21 results on '"Ingason, Haukur"'
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2. Fires in Vehicle Tunnels
- Author
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Carvel, Ricky, Ingason, Haukur, Hurley, Morgan J., editor, Gottuk, Daniel, editor, Hall, John R., Jr., editor, Harada, Kazunori, editor, Kuligowski, Erica, editor, Puchovsky, Milosh, editor, Torero, José, editor, Watts, John M., Jr., editor, and Wieczorek, Christopher, editor
- Published
- 2016
- Full Text
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3. Large Scale Tunnel Fire Tests with Large Droplet Water-Based Fixed Fire Fighting System
- Author
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Ingason, Haukur, Li, Ying Zhen, Appel, Glenn, Lundström, Ulf, and Becker, Conny
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- 2016
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4. A New Methodology of Design Fires for Train Carriages Based on Exponential Curve Method
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Li, Ying Zhen and Ingason, Haukur
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- 2016
- Full Text
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5. Position of Maximum Ceiling Temperature in a Tunnel Fire
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Li, Ying Zhen and Ingason, Haukur
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- 2014
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6. Performance of various water-based fire suppression systems in tunnels with longitudinal ventilation.
- Author
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Li, Ying Zhen, Ingason, Haukur, Arvidson, Magnus, and Försth, Michael
- Subjects
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TUNNEL ventilation , *FIREFIGHTING , *HEAT release rates , *FIRE testing , *WOOD - Abstract
Low pressure, medium pressure and high pressure water-based fire suppression systems were tested in a medium scale tunnel (scale 1:3). The primary objective was to investigate which of these systems are most effective in the suppression or control of different types of tunnel fires. The default low, medium and high pressure systems refer to full scale water flow rates of 10 mm/min, 6.8 mm/min and 3.7 mm/min, respectively. Some other water densities were also tested to investigate the effects, as well as different ventilation velocities and activation criteria. Several series of fire tests were conducted for different fire scenarios. The fire scenarios considered included idle wood pallet fires, loosely packed wood crib fires, loosely packed wood and plastic crib fires, and pool fires, with or without a top cover on the fuel load. Comparisons of the three default systems based on the three parameters: heat release rate, energy released and possibility of fire spread, show that the performance of the default low pressure system is usually the most effective based on the parameters studied. The default high pressure system usually yields results less effective in comparison to the default low pressure system. The performance of the default medium pressure system usually lies in between them. The high pressure system behaves very differently in comparison to the others, in terms of tunnel ventilation velocity, water density, operating pressure, and the presence of the top cover. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
7. Large scale fire tests with different types of fixed fire fighting systems in Runehamar tunnel
- Author
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Ingason, Haukur, Li, Ying Zhen, and Bobert, Magnus
- Subjects
Wood pallets ,heat release rate ,Naturvetenskap ,water density ,time delay ,Natural Sciences ,Fixed Firefighting System (FFFS) - Abstract
The report presents the main results of the six large-scale tests with different types of fixed firefighting system (FFFS) that were carried out in the Runehamar tunnel in June 2016. It describes the background to the tests and the performance of the different systems, and draws conclusions regarding the efficiency of the systems. The fire load consisted of 420 standardised wooden pallets and a target of 21 wooden pallets. Five of the tests were carried out with a 30 mlong deluge zone delivering varying water densities using three different types of side-wall nozzle and an interval distance of 5 m. One test with 93°C glass-bulb nozzles (sprinkler head) in the same zone was also conducted. In the five deluge tests, the detection system was simulated using thermocouples in the tunnel ceiling. The alarm was registered when the ceiling gas temperature reached 141°C, and the system was activated manually after a delay of 4 minutes. The protection goal of the system was to prevent fire spread to a target positioned 5 m from the rear of the main fuel area, and to ensure that the fire did not exceed 30 MW in size. The system setups tested were found to meet these goals.
