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In numerical fire simulations, the calculation of thermal feedback from the flame to the solid and liquid fuel surface plays a critical role as it connects the fundamental gas-phase flame burning and condensed-phase fuel gasification. However, it is a computationally intensive task in CFD fire modelling methods because of the requirement of a high-resolution grid for calculating the interface heat transfer. This paper proposed a real-time prediction of the flame-to-fuel heat transfer by using simulated flame images and a computer-vision deep learning method. Different methanol pool fires were selected to produce the image database for training the model. As the pool diameters increase from 20 to 40 cm, the dominant flame-to-fuel heat transfer shifts from convection to radiation. Results show that the proposed AI algorithm trained by flame images can predict both the convective and radiative heat flux distributions on the condensed fuel surface with a relative error below 20%, based on the input of real-time flame morphology that can be captured by a larger grid size. Regardless of growing or decaying fires or puffing flames induced by buoyancy, this method can further predict the non-uniform distribution of heat transfer coefficient on the interface rather than using empirical correlations. This work demonstrates the use of AI and computer vision in accelerating numerical fire simulation, which helps simulate complex fire behaviours with simpler models and smaller computational costs. [ABSTRACT FROM AUTHOR]

Fire accidents in oil tank farms can trigger domino effects, leading to multiple tank fires with catastrophic consequences. Preventing losses in large‐scale tank farms requires a dynamic assessment of fire‐induced domino accidents. Existing research often focuses on calculating the time to failure (TTF) of storage tanks but overlooks the influence of failure modes. This study develops numerical models to explore failure modes of oil storage tanks with uniform and stepwise walls exposed to thermal radiation. Factors such as the flame heights of combustion tank, adjacent spacings, wall thickness, and tank volumes are considered. The numerical model employs a solid double‐layer flame model to determine thermal radiation intensity and temperature, followed by a dynamic stress–strain and buckling analysis to obtain time to buckling (TTB) and time to yielding (TTY). If TTB < TTY, the failure model is buckling; otherwise, the failure model is yielding. Results indicate that failure modes in nonuniform thermal fields include buckling and yielding, with stepwise walls favoring buckling and uniform walls favoring yielding. When the wall thickness is below the critical value, failure is yielding; otherwise, it is buckling. These findings support risk management and emergency response for fire‐induced domino effects in oil tank farms. [ABSTRACT FROM AUTHOR]

In situ burning (ISB) is an effective technique for burning oil spills that occur in oceans. The need for enhancing the burning characteristics and advancing the technique of burning fuels on the water sublayer has been identified. Following this, the study analyzes the steady burning behavior of a fuel layer floating on a turbulent water surface. The turbulent water surface is generated using an experimental platform comprising an axisymmetric upward-pointing submerged jet, an approach used in studies of free-surface turbulence. The turbulence is isotropic in the horizontal plane and bulk-flow free, with a turbulence intensity equal to 1.7 cm/s comparable to water turbulence in a calm ocean. The turbulent boundary condition causes an increase in heat extraction from the bottom of the fuel layer, thereby reducing the mass burning rate by 45% compared to a case with no turbulence. To improve the burning under turbulent water sublayer condition, a 10 mm conductive object is immersed at different depths in the fuel. The copper rod collects the flame's heat and transmits it into the fuel layer via conduction, thereby increasing the burning rate by more than 1.4 times. A heat transfer model shows that the case with a small rod immersion depth (~10 mm) in a 40 mm fuel layer is best at improving burning because the heat losses from the object to the water sublayer are the lowest. The model also shows that the heat from the flame transmitted by the rod is primarily distributed in a region close to the surface of the fuel, where nucleate boiling is observed around the rod surface. As more of the rod is immersed in the fuel layer, the heat dissipation to the turbulent water increases nearly five times, thereby reducing the bubbling around the rod surface and the burning rate. The implications of burning fuel slicks for fast, slick cleanup during in-situ burning in turbulent water conditions are espoused. [ABSTRACT FROM AUTHOR]

Wind has a significant effect on pool fire behavior, which is relevant to many fire conditions, such as wildfires, building fires, and oil transportation fires. Although fire behavior and morphology changes have received considerable attention and been widely researched, there are few works concerning the flow and flam dynamics of pool fire. A large eddy simulation model is adopted to investigate the flow and flame dynamics of a rectangular pool fire considering the combined effects of wind and slope. The results show that, with a wind speed of 0.5 m/s, a flame develops immediately downstream of the fire source and sustains two flanks of plume. Further downstream, the plume starts to rise due to buoyant force. Temperature, velocity, and vorticity distributions show significantly different shapes at different streamwise locations. Near the fire source, the flame is confined to a small region around the fire source. The air circulation downstream shows a cylindrical spiring pattern. When the wind speed increases, the temperature and velocity become more parallel to the surface and their maximum values increase. On the contrary, the temperature fluctuations and turbulent kinetic energy decrease with the wind speed, and they are more frequent near the flame tails. [ABSTRACT FROM AUTHOR]

The inorganic water-based non-expanding fireproof coating was taked as the research object, and the coating thickness as the main influencing factor, the thermal response tests of liquefied petroleum gas tanks were conducted in a pool fire environment. The wall temperature response, damage time, and failure mode of storage tanks after spray fireproof coatings were studied in pool fire environments. The results show that the inorganic water-based non-expansion fireproof coatings have a significant delayed effect on the explosion time of storage tanks under fire action. For civilian liquefied petroleum gas storage tanks, when the filling level is the same, the tank which coating thickness is 2 cm is 6.91 times that of bare tanks in a pool fire environment, the tank which coating thickness is 3 cm is 1.20 times that of the tank which coating thickness is 2 cm, and the tank which coating thickness is 4 cm is 1.05 times that of the tank which coating thickness is 3 cm. The delayed effect of increasing coating thickness on the damage time of storage tanks in a pool fire environment gradually decreases, so it is suggest that to the coating thickness of 3 cm is suitable for storage tank. The research results have certain significance for the safety protection application of storage tanks in a pool fire environment and the study of fireproof coating. [ABSTRACT FROM AUTHOR]

