Fire Hazards Of Small Hydrogen Leaks - HySafe

9m ago
1.71 MB
28 Pages
Last View : 6d ago
Last Download : n/a
Upload by : Lee Brooke

Third European Summer School on Hydrogen SafetyJuly 21 – 30, 2008Fire Hazards of Small Hydrogen LeaksPeter B. SunderlandDept. of Fire Protection EngineeringUniversity of MarylandCollege Park MD, U.S.1/28

Acknowledgments Third European Summer Schoolon Hydrogen Safety. NIST (Grant 60NANB5D1209)under the technical managementof J. Yang. R.L. Axelbaum(WashingtonUniv.) and B.H. Chao (Univ. ofHawaii). Students: M.S. Butler,Moran, N.R. Morton.C.W.2/28

Unique Fire Hazards of H2 Steel embrittlement Lowest MW of any fuel, thus requiring the highest storage pressure Highest volumetric leak propensity of any fuel Permeation leaks Smallest ignition energy of any fuel in air (0.028 mJ) Lowest autoignition temperature of any fuel ignited by a heated air jet(640 C) Widest flammability limits of any fuel in air (4 – 75% by volume) Highest laminar burning velocity of any fuel in air (2.91 m/s) Smallest quenching distance of any fuel premixed with air (0.51 mm) Dimmest flames of any fuel in air3/28

Present Fire Scenario¾ A small leak develops in a H2 system, e.g., a H2vehicle.¾ The leak could arise from H2 embrittlement, H2permeation, impact, equipment failure, orimproper repair.¾ The leak ignites from static discharge or heat.¾ The leak burns undetected for a long period,damaging the containment system and providingan ignition source for a subsequent largerelease.4/28

Background¾ Swain and Swain (1992) modeled and measuredH2, CH4, and C3H8 leak rates.¾ Quenching and blowoff of CH4 and C3H8 flameswere measured and modeled by Matta et al.(2002) and Cheng et al. (2006).¾ Khan et al. (2002) considered the effects of heaton carbon fabric composites.¾ No codes or standards exist for permissible H2leak rates.5/28

Objectives¾ Measure quenching and blowoff limits forH2, CH4 and C3H8 on small round burners.¾ Measure quenchingcompression fittings.limitsforleaky¾ Examine material degradation arising fromexposure to H2 and CH4 flames.6/28

Experimental¾ Quenching and blowoff limits Fuels: H2, CH4, and C3H8 Diameters: 8 μm – 3.2 mm Leaky compression fittingsPinhole BurnerCurved-wall BurnerTube Burner¾ Materials degradation Fuels: H2 and CH4 Materials: aluminum alloy 1100,galvanized steel, stainless steel, SiC Test times: up to 300 hours7/28

Quenching ScalingFlame length:Lf / d a Re a ρ u0 d / μLength at quenching: Lf Lq / 2Equating these:mfuel π Lq μ / ( 8 a )FuelaLq[mm]SL[cm/s]μ[g/m-s]H2CH4C 3H -27.95e-3mfuel[mg/s]predicted0.0080.0850.0638/28

H2 Pinhole Quenching Limit0.356 mm A H2 flame at itsquenching limit isshown. This flame is notvisible without aidand required 30 scamera exposures. Stand-off height isabout 0.25 mm. Thermocouples wereusedtoidentifyflaming conditions.9/28

Tube Burner Limits1000 Quenching limits arenearly independent ofd.Blowoff LimitsMass Flow Rate (mg/s)10010H2CH4CH3 H2 has the lowestquenching limit andthe highest blowofflimit.8This workMattaChengKalghatgi10.10.0056 mg/sQuenching Limits0.010.00100.511.522.53 CH4 and C3H8 havesimilar quenching andblowoff limits.Tube Diameter (mm)10/28

H2 Quenching Limits0.016Pinhole burner6.35 mm curved-wall pinhole burner1.59 mm curved-wall pinhole burnerTube burnerQuenching Mass Flow Rate 2.5Burner Diameter (mm)3 Three burner typesare shown. For large d thelimits converge. Heat losses aregreatestforpinholes, least fortube burners. Limits increase atthe smallest d. This plot helpedidentify the world’s3.5weakestflame(0.25 W).11/28

Tube Burner Orientation EffectsQuenching Mass Flow Rate (mg/s)0.008 H2 quenching limitsgenerally decreasefor small burnersowingtoheatlosses.0.0070.0060.005 Inverted limits arelowest, attributed tofuel preheating andflame 11.5Tube Diameter (mm)22.512/28

Pinhole Burner Orientation EffectsQuenching Mass Flow Rate (mg/s)0.0120.01 No significant effectof orientation isseen.0.0080.006 Choked flow is dVertical0.002000.511.522.533.5Pinhole Burner Diameter (mm)13/28

