Modern Vehicle Hazards in Parking Structures and Vehicle Carrier
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Modern Vehicle Hazards in Parking Structures and Vehicle Carrier International Conference on Fire in Vehicles (FIVE) Dec 15th, 2020 Haavard Boehmer, P.E., Michael Klassen, PhD., P.E., and Stephen Olenick, P.E. Combustion Science & Engineering, Inc. Presenters Haavard Boehmer, P.E. Haavard R. Boehmer, P.E., MSc. (FPE) is Senior Engineer at CSE with ten years of experience and has worked on a range of complex fire modeling problems both for commercial and for research purposes as well as conducted forensic investigations of residential, industrial, and vehicle fire cases. Michael S. Klassen, P.E., Ph.D Michael S. Klassen, P.E., Ph.D. (Mechanical Engineering) is Principal Research Engineer with over 20 years of experimental fire and combustion research experience. He has been involved in numerous projects involving fire dynamics, experimentation, computer modeling, detection, and suppression. 2 Project summary ■ New vehicle construction techniques and materials. – Modern vehicles are larger, heavier – Increased plastic use ■ Analyzing increased burning energy content of modern vehicles – Existing vehicle fire tests – Material data and properties 3 Project goals ■ Are current design standards/practices appropriate for the hazard? – Should sprinklers be required? – Requirements for open vs enclosed garages – Do modern vehicles burn hotter/longer? ■ What are the knowledge gaps? ■ What further research is needed? Columbus, OH, July 2015 4 The vehicle fire problem Liverpool, UK. 2017 2014 – 2018 average data for USA. Annually; ■ 1,858 total parking garage fires ■ 20 civilian injuries ■ $22.8 million property damage ■ Liverpool: 1,300 vehicles damaged Stavanger, Norway. 2020 ■ Stavanger, Norway; building collapse – 300+ vehicles totaled Source: Ahrens, 2020, “Sprinklers in Commercial Garage Fires “ 5 Existing codes Common code requirements; open vs enclosed ■ Open parking structures – Walls open, interior and exterior – Sprinklers and fire alarms not required ■ Enclosed parking structures – Underground, enclosed, or within other occupancy – Sprinklers required ■ Stacker system require sprinklers . 6 Vehicle fire hazards 1. Vehicle fire tests 2. Plastic content in vehicles 3. Plastic fuel tanks 4. Alternative fuel vehicles 5. Marine vessels Freemont, CA, 2017 7 Plastic content and energy 2 000 ■ 1970-2018 plastic 5 000 energy: 1 600 4 000 – 2,298 MJ increase 1 200 – 91% increase 3 000 ■ Heat of combustion: Plastic Energy 800 30.3 kJ/g (Average) 2 000 Curb Weight [kg] Weight Curb Plastic Energy [MJ] Energy Plastic 1 000 400 0 0 1976 1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 Year 8 Vehicle fire tests Select HRR curves for each decade 10 000 1970s ■ No clear correlation for HRR 9 000 2010s 1980s 1980s 1990s and age. Depends on: 8 000 1990s 2000s – Ignition source, location 7 000 2010s – Ventilation 6 000 – Vehicle size 5 000 2000s HRR [kW] HRR 4 000 3 000 1970s 2 000 1 000 0 0 10 20 Time [min] 30 40 50 9 Fire spread ■ Building Research Establishment (BRE) UK found in 2009 testing: – Spread to 2nd vehicle in 10 min (1 test) and 20 min (2 tests) – Spread to 3rd vehicle (empty spot separating) <4 min later. – 1000°C+ ceiling jet temperature pre-heats interior and aids spread 3 2 1 10 Fire spread EV fire. China, May 2020 Approximately 2 min of elapsed time 11 Plastic fuel tanks ■ Currently 80%+ of fuel tanks are plastic ■ HDPE; HOC = 43.6 kJ/g ■ Average tank 8-10 kg > 349 MJ ■ 2 min fire resistance requirement – ECE R34.01 ■ Failure found at 1:50 – 4:36 min [SwRI, 2003] 12 Battery electric vehicles 6.0 ■ Comparison tests find: ICE 1 – EV lower peak HRR than ICEV 5.0 EV 1 ICE 2 EV 2 – Growth rate similar 4.0 ■ Ignition and fire dynamics main differences 3.0 – Thermal runaway [kW] Release Rate Heat 2.0 – Long reignition period possible 1.0 – Jet flame 0.0 0 10 20 30 40 50 60 Time [min] 13 Evaluating design criteria Enclosed parking garages: ■ Tests indicate sprinklers control fire – Give time for fire department to arrive ■ Effectiveness of sprinklers – Test less ideal configurations? – Life safety concerns in nearby buildings? ■ Fire department access? 14 Evaluating design criteria Marine vehicle carrier vessels ▪ Strict fire safety requirements ▪ Worldwide code enforcement ▪ Notable incidents have been controlled when followed 15 Evaluating design criteria Open parking garages: ■ Open structures main area of concern ■ Faster vehicle fire spread – Conflagrations increasingly likely? ■ No detection or extinguishment required – Solely reliant on fire department – BRE; spread to 2nd car in 10-20 min Sea-Tac airport, April, 2013 ■ NFPA 1710 response criteria; 5:20 min – Survey found 34% exceeded NFPA 1710: Standard for the Organization and Deployment of Fire Suppression Operations, Emergency Medical Operations, and Special Operations to the Public by Career Fire Departments 16 Knowledge gaps 1. Few tests of fire spread between cars 2. Limited testing of fuel tank failure 3. Can sprinklers control car fires? – BRE test limited, but promising – Less ideal configurations/conditions 4. Response time requirements? 5. What fire risk do stacker systems pose? – Effect of different number of levels 6. Effect of openings on fire safety – Evaluate current open garage definition 17 Proposed future work Main areas: 1. Fire spread mechanisms ‒ Configuration; garage and cars ‒ Fuel tanks and leakage 2. Sprinkler system effectiveness ‒ Shielded fires ‒ Wind effects 3. Detection and notification systems 4. ‘Open’ definition ‒ Percentage, placement Conclusions ▪ Parking garage fires relatively rare ‒ Few deaths or injuries ‒ Potentially massive economic losses ▪ Enclosed garages: ‒ Alarms and sprinklers required ▪ Marine carriers well protected ▪ Open parking garages; ‒ Typically sprinklers and alarms not required Newark airport, Jan. 2019 ‒ Main area of concern 19 Conclusions Older vehicle tests should not be used as basis for design or regulation ▪ Older than 2000s significantly different ‒ Curb weight, car width ‒ Plastic content ▪ Rapid vehicle to vehicle spread ▪ Within 10 min in BRE tests ▪ Cars from any decade yield 8 MW+ ‒ HRR dependent on test configuration Gothenburg, Sweden, March. 2011 20 Questions? For further questions please contact: Haavard Boehmer, P.E. Mike Klassen, Ph.D., P.E. Stephen Olenick, P.E., MBA [email protected] [email protected] [email protected] 8940 Old Annapolis Rd, Suite L Columbia, MD, 21045 410-884-3266 www.csefire.com 21.