- Published
- 2016
8. New models for calculating maximum gas temperatures in large tunnel fires
- Author
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Li, Ying Zhen and Ingason, Haukur
- Subjects
maximum ceiling temperature ,Transportteknik och logistik ,Annan samhällsbyggnadsteknik ,velocity ,Infrastrukturteknik ,heat release rate ,Applied Mechanics ,Teknisk mekanik ,Other Physics Topics ,tunnel structure ,Annan fysik ,tunnel cross-section ,Other Civil Engineering ,Infrastructure Engineering ,ceiling height ,Kemiska processer ,Gas temperature ,Chemical Process Engineering ,Transport Systems and Logistics - Abstract
The work presented in this report focuses on estimating maximum gas temperatures at ceiling level during large tunnel fires. Gas temperature is an important parameter to consider when designing the fire resistance of a tunnel structure. Earlier work by the authors has established correlations between excess ceiling gas temperature and effective tunnel height, ventilation rate, and heat release rate. The maximum possible excess gas temperature was set as 1350°C, independent of the tunnel structure and local combustion conditions. As a result of this research, two models have been developed to better estimate possible excess maximum gas temperatures for large tunnel fires in tunnels with differing lining materials and structure types (e.g. rock, concrete). These have been validated using both model- and full-scale tests. Comparisons of predicted and measured temperatures show that both models correlate well with the test data. However, Model I is better and more optimal, due to the fact that it is more conservative and easier to use. The fire duration and flame volume are found to be related to gas temperature development. In reality, the models could also be used to estimate temperatures in a fully developed compartment fire.
- Published
- 2016
9. Large scale tunnel fire tests with different types of large droplet fixed fire fighting systems.
- Author
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Ingason, Haukur and Li, Ying Zhen
- Subjects
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FIREFIGHTING , *FIRE testing , *HEAT release rates , *FLAME spread , *FIRE sprinklers , *SPRAYING & dusting in agriculture , *ALARMS - Abstract
The paper presented the main results of large-scale fire tests with different types of fixed firefighting systems (FFFS) conducted in the Runehamar tunnel in June 2016. The background to the tests, the performance of the different systems, and conclusions regarding the efficiency of the systems were presented. The fire load consisted of 420 standardised wooden pallets and a target of 21 wooden pallets. Five of the tests were carried out with a 30 m long deluge zone delivering varying water densities using three different types of side-wall nozzles with an interval distance of 5 m. One test with 93 °C glass-bulb automatic sprinklers in the same zone was also conducted. In the five deluge tests, the detection system was simulated using thermocouples in the tunnel ceiling. The alarm was registered when the ceiling gas temperature reached 141 °C, and the system was activated manually after a delay of 4 min. The protection goal of the system was to prevent fire spread to a target positioned 5 m from the rear of the main fuel area, and to ensure that the fire did not exceed 30 MW in size. The system setups tested were found to meet these goals. • Larger droplets better penetrate fuel, facilitate surface cooling and supress further flame spread. • The heat release rates were maintained mostly below 20 MW in tests with FFFS. • Maximum temperatures beneath the ceiling never exceed 800 °C in tests with FFFS. • Fire spread to a target at 5 m behind the main fuel load is completely prevented by FFFS. • Feasibility of using automatic sprinklers in tunnels is partly verified. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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10. Spilled liquid fires in tunnels.
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Ingason, Haukur and Li, Ying Zhen
- Subjects
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FLAME spread , *LIQUEFIED gas carriers , *HEAT release rates , *FIRE prevention , *FIREFIGHTING - Abstract
The study focuses on release of liquids inside tunnels from tankers containing dangerous good. Experiments and analysis from large scale tests are presented. The tests include different leakage rates, leakage type, liquids, spillage sizes on sloping surfaces and heat release rates. Models for estimation of leakage rates, spillage sizes and heat release rates for different scenarios are presented. The results are important to use in the design of active fire protections systems in tunnels including ventilation, fixed fire-fighting and drainage systems. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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11. Fire development in a 1/3 train carriage mock-up.