Pool fire with varying ullage height is a common type of accident that occurs in industrial parks. This paper explores the ullage height effects on the burning rate and heat feedback in pool fires through the experimental and theoretical study. A series of experiments were conducted using heptane with four tray sizes and five ullage heights. The results show that, the burning rate initially decreases, then increases and finally decreases as the ullage height increases. These results are mainly dependent on the change of internal flame behavior and thus heat feedback mechanisms with increasing ullage height. In the small ullage height conditions, the convective heat feedback reduces substantially whereas the radiative one rises slightly. When the ullage height reaches to a certain value, the convective heat feedback suddenly increases because of the flame inside the tray. The radiative heat feedback decreases gradually as the ullage height increase continually, while the convective one becomes nearly constant. Based on these results, three regimes are identified in terms of the burning rate variation with heat feedback: (1) convection controlled, (2) convection-radiation controlled and (3) radiation controlled. The new controlling mechanism of the burning rate variation (with ullage height), as a further extension of the classic scaling model by Blinov and Khudyakov on the burning rate variation (with pool diameter), could lay a solid foundation for future studies of the other key parameters in tank fires.

Background and Objective: Diesel storage tanks play a crucial role in hospitals and are constantly at risk of chemical release, explosion, and fire. The present study aimed to assess the consequences of a diesel tank leak in one of Iran’s specialized hospitals. Materials and Methods: This study utilized an applied research approach with scenario modeling using PHAST software (version 8.4). A discharge rate of 1000 L/min was employed for the fixed-duration release scenario. The necessary information for the software, including tank and meteorological data, was collected. The mortality rate and danger radius were calculated and analyzed for two tank volumes of 23600 and 12000 m3 in conditions of Sabzevar region in winter and 1.5 F of the software. Results: According to the tank type and substance released into the environment, the software displayed a pool fire. The most hazardous scenario was determined to be leakage from the 23600 m3 tank in weather conditions of Sabzevar (26°C, wind speed 15 m/s in winter). The maximum and minimum radiation heat from the fire were calculated at 44.7 and 94.2 meters, respectively. The mortality rates for exposure levels of 37.5 kw/m2, 12.5 kw/m2, and 4 kw/m2 were found to be 98.7%, 6.5%, and approximately zero, respectively. Conclusion: Fire safety in hospitals is a critical issue that requires a thorough examination of the factors that can lead to ignition and explosion. To mitigate these risks, it is recommended to strategically place diesel tanks, develop safety models for roadways, construct dams and dikes near tanks, regularly inspect equipment for corrosion and deterioration, and install sensors to detect leaks. These measures are essential for ensuring the safety of patients, staff, and hospital facilities.

In the chemical industry, when a fire occurs, a significant amount of energy is generated due to combustion, impacting other facilities within the plant and potentially leading to severe consequences through a domino effect. For decades, thermal radiation caused by flames has been calculated and predicted through simplified fire modeling. However, with advancements in computing technology, numerical model‐based calculations have greatly improved, allowing for a more realistic implementation that considers actual phenomena. In this study, accident data and 3D modeling information were utilized to conduct fire modeling and simulation based on actual incidents in chemical plants. Through the analysis of simulation results, the initial emergency evacuation distance was provided to minimize the damage caused by thermal radiation, and the final evacuation distance was presented using the probit function. In addition, the study evaluated the impact of generated thermal radiation and overpressure on structures and equipment, providing evidence regarding the potential for secondary incidents. Moreover, the research revealed that the impact of thermal radiation and overpressure decreases due to obstacles, offering insights into the selection of emergency evacuation routes. This study can contribute to supporting effective emergency evacuation strategies in chemical facilities. [ABSTRACT FROM AUTHOR]

Experimental analyses and numerical simulations are carried out on a test case involving an heptane pool fire within a large under-ventilated environment. During the experiments, the temperature history at several locations within the room is monitored by means of thermocouples, and the fire radiative heat transfer estimated through a plate thermocouple. The experimental layout is then replicated numerically and tested using OpenFOAM CFD code. The study is a preliminary analysis performed for code validation purposes on a full-scale fire scenario. The results of the simulations are compared to the experimental results and critically analysed, finding a reasonable agreement overall. Critical issues in fire modelling are also highlighted. In fact, due to the problem complexity and the limitations of the numerical models available some important aspect that can significantly influence the outcome of the simulations must be calibrated a posteriori, somewhat limiting the general predictive applicability of the fire models. Primarily, these are the heat release rate history, the combustion efficiency, and, to a lesser extent, the convective heat transfer boundary condition at the wall. [ABSTRACT FROM AUTHOR]

This article focuses on using machine learning to predict the distance at which a chemical storage tank fire reaches a specified thermal radiation intensity. DNV's Process Hazard Analysis Software Tool (PHAST) is used to simulate different scenarios of tank leakage and to establish a database of tank accidents. Backpropagation (BP) neural networks, random forest models, and the optimized random forest model K-R are used for model training and consequence prediction. The regression performance of the models is evaluated using the mean squared error (MSE) and R 2 . The results indicate that the K-R regression prediction model outperforms the other two machine learning algorithms, accurately predicting the distance at which the thermal radiation intensity is reached after a tank fire. Compared with the simulation results, the model demonstrates higher accuracy in predicting the distance of tank fire consequences, proving the effectiveness of machine learning algorithms in predicting the range of consequences of tank storage area fire events. [ABSTRACT FROM AUTHOR]

The response of objects engulfed in, and adjacent to, large-scale pool fires is of interest in accident and safety assessments. In this study, Fuego, a low-Mach turbulent reacting flow code was used to study conjugate heat transfer in a 7.9 m diameter JP-8 pool fire. Simulations were designed to replicate past experimental measurements (Blanchat et al., 2006) of incident heat flux to three cylindrical calorimeters in and around the pool fire. Two turbulent combustion models were compared directly - the eddy dissipation concept and a more recently developed unsteady flamelet model. First and second order spatial and temporal discretization schemes were also compared to assess the performance of low-dissipation numerical operators. Heat flux predictions to the transportation size calorimeter outside the fire were within experimental uncertainties. Inside the fire, experimental measurements were higher than predicted values and may have been a consequence of soot deposition and augmented participating media radiation from soot and fuel vapor. Simulation predictions improved in cases where turbulent kinetic energy and mixing were more resolved. This work, and others referenced herein, suggest that spatial resolution on the order of 0.5–1.0 cm may be required to fully resolve fluid instabilities, vortex production between fire plumes and crosswind, soot production, and fuel-air mixing. This presents a substantial computational challenge for safety assessments of engulfed objects in fully turbulent pool fires.

