Electric Trucks – Fire Safety Aspects
2023 (English)Report (Other academic)
Abstract [en]
This study was performed by RISE Research Institutes of Sweden on behalf of Volvo Trucks. RISE Research Institutes of Sweden was requested to conduct a study regarding the differences between fires in conventional internal combustion engine (ICE) trucks and electric trucks. A set of guiding questions (see section Aim) were given by Volvo Trucks and in this report these questions have been answered. The questions have been answered by performing literature searches and through previous knowledge of RISE. However, for some questions, due to scarcity of data on electric truck fires, knowledge regarding electric passenger cars has been used. In addition, contact has been made with fire and rescue services around the world (Australia, UK, USA, Sweden and Finland) to collect their views on management of fires in electric vehicles (EVs). The main conclusions are: • Data on electric truck fires are scarce due to the low number of vehicles as well as the low number of fire incidents. Available data show that battery electric passenger vehicle fires are less common than ICE vehicle fires, but that the risks are different. The main differences are that battery fires tends to be harder to extinguish than fires in ICE vehicles and that there is a risk of accumulation of flammable gases, especially in enclosed spaces, upon thermal runaway. • Lithium iron phosphate (LFP) type cells, in comparison with nickel-based type cells (such as lithium nickel manganese cobalt oxide (NMC) and lithium nickel cobalt aluminium oxide (NCA)), have a higher thermal runaway onset temperature, a slower temperature increase rate, a lower maximum temperature as well as a lower gas production in total amount. However, the specific total gas production (L Ah-1) can sometimes be higher for LFP-type cells and depends on the state of charge and on the amount of electrolyte in the cell. However, the safety of a battery pack in a vehicle is determined by several factors such as preventive measures aimed at reducing the occurrence of fires (safe design). For example, by early detection and pro-active mitigation using the battery management system and thermal management system and by limiting the thermal propagation in the battery pack, reducing the extent of damage. • Fires in enclosed spaces, such as in underground parking garages and tunnels, generally imply a higher risk for firefighters due to the trapped smoke, decreased visibility and longer access routes than in open structures. Risk reduction measures for battery fires should focus on early detection of harmful events, reducing thermal propagation in the battery pack and on limiting the extent of fire spread. The severity of the consequences of vehicle fires (no matter if is an EV or an ICEV) in enclosed spaces could be reduced using suppression systems, such as a water sprinkler system, to hinder fire spread between vehicles.
Place, publisher, year, edition, pages
RISE Research Institutes of Sweden , 2023. , p. 21
Keywords [en]
Electric truck, fire safety, vehicle fire, electrical safety, enclosed space
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:ri:diva-67757OAI: oai:DiVA.org:ri-67757DiVA, id: diva2:1812157
Note
Projektet är finansierat av Volvo Trucks.
2023-11-152023-11-152023-11-21Bibliographically approved