STUDY OF INDICATORS DESCRIBING THE COMBUSTION PROCESSES OF ELECTRIC VEHICLES
Abstract
The number of electric vehicles in private or commercial use continues to grow rapidly. The increase in the number of such vehicles, both in absolute and relative terms, leads to an increase in various hazards. One of these important hazards is the fire of these vehicles.
The aim of this paper is to analyse and characterise the development of electric vehicle combustion processes, as well as the indicators that these processes can describe.
Analysis, interrelation and understanding of the indicators describing electric vehicle fires will create the basis for developing an understanding of the characteristics of such fires, as well as prerequisites for effective methods of combating them.
Based on the analysis of modern domestic and foreign literature, it has been established that insufficient attention has been paid to the study of indicators that comprehensively describe and summarise the processes of combustion of electric vehicles. This gives grounds to assert the expediency of conducting a study of this kind.
During electric vehicle fires, the temperature of the combustion products can reach up to 1500 °C, and when the power battery alone burns, it can reach 800-900 °C.
The total heat release energy from the combustion of electric vehicles depends on the capacity of the power battery, the degree of its charge, and for an electric vehicle with a fully charged 64 kWh battery, it is more than 9 GJ.
In the case of electric vehicle fires, the heat flux power also depends on the capacity and charge of the power battery and ranges from 6 MW for an electric vehicle with a battery capacity of 39 kWh, while the heat flux density is in the range of 40-50 kW/m2.
According to the fire growth rate coefficient, such fires are fast, with a fire growth rate coefficient of more than 0.0111 kW/s2.
The specific heat of combustion of modern electric vehicles is more than 30.5 MJ/kg, which is more than 2 times higher than the combustion of lumber.
During the release of gases, with the formation of an explosive concentration, the explosion pressure in an electric vehicle fire can range from 1,35 kPa to 1,45 kPa.
