THE INFLUENCE OF ENCLOSURE ON BURNING CHARACTERISTICS OF OSB FURNISHINGS

This paper presents a series of full-scale tests conducted with office furniture made from OSB boards. Ignition source (30 kW gas burner) position and enclosure effects, free burn vs. ISO 9705 room, were evaluated from the perspective of instantaneous (HRR) and total heat (THR) released by the fuel packages. It was found that both of the evaluated factors have impact primarily on HRR – the peak ranging from 874 kW to 1 154 kW was delayed by approx. 50 to 60 s in the free-burn experiments; the THR remained relatively consistent at approx. 875 ± 30 MJ, meaning that in the observed period very similar amounts of fuel were burned. The thermal feedback within the enclosure seemed to be partially counteracted by the lack of oxygen, resulting in slightly higher HRR in free-burn test following the first peak. The findings of the research are applicable to fire hazard prediction by fire modelling.

Pre-incident planning of fires in underground hard rock mines: old and new risks

Fires in underground mines may pose a challenge to fire and rescue personnel where the complex environment and multiple influences of a fire are poorly considered during pre-incident planning. A better knowledge of pre-incident planning in underground mines would improve the safety of personnel. This study on pre-incident planning in underground mines applied data from experiments, inventories and design fire studies. A number of questions were considered related to information sources, fire modelling, capturing complexity and using fire scenarios. When performing fire modelling, empirical models could be used to complement other modelling tools. The study found that for modelling of spatially extensive mine sections, the use of ventilation network-based mine fire simulations could be a better option. Using an analytical toolbox, an iterative testing of plans and an ongoing planning process, the pre-planning challenges for a mine can be mitigated. The purpose of this study was to examine existing pre-incident planning and propose information sources, tools and specific actions for future plans.

Analysis of Zone Fire Models and their Application in Structural Fire Design

This paper is focused on a comparison of zone fire modelling software tools and their application in structural fire design. The analysis of the zone models is performed for five selected computer programs, namely Argos, Branzfire, B-RISK, CFAST, and OZone. The limits and input parameters ofthe zone fire modelling software tools are described. In each software, two variants of the analysed compartment are created for simulating two types of fire scenario, including the fuel-controlled fire and the ventilation-controlled fire. The burning regimes are defined based on two heat release rate(HRR) curves, determined according to EN 1991-1-2. The HRR curves parameters are used as the main input data into the fire modelling software. The fire simulation method in each fire modelling software is selected based on the software capabilities. Although each program requires a different amount of input parameters, the aim was to create the same model in all programs and to compare the results. The fire modelling software outputs are exported into a spreadsheet. Subsequently, a comparison of the resulting graphs is performed, particularly the heat release rate graphs and the upper layertemperature evolution graphs. The fire resistance assessment of a simply-supported concrete slab panel is performed for all zone fire models and then the results are compared. The fire modelling software tools are finally quantitatively and qualitatively evaluated and compared to assess their differences.

Existing Improvements in Simulation of Fire–Wind Interaction and Its Effects on Structures

This work provides a detailed overview of existing investigations into the fire–wind interaction phenomena. Specifically, it considers: the fanning effect of wind, wind direction and slope angle, and the impact of wind on fire modelling, and the relevant analysis (numerical and experimental) techniques are evaluated. Recently, the impact of fire on buildings has been widely analysed. Most studies paid attention to fire damage evaluation of structures as well as structure fire safety engineering, while the disturbance interactions that influence structures have been neglected in prior studies and must be analysed in greater detail. In this review article, evidence regarding the fire–wind interaction is discussed. The effect of a fire transitioning from a wildfire to a wildland–urban interface (WUI) is also investigated, with a focus on the impact of the resulting fire–wind phenomenon on high- and low-rise buildings.

Calorimetric Behaviour of Electric Cables

A routine cone calorimeter procedure, the theoretical analysis method, based on a set of ignitability data from the cone calorimeter, has been performed. The five sets of ignition times at different irradiance levels were used for obtaining experimental data needed for analysis. The cone calorimeter tests were performed with horizontal specimens of the size 100 mm × 100 mm consisting of eight pieces of commercial poly(vinyl chloride) coaxial power cable. Specimen combustion was carried out under external heat flux of constant values equal to 10, 20, 30, 40 and 50 kW·m−2, respectively. Standard fire parameters and time to ignition were used for analysis. The results indicate that for each fire parameter, a rising trend with an increase in radiant heat flux has been observed. It was shown that the use of poly(vinyl chloride)-based cables is a potential fire safety hazard due to the emission of heat and a large amount of acid smoke. Quintiere’s theory has been shown as a useful tool for fire modelling by using the data from small-scale tests rather than large geometrical scale cable experiments. Large scale cable test (EN 50399) results are also presented and compared with cone calorimeter data.

Evaluation of unprotected steel beam temperature during fire using CFD simulation

Fire resistance of building construction is essential part of the design process. Thermal loading of loadbearing elements can be obtained by using simplified standard fire curve or advanced numerical fire model. The paper shows the process of numerical fire modelling in unprotected steel structure carpark using the Computational Fluid Dynamics (CFD) method. In Fire Dynamics Simulator (FDS) software, three scenarios are created to represent open, semi-open and closed carpark building. The resultant HEB500 beam temperatures are compared with standard evaluated temperatures.

Recommendations for Jet Fire Model Selection When Performing Consequence Assessments of Onshore Natural Gas Pipelines and Facilities

The thermal radiation from a jet fire is the dominant hazard resulting from accidental natural gas releases from onshore pipelines or facilities. To assess the consequences to both individuals and equipment, we require models to estimate the incident radiation from the jet fire to the surroundings. Simpler models with shorter implementation and run times are more viable for use in a full probabilistic risk assessment, in which the number of scenarios assessed could number in the millions. However, the level of accuracy within these models must be considered to ensure a reasonably conservative estimate is produced. A review and comparison of semi-empirical models from literature was performed and used to develop a decision tree to recommend the most computationally efficient jet fire modelling approaches based on the release scenario, while maintaining reasonable conservatism. Options for both vertical and non-vertical releases are presented, as well as corrections for lift-off, wind, and buoyancy. Additionally, an efficient algorithm from the area of computer graphics was adapted and applied to a weighted multiple point source jet fire model to account for the reduction in incident radiation to a receptor due to topography or structures partially obstructing the view of the jet fire.