽  
Pure Hydrogen ◽  
Combustion Engines ◽  
End User ◽  
Storage Container ◽  
Real Issue ◽  
Formed Hydrogen

Storing hydrogen gas under pressure to provide an energy source for fuel cells or internal combustion engines is a real issue that must be addressed. Diatomic hydrogen does not occur naturally and therefore, must be made through electrolysis, methane reforming or some other process. From the production of pure hydrogen to the final end user, the entire cycle must be considered. Once formed, hydrogen will need to be compressed to a storage container. A hydrogen based transportation system will be both an economic and engineering challenge.

Numerical Modeling of a Turbulent Gas Jet Flame in a Swirling Air Stream

2002 ◽  
Author(s):  
Ala R. Qubbaj ◽  
S. R. Gollahalli ◽  
John Villarreal
Keyword(s):  
Numerical Simulation ◽  
Software Package ◽  
Reaction Model ◽  
Swirl Flow ◽  
Gas Jet ◽  
Combustion Analysis ◽  
Jet Flame ◽  
Benchmark Study ◽  
Air Stream ◽  
Mixing Rates

A numerical simulation of a turbulent natural gas jet diffusion flame at a Reynolds number of 9000 in a swirling air stream is presented. The numerical computations were carried out using the commercially available software package CFDRC. The instantaneous chemistry model was used as the reaction model. The thermal, composition, flow (velocity), as well as stream function fields for both the baseline and airswirling flames were numerically simulated in the near-burner region, where most of the mixing and reactions occur. The results were useful to interpret the effects of swirl in enhancing the mixing rates in the combustion zone as well as in stabilizing the flame. The results showed the generation of two recirculating regimes induced by the swirling air stream, which account for such effects. The present investigation will be used as a benchmark study of swirl flow combustion analysis as a step in developing an enhanced swirl-cascade burner technology.

Basic Experimental Study on Effectiveness of Nuclear Waste Long-Term Storage Containers With PAR for Reducing Concentration of Hydrogen Gas: Part 2 — Hydrogen Behavior in a Small-Scale Modeled Container

2018 ◽  
Author(s):  
Y. Hiraki ◽  
G. Takase ◽  
Y. Suzuki ◽  
Y. Tanaka ◽  
K. Takase
Keyword(s):  
Hydrogen Concentration ◽  
Nuclear Power ◽  
Hydrogen Gas ◽  
Small Scale ◽  
Storage Container ◽  
Long Term Storage ◽  
Waste Storage ◽  
Experimental Apparatus ◽  
Hydrogen Supply

As for the decommissioning of Fukushima Dai-ichi nuclear power plant (1F), a long-term waste storage container with high safety is requested to store radioactive materials such as fuel debris for a long period of time. Since hydrogen is generated by radioactive decomposition of water, it is important to keep the concentration of hydrogen gas below the explosion limit in order to ensure the safety of the container. Then, use of passive autocatalytic recombiner (PAR) was proposed to reduce the hydrogen concentration. PAR is installed in the container. In order to experimentally confirm the reduction of hydrogen concentration by PAR and hydrogen behavior in the container, an experimental apparatus consisting of a small-scale modeled container and a hydrogen supply system was provided. Preliminary experiments were begun for confirming fundamental performance of the experimental apparatus under the conditions that PAR and simulated fuel debris are not installed in the container. Moreover, the hydrogen behavior in the container was analyzed numerically. In addition, the steam behavior generated by the chemical reaction of hydrogen and oxygen by PAR was also predicted. This paper describes both results of the preliminary experiments and numerical simulations. The experimental results showed that the hydrogen behavior can be predicted using the temperature distributions in the container. The analysis results clarified the controlling factors on the hydrogen behavior and the steam distribution in the container by PAR.

Turbulent Gas Jet Flames in Cross-Flow at Low Momentum Flux Ratios

1994 ◽  
Author(s):  
S. R. Gollahalll ◽  
B. Nanjundappa
Keyword(s):  
Momentum Flux ◽  
Flame Structure ◽  
Axisymmetric Flow ◽  
Cross Flow ◽  
Flux Ratio ◽  
Gas Jet ◽  
Jet Flame ◽  
Flow Recirculation ◽  
Two Dimensional Flow ◽  
The Stability

An experimental study of the stability and structure of a propane gas jet flame in cross-flow at a low jet to cross-flow momentum flux ratio (0.024) is presented. The flame structure is characterized by two distinct zones. A two-dimensional flow recirculation zone attached to the burner tube in its wake forms the first zone. An axisymmetric flow follows the first zone downstream. The junction of the two zones is characterized by an intense mixing of jet and cross-flow streams. This paper deals with the structure of the first zone. The temperature and concentration profiles show that the physico-chemical processes and combustion in that zone are diffusion controlled.

Effects of Buoyancy on Steady Hydrogen Gas-jet Diffusion Flames

1998 ◽  
Vol 140 (1-6) ◽  
pp. 51-68 ◽  
Author(s):  
A. K. AGRAWAL ◽  
S. M. CHERRY ◽  
S. R. GOLLAHALLI
Keyword(s):  
Diffusion Flames ◽  
Hydrogen Gas ◽  
Gas Jet ◽  
Jet Diffusion Flames

LIF-LII measurements in a turbulent gas-jet flame

1997 ◽  
Vol 23 (4) ◽  
pp. 281-287 ◽  
Author(s):  
R. L. Vander Wal
Keyword(s):  
Gas Jet ◽  
Jet Flame

RELATIVISTIC SELF-FOCUSING OF AN ULTRA-INTENSE LASER PULSE IN A PLASMA

1995 ◽  
Vol 04 (03) ◽  
pp. 547-566 ◽  
Author(s):  
G. MAINFRAY
Keyword(s):  
Laser Pulse ◽  
Thomson Scattering ◽  
Hydrogen Gas ◽  
Intense Laser ◽  
Gas Jet ◽  
Intense Laser Pulse ◽  
Self Focusing ◽  
Rayleigh Length ◽  
Relativistic Regime ◽  
Order Of Magnitude

New compact multiterawatt lasers allow us to study the relativistic regime of laserplasma interaction. The propagation of a multiterawatt subpicosecond laser pulse in a plasma has been investigated theoretically and experimentally. A 10 TW laser pulse at a 1064 nm wavelength has been focused in a hydrogen gas jet. Thomson scattering observations show that a relativistic self-focusing and channeling occur when the laser power exceeds a critical value predicted by theory. The amount of enhancement in self-focused intensity exceeds one order of magnitude. The laser pulse propagates through the plasma over a distance much larger than the Rayleigh length determined by vacuum diffraction.

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