A Method Evaluating Fire Hazard of Multiple-Layer Cable Tray and its Validation

2017 ◽  
Author(s):  
Xianjia Huang ◽  
Kun Bi ◽  
Jun Xiao ◽  
Lan Peng ◽  
He Zhu ◽  
...  
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Zone Model ◽  
Fire Source ◽  
Multiple Layer ◽  
Cat Model ◽  
Tray Fire

Multi-layer cable tray fire has special burning characteristics that the cable flame spreads horizontally along cable tray and propagates vertically from bottom layer to upper layer at the same time. With respect of accuracy and speed of calculation, simulation of multi-layer cable tray fire remains a challenge for fire models. In this paper, a method is proposed to simulate multi-layer cable tray fire. By developing a more accurate fire source description, this method can provide accurate simulation for multi-layer cable tray fire rapidly. In this method, Firstly, the heat release rate of each burning cable tray is evaluated by FLASH-CAT model. Based on the results from FLASH-CAT, a more accurate fire source definition for multiple lay cable tray is developed for zone model. Taking account of each burning cable tray considered as one fire source point, zone model is applied to predict the fire dynamics process. In order to validate this method, four-layer cable tray fire experiments and replicated experiments were carried out in a confined compartment. The histories of mass loss rate of cable tray and temperatures at the middle of compartment were recorded during the cable fire. From the replicated experimental results of total mass loss rate, it is concluded that the four-layer cable tray fire experiment has good repetition in this scenario. Vertical temperature profile shows that the fire circumstance generated by multiple-layer cable tray burning can be divided into upper hot layer and lower cool layer, which conforms to the basic assumption of zone model. As a consequence, the zone model can be applied to simulating multiple-layer cable tray fire. By comparing the experimental total heat release rate with predictions, it is found that characteristics of multiple-layer cable tray fire are well captured. On account of good prediction on overall heat release rate for multi-layer cable tray fire, predicted heat release rate for each burning cable layer by FLASH-CAT model is believed to be reliable. Then, each burning cable layer is set as one fire source and the heat release rate of each burning cable layer is input into zone model, respectively. The comparisons between simulations and experimental data show that the predicted upper layer temperature and lower layer temperature agree well with experimental data. As a result, it can be concluded that this method provides reliable prediction for multiple-layer cable tray fire rapidly.

Retardant Properties of Nanosilica/PTFE Nanoparticals-Reinforced Polypropylene

2014 ◽  
Vol 1004-1005 ◽  
pp. 77-84 ◽  
Author(s):  
Zhen Lu Zhang ◽  
Dong Li Li ◽  
Wen Cai Xu ◽  
Ya Bo Fu ◽  
Rui Juan Liao
Keyword(s):  
Mass Loss ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Thermoplastic Polymer ◽  
Maximum Heat ◽  
Average Mass ◽  
Melting Characteristics

This work reports the flammability properties of Nanocomposites reinforced with silica and PTFE nanoparticles and toughened with an elastomeric ethylene-vinyl acetate (EVA). Through trial and simulation study of the flame retardant thermoplastic polymer and melting characteristics of PP in the combustion process.The study found that modified PP composites have good flame retardancy compared to PP in case of fire relatively.In the study,the melting characteristics of the thermoplastic polymer affected the mass loss rate in the combustion stage.Nanocomposites experienced low plastic mass loss compared with PP, this has been related to pyrolysis mechanism of polymer.In general,The polymers undergoing depolymerization will lead to a rapid volatilization and therefore experienced much less melting.The results showed that:total heat release of nanocomposites was higher than polypropylene, while the average heat release rate, the maximum heat release rate, the average effective heat of combustion, the average mass loss rate, the average specific extinction area, and other indicators were lower than polypropylene.

Applicability of FLASH-CAT Model to Cable Tray Fire Modeling in Zone Model BRI2002

2020 ◽  
Author(s):  
Koji Shirai ◽  
Koji Tasaka ◽  
Toshiko Udagawa
Keyword(s):  
Mass Loss ◽  
Large Scale ◽  
Fire Test ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Zone Model ◽  
Gas Temperature ◽  
Fire Source ◽  
Gas Burner ◽  
Tray Fire

