scholarly journals Effect of Heat of Reaction and Charring Properties on Heat Release Rate during Combustion

2021 ◽  
Vol 35 (6) ◽  
pp. 1-7
Author(s):  
Myung-Kyu Lee ◽  
Seul-Hyun Park
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Computational Analysis ◽  
Heat Of Reaction ◽  
Cone Calorimetry ◽  
Reaction Heat ◽  
Thermal Pyrolysis ◽  
Effective Heat Of Combustion ◽  
The Relationship

The heat release rate (HRR) of fires can be determined from the relationship between the thermal pyrolysis rate of combustibles and the effective heat of combustion. To accurately determine the thermal pyrolysis rate of combustibles, it is important to understand the heat of reaction of combustibles. However, this parameter is difficult to measure for combustibles, such as wood, that produce charring during combustion because they undergo a multi-step pyrolysis reaction. In this study, the ISO 5660-1 standard method was used to perform cone calorimetry experiments to understand how the HRR is affected by the heat of reaction heat and charring properties of combustibles. To this end, the HRR calculated using FDS computational analysis was compared to the measured value from the ISO 5660-1 cone calorimetry experiments. A dehydrated Douglas-fir, an evergreen tree of the pine family, was used as a combustible material. The cone calorimetry experiment and FDS computational analysis results confirmed that increases in the heat of reaction and charring properties were directly correlated with the decrease in the HRR.

Fire performance of continuous glass fibre reinforced polycarbonate composites: The effect of fibre architecture on the fire properties of polycarbonate composites

2018 ◽  
Vol 53 (12) ◽  
pp. 1705-1715 ◽  
Author(s):  
Yousof M Ghazzawi ◽  
Andres F Osorio ◽  
Michael T Heitzmann
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Glass Fibre ◽  
Mass Loss Rate ◽  
Fibre Reinforcement ◽  
Fire Performance ◽  
Cone Calorimetry ◽  
Glass Fibre Reinforced ◽  
Fire Properties

The fire performance of polycarbonate resin and the role of glass fibre reinforcement in altering the fire performance was investigated. Three different fibre weaves with comparable surface density, plain, twill, and unidirectional glass fabrics, were used as reinforcements. E-glass fabrics were solution-impregnated with polycarbonate/dichloromethyl, laid up, and compression-moulded to consolidate the glass fibre reinforced polycarbonate composite. Cone calorimetry tests with an incident radiant flux of 35 kW/m2 were used to investigate the fire properties of polycarbonate resin and its composites. Results showed that glass fibre reinforcement improves polycarbonate performance by delaying its ignition, decreasing its heat release rate, and lowering the mass loss rate. The three fibre weave types exhibited similar time to ignition. However, unidirectional fibre had a 35% lower peak heat release rate followed when compared to plain and twill weave fibres.

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 Estimation of heat release rate for polymer–filler composites by cone calorimetry

2004 ◽  
Vol 23 (2) ◽  
pp. 225-230 ◽  
Author(s):  
Jun Zhang ◽  
Xuyun Wang ◽  
Feng Zhang ◽  
A Richard Horrocks
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimetry ◽  
Polymer Filler

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 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.

scholarly journals An Examination of the Relationship between Flow Parameters and Symptoms According to Fire Phase in a Mine Model

2017 ◽  
Vol 6 (2) ◽  
pp. 58
Author(s):  
Selçuk Keçel
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Ventilation System ◽  
Underground Mine ◽  
Computational Fluid Dynamics Cfd ◽  
The Relationship

This study examines the relationship between temperature, CO dispersions, symptoms, and COHb% levels accumulated in the blood on available ventilation conditions in cases of fire at point in an underground mine model. Based on operating parameters (air velocity and direction) of the ventilation system in the underground mine model, fast growing phase fire analyses were conducted according to the heat release rate (HRR) value in the range of 0-61.34MW. In fire scenarios prepared according to the hydrocarbon fuel type (C2.3H4.2O1.3), boundary conditions were calculated depending on the combustion equation considering fuel lower heating value (Qc). CO dispersions inside the tunnel were examined by transferring the time-dependent boundary conditions to the computational fluid dynamics (CFD) program.  yCO, COHb%, and COHb%/∆t changes were calculated according to the HRR value.  Findings regarding the effects of CO emission (acute and chronic poisoning), were expressed according to the HRR value. Keywords Combustion Model Design, Heat Release Rate (HRR), Carbon Monoxide emission, Symptoms and Survival Time, Computational Fluid Dynamics (CFD);

