scholarly journals Fire Risk of Halogen-Free Electrical Cable

2018 ◽  
Vol 26 (42) ◽  
pp. 21-27
Author(s):  
Jozef Martinka ◽  
Peter Rantuch ◽  
Igor Wachter ◽  
Karol Balog
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Risk ◽  
Heat Of Combustion ◽  
Total Heat Release ◽  
Electrical Cable ◽  
Effective Heat ◽  
Effective Heat Of Combustion ◽  
Halogen Free

Abstract This paper deals with the fire risk of a selected halogen-free electrical cable. The research was objected to a three-core power electric cable for a fixed installation CHKE J3x1.5 (cross section of each copper core was 1.5 mm2) with a declared class of reaction to fire B2ca, s1, d1, a1. The electrical cable was manufactured and supplied by VUKI, a. s., Slovakia. The fire risk of the electric cable was evaluated based on the heat release rate, total heat release, smoke release rate, total smoke release and effective heat of combustion. These parameters were measured using a cone calorimeter at 50 kW m−2 (specimens and cone emitter were placed horizontally during the test). The measured electrical cable showed a maximum heat release rate of nearly 150 kW m−2, a maximum average heat emission rate of almost 100 kW m−2, a total heat release of almost 130 MJ m−2, a maximum smoke release rate of almost 2.5 s−1, a total smoke release of more than 800 m2 m−2, an effective heat of combustion (cable as a whole) of nearly 9 MJ kg−1 and an effective heat of emission (polymeric parts of the cable) of 26.5 MJ kg−1.

scholarly journals Fire Behavior of Thermally Thin Materials in Cone Calorimeter

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1297
Author(s):  
Marouane El El Gazi ◽  
Rodolphe Sonnier ◽  
Stéphane Giraud ◽  
Marcos Batistella ◽  
Shantanu Basak ◽  
...  
Keyword(s):  
Heat Flux ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Fire Hazard ◽  
Heat Of Combustion ◽  
Sample Weight ◽  
Effective Heat ◽  
Effective Heat Of Combustion

In this study, a representative set of thermally thin materials including various lignocellulosic and synthetic fabrics, dense wood, and polypropylene sheets were tested using a cone calorimeter at different heat fluxes. Time-to-ignition, critical heat flux, and peak of heat release rate (pHRR) were the main parameters considered. It appears that the flammability is firstly monitored by the sample weight. Especially, while the burning rate of thermally-thin materials does never reach a steady state in cone calorimeter, their pHRR appears to be mainly driven by the fire load (i.e., the product of sample weight and effective heat of combustion) with no or negligible influence of textile structure. A simple phenomenological model was proposed to calculate the pHRR taking into account only three parameters, namely heat flux, sample weight, and effective heat of combustion. The model allows predicting easily the peak of heat release rate, which is often considered as the main single property informing about the fire hazard. It also allows drawing some conclusions about the flame retardant strategies to reduce the pHRR.

Heat Release Rate and Effective Heat of Combustion Measurements: A Comparative Study of Thermal and Oxygen Consumption Techniques

1995 ◽  
Vol 13 (6) ◽  
pp. 482-499 ◽  
Author(s):  
Fatima Moussan ◽  
Jean-Louis Delfau ◽  
Christian Vovelle ◽  
Christian Pham Van Cang ◽  
Gérard Bosseboeuf
Keyword(s):  
Oxygen Consumption ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Radiant Heat ◽  
Heat Of Combustion ◽  
Second Step ◽  
Thermal Method ◽  
Effective Heat ◽  
Effective Heat Of Combustion

A new calorimeter especially built for the measurement of the heat release rate and effective heat of combustion of composite materials is pre sented. Two procedures can be used to obtain these data: the first one is based on the direct measurement of the convective and radiant heat liberated by the flame, the second involves oxygen consumption measurement. Preliminary ex periments were carried out with a gas burner to calibrate and check the inertia of the thermal method. In a second step, measurements were performed on PMMA and PVC samples. The results obtained with both methods are very similar and in agreement with literature values.