According to the provisions on fire separation distance between industrial and civil buildings in the latest 'General Code for Fire Protection of Buildings and Constructions' (GB 55037-2022). Radiant heat intensity is one of the main factors in calculating the fire separation distance between buildings. Therefore, the design process involves a lot of calculation of radiant heat intensity. This paper mainly studies the prediction model of radiant heat flux. Three different view factor calculation models, Mudan, Mudan-Sparrow, and Rai-Kalelkar, are used to evaluate the influence of key factors such as the diameter of the pool and the distance between the target and the center point of the liquid pool on the calculation results of radiant heat flux. The results show that when it came to estimating the radiant heat flux, the Mudan and Mudan-Sparrow models yielded comparable results. The calculation of the Rai-Kalelkar model shows that the radiant heat flux is about half of the heat flux in the first two models. When calculating the minimum fire separation distance for combustible liquid storage tanks with a fire dike, the results show that all three models can provide a larger safety margin than the point source model.

Wind has a significant effect on pool fire behavior, which is relevant to many fire conditions, such as wildfires, building fires, and oil transportation fires. Although fire behavior and morphology changes have received considerable attention and been widely researched, there are few works concerning the flow and flam dynamics of pool fire. A large eddy simulation model is adopted to investigate the flow and flame dynamics of a rectangular pool fire considering the combined effects of wind and slope. The results show that, with a wind speed of 0.5 m/s, a flame develops immediately downstream of the fire source and sustains two flanks of plume. Further downstream, the plume starts to rise due to buoyant force. Temperature, velocity, and vorticity distributions show significantly different shapes at different streamwise locations. Near the fire source, the flame is confined to a small region around the fire source. The air circulation downstream shows a cylindrical spiring pattern. When the wind speed increases, the temperature and velocity become more parallel to the surface and their maximum values increase. On the contrary, the temperature fluctuations and turbulent kinetic energy decrease with the wind speed, and they are more frequent near the flame tails.

To investigate the fire danger of mattresses, combustion experiments were conducted with a mattress installed at different heights above the floor to better understand their combustion behavior. The installation height was varied because the height of a mattress varies depending on the bed frame, and the combustion behavior is expected to change with the installation height. Experiments with a mattress installed at 0–515 mm above the floor revealed that the fire growth was faster, and the maximum heat release rate (HRR) increased with installation height. In contrast, in a series of experiments where a mattress was installed above a water pool, the flame spread rates and HRR histories were comparable for all installation heights. This demonstrate that the combustion behavior of the mattress was affected by the combustion of the molten mattress material that dropped to the floor, and this effect was influenced by the mattress installation height. Furthermore, we analyzed the HRR per unit area of mattress construction material using cone calorimeter tests to mimic the combustion taking place on the floor. Combining these results with the relation between the length of the burning part of a mattress at the front of flame spread and the HRR, we proposed a model for predicting the HRR history of mattress for a flame ignition at the center of its longitudinal side. The derived predictive model for the HRR history of mattress combustion emphasize that it is necessary to understand factors such as the intense radiant heat from the pool fire. [ABSTRACT FROM AUTHOR]

Background and Objective: Diesel storage tanks play a crucial role in hospitals and are constantly at risk of chem ical release, explosion, and fire. The present study aimed to assess the consequences of a diesel tank leak in one of I ran's specialized hospitals. Materials and Methods: This study utilized an applied research approach with scenario modeling using PHAST software (version 8.4). A discharge rate of 1000 L/min was employed for the fixed-duration release scenario. The necessary information for the software, including tank and meteorological data, was collected. The mortality rate and danger radius were calculated and analyzed for two tank volumes of 23600 and 12000 m3 in conditions of Sabzevar region in winter and 1.5 F of the software. Results: According to the tank type and substance released into the environment, the software displayed a pool fire. The most hazardous scenario was determined to be leakage from the 23600 m3 tank in weather conditions of Sabzevar (26°C, wind speed 15 m/s in winter). The maximum and minimum radiation heat from the fire were calculated at 44.7 and 94.2 meters, respectively. The mortality rates for exposure levels of 37.5 kw/m2, 12.5 kw/m2, and 4 kw/m2 were found to be 98.7%, 6.5%, and approximately zero, respectively. Conclusion: Fire safety in hospitals is a critical issue that requires a thorough examination of the factors that can lead to ignition and explosion. To mitigate these risks, it is recommended to strategically place diesel tanks, develop safety models for roadways, construct dams and dikes near tanks, regularly inspect equipment for corrosion and deterioration, and install sensors to detect leaks. These measures are essential for ensuring the safety of patients, staff, and hospital facilities. [ABSTRACT FROM AUTHOR]

Multiple Pool Fire (MPF) reasonably enhances the flame height, the rate of fuel combustion and irradiation due to cascading effect and flame merging of multiple pools. The distribution of temperature and radiative heat flux from the source is the key parameter in predicting safety distance. The current study's major objective is to develop a Computational Fluid Dynamics (CFD) model to calculate the safety distance of MPF and validate the predicted results (flame temperature, radiative heat flux, CO2 and O2 mass fraction) with the experimental data. The flame structure and its thermal properties have been evaluated using the Reynolds Averaged Navier Stokes (RANS) and the Large Eddy Simulation (LES) model. The CFD results are found to be in close agreement with the experimental findings. The LES turbulence model predicts more accurately the flame structures and the fluctuations with an error of less than 3%, while the Re-Normalization Group k-ε model predicts the average characteristics. This authenticates the accuracy of computational methodology and robustness of the LES turbulence model to predict MPF flame characteristics. Furthermore, this computational methodology can be utilised by the industries for quantitative risk assessment and the worst-case scenario of various pool fires to save the human and material of the workplace beforehand. [ABSTRACT FROM AUTHOR]

