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Despite the fact that LPG (Liquefied Petroleum Gas) is used in a large number of cars, tests have not yet been carried out to ascertain how hazardous can be the release of LPG from the car when parked in enclosed garages. The problem applies to both public and industrial parking areas, especially in Poland, where more than 10% cars are fueled by LP...
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The Event Tree Analysis (ETA) is a tool for assessing system and process safety. It facilitates detecting potential risks, as well as relations existing between actions or events. This method explores the path from the initiating event to the outcome (most often representing the immobilization of the tested object), with particular emphasis on inte...
Citations
... Cai et al. 12 conducted relevant experiments to study the diffusion law after indoor natural gas leakage and the hazards after an explosion and determined the distribution law of indoor natural gas volume fraction under different leakage conditions, as well as the propagation laws of flames and shock waves in an explosion. Brzezinśka et al. 13 conducted a series of experiments to study the dispersion distribution of leakage LPG in a confined garage, showing that under unventilated conditions, leakage LPG can accumulate on the floor of a confined garage for a prolonged time, creating a high explosion hazard. ...
Gas microleakage, which results in gas diffusion and accumulation in domestic gas appliances, is the leading cause of indoor gas explosion accidents. To research the diffusion and accumulation characteristics of microleakage gas in domestic gas appliances, this study took an integrated stove as the research object and analyzed the effects of different leakage rates and leakage locations on the diffusion and accumulation characteristics of microleakage liquefied petroleum gas (LPG) in its interior using the computational fluid dynamics (CFD) numerical simulation method. The results show that microleakage LPG is characterized by a downward diffusion flow driven by gravity and the concentration inside the integrated stove cavity generally increases with the increase of leakage time; however, the spatial distribution is extremely inhomogeneous. In addition, the volume of the dangerous area rapidly changes with the continuous accumulation of microleakage LPG, occupying more than 50% of the cavity volume. Microleakage LPG diffusion and accumulation process are highly similar under different leakage rates; on the contrary, the location of the leakage source is closely related to the diffusion and accumulation characteristics. The diffusion distribution and accumulation position of microleakage LPG at different leakage locations present obvious differences. Typically, there is a concentration difference of 0.1-0.2% between the top and the bottom when the leakage source is located above the gas stove baffle and a concentration difference of 1.0-1.3% between the top and the bottom when the leakage source is located below the gas stove baffle. In addition, the difference in the leakage location has a significant impact on the time the concentration of LPG reaches the critical concentration, which indicates that the combustion and explosion risk of different leakage locations are highly related to the leakage time. The research can provide certain technical support for microleakage gas explosion accident prevention.
... For fire engineering evaluation purposes, the heat release rate (HRR) or the total heat release from fire is the standard measurement of fire size and is the most important parameter of the EV fire hazard assessment [78], for use when assessing car park fire safety system designs [90][91][92][93]. The HRR can be taken as: ...
Even though electric vehicles (EV) were invented over a century ago, their popularity has grown significantly within the last 10 years due to the development of Li-ion battery technology. This evolution created an increase in the fire risk and hazards associated with this type of high-energy battery. This review focuses on lessons learned from electric vehicle fires and fire risk mitigation measures for passenger road vehicles partially or fully powered by Li-ion batteries. The paper presents EV fire risks, as well as historical car fires, published large-scale fire tests, and some proposed fire protection strategies in the aspect of electromobility safety for the future. Technical solutions for EV fire hazard mitigation are discussed, and methods of performance-based analysis and simulations for fire safety in car park evaluation are demonstrated. The Fire Dynamic Simulator (FDS) was used for the CFD simulations for the prediction of smoke dispersion and temperature distribution during an EV fire. The presented case study demonstrates how fire simulations could predict conditions for the safe evacuation of people and Fire Brigade intervention conditions in the case of an EV fire in a car park.
... Initially, the program was created for fire-driven fluid flow modeling. However, the authors' experience shows that it can also be successfully used to analyze the spread of gases in enclosures [13,[27][28][29][30]. The software uses a large eddy simulation (LES) turbulence model appropriate especially for buoyancy flows, which is widely used for hydrogen dispersion phenomenon modeling [21,[31][32][33][34]. ...
Hydrogen is an explosive gas, which could create extremely hazardous conditions when released into an enclosure. Full-scale experiments of hydrogen release and dispersion in the confined space were conducted. The experiments were performed for hydrogen release outflow of 63 × 10−3 m3/s through a single nozzle and multi-point release way optionally. It was found that the hydrogen dispersion in an enclosure strongly depends on the gas release way. Significantly higher hydrogen stratification is observed in a single nozzle release than in the case of the multi-point release when the gas concentration becomes more uniform in the entire enclosure volume. The experimental results were confirmed on the basis of Froud number analysis. The CFD simulations realized with the FDS code by NIST allowed visualization of the experimental hydrogen dispersion phenomenon and confirmed that the varied distribution of hydrogen did not affect the effectiveness of the accidental mechanical ventilation system applied in the tested room.