Calculations of the Heat Release Rate by Oxygen Consumption for Various Applications

1984 ◽  
Vol 2 (5) ◽  
pp. 380-395 ◽  
Author(s):  
W.J. Parker
Keyword(s):  
Oxygen Consumption ◽  
High Temperature ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Tests ◽  
Total Heat Release ◽  
Exhaust Duct ◽  
Closed Systems ◽  
Gas Burner

The calculation of heat release rate by oxygen consumption is based on the assumption that all materials release approximately the same amount of heat per unit mass of oxygen consumed. This technique is now being employed to determine the heat release rate of materials in various heat release rate cal orimeters. Other uses include the heat release rate of assemblies in the fire en durance furnaces and the total heat release rate in room fire tests. These dif ferent applications lead to different experimental procedures which require dif ferent formulas. The experimental choices or constraints include open or closed systems, paramagnetic or high temperature oxygen analyzers, CO2 analyzers or CO2 traps, and the use of a gas burner whose heat release rate must be deducted from the total. Various assumptions about CO levels in the exhaust duct and vitiation and humidity in the incoming air are made. General formulas for the heat release rate by oxygen consumption are developed in this paper from which the formulas for specific applications can easily be derived.

scholarly journals The effect of intumescent mat on post-fire performance of carbon fibre reinforced composites

2019 ◽  
Vol 37 (3) ◽  
pp. 257-272 ◽  
Author(s):  
Chenkai Zhu ◽  
Jingjing Li ◽  
Mandy Clement ◽  
Xiaosu Yi ◽  
Chris Rudd ◽  
...  
Keyword(s):  
Carbon Fibre ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Reinforced Composites ◽  
Fire Performance ◽  
Total Heat Release ◽  
Reinforced Composite ◽  
Peak Heat Release Rate ◽  
Fibre Reinforced Composites

This study investigated the effect of intumescent mats (M1 and M2) with different compositions on the post-fire performance of carbon fibre reinforced composites. The sandwich structure was designed for composites where M1 (carbon fibre reinforced composite-M1) or M2 (carbon fibre reinforced composite-M2) mats were covered on the composite surface. A significant reduction in the peak heat release rate and total heat release was observed from the cone calorimetric data, and carbon fibre reinforced composite-M1 showed the lowest value of 148 kW/m2 and 29 MJ/m2 for peak heat release rate and total heat release, respectively. In addition, a minor influence on mechanical properties was observed due to the variation of composite thickness and resin volume in the composite. The post-fire properties of composite were characterised, and the M1 mat presented better retention of flexural strength and modulus. The feasibility of two-layer model was confirmed to predict the post-fire performance of composites and reduce the reliance on the large amounts of empirical data.

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.

Study the Characteristics in the Growth Phase of Wood Crib Fires

2009 ◽  
Author(s):  
Qiang Xu ◽  
G. J. Griffin ◽  
XuHong Miao ◽  
ZhenYu Xu ◽  
Y. Jiang
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Growth Phase ◽  
Mass Loss Rate ◽  
Heat Of Combustion ◽  
Medium Size ◽  
Wood Crib ◽  
Rate Of Heat Release ◽  
The Relationship

Tests were conducted with ISO 9705 room to investigate the combustion behavior of medium size wood cribs. Cribs were burnt at the center and corner inside ISO room and also under the hood of the ISO room. Effective heat of combustion and increase rate of heat release rate in growth phase is compared for cribs with different nominal heat release rate and in different positions. The relationship between scaled steady mass loss rate and porosity factor of wood crib is quite different from those in literatures. The average effect heat of combustion is 12.18 MJ kg−1, which is close to commonly accepted value 12 MJ kg−1 for wood sample burning with diffusion flame.

scholarly journals Flammability Characteristics of Green Roofs

Buildings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 126
Author(s):  
Nataliia Gerzhova ◽  
Pierre Blanchet ◽  
Christian Dagenais ◽  
Sylvain Ménard ◽  
Jean Côté
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Green Roof ◽  
Fire Risk ◽  
Green Roofs ◽  
Fuel Load ◽  
Growing Media ◽  
Maximum Heat ◽  
Flammability Characteristics

