Change search
Refine search result
4567 301 - 329 of 329
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 301.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Letalick, Dietmar
    Larsson, Håkan
    Measurements with Laser Radar during Fire Experiments in a Tunnel2008Report (Refereed)
    Download full text (pdf)
    FULLTEXT01
  • 302.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Li, Ying Zhen
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Ny rapport om Runehamarförsöken2011In: Brandposten, no 45, p. 21-Article in journal (Other (popular science, discussion, etc.))
  • 303.
    Lönnermark, Anders
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Kumm, Mia
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Fire development in a 1/3 train carriage mock-up2017In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 91, p. 432-440Article in journal (Refereed)
    Abstract [en]

    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.

  • 304.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Simonson, Margaret
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Nytt deltagarrekord på ISTSS-symposiet i New York2012In: Brandposten, no 46, p. 26-27Article in journal (Other (popular science, discussion, etc.))
  • 305.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Lindström, Johan
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research, Branddynamik.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Unika fullskaleförsök i Brunsbergstunneln2011In: Brandposten, no 45, p. 4-6Article in journal (Other (popular science, discussion, etc.))
  • 306.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Lindström, Johan
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research, Branddynamik.
    Li, Ying Zhen
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Kumm, Mia
    Large-scale Commuter Train Fire Tests - Results from the METRO Project2010In: Proceedings from 5th International Symposium on Tunnel Safety and Security, SP , 2010, , p. 447-456Conference paper (Other academic)
  • 307.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Persson, Bror
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP Sveriges tekniska forskningsinstitut / Brandteknik, forskning (BRf ).
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Pulsations during large-scale fire tests in the Runehamar tunnel2006In: Fire Safety Journal, Vol. 41, p. 377-389Article in journal (Refereed)
  • 308.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut. Mälardalen University, Sweden.
    Vylund, Lotta
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut. Lund University, Sweden.
    Palm, Anders
    Storstockholms Brandförsvar, Sweden.
    Palmkvist, Krister
    Södra Älvsborgs Räddningstjänstförbund, Sweden.
    Kumm, Mia
    RISE, SP – Sveriges Tekniska Forskningsinstitut. Mälardalen University, Sweden.
    Frantzich, Håkan
    Lund University, Sweden.
    Fridolf, Karl
    RISE, SP – Sveriges Tekniska Forskningsinstitut. Lund University, Sweden.
    Recommendations for Firefighting in Underground Facilities2016In: Proceedings from the 7th International Symposium on Tunnel Safety and Security, 2016, p. 115-125Conference paper (Other academic)
    Abstract [en]

    The need for a successful fire and rescue operation in an underground facility, e.g., a tunnel, introduces challenges both in the planning phase and during the incident. This is because these types of facilities can be very complex, and thus, specific tactics are needed compared to the more common incidents, e.g. in residential premises. When planning a fire and rescue operation and developing the tactics many different aspects need to be considered: complexity of the facility, the expected number of people involved in the operation, information available about the incident, the purpose of operation, etc. This paper contains recommendations for firefighting in underground facilities. The recommendations are structured in accordance to the sequential time period during which some specific fire safety design measures are taken. These periods are the design phase, the construction phase and finally when the facility is in operation. The recommendations presented in this paper are based on the results of the Swedish TMU research project (Tactics and methodologies for firefighting in underground facilities), results from other research projects and experience from real fire and rescue operations.