This study investigates the impact of ventilation, specifically modeled by a radiator fan, on heptane pool fires within a military ground vehicle engine compartment. Experiments were conducted in a 2.44 m3 scale-1 compartment with varying fan-generated inflow velocities, initial fuel thicknesses, and pan diameters. The primary objective is to comprehensively assess how ventilation conditions affect pool fire behavior, focusing on properties such as mass loss rate, heat release, temperature, and heat flux in both the boiling and steady stages. The results reveal that the boiling stage occurs at initial fuel thicknesses of 10 and 15 mm, allowing us to analyze the boiling-to-steady ratio. This ratio exhibits variation across parameters. For burning duration, the ratios range from 0.45 to 0.93, while for mass loss rate, the ratios range from 2.3 to 3.5. Regarding total heat flux, the ratios span from 2.5 to 4. The boiling-to-steady ratio for temperature varies by position: in the vertical tree, it ranges from 1.1 to 1.7; in the ceiling tree, it ranges from 2.2 to 2.9; and in the ceiling side tree, it ranges from 1.2 to 2.25. Ventilation influences the boiling-to-steady ratio. Increasing inflow velocity generally increases the ratio for burning duration and ceiling tree temperature while decreasing the ratio for mass loss rate. The impact of ventilation on other properties depends on pan diameter and initial fuel thickness. [ABSTRACT FROM AUTHOR]

In-situ burning is a fast, cheap, and effective means of cleaning up spilled fuel in the environment. Much in-situ burning takes place at sea and on the ocean surface. Some studies have been conducted which examine the impact of a water sublayer, fuel thickness, pool diameter, and other parameters on the burning rate of a pool fire. Very little research has been conducted which examines the influence of water waves on the burning characteristics of a fuel floating on water. This study analyzes the burning behavior of an 80 cm kerosene pool fire of constant thickness floating on wavy water. A custom modular freshwater wave tank was built to accommodate the experiments. Wave generation and absorption equipment ensure linear wave composition for experimental study. Four different wave profiles with steepness ranging from 0.008 to 0.017 representing a Beaufort Sea state of 1 were used. It is observed that waves increased convective cooling by the water sublayer, decreased flame heat feedback, and lowered regression rates. As the thickness of the fuel is increased the influence of the wave is reduced, with thicker fuels experiencing less dramatic effects than thinner fuels. [ABSTRACT FROM AUTHOR]

The fire behaviour and smoke behaviour of a fire in an underground mine will be largely dictated by the heat release rate of the fire. The heat release rate per unit area is generally the output from small-scale fire experiments and can be applied for larger objects with varying surface area. This paper studies the impact of varying heat release rate per unit area for fires in materials and substances typically found underground. Data from earlier fire experiments were analysed and discussed, and several different heat release rate curves and flame spread velocities for various fuel components were developed and discussed. It was found that the hydraulic hose presented the highest peak heat release rate per unit area of the solid fuel items, followed by the low-voltage cable, cab interior, and tyre in descending order. The increase in the peak heat release rate was highest for the highest incident heat flux levels, representative for scenarios underneath a mining vehicle. The heat release rate per unit area of pool fires underneath a vehicle is significantly higher than a corresponding free burning case - attributed to the higher incident heat flux – but a gravel surface underneath a pool fire will reduce the heat release rate considerably. Line fires in larger bundles of electrical cables were modelled and found to attain the peak flame spread velocity more rapidly compared with a fire in hydraulic hoses. This was caused by the higher heat release rate of the initial fire and ignited segments in the electrical cable case. [ABSTRACT FROM AUTHOR]

In the Republic of Korea, a new rocket launchpad was constructed to launch the KSLV-II on an island, and all the launchpad facilities are located in basement. Because of the complex and diverse facilities, fire accidents have increased. Using the FDS (Fire Dynamics Simulator) to predict the damage from kerosene storage and drain tank pool fires is garnering more attention as a tool of choice. The FDS supports a sprinkler model, which is needed to analyze fire extinguishing by water sprinkling. To predict and estimate the resistance of the building and thermal damage, the main analysis factors for a kerosene tank pool fire accident are temperature and HRR (heat release rate per unit volume). In 3 m 3 release cases, the maximum temperature decreased by 33% from 900 K to 600 K by sprinkled water, and the maximum HRR decreased by 70% from 20,000 kW/ m 3 to 6000 kW/ m 3 . In 10 m 3 release cases, the temperature and HRR decreased by 44%, from 800 K to 450 K and 68% from 25,000 kW/ m 3 to 8000 kW/ m 3 , respectively. [ABSTRACT FROM AUTHOR]

RP‐3 aviation kerosene is a standard fuel that is used in civil aircraft and is a substitute for Jet‐A fuel. This paper investigates the combustion behaviour of RP‐3 aviation kerosene in an open space in the low‐pressure environment of a plateau. A series of large‐scale pools with diameters ranging from 0.4 m to 2.82 m combustion experiments are performed. Typical combustion characteristic parameters, including combustion rate, flame height and axial plume temperature distribution is measured. Results show that a low‐pressure environment significantly affects pool fires. With combustion rate, there is a linear variation law between oil pool size and combustion rate. The experimental data are fitted as a means of obtaining the large‐scale combustion rate relationship equation at low pressure. Experimental flame height data is compared using classical prediction models. Prediction model coefficients at low pressure are determined. The axial plume temperature distribution is greater than in the literature findings due to flames becoming longer in a low‐pressure environment. The three regimes in McCaffery's model are redefined and correlate well with the vertical temperature profile of the pool centreline. The results of the experimental investigation will help research fire hazards in low‐pressure environments while also contributing to the provision of basic data for the development of firefighting operation strategies. [ABSTRACT FROM AUTHOR]

This article focuses on using machine learning to predict the distance at which a chemical storage tank fire reaches a specified thermal radiation intensity. DNV’s Process Hazard Analysis Software Tool (PHAST) is used to simulate different scenarios of tank leakage and to establish a database of tank accidents. Backpropagation (BP) neural networks, random forest models, and the optimized random forest model K-R are used for model training and consequence prediction. The regression performance of the models is evaluated using the mean squared error (MSE) and R2. The results indicate that the K-R regression prediction model outperforms the other two machine learning algorithms, accurately predicting the distance at which the thermal radiation intensity is reached after a tank fire. Compared with the simulation results, the model demonstrates higher accuracy in predicting the distance of tank fire consequences, proving the effectiveness of machine learning algorithms in predicting the range of consequences of tank storage area fire events.

