Theoretical and numerical study on influence of wind on mass loss rates of heptane pool fires at different scales

Yao, Yongzheng; Li, Ying Zhen; Ingason, Haukur; Zhang, Heping

doi:10.1016/j.firesaf.2020.103048

Cited by 22 publications

(4 citation statements)

References 17 publications

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“…Such computational procedures are aimed at detecting physical phenomena that occur when extinguishing fires and are not aimed at creating samples of automatic fire extinguishing systems. This is confirmed by the example given in [17], which presents studies of the effect of wind on the coefficient of mass loss per unit area (MLRPUA) during a heptane fire. For different scales of heptane fires, simulations were carried out using FDS in a wide range of Froude numbers -from 0 to 2.5.…”

Section: Literature Review and Problem Statementsupporting

confidence: 54%

Determining the dynamic characteristics of a class B fire in the case of extinguishing by water spray

Kolomiiets,

Abramov,

Basmanov

et al. 2023

EEJET

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The object of this study is a class B fire, which is extinguished with sprayed water. The subject of the study is the characteristics of class B fires when they are extinguished with sprayed water. Diffusion burning of a flammable liquid is considered as such a fire, and its extinguishing is carried out by cooling the flame. Heat and oxygen balance equations are used to build a mathematical model describing the fire extinguishing process. The components of the heat balance equation are the power of heat during heat release due to the chemical reaction of liquid combustion and the power of heat dissipated to the environment. The second component takes into account heat removal due to radiation, convection, and evaporation. The component of removed heat due to evaporation takes into account the Sreznevsky constant. The mathematical model that describes the process of extinguishing a class B fire is built in the class of models belonging to differential equations with constant coefficients. Analytical expressions were obtained for these static and dynamic coefficients, which include thermophysical, kinematic, and geometric parameters of the flame and fire extinguishing agent. To determine these characteristics, the constructed mathematical fire model was transformed using the integral Laplace transform. The dynamic characteristics of the fire were obtained in the time domain – the transient function of the fire, and in the frequency domain – the amplitude-frequency and phase-frequency characteristics of the fire. It is shown that the parameters of these dynamic characteristics should be determined experimentally. Experimental methods for determining parameters of dynamic fire characteristics have been devised. The presence of dynamic characteristics of class B fire makes it possible to spread the proven methods of the theory of control systems to design effective fire extinguishing systems

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Section: Literature Review and Problem Statementsupporting

confidence: 54%

Determining the dynamic characteristics of a class B fire in the case of extinguishing by water spray

Kolomiiets,

Abramov,

Basmanov

et al. 2023

EEJET

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“…The atomization effect of high-pressure water mist is more obvious, which can make the water mist fill the entire fire extinguishing space. This makes the impact of water mist on the fire source more effective and has a stronger ability to reduce heat radiation [26]. To sum up, the hot water mist has the best fire extinguishing effect and the fastest fire extinguishing time under the pressure of 9 MPa, which improves safety.…”

Section: Analysis Of the Changes In The Flame Temperaturementioning

confidence: 99%

Influence of Water Mist Temperature Approach on Fire Extinguishing Effect of Different Pool Fires

et al. 2022

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The aim of this paper was to study the suppression influence of water mist on oil pool fires, taking diesel fires and n-heptane fires as experimental objects. The effects of spray pressure and temperature on water mist suppression were examined, and an experimental platform for the suppression of water mist in a small space was set up. Their fire prevention performance and fire extinguishing mechanisms were analyzed by comparing the flame temperature and extinguishing time of diesel and n-heptane pool fire. Three types of spray pressure were set. Water mist was designed at different temperatures and design experiments were carried out for this purpose. The change process of smoke concentration, thermocouple temperature, and flame combustion under different working conditions were analyzed, and the factors affecting the fire extinguishing effect of water mist on oil pool fire were discussed. The results show that 20 °C water mist is more effective at medium and high pressure than at low pressure. Moreover, 80 °C water mist at 9 MPa is more effective in extinguishing n-heptane fire. The flame extinction time is about 10 s, which is more than 40 s higher than that of cold water.

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“…Wang et al (2018) suggest that in a sealed compartment, the average combustion efficiency of heptane during the whole combustion process is about 0.75. For a fuel-controlled heptane pool fire, the combustion efficiency is a constant at about 0.92, according to the work in Yao et al (2021). In this study, x = 0.75 is used for tests with fire self-extinction (Test 1-1, 1-2 and 1-11).…”

Section: Heat Release Ratementioning

confidence: 99%

Effect of opening geometries on fire development in a ro-ro space

Lei

Olofsson

Ingason

et al. 2022

Ships and Offshore Structures

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A series of model scale experiments were conducted to study the fire development in a ro-ro deck with various opening geometries. The experiments were performed in a 1/8 reduced scale model with a heptane pool fire as fire source. Experimental results show that both the ventilation factor and the opening position affect the fire development. The critical opening ratio for the fire to self-extinguish is 4%, with the opening locating at the bottom of the side walls while no self-extinction is found for other tests. A higher opening position and a larger opening height provide better flow exchange between the deck and the ambient, but this effect is only obvious for 4% opening. Numerical study shows that Fire Dynamic Simulator used with default simple settings underestimates the fire development and yields an early extinction when fire self-extinction occurs. For freely developed fire with large openings, FDS gives more close results to experiments.

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Theoretical and numerical study on influence of wind on mass loss rates of heptane pool fires at different scales

Cited by 22 publications

References 17 publications

Determining the dynamic characteristics of a class B fire in the case of extinguishing by water spray

Determining the dynamic characteristics of a class B fire in the case of extinguishing by water spray

Influence of Water Mist Temperature Approach on Fire Extinguishing Effect of Different Pool Fires

Effect of opening geometries on fire development in a ro-ro space

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