- Author
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Lönnermark, Anders, Ingason, Haukur, Li, Ying Zhen, and Kumm, Mia
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FLASHOVER , *HEAT release rates , *IGNITION temperature , *SMOKE , *FLAME spread , *MATHEMATICAL models - Abstract
To study what parameters that control the initial fire spread and the development to local flashover in a metro carriage, a total of six fire tests were conducted in a mock-up of a metro carriage that is about 1/3 of a full wagon length. They were carried out under a large scale calorimeter in a laboratory environment. The focus was on the initial fire development in a corner scenario using different types of ignition source that may lead to a fully developed fire. The ignition sources used were either a wood crib placed on a corner seat or one litre of petrol poured on the corner seat and the neighbouring floor together with a backpack. The amount of luggage and wood cribs in the neighbourhood of the ignition source was continuously increased in order to identify the limits for flashover in the test-setup. The tests showed that the combustible boards on parts of the walls had a significant effect on the fire spread. In the cases where the initial fire did not exceed a range of 400–600 kW no flashover was observed. If the initial fire grew up to 700–900 kW a flashover was observed. The maximum heat release rate during a short flashover period for this test set-up was about 3.5 MW. The time to reach flashover was highly dependent on the ignition type: wood cribs or backpack and petrol. A full developed carriage fire was achieved as a result of intense radiation from the flames and ceiling smoke layer. This was mostly dependent on the amount of fire load nearby the ignition source and how strong the vertical flame spread on the high pressure laminate boards mounted to walls and ceiling above the ignition source was, leading to a ceiling flame. In such cases, the seats alone did not contain sufficient fuel for the fire to spread within the train, and additional fuel (luggage) is required near the seats. For fully developed carriage fires, the fire starting on the seat in the corner spread to the opposite seat on the same side of the aisle, then horizontally spread to seats on the other side of the aisle, and finally a longitudinal flame spread along the carriage was observed. When and where the fire stopped or whether it reached a fully developed stage was mostly dependent on the amount of fire load nearby the ignition source and how strong the vertical flame spread on the high pressure laminate boards mounted to walls and ceiling above the ignition source was. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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12. Scaling of wood pallet fires.
- Author
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Li, Ying Zhen and Ingason, Haukur
- Subjects
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PALLET industry , *FIRE prevention , *HEAT release rates , *TIME-resolved spectroscopy , *SCALING laws (Nuclear physics) - Abstract
A method for scaling time-resolved burning behaviors of wood pallet fires has been developed. A series of validation tests was carried out in two different scales and the time-resolved heat release rates were obtained and compared. The results show that the scaling method proposed works very well. The scaling method proposed could be applied to general wood pallets. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
13. Runehamar tunnel fire tests.
- Author
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Ingason, Haukur, Li, Ying Zhen, and Lönnermark, Anders
- Subjects
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FIRE testing , *TUNNEL design & construction , *VENTILATION , *PULSATION (Electronics) , *FIRE prevention - Abstract
Five large-scale fire tests, including one pool fire test and four HGV mock-up fire tests, were carried out in the Runehamar tunnel in Norway in year 2003. New data and new analyzes are presented in this paper, together with a short summary of previous work on these tests. Heat release rate (HRR), radiation, fire spread, gas production, backside wall temperature, visibility, backlayering, fire growth rate, gas temperature, flame length, ventilation and pulsation are investigated. Simple theoretical models are developed to estimate and predict these parameters. The correlations developed can be used by engineers working on fire safety in tunnels. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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14. Heat release rate measurements of burning mining vehicles in an underground mine.