Spill fire is common in industry, with the characteristics of large burning area and difficult to extinguish. To study its mechanism more deeply, a series of experiments of ethanol spill fire were carried out on sand substrate. The flame spread distance was measured, and the heat feedback and burning rate were analyzed. The experimental results showed that 0.25 mm sand made the proportion of heat conduction feedback in the quasi-steady stage reach about 70% of all thermal heat feedback, and the steady burning rate also reached the maximum value. With the increase of sand size, the proportion of heat conduction feedback decreased, the heat convection feedback gradually dominated, and ultimately the steady burning rate decreased first and then increased. This showed that sand affected the heat transfer in the quasi-steady stage of spill fire by changing the heat transfer process and the proportion of three modes of heat transfer, thus changed the steady burning rate. Furthermore, the influence of sand on the spread of ethanol in terms of mass transfer was also analyzed. For the initial spread stage, the obstructive effect of sand on the fuel spread was quantified based on Darcy's law. It was found that the obstructive capacity of sand on fuel spread had a quadratic relationship with its specific surface area. [ABSTRACT FROM AUTHOR]

The consumption of alternative fuels accelerated in recent years because of the depletion of petroleum fuel sources, and, nowadays, the blended fuel demand is increasing worldwide. Blended fuel structure and burning characteristics are significantly different from pure fuels. The combustion behavior of pool fire of n-propanol, diesel, and their blends was experimentally studied under quiescent ambient air conditions. The fuels were burned in a circular pan of three sizes (D = 0.20, 0.10, and 0.05 m) to explore the burning properties. Blends of diesel with n-propanol were tested with an n-propanol concentration of 10 and 30 % by volume. The mass burning rate (MBR), fuel temperature, and total heat flux from flames were recorded. The combustion parameters of diesel, n-propanol, and blends with different pans were comparable. The propanol fraction enhances the burning rate of diesel, and soot formation is less visible in blended fuels. The average MBR recorded for pure propanol in 0.20 m pan diameter is 0.01548 kg/m2.s. The mean fuel temperature difference between thermocouples in diesel is 40 °C, and n-propanol is 20 °C, and for P10, the temperature difference is closer to the diesel. Thermal heat flux is estimated by using a low-cost thin-film heat flux sensor. The total heat flux profile of 0.20 m diameter P10 and P30 blends develops a V-shaped curve between the burning time range of 300 to 650 seconds and 400 to 750 seconds. These characteristics of pool fire combustion aid in the safe storage and handling of blended fuel. [ABSTRACT FROM AUTHOR]

The need for sustainable energy sources has recently promoted the use of liquefied natural gas (LNG) as a low-carbon fuel. Although economic evaluations indicate the transportation of LNG as a convenient solution for long distances between markets and reservoirs, several concerns are still present regarding its safe use and transportation. The preliminary evaluations performed in this work indicate that credible releases deriving from real bunkering operations result in pools having a diameter smaller than 1 m, which has been poorly investigated so far. Hence, an experimental campaign devoted to the characterization of a medium-scale release of LNG was carried out either in the presence or absence of an ignition source. An evaporation rate of 0.005 kg s−1 m−2 was collected for the non-reactive scenario, whereas the measured burning rate was 0.100 kg s−1 m−2. The reduction factor of 20 demonstrates the inaccuracy in the commonly adopted assumption of equality between these values for the LNG pool. Flame morphology was characterized quantitatively and qualitatively, showing a maximum ratio between flame height and flame diameter equal to 2.5 and temperatures up to 1100 K in the proximity of the flame. [ABSTRACT FROM AUTHOR]

In order to investigate the thermodynamic characteristics of UDMH pool fire, a series of numerical simulations of partial dimethyl hydrazine pool fire were carried out under the conditions of no wind and wind. The influence of oil pool size (1 ~ 9 m) on flame structure, axial and transverse temperature distribution and radiative heat flux were analyzed, and the dynamic characteristics of dimethyl hydrazine tank in windy condition varies with the ambient wind speed (1 ~ 4 m / s) were discussed. The results show that the flame height increases from 2. 67 m to 13. 22 m, the maximum temperature increases from 1 006. 23 ℃ to 1 160. 92 ℃, and the transverse radiant heat flux decreases with the increase of the distance. When the wind speed increases from 0 to 4 m / s in the windy environment, the flame height of the oil pool fire decreases, and the flame inclination angle gradually increases from 0° to 82. 3°. The axial temperature distribution decreases monotonically when the wind speed reaches 1. 5 m / s, and the temperature and radiant heat flux on the downwind side increase significantly due to the flame inclination. The engineering correlations that can accurately predict flame height, flame inclination and transverse radiant heat flux in no / windy environment are obtained by fitting, and the deviations are all within 15% . [ABSTRACT FROM AUTHOR]

Pool fires, commonly associated with industrial accidents, have posed a significant threat to the safety of industrial processes. This is particularly relevant in environments where storage tanks, engine cabinets, and boiler rooms are typically maintained. The effects of ambient temperature on the flame characteristics of gaseous pool fires were explored through a series of experiments conducted in a temperature-controlled chamber, with temperatures ranging from 40 ℃ to − 20 ℃. A modified flame height correlation accounting for the temperature effect was proposed. These findings have potential implications for enhancing the reliability of industrial design and fire risk assessment in environments with varying temperature conditions. [ABSTRACT FROM AUTHOR]

