scholarly journals Influence of fiberglass mesh on flammability of EPS used as insulation of buildings

2018 ◽  
Vol 22 (2) ◽  
pp. 1025-1036
Author(s):  
Qiang Xu ◽  
Cong Jin ◽  
Gregory Griffin ◽  
Jordan Hristov ◽  
Dejan Cvetinovic ◽  
...  
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Behavior ◽  
Fire Spread ◽  
Expanded Polystyrene ◽  
Heat Fluxes ◽  
Release Capacity ◽  
Heat Release Capacity ◽  
Combustion Calorimeter

Different scale tests to explore the influence of fiberglass mesh on the fire behavior of expanded polystyrene (EPS) have been conducted. Micro scale combustion calorimeter to measure the heat release rate per unit mass, heat release capacity, and the total heat release of EPS and as well as the fiberglass for milligram specimen mass has been used. Cone colorimeter bench scale burning tests with the EPS specimens and EPS-fiberglass compound specimens have been carried out. The heat release rate per unit area, ignition times, and the derived minimum igniting heat fluxes were determined. Comparative burning tests on the fire spread tendency of EPS and EPS-fiberglass compound specimens have been carried out. It was established that the fiberglass mesh stabilizes the EPS fire as a wick fire due to the adherence of the melting polystyrene adheres to the fiberglass mesh and this causes an upwards fire spread.

scholarly journals A Study on the Heat Release Characteristics of Fire Load for Performance Based Design of Multiplexes: A Focus on the Heat Release Rate and Fire Spread Rate of Cinema Seats

2020 ◽  
Vol 34 (1) ◽  
pp. 11-17
Author(s):  
Dong-Gun Nam ◽  
Hyo-Yeon Jang ◽  
Cheol-Hong Hwang ◽  
Ohk-Kun Lim
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Behavior ◽  
Fire Spread ◽  
Performance Based Design ◽  
Unit Mass ◽  
Spread Rate ◽  
Fire Hazards ◽  
Evacuation Safety

As performance-based design (PBD) has a direct impact on evacuation safety assessments, designing fire scenarios based on real fire tests is essential. To improve the reliability of the PBD for fire safety in multiplexes, information on fire behavior, such as heat release rate (HRR) and fire spread rate, are provided in this study by conducting a standard fabric flammability test. To this end, several chairs were arranged in a pattern that resembled a theater-style seating. The peak HRR and heating value per unit mass for each chair ranged from 415 kW to 988 kW and 15.2 MJ/kg to 23.8 MJ/kg, respectively. The heating values per unit mass of the new and old chairs were 23.6 MJ/kg and 16.7 MJ/kg, respectively. As the quantity of plastic and cushioning materials in the new chairs was more than that of the old ones, the new chairs were more vulnerable to fire hazards. Furthermore, when the chairs were arranged in a line, the fire spread rate was observed to be 0.39–0.42 m/min, regardless of the ignition location. Finally, a fire growth curve showing the peak HRR and fire spread rate was also demonstrated.

scholarly journals Experimental Study on Occurrence Limit Heat Release Rate of Flashover in a Building Fire

2021 ◽  
Vol 21 (2) ◽  
pp. 65-71
Author(s):  
Seunggoo Kang ◽  
Yi Chul Shin
Keyword(s):  
Experimental Study ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Large Scale ◽  
Fire Behavior ◽  
Design Calculation ◽  
Building Fire ◽  
Fire Source ◽  
Combustion Tests

In this study, to allow the flashover to occur, combustion tests were conducted by setting the conditions of a fire source using a large-scale compartment and changing the opening condition. As a result, the inside temperature of the compartment was measured under the fire source conditions. Moreover, according to the “Handbook on Design Calculation &#x0004d;ethods of Fire Behavior” by the Architectural Institute of Japan, the validity of the heat release rate required for the flashover to occur was verified through the correlation between <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>Q</mi><mrow><mi>F</mi><mi>O</mi></mrow></msub><mo>/</mo><msub><mi>Q</mi><mrow><mi>v</mi><mi>m</mi><mi>a</mi><mi>x</mi></mrow></msub></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><msub><mi>A</mi><mi>T</mi></msub><msup><mrow><mo>(</mo><mi>k</mi><mi>p</mi><mi>c</mi><mo>)</mo></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup><mo>/</mo><msub><mi>c</mi><mrow><mi>P</mi></mrow></msub><mn>0</mn><mo>.</mo><mn>5</mn><mi>A</mi><msup><mi>H</mi><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></math>.