Fire Performance of Nylon Nanocomposites Fabricated by Melt Intercalation

2007 ◽  
Vol 334-335 ◽  
pp. 737-740
Author(s):  
Russel J. Varley ◽  
Andrew M. Groth ◽  
Kok Hoong Leong
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Fire Performance ◽  
Fire Retardancy ◽  
Cone Calorimetry ◽  
Char Layer ◽  
Transmission Electron ◽  
Peak Heat Release Rate ◽  
In Fire

This paper presents results of a study carried out to evaluate the effects of an organomodified nanoclay, either on its own or in combination with a polyimide, upon the fire performance of a commercially available nylon. The fire performance, as determined using cone calorimetry showed that up to 40% improvement in the peak heat release rate could be achieved at addition levels of only around 5wt% of nanoclay. The level of improvement was shown to be strongly dependent upon nanoscale dispersion with a more highly exfoliated morphology, as determined using transmission electron microscopy, which showed a greater reduction in the peak heat release rate compared to a more ordered intercalated structure. Investigation of the mechanism of fire retardancy showed that the reduction in the heat release rate is due to the nanoclay reinforcing the char layer which prevented combustible products from entering in to the gaseous phase. Generally, though, the time to ignition is unaffected by nanoclay additions. The addition of the polyimide to the nanoclay reinforced nylon was inconclusive showing little evidence of further improvements in fire performance.

Cone calorimeter evaluation of reinforced hybrid wood–aluminum composites

2016 ◽  
Vol 35 (2) ◽  
pp. 118-131
Author(s):  
Junfeng Hou ◽  
Zhiyong Cai ◽  
Keyang Lu
Keyword(s):  
Aluminum Alloy ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Mass Loss Rate ◽  
Alloy Sheet ◽  
Aluminum Alloy Sheet ◽  
Aluminum Composites ◽  
Cone Calorimetry ◽  
Combustion Performance

Combustion performance for three types of wood–aluminum composites was investigated using cone calorimetry tests. The results revealed that time to ignition of the specimens was increased and more than 100 times after the lamination of 1.6-mm-thick aluminum alloy sheet on the surface (from 17 to 1990 s). And residual mass of the wood–aluminum composites was improved and almost quadrupled (from 21.795% to 81.664%). The peak heat release rate, average heat release rate, total heat release, and mean mass loss rate of wood–aluminum composites with 1.6-mm-thick aluminum alloy sheet on the surface were decreased to 70.18%, 48.71%, 24.27%, and 80.60%, respectively. However, yields of both CO and CO2 are slightly improved with the increase in the thickness of aluminum alloy sheet because of incomplete combustion. The application of aluminum alloy sheets to the wood-based composites is an effective method for improving the combustion performance.

scholarly journals Characteristics of Heat Release Rate Predictions of Fire by a Fire Dynamics Simulator for Solid Combustible Materials

2020 ◽  
Vol 34 (4) ◽  
pp. 22-28
Author(s):  
Dong-Gun Nam ◽  
Ter-Ki Hong ◽  
Myung-Ho Ryu ◽  
Seul-Hyun Park
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Computational Analysis ◽  
Fire Dynamics ◽  
Fire Dynamics Simulator ◽  
Pu Foam ◽  
Pyrolysis Model ◽  
Good Agreement ◽  
Room Corner Test

The heat release rate (HRR) of fire for solid combustibles, consisting of multi-materials, was measured using the ISO 9705 room corner test, and a computational analysis was conducted to simulate the fire using an HRR prediction model that was provided by a fire dynamics simulator (FDS). As the solid combustible consisted of multi-materials, a cinema chair composed primarily of PU foam, PP, and steel was employed. The method for predicting the HRR provided by the FDS can be categorized into a simple model and a pyrolysis model. Because each model was applied and computational analysis was conducted under the same conditions, the HRR and fire growth rate predicted by the pyrolysis model had good agreement with the results obtained using the ISO 9705 room corner test.

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