- Author
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Hansen, Rickard and Ingason, Haukur
- Subjects
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HEAT release rates , *MINERAL industries , *MINES & mineral resources , *DRILLING & boring , *CARBON monoxide , *DIESEL fuels - Abstract
Abstract: Heat release rates from two full-scale fire experiments with mining vehicles in an underground mine are presented. The mining vehicles involved were a wheel loader and a drilling rig typical for mining operations. The calculated peak heat release rate of the loader was 15.9MW and occurred after approximately 11min from ignition. The calculated peak heat release rate of the drilling rig was 29.4MW and occurred after approximately 21min from ignition. The heat release rate was calculated from measured data of gas concentrations of oxygen, carbon monoxide and carbon dioxide, measured gas velocity and measured gas temperatures. The fuel load of the wheel loader consisted mainly of the tyres, the hydraulic oil and the diesel fuel. The fuel load of the drilling rig consisted mainly of the hydraulic oil and the hydraulic hoses. The calculated heat release rate curves were controlled by comparing the summed up energy contents of the participating components with the integrated heat release rate curves. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
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15. The maximum ceiling gas temperature in a large tunnel fire
- Author
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Li, Ying Zhen and Ingason, Haukur
- Subjects
- *
TUNNEL ventilation , *CEILINGS , *COAL gas , *TEMPERATURE , *FIRES , *HEAT release rates , *TUNNEL design & construction , *SCALED Curriculum Achievement Levels Tests - Abstract
Abstract: Effects of different ventilation systems, ventilation velocities, heat release rates, tunnel geometries and fire sources on the maximum excess gas temperature beneath the ceiling in large tunnel fires are analyzed. Data from numerous model scale tests and most of the large scale tunnel fire tests that have been performed worldwide are used and analyzed. Correlations for the maximum ceiling excess gas temperature in the vicinity of the fire source are proposed for low and high ventilation flows. The temperature data indicate two regions, depending on the dimensionless ventilation velocity. Each can be divided into two sub-regions. The first sub-region exhibits linear increase which transits into a constant period, depending on the fire size, ventilation and the effective tunnel height. The maximum excess gas temperature is found to be 1350°C. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
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16. An engineering tool to calculate heat release rates of multiple objects in underground structures
- Author
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Hansen, Rickard and Ingason, Haukur
- Subjects
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STRUCTURAL engineering , *FIRE testing , *MATHEMATICAL models , *TUNNELS , *HEAT flux , *EXPERIMENTAL design , *HEAT of combustion , *TEMPERATURE effect - Abstract
Abstract: Simple theoretical calculations of the overall heat release rate (HRR) of multiple objects have been carried out. The results were compared to fire experiments in a model tunnel using wood cribs placed at equal distances from each other. Three different methods are presented which are based on physical relations for fire spread between the wood cribs. The first method uses a critical heat flux as ignition criteria while the other two methods use an ignition temperature. The method using the critical heat flux as ignition criteria shows very good agreement with the corresponding experimental results used. The two methods using the ignition temperature as ignition criteria did not agree well with the corresponding experimental results. The prerequisites, that the methods should be kept relatively simple to be of practical use and that the burning objects should not necessarily have to be of uniform composition, were fulfilled. [Copyright &y& Elsevier]
- Published
- 2011
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17. Model scale tunnel fire tests with longitudinal ventilation
- Author
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Ingason, Haukur and Li, Ying Zhen
- Subjects
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FIRE prevention , *TUNNELS , *LONGITUDINAL method , *VENTILATION , *MATHEMATICAL models , *FIRE testing , *SIMULATION methods & models , *HEAVY vehicle simulators , *THERMAL properties of gases , *SAFETY - Abstract
Abstract: Results from a series of tests in a model tunnel (1:23) are presented. Tests were carried out with longitudinal ventilation under different fire conditions. Wood cribs were used to simulate the fire source, which was designed to correspond to a scaled-down HGV (Heavy Goods Vehicle) fire load. The parameters tested were: the number of wood cribs, type of wood cribs, the longitudinal ventilation rate and the ceiling height. The heat release rate, fire growth rate, maximum gas temperature beneath the ceiling, temperature distribution, total heat flux at floor level, flame length, and back-layering length were investigated. Correlations for these parameters were investigated and proposed for longitudinal flow in tunnels. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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18. Parametric study of design fires for tunnels with water-based fire suppression systems.
- Author
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Li, Ying Zhen and Ingason, Haukur
- Subjects
- *
TUNNEL design & construction , *FIRE , *SMOKE , *FIREFIGHTING , *FIRE testing , *EXPERIMENTAL design , *HEAT release rates - Abstract
A series of tests was carried out to investigate the influence of different parameters on design fires for tunnels with water-based fire suppression systems in a 1:4 scale tunnel. The key parameters tested included fuel load covers, activation time, water density, nozzle type, ventilation velocity, sprinkler section length and tunnel width. Analyses of test data are presented with a focus on the influence of these parameters on the design fire. The main findings are that the fuel load covers, activation time and ventilation velocity all play significant roles in the fire development. Further, suggestions on design fires for tunnels with water-based fire suppression systems are proposed. • A series of fire tests was conducted in a 1:4 scale tunnel with suppression system. • Fire suppression system should be activated early. • Windbreaks have positive effects on fire suppression. • Low ventilation is preferred for fire suppression. • Fire size decreases by more than 70% for the tested systems with wind breaks. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
19. Uncertainties in the use of oxygen consumption calorimetry for heat release measurements in lithium-ion battery fires.