Upstream Pressure Effects60 Upstream pressurerequired for 8 μg/sH2isentropicchokedflowisshown. Viscous effects areneglected here. This predicts thatvery small pinholescan support flamesin high pressure H2systems.Hole Area (μm 2)5040302010002468Pressure (bar)101214/28

Leaky Fittings Tests Leakpathshownobtained with loosefittings. Flow rates were measureddownstream of the leaks.15/28

16/2813 mm tube6.4 mm tube3.2 mm tube

Leaky Fittings0.63.1 mm Fitting0.56.3 mm FittingMinimum Flowrate (mg/s)12.6 mm Fitting0. thanePropane Previousslideshowsflaming leak quenchinglimitsforcompressionfittings (vertical orientation). H2 flame is smallest here,attributed to quenchingdistance. H2 mass flow rate is anorder of magnitude lowerthan CH4 or C3H8. Leaks large enough to burnproduce bubbles whensoap water is applied.17/28

Effects of Upstream PressureMinimum Flowrate (mg/s)0.40.378 mg/s0.30.336 mg/sHydrogenMethanePropanehmpLinear (h)Linear (m)Linear (p) mg/s0110100Pressure (bar)1000 Quenching limitsfor a 6 mmcompression fitting are shown. H2 limits are thelowest. Limitsareindependentofpressure. Resultsshouldguide future codesand standards.18/28

Orientation Effects0.4 Quenching limits for 6mm compression fittings are shown. Orientation has aweak effect. Invertedorientationhas the lowest heatloss rates.Minimum Flowrate MethanePropane19/28

Materials Degradation20/28

Al Degradation10 mmAluminum / H21 – hr exposure21/28

Al Degradation¾Aluminum failed in H2 flame at 8 hours.10 mm10 mmH2CH422/28

304 SS Degradation¾ Corrosion after prolonged H2 flame exposure.23/28

SiC Degradation¾ SiC filaments failed at 12 minutes in the H2flame, and at 356 minutes in the CH4 flame.5 mm5 mmH2 FlameCH4 Flame24/28

Al Degradation Microscopy Control specimen is shown.25/28

Al Degradation Microscopy Images following exposure to H2 flame.26/28

Possible Mitigation Strategies¾ Apply intumescent paints.¾ Apply steel wool or ceramic blankets.¾ Consider novel flame detectors:- Cable heat detectors- UV and IR detectors27/28

Conclusions¾ Stable H2 flames were observed on roundburners and leaky compression fittings at flowrates down to 4 and 28 μg/s, respectively.¾ Fuel mass flow rate at quenching is largelyindependent of burner diameter.¾ H2 has a lower mass flow rate at quenchingand a higher mass flow rate at blowoff thaneither CH4 or C3H8.¾ H2 flames caused much faster corrosion thanCH4 flames to aluminum and SiC fibers.28/28

Tube burner 1.59 mm curved-wall pinhole burner Pinhole burner 6.35 mm curved-wall pinhole burner Burner Diameter (mm) Quenching Mass Flow Rate (mg/s) H 2 Quenching Limits Three burner types are shown. For large d the limits converge. Heat losses are greatest for pinholes, lea

Related Documents:

NEL ASA Bjørn Simonsen Vice President Market Development and Public Relations . 2 A PURE-PLAY HYDROGEN COMPANY HYDROGEN PRODUCTION TECHNOLOGY HYDROGEN REFUELLING TECHNOLOGY Nel Hydrogen Solutions SYSTEM INTEGRATION PROJECT DEVELOPMENT FINANCING & OWNERSHIP Nel Hydrogen Fueling Nel Hydrogen Electrolyser . 3 Hydrogen production Hydrogen .

Hydrogen Enabler Nel Hydrogen is a global, dedicated hydrogen company, delivering optimal solutions to produce, store and distribute hydrogen from renewable energy. We serve industries, energy and gas companies with leading hydrogen technology. Since 1927 Nel Hydrogen has proudly developed and continually improved hydrogen plants. Our proven

Nel Hydrogen today Pure-play hydrogen company listed on the Oslo Stock Exchange (NEL.OSE) . Hydrogen Electrolysers Hydrogen Fueling Hydrogen Solutions. Environment Ecomony Energy Security Motivation today: Hydrogen must, and will be renewable. 7 9 16 23 40 71 100 137 177 232 312 0 0,5 1 1,5 2 2,5 3 3,5 4 0 50 100 150 200 250 300 350

social or cultural context (livelihoods, festivals, traditional, conflict) and perhaps regulatory framework (permit fires, illegal fires). The terms include fires, wildfires, wildland fire, forest fire, grass fire, scrub fire, brush fire, bush fire, veldt fire, rural fire, vegetation fire and so on (IUFRO 2018). The European Forest Fire

Natural Hazards 1.1 Engage Natural Hazards Western Australia experiences a range of natural hazards each year, which include bushfire, severe storms, floods, cyclones, earthquake and possibly tsunami. These are called natural hazards because they are elements of nature that can be extreme and dangerous. These hazards (apart from some