In this study, three types of rectangular pool fires with the same equivalent area were conducted in a simulated cargo compartment to investigate the effects of sidewall distance and ambient pressure on fire behavior. Three dimensionless distances ( λ = 0 , λ = 0.25 , and λ = 0.25 ) and three ambient pressures (50 kPa, 76 k Pa, 101 kPa) were used in the experiments. The results showed that the sidewall had a significant impact on the burning of n-heptane pool fires, with the flame height increasing as the sidewall distance decreased and lower ambient pressure intensifying this trend. The shape of the flame also directly affected the sidewall temperature, which showed a different trend in different test cases due to the combined effect of air entrainment limitation and radiation enhancement from the flame. In addition, models for calculating the burning rate and flame height were developed by modifying classical models using the dimensionless distance λ , entrainment coefficient EF , and equivalent diameter D eq . [ABSTRACT FROM AUTHOR]

This work studies lip height effects on the heat transfer and combustion characteristics of pool fire. Fire experiments of n -heptane and ethanol with pool diameters (D) of 0.1 m, 0.15 m and 0.2 m were carried out, in which the lip height (h) was increased from 0 until the burning could not be sustained. Results show that for both fuels, as the lip height increases, the flame enters the pool and the flame sheet becomes wrinkled and deformed. The n -heptane fire shows two distinct burning behaviors inside and outside the pool, and the burning rate decreases with the lip height due to heat feedback attenuation and air entrainment restriction. The conductive feedback rate remains almost unchanged with different lip heights for both fuels. For n -heptane, the radiative and convective heat feedback rates generally decrease with the lip height, and the convective heat feedback fraction increases as the flame enters into the pool, suggesting intensified turbulence motion. For ethanol, the radiative heat feedback rate decreases monotonically with the lip height, and the convective heat feedback rate increases slightly, followed by a decrease with h / D. A mass flux correlation based on the modified stagnant film theory is developed for the convection-dominated pool fires, which is in good agreement with the experimental data. [ABSTRACT FROM AUTHOR]

Engine fire hazards in vehicles are a threat to the personnel, inducing potential fatal injuries as well as damage to the vehicles themselves and their operational capabilities. Thus, it is important to assess the fire dynamics inside a non-confined engine compartment, here with an engine-cooling fan flow. A n -heptane pool fire was used to conduct a parametric study varying pan diameter, fuel depth and ventilation flow rate in a scale 1 compartment representative of the engine block of an APC (Armored Personnel Carrier). The results showed that an increase of the ventilation flow rate decreases the mean top temperature alongside the hood but increases the mean temperature in the wheel arches. The latter can be explained by the movement of hot gases to the sides of the compartment and was confirmed with a side to center temperature ratio. For the biggest ventilation flow rate, the temperature in the wheel arches of the compartment exceeds the temperature directly above the flame in the steady state of the fire. This temperature evolves linearly along the slope of the hood. A spectral analysis of the flame showed that the oscillation frequency is tied to the pan diameter from standard correlations but is insensitive to the fuel depth or ventilation flow rate investigated range. • The paper investigates the heat transfer inside a non-confined engine compartment with an engine cooling-fan blowing in. • An increase of the ventilation decreases the gas temperature on top of the fire and increases it in the wheel arches. • A ratio of temperatures between the wheel arches and at the top of the fire is developed to analyze the heat transfer. • Hot smoke is accumulating in the wheel arches, posing a risk of reflash, should fuel spilling occur in this region. • The flame frequency is independent of the fuel depth or ventilation flow rate increase in the considered ranges of values explored. [ABSTRACT FROM AUTHOR]

Pool fires cause immense damage to fuel storage tank farms. Reduced fire escalation risk in tank farms improves fire safety. Computational fluid dynamics (CFD) has proven effective in assessing escalation of fire-related domino effects and is being utilized for pool fire consequences in tank farms. The past CFD-based analysis focused on primary fire effects on secondary targets. This study used fire dynamics simulator (FDS) to model complete evolution of the domino effect under different wind speeds and primary pool fire locations. Dynamic escalation probability (DEP) and fire spread probability of the tank farm were calculated. Offset tank failure increased by 3% and 31%, while inline tank failure dropped by 36% and 90%, at 2 and 8 m/s, respectively. An artificial neural network (ANN) incorporating the Levenberg–Marquardt algorithm is used to predict fire spread probability based on numerical data set. The use of ANNs for this purpose is one of the first attempts in this regard. ANNs can reliably predict dynamic fire spread probability and could be utilized to manage fire-induced domino effects. Moreover, dynamic fire spread probability in tank farms obtained from ANN modelling can be used for safety applications, such as updating mitigation time when fire spread probability is unacceptable for a specific wind speed. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Water wall systems (WWSs) are increasingly being used as glass façades in modern green buildings owing to their enhancement in building energy efficiency. However, little is known about their performance when exposed to fire. In this study, 500 × 1000 mm2 sized water wall systems with 30 mm, 50 mm and 100 mm thick water columns were tested and compared to the thermal performance of a 500 × 1000 mm2 sized single skin glass façade system. These façade systems were heated by a 400 × 600 mm2 isopropanol pool fire. The distance from the pan centre to pane 1 of the façade was 350 mm. Time to first crack and surface temperatures were measured. The experimental results indicate that single skin glass façades are more vulnerable to cracking than water wall systems, but exposed glass pane fallout can easily occur in water wall systems compared to single skin façades. Since the overall performance is dependent on the failure of the fire unexposed glass pane, water wall systems are more fire resistant than single skin glass façades. The water layer thickness significantly affects the WWS thermal performance, where a 50 mm thick water layer would result in a longer time to first crack. The experimental findings of this study are useful for developing practical guidelines for fire-safe glass façade designs. [ABSTRACT FROM AUTHOR]

