Fire Tests

At the beginning of the project, there was little to no reliable or publicly available information on the fire behaviour of new energy carriers. For this reason, one of the main focuses of the SUVEREN project was to conduct full-scale fire tests, especially with lithium-ion batteries. In a total of three test series, data on the fire behaviour of modern vehicles, including electric vehicles and their batteries as individual fire loads, were obtained. The suitability of fire-fighting equipment and detection systems was also investigated in the tests.

Fire test series 1:

In May and June 2019, the first series of fire tests was conducted as part of the SUVEREN project. One aim was to understand the basic fire behaviour of lithium-ion batteries. For this purpose, a calorimeter was specially set up, which was mechanically ventilated. The batteries tested contained prismatic or cylindrical cells and had energy contents of 5 to 24 kWh. The batteries were ignited by drilling. In order to gain knowledge about the effectiveness of high-pressure water mist in battery fires, a corresponding system was installed in the calorimeter.

Numerous data were collected during the trials. These included:

  • Temperatures on the batteries and in the airspace
  • Gases released (esp. FTIR)
  • Extinguishing water analysis
  • Mass
  • Optical and IR cameras
  • Detection systems

In addition, tests were conducted with reference fire loads for pressurised gas vessels blowing off as well as for modern passenger cars with a potential maximum heat release rate of 7 MW. High-pressure water mist was also used in these tests to investigate the interaction of fire events and water mist droplets in multiphase flows.

Fire test series 2:

Further fire tests with lithium-ion batteries were conducted in December 2019 and January 2020. Based on the first series of tests in the spring, different gas-based as well as water-based extinguishing agents were tested for their effectiveness in battery fires. These included:

  • Sprinklers
  • High and low pressure water mist
  • Foam
  • F-500
  • Aerosol
  • Nitrogen
  • Carbon dioxide

Various detection systems were also used. Therefore, the calorimeter was modified for this series of experiments and equipped with a flat roof. The fire load consisted of two adjacent modules of cylindrical cells with a total energy content of 5 kWh. One of the modules was ignited in each case by overcharging; the spread of fire to the neighbouring module was to be prevented as far as possible by the extinguishing agents used.

Extensive data was recorded again this time:

  • Temperatures on the batteries and in the airspace
  • Gases released (esp. FTIR)
  • Extinguishing water analysis
  • Mass
  • Optical and IR cameras
  • Detection systems (point detectors, RAS, DTS)

Fire test series 3:

A third series of fire tests was conducted in October 2020. In these tests, the focus was on the overall system “car in a parking garage” and the evaluation of stationary firefighting. To ensure a high degree of reproducibility, mock-ups for the vehicle incl. battery and garage were used. The energy content of the reference car fire load followed the design fire curve developed in the project with a maximum heat release of 7 MW. The vehicle was ignited via the battery reference fire load.

The tests compared different firefighting systems: sprinklers and high-pressure water mist as well as automatic and open systems. In order to be able to evaluate the fire spread or rather the possibilities for fire containment, target fire loads were positioned around the vehicle and temperatures were measured in the vicinity of the vehicle, especially under the ceiling.

After successful completion of the tests, a concept for verification of stationary fire fighting systems in parking garages as well as a fire protection guideline for parking garages were derived.

This post is also available in: German