Firefighter Safety in Battery Energy Storage System Fires

Transcription

1 Firefighter Safety in Battery Energy Storage System Fires Erik Archibald, P.E. Kevin Marr, PhD, P.E. NFPA SUPDET November 30, 2018

2 Core Team O.A. (DK) Ezekoye The University of Texas at Austin UTFRG Casey Grant Fire Protection Research Foundation Ronald Butler ESSPI Judy Jeevarajan UL Kevin Marr The University of Texas at Austin UTFRG Daniel Gorham* Fire Protection Research Foundation

3 UTFRG Research Team Erik Archibald Structural Dynamics, Explosion Analysis Cell Array Experiments Austin Baird Fire Protection, Hazard Analysis Serhat Bilyaz Computational Modeling Robert Kennedy Design of Experiments,Testing Tyler Buffington Statistical Modeling

4 Energy Storage Grid Applications Energy storage is an integral part of the next generation grid to improve grid performance and reliability, reduce energy costs, and reduce reliance on fossil fuels. With the cost of lithium-ion batteries decreasing, Li-BESS are becoming more economical. Li-BESS sites are being proposed in both outdoor and indoor locations. Smart Phone ~ 10 Wh Laptop ~ Wh

5 Firefighter Safety Concerns What are credible sequences of events that can result in explosive conditions? Fire What is the likelihood of such events? How do results from limited tests translate to other ESS and installation sites? How can cell/cell array tests be used to inform hazard assessment of full-scale systems? Stranded Energy Firefighter Safety Explosion Are there critical gaps in fire service SOGs/SOPs that increase risk to firefighters? Do current SOGs/SOPs effectively mitigate explosion hazards? Toxicity Electrical

6 ESS Incident in Belgium Fire occurred Nov. 11, 2017 at a test site in Drogenbos, Belgium that had launched in July. 1 MW container supplied by Engie Ineo. What s in the plume (toxicity)? Is this an explosion hazard? Blum and Long (2016) How do we suppress it? After suppression, are there electrical hazards? Hill, et al. (2017)

7 Houston Rail Car Explosion Car was carrying used li-ion consumer batteries to recycling facility April 2017 Houston Train Explosion, Union Pacific 53 double stacked rail car Explosion broke windows about 500 ft away

8 Understanding the Hazard Cell Failures No Ignition Immediate Ignition Fire Gas Accumulation Extinction Ignition in Rack Ignition in Room Explosion in Rack Explosion in Room Flammable Mixture Delayed Ignition

9 FAA FRC Experiment Cylindrical Cells ~ 40 kwh of energy storage Fire Resistant Container designed to limit oxygen to contain Class A fires Aerosol fire suppressant extinguished fire at about 20 minutes Explosion occurs after 45 minutes Cell Failures Immediate Ignition Fire Extinction Ignition in Room Explosion in Room

10 Cell Failure Venting Immediate Ignition Fire Extinction Venting until Flammable Mixture Yes Possible Explosion Hazard Yes No Fire Extinguished Yes Yes Ongoing Fire No Yes No Fire burns out No No Hazard No Yes No Possible Explosion Hazard Gas dissipates

11 Modeling Scales Cell Module Rack Room Site Thermal Runaway Gas Characteristics Runaway Propagation by: Conduction Convection Radiation Ventilation Gas Mixing Ignition Fire Consequence: Heat release Structural Damage Blast Consequence: Structural Damage Injuries

12 Literature on Gas Characterization Need to characterize: Gas composition Gas release rate Amount of gas released Gas flammability HC, 19% CO2, 30% H2, 28% CO, 23% Somandepalli, Marr and Horn (2014)

13 Maximum Explosion Overpressure Calculated based on gas mixture properties in Cantera Calculate thermodynamic, equilibrium pressure for constant volume, adiabatic process Compared against experiment by Somandepalli, Marr and Horn in 2014

14 Laminar Flame Speed Flame speed calculated based on gas mixture properties using Cantera

15 Simple Model for Vented Gas Explosion Mass Conservation Energy Conservation Burning Rate

16 NFPA 68 K g Deflagration Index Max rate of pressure rise Volume Experiment data from Somandepalli, Marr and Horn (2014)

17 Flammability Comparison H2, CO2, 30% HC, 19% 28% CO, 23% Hydrogen Methane Propane 100% SOC Vent Gas Molar Mass (gm/mol) Flammability in Air (%) * Stoichiometric Ratio in Air (%) 17 % 9.5 % 4 % 19% Energy Content (MJ/kg) Energy Content (kj/l) Burning Velocity (m/s) Kg (m-bar/s) * Maximum Overpressure (bar-g) * Calculated using mixture properties based on composition by Somandepalli et al. * From Somandepalli et al.

18 Energy Density & Fire Load Density FAA FRC Experiment Storage Density: Gas Generation: Fire Load Density*: 5 kwh m m3 m 2 30 MJ m 2 Indoor dedicated storage Storage Density: 55 kwh m 2 Gas Generation: 17.5 m3 m 2 Fire Load Density*: 315 MJ m 2 20 or 40 Container Storage Density: Gas Generation: Fire Load Density*: 170 kwh m 2 55 m3 m MJ m 2 Fire Load Density of Dwelling ~ 780 MJ m 2 *Fire Load Density due to battery gas releases only. Does not include battery self-heating or flammable packaging and other materials.

19 Experiments Models Scales Cell Module Rack Room Site Thermal Runaway Propagation CFD Model of Mixing Blast Model Thermal Runaway Gas Properties Cell to Cell Propagation Module in Compartment

20 Thermal Runaway Experiment & Models Goals: Understand onset of thermal runaway Model heat generation Predict onset of runaway Experiments: Measure temperatures for thermal runaway Models: Equation for heat generation

21 Gas Characterization Experiments & Models Goals: Determine composition and volume of gas release Measure temperature of gases released Determine flammability properties of gases Experiments: Cell thermal runaway in vessel Perform for different size, chemistry cells Models: Cantera model of mixture properties

22 Propagation Experiments & Models Goals: Model heat flux from cell to cell Model next cell thermal runaway Predict propagation rates Experiments: Cell array thermal runaway Models: Finite difference heat transfer model

23 Explosion Experiments & Models Goals: Demonstrate explosion Validate explosion models Experiment: Small vented explosion Models: Thermodynamic Equilibrium 0D Explosion Model

24 Planned Work Development of CFD models Module to module propagation Rack to rack propagation Gas dispersion Models of Consequences Blast Overpressure Structural damage Full-scale module experiment Develop physical Li-BESS simulator

25 QUESTIONS? Erik Archibald - archy@utexas.edu Kevin Marr - kevin.c.marr@utexas.edu

26 EXTRA SLIDES

27 FAA FRC Data