Aim: The aim of this article is to determine the characteristics of a pool fire, including the temperatures and thermal radiation densities caused by it. Mappings of pool fires occurring in actual emergency events were conducted by performing large-scale polygon tests. Project and methods: Experimental study of pool fire of technical ethanol was carried out on a specially built test stand in the training area of the Training Centre in Pionki of the Regional Headquarters of the State Fire Service in Warsaw. The pool fire test stand consisted of a test tray, with a test chamber with the diameter of 300 cm, founded on a reinforced concrete slab. Using a developed measurement system with data acquisition that included measurement sensors mounted at defined locations relative to the fire, temperatures and thermal radiation densities were measured at various distances/locations relative to the fire. Metrological data such as air temperature, atmospheric pressure, humidity, wind direction and speed were monitored and recorded using the weather station. The height of the fire flame was measured by comparing it to racks set up nearby with marked scales of specific lengths. Results: A polygon stand that was built to study pool fires, equipped with a temperature and thermal radiation density measuring system with measuring sensors distributed in defined locations, is discussed. A study of a pool fire resulting from the combustion of dehydrated, fully contaminated ethanol was conducted. The study measured emperatures, thermal radiation densities, and flame heights. The average and maximum values of temperatures and thermal radiation densities during the steady-state combustion stage (i.e., phase II of the fire) were determined. Conclusions: Based on the presented results of temperature and thermal radiation density measurements at various distances/locations relative to the pool fire site, there was a significant effect of wind direction and speed on these values. Higher temperature and heat radiation density were recorded at the sensors on the leeward side than on the windward side. As the wind speed decreased, there was an increase in the temperature values recorded on the thermocouples located above the centre of the bottom of the tray test chamber due to the flame, which, when not blown away, was allowed to rise vertically upward and fully sweep the temperature sensors.

In the pool fire environment, it is very easy to cause failure fracture and explosion accidents in the common vertical vault tanks under the combined action of flame thermal radiation and convection, which poses a huge threat to the safety of rescuers and oil storage tanks nearby. Based on the failure mechanism of oil storage tank under the pool fire, a 5 000 m3 vertical vault oil tank with frangible roof structure was studied with ANSYS and LS-DYNA softwares in combination. Specifically, the dynamic failure process under pool fire was numerically simulated. As shown in the results, the internal pressure of tank increases under the pool fire, and the fracture failure arises firstly at the frangible roof structure of the tank, with the maximum stress reaching 294.2 MPa. In addition, the maximum temperature is distributed in the gas zone, up to 348.7℃. In order to verify the feasibility of numerical simulation analysis on dynamic tank failure, a tensile test on weak connection was designed, which provides a theoretical basis for safety rescue under the pool fire. Generally, the research results, with safety warning provided for firefighting and disaster relief of tank, are significant to guide the disaster relief, reduce the loss of life and property, and guarantee the safety of national oil reserve bases.

Mechanical ventilation is essential to ensure the safety of persons, equipment, and structures in cruise ship fire incidents. The mass loss rate, smoke temperature, and comprehensive heat transfer coefficient during large-scale fire experiments are researched in cruise ship flat space. The results indicate that the mass loss rate of four pool fires with different sizes presents different rules in mechanical ventilation conditions compared with open conditions. In addition, the vertical distribution of temperature appears to be stratification, which aligns with the "dual-zone model". The horizontal distribution of the temperature has a "mutation point". With the mutation point as the boundary, the temperature drops rapidly from the fire source to the mutation point and decreases more slowly. Furthermore, the distribution model of comprehensive heat transfer coefficient and average temperature are established. The comprehensive heat transfer coefficient is in direct proportion to the 1.00 power of heat release rate and inversely in proportion to the 0.69 power of the number of mechanical ventilation. However, the average temperature is in direct proportion to the 0.52 power of heat release rate and inversely in proportion to the 1.40 power of the number of mechanical ventilation. [ABSTRACT FROM AUTHOR]

In the Republic of Korea, a new rocket launchpad was constructed to launch the KSLV-II on an island, and all the launchpad facilities are located in basement. Because of the complex and diverse facilities, fire accidents have increased. Using the FDS (Fire Dynamics Simulator) to predict the damage from kerosene storage and drain tank pool fires is garnering more attention as a tool of choice. The FDS supports a sprinkler model, which is needed to analyze fire extinguishing by water sprinkling. To predict and estimate the resistance of the building and thermal damage, the main analysis factors for a kerosene tank pool fire accident are temperature and HRR (heat release rate per unit volume). In 3 m3 release cases, the maximum temperature decreased by 33% from 900 K to 600 K by sprinkled water, and the maximum HRR decreased by 70% from 20,000 kW/m3 to 6000 kW/m3. In 10 m3 release cases, the temperature and HRR decreased by 44%, from 800 K to 450 K and 68% from 25,000 kW/m3 to 8000 kW/m3, respectively.

The risk posed by spill and subsequent fire during road transportation of flammable liquid is considered in the paper. Attention is paid to a pool fire than can occur in roadside terrain. Circumstances and road situations increasing the likelihood of a spill and fire accident are analysed. The problem under study is an assessment of thermal radiation induced by a roadside pool fire. This study applied a pool fire model known as a trench fire to a roadside situation. The trench fire is considered to be a likely type of a pool fire due to presence of roadside ditches and other oblong low areas along the road. The estimation of the thermal radiation from trench fires is carried out in the deterministic way due to actual lack of systematic uncertainty modelling related to pool fires. Deterministic models developed for estimating the radiation of pool and trench fires are presented and illustrated by a transportation case study. The case study reveals that the thermal radiation emitted by a trench fire can endanger objects positioned in the intermediate vicinity to the road. Further spread of fire into more distant locations is possible only through the domino effect. Incorporation of the thermal radiation models into a transportation risk assessment is discussed in brief. Findings of this study are viewed as knowledge that can be used for refining the estimation of risk posed by transportation of hazardous materials.

With the enlargement and intensification of oil storages, the technologies and equipment used in the tank farm are quite complicated. Hence, once any fire accident occurs, the domino effect may be triggered with catastrophic consequences. In order to reduce the impact of oil storage accidents on the surrounding personnel and environment, the model of safety barrier was established with the event tree and Bayesian network method by considering the performance of three types of safety barrier, including the active, passive, emergency and response measures, and the probability of the domino effect was evaluated quantitatively. The results show that: the multi-layer safety barriers can reduce the probability of domino effect by 3 to 7 orders of magnitude and the probability of the multi-level domino effect to a greater extent. Besides, the passive protection barrier is the most effective, followed by the emergency and response measures, and the active barrier is the least effective. Generally, the research results can provide some guidance for reducing the damage and impact of regional accidents in the areas where multiple devices are concentrated.