Assessing the fire risk of vegetated roofs includes the determination of their possible contribution to fire. Green roof components such as plants and growing media are organic materials and present a fuel that can catch and support the spread of fire. The flammability characteristics of these components were analyzed and compared to a typical roof covering. Growing media with 15% of organic matter were tested using cone calorimeter apparatus. The fuel load and heat release rate of the growing media were measured in both moist (30%) and dry conditions. It was observed that growing media in a moist condition do not present a fire risk, reaching a maximum heat release rate of 33 kW/m2. For dry substrates, a peak heat release rate of 95 kW/m2 was recorded in the first minute, which then rapidly decreased to 29 kW/m2 in the second minute. Compared to a typical bitumen roof membrane, the green roof showed a better fire performance. The literature data report more severe results for plant behavior, reaching peak heat release rates (HRRs) of 397 kW/m2 for dried and 176 kW/m2 for a green material. However, a rapid decrease in HRR to much lower values occurs in less than 2 min. The results also show that extensive and intensive types of green roofs present 22% and 95% of the additional fire load density when installed on a modified bitumen membrane, 19.7 and 85.8 MJ/m2, respectively.

scholarly journals Analysis of Combustion and Smoke Characteristics According to the Aging of Class 1E Cables in Nuclear Power Plants

2021 ◽  
Vol 35 (1) ◽  
pp. 20-27
Author(s):  
Seok-Hui Lee ◽  
Min-Ho Kim ◽  
Sangkyu Lee ◽  
Ju-Eun Lee ◽  
Min-Chul Lee
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Total Heat ◽  
Total Heat Release ◽  
Char Layer ◽  
Cone Calorimeter Test

In this study, combustion and smoke characteristics according to the aging of class 1E cables in nuclear power plants were analyzed through a cone calorimeter test. In the case of combustion characteristics, during the early period, which was the first peak of the heat release rate, the peak value of the non-aged cable was higher by approximately 20-50 kW/m<sup>2</sup> than that of aged cables. However, in the mid-late periods, which was the second peak, the value of the aged cables were higher than the non-aged cable due to the decrease in flame retardant performance with aging deterioration. In addition, the duration of the char layer of the aged cables was shortened by 200 s than that of the non-aged cables due to the unstable formation of char layer. The total heat release measured was approximately 1.4 times higher in the aged cables than in the non-aged cables. In the case of smoke characteristics, the smoke production rate and total smoke release show a similar trend with the heat release rate and total heat release. The total smoke release of the aged cables was measured to be higher than that of the non-aged cables. The tendency of the smoke factor increased with aging deterioration, and the values of the smoke factor in the aged cables beyond 4 years were approximately 1.76-2.0 times different from those in the non-aged cables. Consequently, the smoke risk increased with aging deterioration. Therefore, the risk of heat and smoke release increased as aging progressed.

Research on the Combustibility of PI Needle Punched Nonwovens by Cone Calorimeter

2011 ◽  
Vol 332-334 ◽  
pp. 1335-1338
Author(s):  
Shu Gan Li ◽  
Xiao Ning Jiao ◽  
Qing Long Jia
Keyword(s):  
Mass Loss ◽  
Heat Release ◽  
Heat Release Rate ◽  
Fire Resistance ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Ignition Time ◽  
Total Heat ◽  
Total Heat Release ◽  
Resistance Performance

This paper demonstrates the combustibility of PI needle punched nonwovens by Cone Calorimeter. Ignition parameter, heat release parameters, smoke and toxicity parameters and mass loss parameters of the fabric were obtained from it. It was found that ignition time is 38 s; the peak of heat release rate is 65 kW/m2; total heat release is 7 MJ/m2; smoke release rate is 1.5 L/s; smoke factor is 1.3 MW/m2 and mass lose rate is 73.3%. Therefore the results show that PI needle punched nonwovens has excellent fire-resistance performance.

Research on Fire Retardant Performance of Chinese Fir with the Compound of Disodium Octaborate Tetrahydrate and SiO2 Gels

2011 ◽  
Vol 477 ◽  
pp. 175-184
Author(s):  
Qing Qing Ye ◽  
Xiao Qian Qian ◽  
Jun Ying Lai
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Ignition Time ◽  
Fire Retardant ◽  
Chinese Fir ◽  
Total Heat ◽  
Fire Retardancy ◽  
Total Heat Release ◽  
Disodium Octaborate Tetrahydrate

The environmental fire retardant mentioned in this paper was compounded of disodium octaborate tetrahydrate and silicon dioxygen(SiO2)gels. Specimens of Chinese fir were impregnated with the compound by pressure and its fire retardant performance was studied. Results showed that, the anti-loss performance of disodium octaborate tetrahydrate was improved obviously. Compared with the untreated specimen, total heat release of the treated specimens decreased by 44.5% on average, while heat release rate decreased by 50.85% on average and ignition time prolonged obviously, which indicates that this compound possess good fire retardancy effect

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