Abstract To clarify the heat and smoke propagation in multi-compartments under the spread of cable fire, a large-scale multi-compartment fire test (hereinafter the CFS-2 test) was performed by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) in France within the framework promoted by the Nuclear Energy Agency (NEA) in Organization for Economic Co-operation and Development (OECD) program PRISME2 (OECD/NEA, 2017). In the CFS-2 test, two rooms of a large-scale facility were adopted and these rooms have an identical volume (120 m3) enclosed with fire walls and were connected by a doorway (0.8 m in width and 2.17 m in height). As a fire source, five-layer cable trays (tray length of 2.4m, tray width of 0.45m and separation distance between trays of 0.3 m) with a fire-retardant PVC cable (77 kg) were used and ignited by a propane gas burner. The power level of the propane gas burner was set to around 80 kW. Moreover, all rooms were mechanically ventilated, and the renewal rate was 15 times per hour (3600 m3/h). During the fire test, the mass loss rate of fuel, gas and soot mass concentration, gas temperature, and etc. were measured. The measured peak values of the HRR, the mass loss rate and gas temperature were about 800 kW, 58 g/s and greater than 600 °C, respectively (Zavaleta, 2017). As a fire model predicting fire characteristics in a compartment, a two-zone model, which divides the fire room into the hot smoke upper layer and lower layer consisting of cool fresh air, is widely used due to the advantages of the brevity of the calculation routine and the reliability of the calculation results. Among them, the BRI2 series, developed in Japan, is now reaching the current BRI2002 software (Wakamatsu, 2004) after several upgrades to improve the calculation precision. The Central Research Institute of Electric Power Industry (CRIEPI) introduced the cable tray fire source model based on the FLASH-CAT (Flame Spread over Horizontal Cable Trays) developed by National Institute of Standards and Technology (NIST) (McGrattan, 2012) into the zone code BRI2002. By comparing the numerical results with the experimental values measured during the CFS-2 test, the methodology for ignition time delay of each tray and horizontal flame propagation speed for each tray were discussed.

Research on the Capability and Application of Flame Retardant Cable

2011 ◽  
Vol 217-218 ◽  
pp. 631-635
Author(s):  
Yong Wang
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Heat Release Rate ◽  
Release Rate ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Fire Retardant ◽  
Flame Retardant Property ◽  
Time To Ignition ◽  
Carbon Monoxide Yield

This paper, analyzes some parameters with the help of Cone Calorimeter (CONE) for the time to ignition, smoke extinction area, heat release rate, carbon monoxide yield and mass loss rate. The results show that the fire retardant agents affect KVV’s flame retardant property. Such as TTI ( time to ignition ) is prolonged to nearly two times, and the average HRR ( heat release rate ) reduces about 18% compared with the ordinary one and the maximum HRR down about 33%of its counterpart.

scholarly journals FIRE TESTS ON WOOD PRODUCTS SUBJECTED TO DIFFERENT HEAT FLUXES

2010 ◽  
Vol 16 (4) ◽  
pp. 484-490 ◽  
Author(s):  
Romualdas Mačiulaitis ◽  
Vladas Praniauskas
Keyword(s):  
Mass Loss ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Wood Products ◽  
Fire Tests ◽  
Smoke Production

The paper analyses three different wood products used for research exposing them to the surface heat flow density of 30 kW/m2, 50 kW/m2 and 70 kW/m2 and applying the test method described in ISO 5660–1 Reaction‐to‐fire tests – Heat release, smoke production and mass loss rate – Part 1: Heat release rate (Cone calorimeter method). Research was performed applying 18 mm and 29 mm thick laminated wood chipboards and 24 mm thick medium density fibreboard. The paper provides an overview of the fire properties of wood products and discusses testing methods and the percentage composition of the tested wood products. Mean time to their ignition was determined. The mean values of the maximum heat release rate and time required to achieve them were investigated. Furthermore, the measurements of the released heat and efficient heat of combustion were taken. Further research covers the performance of statistic analysis, deriving empiric equations, correlation and determination coefficients, standard errors and Student criterion. The results of research are summarized. Conclusions are provided at the end of the paper. Santrauka Straipsnyje nagrinejami trys skirtingi medienos gaminiai, su kuriais atlikti tyrimai veikiant 30 kW/m2, 50 kW/m2bei 70 kW/m2 paviršiniais šilumos srautais taikant ISO 5660–1 “Reaction‐to‐fire tests – Heat release, smoke production and mass loss rate – Part 1: Heat release rate (Cone calorimeter method)” bandymo metoda. Tyrimai atlikti su 18 mm ir 29 mm storio laminuotomis medžio drožliu plokštemis bei 24 mm storio vidutinio tankio plaušo plokšte. Darbe apžvel‐giamos medienos gaminiu gaisrines savybes. Aptariama bandymo metodika ir tirtu medienos gaminiu procentine sudetis. Nustatytas vidutinis laikas iki ju užsidegimo. Ištirti vidutiniai maksimalios šilumos išsiskyrimo greičio ir laiko iki ju pasiekimo dydžiai, taip pat išmatuota visa išskirta šiluma ir efektyvi degimo šiluma. Atlikta statistine analize, gautos em‐pirines lygtys, koreliacijos bei determinacijos koeficientai, standartines paklaidos bei Stjudento kriterijai. Apibendrinami tyrimo rezultatai. Darbo pabaigoje suformuluojamos išvados.

scholarly journals Performance analysis of a heat transfer and sub-grid chemical reaction distributed activation energy model for fire simulations