6 Hydrogen Liquefaction ¾There are 10 hydrogen liquefaction plants in North America zTrain size ranges from 6 to 35 TPD (5,400 to 32,000 kg/day) ¾In the 1960’s, liquid hydrogen plants were built to support the Apollo program. Today, liquid hydrogen is used to reduce the cost of hydrogen distribution. zDelivering a full tube traile

Gas Infrared heaters for houses . Sterling Engine for Hydrogen reach fuel can be extremely useful for syngas produced from biomass and for microengine. Hydrogen Energy: Research of Hydrogen detonation phenomena (Shock waves in Hydrogen and hydrogen reach fuels)

Fire Exit Legend Basement N Blood Fitness & Dance Center Fire Safety Plans 7.18.13 Annunciator Panel Sprinkler Room AP SR FIRE FIRE SR ELEV. Evacuation Route Stair Evacuation Route Fire Extinguisher Fire Alarm FIRE Pull Station Emergency Fire Exit Legend Level 1 N Blood Fitness & Dance Center Fire Safety Pl

Squirrel threw the fire to Chipmunk. The Fire Beings ran after the fire. One Fire Being grabbed Chipmunk’s back. The Fire Being’s hot hand put three stripes on Chipmunk’s back. Chipmunk threw the fire to Frog. The Fire Beings ran after the fire. One Fire Being grabbed Frog’s tail. Frog jumped, and

Appendix B: Glossary of Terms A p p e n d i x B-G l o s s a r y o f T e r m s Fire Depletion Area Burned: Fire Impacts: Fire Intensity: Fire Load: Fire Management: Fire Management Zone: Fire Prevention: Fire Protection: Fire Regime: Fire Risk: Area burned that directly impacts wood supply to the forest industry. This could include allocated .

Safety & Seismic Safety Element is a required element of the Master Plan per NRS 278.160. For purposes of the City of Las Vegas, the Safety & Seismic Safety Element will address the following sub-elements: Fire Hazards Flood Hazards Seismic Hazards Noise Hazards Hazardous Materials Landslide Hazards

Chapter 2 Methods of Fire Extinguishment 43-47 Chapter 3 Extinguishing Media 48-65 Chapter 4 Fixed Fire Extinguishing Systems 66-164 Chapter 5 First-aid Fire Fighting Equipment 165-174 Section-5 Building Fire Hazards 175-185 Section-6 Life Hazards in Buildings and 186-201 Means of Escape / Egress / Exit Section-7 Fire Safety in Building Design .

Florez Jennifer 166204283 3/14/2022 Denver Fire Department Denver Fire Department Fire Inspector II Florez Joseph 196209071 9/29/2022 Denver Fire Department Denver Building Department Fire Inspector II Foster Joel 186607830 12/27/2021 Canon City Area Fire Protection District Canon City Area Fire Protection District Fire Suppression System Inspector

Colerain Fire Department 360.00 Belmont Vol. Fire Department 480.00 Lafferty Vol. Fire Department 1,080.00 Somerton Vol. Fire Department 1,080.00 Powhatan Point Vol. Fire Department 480.00 Bellaire Volunteer Fire Department 720.00 Brown Higginsport Vol. Fire & EMS 1,080.00 Mt. Orab Fire Department 1,440.00

The conventional fire alarm detection process of our country cannot locate the exact fire origin on time causing fire hazards. The addressable fire alarm system resolves the problem by assigning a unique address to each detector to locate the exact position of the fire for further protection system. In this paper, an addressable fire alarm

2 Natural Hazards Observer June 2016 The mission of the Natural Hazards Center is to ad-vance and communicate knowledge on hazards mitigation and disaster preparedness, response, and recovery. Using an all-hazards and interdisciplinary framework, the Cen-ter fosters information sharing and integration of activities

Natural Hazards Influenced by Climate Change 192 3.12.1 Health and Natural Hazards Data 192 3.12.2 Type of Natural Hazards Considered 193 3.12.3 Direct and Indirect Impacts on Health 193 3.12.4 Impacts of Combined Natural Hazard Events 193 3.12.5 Cascading Impacts of Hazards and Health System Impacts 194 3.12.6 Behaviours and Lifestyle 194

natural hazards deemed to threaten property and persons within the campus boundaries, and also . Hazard mitigation is any action taken to permanently reduce or eliminate long-term risk to people and property from the effects of hazards. These hazards can be of any type, including natural hazards (such as tornados, floods, winter storms .

Natural hazards are extreme natural events that can cause loss of life, extreme damage to property and disrupt human activities. Some natural hazards, such as flooding, can happen anywhere in the world. Other natural hazards, such as tornadoes, can only happen in specific areas. And some hazards need climatic or tectonic conditions to

the landscaping industry and ways in which workers can adopt basic safety techniques that can help to prevent accidents. The hazards covered in this section are the following: Sun and High Temperatures Machine Hazards Fall Hazards Electrical Hazards Pesticides Traffic Hazards