Liquefied natural gas (LNG) is widely used, because it provides an easy and economic solution to the transport and storage of natural gas (NG), especially on long distances or when transport by pipeline is not viable. The LNG pool fire is one major process safety accident at the LNG facilities according to the report of the U.S. Government Accountability Office. Moreover, due to the high surface emissive power of LNG compared to other hydrocarbon fuels, LNG pool fires have a high potential in causing domino effects and cascading events in process industry. Previous studies developed Computational Fluid Dynamics (CFD) models of LNG pool fires, but the mass burning rate was fixed manually as a model input, not considering that the mass burning rate is determined by the fuel's physical properties and heat input vaporizing the fuel. In this study, a model of LNG pool fire controlled by material physical properties was developed using fire dynamics simulator (FDS), and was validated against LNG pool fire experiments carried out by Mary Kay O'Connor Process Safety Center (MKOPSC). Statistical performance measurement shows that the model is superior to the semi-empirical approaches in predicting the mass burning rate of LNG pool fire under different pool sizes. A flame geometry analysis software was developed comparing different algorithms, and the centroid method was selected. The results show that the fire model (200 kW/m3 as flame contour) can accurately predict the flame geometry observed in the experimental runs. The influence of wind velocity and dike height on the mass burning rate was also investigated. The results show that the height of the concrete dike is negatively correlated with the mass burning rate of LNG pool fire. The effect of wind velocity on LNG mass burning rate is twofold. The forced convective boundary layer at lower wind velocity promotes LNG combustion and increases the mass burning rate, while higher wind velocities reduce the mass burning rate due to the reduction of the thermal radiation feedback. The findings in this study will contribute to an accurate risk assessment of LNG pool fire accidents in the process industry. [ABSTRACT FROM AUTHOR]

In this study, a fuzzy Bayesian network (FBN) approach was proposed to analyze the domino effects of pool fire. Failure probabilities were calculated using triangular fuzzy numbers, the combined center of area (CoA)/sum-product method and the BN approach. Consequence modeling, probit equations and leaky–noisy-OR (L-NOR) gates were used to analyze the domino effects, and modify conditional probability tables (CPTs). Methanol storage tanks were selected to confirm the practical feasibility of the suggested method. The domino probability using bow-tie analysis (BTA) and FBN in the first and second levels was compared, and the ratio of variation was used for sensitivity analysis. Probability of the domino effect in the first and second levels (FBN) was 0.0071472631 and 0.0090630640, respectively. The results confirm this method is a suitable tool for analyzing the domino effects and that using FBN and L-NOR gate is a good way to assess the reliability of tanks. [ABSTRACT FROM AUTHOR]

Tank farms are commonly used for storing large quantities of liquid fuels. The design, construction, operation, and maintenance of a tank farm must be in accordance with standards/codes applicable to specific countries. Existing codes on the design of storage tank farms are largely based on tests performed at standard atmospheric pressure and associated thermal hazard analysis. Studies based on small-scale experiments, however, have shown that the burning behavior and associated radiation impact of liquid fuels could be substantially affected by the reduced pressure at high altitude. In this study, large-scale n-heptane pool fire experiments with different pool diameters were carried out at sub-atmospheric pressure to firstly investigate their burning characteristics. Subsequently, specific fire scenarios for the cases under both standard and sub-atmospheric conditions were selected for assessing and comparing their thermal hazards. The experimental results showed that the burning rate at sub-atmospheric pressure is reduced, whereas the flame height is increased. Correlations for both the burning rate and flame height including the pressure effect were proposed and validated against the experiment data in this and existing studies obtained at different pressure conditions. The flame radiative fraction was found to decrease exponentially with the pool diameter. The thermal hazard analysis showed that whilst the thermal hazard at sub-atmospheric pressure is lower than that at standard atmospheric pressure, this difference gradually reduces with increasing tank diameter. The present results not only are important in understanding the effects of pressure on the burning characteristics of large-scale pool fires but provide guidance on the applicability and limitations in the use of design codes developed for standard atmospheric pressure for plateau regions. [ABSTRACT FROM AUTHOR]

There is a large proportion of pool fire occurrence on the upper part of offshore platforms. In order to reduce the occurrence of fire disasters, the fire risk assessment of FPSOs should be carried out. According to the temperature characteristics of offshore platform fires based on computational fluid dynamics, the temperature field of the superstructure of the offshore platform under pool fire has been analyzed, the regularities of the distribution of the wall temperature of the platform of FPSO under different wind speeds are studied, and research on the distribution of heat radiation flux of different fire is made. Based on the finite element method, the structural response of the platform structure in different fire scenarios has been made. In consideration of the pool fires caused by liquid leakage of the upper part of the platform structure, with the basis of the changes of temperature field and radiation field being obtained by CFD, a structural response analysis of the offshore platform structure using the finite element method and a risk assessment method based on quantitative analysis for pool fires caused by liquid leakage is proposed. [ABSTRACT FROM AUTHOR]

Copyright of Fire Safety Science is the property of Fire Safety Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of High Pressure Physics is the property of Chinese Journal of High Pressure Physics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study presents a heat transfer model for prediction of the effect of immersed objects with high thermal conductivity (refluxer) on the mass burning characteristics of a pool fire. The refluxer forms a second thermal loop between the flame and the fuel pool, enhancing the heat feedback to the fuel. Consequently, additional fuel vaporization occurs thus improving the burning characteristics. In the study, a theoretical model solves the steady state energy equation to analyze the effectiveness of the refluxer by determining the heat transfer to the fuel pool based on input parameters (refluxer material, dimensions, and fuel properties). A non-dimensional model solution as a function of the input parameters, in the form of polynomial fits, for prediction of refluxer output is also reported in the paper. The model solution also envisions an optimal design based on prescribed end-use of the refluxer. [ABSTRACT FROM AUTHOR]