2018 ◽  
Vol 37 (1) ◽  
pp. 18-46 ◽  
Author(s):  
Abhishek Bhargava ◽  
Patrick Van Hees ◽  
Bjarne Husted ◽  
Antonio Rodolfo Junior ◽  
Corina Neumeister
Keyword(s):  
Heat Transfer ◽  
Mass Loss ◽  
Heat Release ◽  
Chemical Reaction ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Loss Rate ◽  
Mass Loss Rate ◽  
Heat Released

A heat transfer and sub-grid chemical reaction kinetic model for solid phase combustion of a charring polymer is presented based on distributed reactivity modeling approach. The model is used to compute flammability parameters of a polymer sheet of a given thickness to simulate test results of a cone calorimeter experiment. Comparison of model simulations with cone calorimeter test data shows that it gives reasonable prediction of mass loss rate, heat release rate, and total heat released of poly-vinyl chloride (PVC) and ethyl vinyl acetate–aluminum tri-hydroxide (EVA-ATH). The solution of governing equations with the current form of distributed reactivity modeling model poses numerical challenges due to appearance of a double integral in the chemical reaction model. Hence, an analytical approximation has been derived to solve mass and energy conservation equations representing the model. Simulation results indicate that with the approximated form of the distributed reactivity modeling model, along with the input parameters retrieved from literature, the model shows comparatively good predictions for EVA-ATH for mass loss rate, heat release rate, and total heat released, but calculates under-predicted values for PVC.

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.

Modified carbon-dioxide measurement to predict the heat release rate of fire burning in a compartment based on the three-zone model

2019 ◽  
Vol 43 (3) ◽  
pp. 256-265 ◽  
Author(s):  
Ying Zhang ◽  
Kaixuan Tang ◽  
Hong Duan ◽  
Yi Niu ◽  
Xianjia Huang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Zone Model ◽  
Carbon Dioxide Measurement

Numerical Simulation on Ghosting Fire in the Confined Underground Space

2014 ◽  
Vol 580-583 ◽  
pp. 2667-2670
Author(s):  
Pei Hong Zhang ◽  
Xiao Wei Lu ◽  
Xiao Ming Zhang
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Source Area ◽  
Confined Space ◽  
Source Areas ◽  
Fire Source ◽  
Underground Fire ◽  
Two Parameters ◽  
Air Vent

The phenomenon of ghosting fire development in underground confined space is simulated to analyze the impacts of ghosting fire generation via some conditions -- different air vent sizes and different fire source areas. FDS is used to establish a physical model of underground fire laboratory in Northeastern University, the simulation is conducted by setting two parameters, the air vent size and the fire source area. The fire heat release rate, temperature, concentration of CO, O2 are measured to analyze the case of ghosting fire generation in underground confined space with different air vent sizes and different fire source areas. It’s most likely to generate ghosting fire when the simulating parameter is that the air vent size is 0.4m × 0.4m and the fire source area is 0.96m2. The conclusion is that increasing the air vent size is not a simple ascending and descending relationship with the occurrence time and duration time of the ghosting fire. Increasing the fire source area can improve the fire heat release rate effectively, and promote the formation of ghosting fire.

scholarly journals INVESTIGATION THE FIRE HAZARD OF PLYWOODS USING A CONE CALORIMETER

Wood Research ◽  
2021 ◽  
Vol 66 (6) ◽  
pp. 933-942
Author(s):  
ZHIGANG WU ◽  
XUE DENG ◽  
LIFEN LI ◽  
LIPING YU ◽  
JIE CHEN ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
High Efficiency ◽  
Fire Hazard ◽  
Mass Loss Rate ◽  
Fire Retardant ◽  
Safety Level

A high-efficiency fire retardant composition was prepared with dicyandiamide, phosphoric acid, boric acid, borax, urea and magnesium sulfate and it was used to process veneers which were then to prepare the plywood. Meanwhile, heat release and smoke release from combustion of plywood were tested by a cone calorimeter, including heat release rate, mass loss rate, CO yield, CO2 yield and oxygen consumption. Results showed that the plywood with this fire retardant treatment had the better flame-retardant performance and smoke suppression effect as well as the stronger char-forming capability compared to plywood without fire retardant treatment. The average heat release rate, total heat release, average effective heat of combustion, total smoke release, CO yield and oxygen consumption of the plywood with fire retardant treatment were decreased by 63.72%, 91.94%, 53.70%, 76.81%, 84.99% and 91.86%, respectively. Moreover, the fire growth index of plywood treated by fire retardant was relatively low (3.454 kW·m-2·s-1) and it took longer time to reach the peak heat release rate, accompanied with slow fire spreading. The fire performance index was relatively high (0.136 s·m2·kW-1) and it took longer time to be ignited, thus leaving a long time for escaping at fire accidents. The fire hazard of plywood with fire retardant treatment was low, and its safety level was high.

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