In this article, some of the combustion properties of three carbonate solvent mixtures commonly used as the electrolytes of lithium ion batteries are considered by means of the ISO 5660 cone calorimeter. Experimental findings reveal that the heat release rate, the most important parameter in fire science, exhibits a significant variation among the carbonate mixtures. Other key parameters governing the fire-induced hazards such as total heat release, mass loss rate, combustion efficiency, and concentration of the major exhaust gases are also determined and analyzed. Furthermore, as some researchers argue that oxygen consumption calorimetry is likely to overpredict the chemical heat release for lithium ion cells, another thermal chemistry method based on stoichiometry for heat release rate calculation is adopted. Heat release rate results of the three carbonate solvent mixtures obtained by these two separate methods are found to be in good agreement. Thus, oxygen consumption calorimetry is considered to be an appropriate technique to determine the heat release in fires in relation to electrolytes of lithium ion batteries.

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Summary To study the low pressure influence on the flash point and fire hazard of organic fuels and their aqueous solutions, a series of experiments has been conducted to measure the open‐cup and closed‐cup flash points of methanol, ethanol, and n‐decane aqueous solutions including different mole fractions under different static pressures ranging from 35 to 101 kPa. The results show that both the pressure and fuel mole fraction have a nonlinear correlation with the flash point of the miscible fuel specimens like the correlation provided in this paper. For the partially miscible fuel specimens with a lower density than water, the water content has almost no influence on the flash point. The fire risks of the experimental results were analysed based on the standard GB50160‐2008, which shows that the fire risk becomes higher at low pressures, and there is a critical pressure at the turning point of the change in fire classification. A method to achieve the critical low pressure of different fuels or aqueous solutions from the fire hazard classification is derived in this paper.

The aim of this study was to evaluate the transport phenomena of smoke flow and vertical temperature distribution in a 21-story stairwell with multiple fire locations and openings. A large eddy simulation (LES) method was used to model the smoke flow in a stairwell model with a set of simulation parameters, wherein the fire heat release rate (HRR) and fire location were varied. Based on the results, a wall attachment effect was found in three-dimensional figures. Moreover, with an increase in the fire HRR, the effects were more pronounced. The simulation results verified that the vertical temperature distribution is an index model with a natural logarithm, where the pre-finger factor and attenuation coefficient increase considerably in accordance with an increase in the fire HRR. Moreover, there was a decrease in the maximum temperature (Tm) with an increase in the fire location factor (h*) due to the upward thermal smoke. Moreover, heat mainly accumulates in the area above a fire source. However, h* has a slight influence on the time required to reach Tm within the range of 53–64 s. Furthermore, the direction of the airflow at each side opening in the stairwell varied in accordance with the variation in the fire location changes, and a regular calculation was carried out.

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