Numerical and Experimental Study of Merging Fires in Square Arrays

2007 ◽  
Author(s):  
Kohyu Satoh ◽  
Liu Naian ◽  
Liu Qiong ◽  
K. T. Yang
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Forest Fires ◽  
Large Scale ◽  
Gas Flow ◽  
Fire Spread ◽  
Total Heat ◽  
Total Heat Release ◽  
Convective Gas Flow

In large-scale forest fires and city fires, merging fires and fire whirls have often been observed, which cause substantial casualties and property damages. It is important to know particularly where and under what conditions of weather such merging fires and fire whirls appear in cities or forests. However, there have been no adequate answers, since the detailed physical characteristics about them are not fully clarified yet, although previous studies have examined the phenomena of merging flames. Therefore, we have carried out preliminary studies and found that the merged tall fires can enhance the fire spread, and developed a method to analyze burn-out data of fire arrays. If sufficient knowledge can be obtained by relevant experiments and numerical computations, it may be possible to mitigate the damages due to merged fires and fire whirls. The objective of this study is to investigate the merging conditions of fires in square arrays in laboratory experiments and also by CFD numerical simulations, varying the size of square array, inter-fire distance and heat release rate, to judge ‘unmerged’ or ‘merged’ conditions in the fire array. It has been found that the fire merging is dependent on the inter-fire distance in the array and also on the total heat release rate of all fires surrounding the center region of the array. Also found that the experimental and simulated results on the merged and unmerged cases in the fire array, as affected by the total heat release rate and the inter-fire distance, which control the convective gas flow into the array, behave very similarly. Therefore, it can be concluded that the fire merging in array fires are highly based on the convection in the flow field due to fires and can be predicted by simple CFD simulations.

Bench-scale experimental study on the fire behavior of electric cable arrays by considering different layouts

2021 ◽  
pp. 073490412110432
Author(s):  
Zhou Cai ◽  
Xiao Chen ◽  
Jiaqing Zhang ◽  
Shouxiang Lu
Keyword(s):  
Heat Flux ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Behavior ◽  
Radiant Heat ◽  
Radiant Heat Flux ◽  
Total Heat Release ◽  
Electric Cable ◽  
Peak Heat Release Rate

The effect of different cable layouts on the fire behavior of electric cable arrays was experimentally studied. The influence of external heat flux on cable fire characteristics was investigated. Several parameters for electrical cables such as the post-burning morphology, ignition time, heat release rate, peak heat release rate and total heat release were obtained. The results show that cable layouts could affect cable charring degrees according to the post-burning morphology. A linear relationship was found in the transformed form of time to ignition and radiant heat flux, and the critical radiant heat flux value for the single cable array appeared smaller than that for the other two layouts. The peak heat release rate for Cables A–D with the single array presents the increasing trend with an increase in radiant heat flux, while the two parallel and intersectional cable arrays present the different trends. Moreover, the total heat release values of Cables A–D in the different cable layouts were analyzed. This work provides the basic data and preliminary investigation to fire engineering of cable arrays with the different layouts.

Influence of grammage on heat release rate of polypropylene fabrics

2017 ◽  
Vol 36 (1) ◽  
pp. 30-46 ◽  
Author(s):  
Nicolas Hernandez ◽  
Rodolphe Sonnier ◽  
Stéphane Giraud
Keyword(s):  
Heat Flux ◽  
Growth Rate ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Heat Fluxes ◽  
Fire Growth ◽  
Time To Ignition ◽  
Moderate Change

The flammability of nine polypropylene fabrics or sheets has been tested using cone calorimeter at various heat fluxes (25, 35, 50, and 75 kW/m2) in order to assess the relevance of this fire test for thermally thin materials. The chosen procedure uses a grid and allows maintaining a constant exposed surface during the test, except for the lightest fabric. The structure of the knitted fabrics has a relatively small influence on the main flammability parameters. On the contrary, the area density of the sample (from 218 to 5729 g/m2) impacts strongly the time to ignition, the peak of heat release rate, and the increase in heat release rate after ignition (fire growth rate). At a fixed heat flux, thicker is the sample, higher are the time to ignition and the peak of heat release rate and lower is the fire growth rate. Moreover, thick samples exhibit the highest sensitivity of peak of heat release rate and the lowest sensitivity of fire growth rate to heat flux. This study emphasizes the fact that a moderate change in weight may have a significant influence on cone calorimeter results, without any significance on real flammability.

scholarly journals HEAT RELEASE RATE AS A PARAMETER FOR FIRE SPREAD – A CASE STUDY

2020 ◽  
pp. 101
Author(s):  
Darko N. Zigar ◽  
Dusica J. Pesic ◽  
Milan Đ. Blagojevic
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Simulation Method ◽  
Fire Spread ◽  
Fire Dynamics ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Fire Spreading

Indoor fires very often may cause great material damage and endanger human lives. The heat produced by fire affects the heating and ignition of surrounding flammable materials, as well as the heating of the building structure, causing its damage. It is well known that fire spread mostly depends on flammability and quantity of surrounding material, but small differences in the amount of fuel can significantly affect the speed of fire spread, and consequently, rate of heat released by fire. In this paper, the influence of the heat release rate on fire spreading is shown. The Large Eddy Simulation method of Fire Dynamics Simulator software package has been used to investigate the prediction of fire dynamics in a compartment. Numerical results show that the fire dynamics in the compartment is largely dependent on the quantity of fire load mass and the heat release rate during the fire.

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