- Author
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Willstrand, Ola, Pushp, Mohit, Ingason, Haukur, and Brandell, Daniel
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OXYGEN consumption , *CALORIMETRY , *HEAT release rates , *ENTHALPY , *LITHIUM-ion batteries , *FIRE testing - Abstract
Accurate measurement of the heat release from a battery fire is vital for risk management, product development and construction of accurate models. Oxygen consumption calorimetry is the most common method for heat release measurements in experimental fire tests. The strength of the method is that it can be applied to unknown compositions of fuel with sufficient accuracy. Despite that this method is used to estimate heat release from battery fires, the method is subject to discussion. In this work, the method is studied in-depth, and potential errors are structured and quantified. Uncertainties associated with self-generated oxygen and internal heat generation, total gas release from the battery and impact on the heat release calculations, as well as the assumed E -factor (i.e., heat release per unit mass of oxygen consumed), are thoroughly discussed. For a Li-ion battery fire, it is concluded that oxygen consumption calorimetry will exclude internal heat generation and underestimate the total heat released from the external flaming fire by up to 10 %. In addition, high rate of combustion reactions can result in that the measured peak heat release rate is underestimated much more, up to 100 %. [Display omitted] • OCC will underestimate the THR from the external flaming battery fire by up to 10 %. • On cell level, peak HRR was underestimated by up to 100 %. • Self-generated oxygen has limited impact on the OCC measurements. • CO correction is not recommended when using OCC for battery fires. • For battery fires, OCC and CDG measurements are expected to diverge. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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20. Effect of cross section and ventilation on heat release rates in tunnel fires.
- Author
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Li, Ying Zhen, Fan, Chuan Gang, Ingason, Haukur, Lönnermark, Anders, and Ji, Jie
- Subjects
- *
GEOLOGICAL cross sections , *VENTILATION , *HEAT release rates , *TUNNEL design & construction , *FIRES - Abstract
Model scale fire tests were performed in tunnels with varying tunnel widths and heights in order to study the effect of tunnel cross-section and ventilation velocity on the heat release rate (HRR) for both liquid pool fires and solid fuel fires. The results showed that for well ventilated heptane pool fires, the tunnel width nearly has no influence on the HRR whilst a lower tunnel height clearly increases the HRR. For well ventilated solid fuel fires, the HRR increases by approximately 25% relative to a free burn test but the HRR is not sensitive to either tunnel width, tunnel height or ventilation velocity. For solid fuel fires that were not well ventilated, the HRRs could be less than those in free burn laboratory tests. In the case of ventilation controlled fires the HRRs approximately lie at the same level as for cases with natural ventilation. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
21. The maximum temperature of buoyancy-driven smoke flow beneath the ceiling in tunnel fires
- Author
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Li, Ying Zhen, Lei, Bo, and Ingason, Haukur
- Subjects
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HIGH temperatures , *CEILINGS , *TUNNELS , *FIRE protection engineering , *ESTIMATION theory , *LONGITUDINAL method , *TUNNEL ventilation , *SMOKE - Abstract
Abstract: In order to detect a fire and provide adequate fire protection to a tunnel structure, the maximum gas temperature beneath the ceiling to which the structure is exposed needs to be estimated. Theoretical analysis of maximum gas temperature beneath a tunnel ceiling based on a plume theory is given. The heat release rate, longitudinal ventilation velocity and tunnel geometry are taken into account. Two series of model-scale experimental tests were also carried out. The results of both analysis and experiments show that the maximum excess gas temperature beneath the ceiling can be divided into two regions. When the dimensionless ventilation velocity is greater than 0.19, the maximum excess gas temperature beneath the tunnel ceiling increases linearly with the heat release rate and decreases linearly with the longitudinal ventilation velocity. When the dimensionless ventilation velocity is less than 0.19, the maximum excess gas temperature beneath the ceiling varies as the two-thirds power of the dimensionless heat release rate, independent of the longitudinal ventilation velocity. In both regions, the maximum excess gas temperature varies as the −5/3 power of the vertical distance between the fire source bottom and tunnel ceiling. The investigation presented here considers only the cases when the continuous flame region is lower than the ceiling height. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
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