2019

Välisalo, Tero

The goal of this literature study is to clarify according to the available literature how the firefighters should operate in case a Li-Ion battery-powered work machine catches fire in underground conditions, e.g. in a mine. Another goal is to find ideas and topics for further research to promote fire safety of battery-powered work machines. Battery powered electrical drives are nowadays been designed also for underground mining applications. Lithium-ion based rechargeable batteries are common also in heavy work machine applications. They are relatively safe, as there is no lithium metal present in the battery structure. However, Li-ion batteries can reach a self-heating stage that can lead to thermal runaway. All needed components of fire are present in the li-ion cell: fuel, heat and oxygen. Lithium-ion battery fire suppression is generally recommended to be accomplished mainly with lots of pure water or water-based extinguishing foam. In underground solutions, it is not an ideal option to allow the battery pack burn to self-extinguishment because of the rock integrity decreases due to heat and because of the loss of production as the underground operations should be stopped in the case of battery fire. There were no indications in any emergency guides or research papers that there might be danger of electrical shock for the firefighters while the battery pack is extinguished with water.To ease the work of the first responders, machine type specific instructions should be prepared. The conventional personal protective equipment used by rescue personnel in ICE car fires should be effective enough also in the case of EV battery fire, although the subject should be studied more further.