  • 309.
    Lönnermark, Anders
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Vylund, Lotta
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research, Branddynamik.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Palm, Anders
    Palmkvist, Krister
    Kumm, Mia
    Frantzich, Håkan
    Fridolf, Karl
    Rekommendationer för räddningsinsatser i undermarksanläggningar2015Report (Refereed)
    Download full text (pdf)
    FULLTEXT01
  • 310. Nyman, Hans
    et al.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Air curtains as smoke barriers - model scale tests and CFD calculations2014In: Proceedings of Sixth International Symposium on Tunnel Safety and Security., SP Sveriges Tekniska Forskningsinstitut , 2014, , p. 363-371Conference paper (Other academic)
  • 311. Nyman, Hans
    et al.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Luftridå som rökbarriär: försök och beräkningar2014Report (Refereed)
    Download full text (pdf)
    FULLTEXT01
  • 312. Nyman, Hans
    et al.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Rumsbrand med lågt placerade ventilationsdon - modellskaleförsök2014Report (Refereed)
    Download full text (pdf)
    FULLTEXT01
  • 313. Ochoterena, Raul
    et al.
    Gehandler, Jonatan
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research, Branddynamik.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Extern detektering av brand på tåg i rörelse2013In: Brandposten, no 48, p. 9-Article in journal (Other (popular science, discussion, etc.))
  • 314.
    Olofsson, Anna
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Safety.
    Evegren, Franz
    RISE Research Institutes of Sweden, Safety and Transport, Safety.
    Mindykowski, Pierrick
    RISE Research Institutes of Sweden, Safety and Transport, Safety.
    Jiang, Lei
    RISE Research Institutes of Sweden, Safety and Transport, Safety.
    Ukaj, Kujtim
    RISE Research Institutes of Sweden, Safety and Transport, Safety.
    Zawadowska, Aleksandra
    RISE Research Institutes of Sweden.
    Ingason, Haukur
    RISE Research Institutes of Sweden, Safety and Transport, Safety.
    RO5 ro-ro space fire ventilation: Summary report2020Report (Other academic)
    Abstract [en]

    This report is the final report from the research project RO5. The report summarises the results from the research project RO5. The report consists of summary from a literature study, from computer simulations and from model scale tests. This, together with results from full scale demonstrational test (documented only in this report) leads to the conceptional solutions and recommendations presented in this report. The project focused aim was to investigate the effects of ventilation on fire development in ro-ro spaces with different ventilation conditions.

    Important conclusion from the literature study is that ventilation is primary to prevent flammable and other harmful gases from accumulating in the spaces, and the mechanical ventilation is not designed to be functional in case of fire. It is a must for the crew to gain knowledge about the ventilation system (i.e. fans, inlets and outlets) and its capacity from tests and experiences. It is important that guidelines, rules and routines are established for using the ventilation system in typical conditions (loading/unloading etc.) and that it is documented and passed on to provide guidance for the ship's crew.

    One of the most important conclusions from the model scale tests and numerical simulation study is that distinct limitation is found for 4% opening of space sides (natural ventilation) for the fire self-extinction to occur. This is dependent on the height and shape of the opening. For the mechanical ventilation case, in case of fire, stopping the ventilation is the best way to reduce the fire intensity. The tests show that mechanical ventilation is vital for the fire to continue to burn. The recommendations aim at giving advise concerning ventilation in case of fire and how to deal with the ventilation at different ro-ro spaces.

    Download full text (pdf)
    fulltext
  • 315.
    Olofsson, Anna
    et al.
    RISE Research Institutes of Sweden, Safety and Transport.
    Mindykowski, Pierrick
    RISE Research Institutes of Sweden, Safety and Transport.
    Jiang, Lei
    RISE Research Institutes of Sweden, Safety and Transport.
    Rakovic, Alen
    RISE Research Institutes of Sweden, Safety and Transport.
    Ingason, Haukur
    RISE Research Institutes of Sweden, Safety and Transport.
    Model scale tests of a ro-ro space fire ventilation2019Report (Other academic)
    Abstract [en]

    The report contains results from a parametric study using model scale tests with natural and mechanical ventilation on ro-ro ship. Two types of fuels were used, heptane liquid fire and wood cribs. The heptane fire was used for the test series using natural ventilation and wood cribs were used in the test series using mechanical ventilation. The tests were carried out in a scale model 1:8 made of steel covered with 6 mm thick gypsum boards. The size of the model was 14.4 m long, 2.8 m wide and 0.6 m high. For natural ventilation different opening sizes (0, 1, 4 and 10% of the area of the walls along the sides) and shapes were located at different hull sides and sill heights. For mechanical ventilation both inlets supply, and outlets extracts were attached to the model and external fans combined with opening or closing of one end side. The air change per hours (ACPH) were set at 0, 10 and 20.

    Download full text (pdf)
    fulltext
  • 316.
    Palm, Anders
    et al.
    Greater Stockholm Fire Brigade, Sweden.
    Kumm, Maria
    Mälardalen University, Sweden.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ). Lund University, Sweden.
    Full Scale Firefighting Tests in the Tistbrottet Mine2015In: Fire technology, ISSN 0015-2684, E-ISSN 1572-8099, Vol. 52, no 5, p. 1519-1537Article in journal (Refereed)
    Abstract [en]

    The paper describes full-scale fire-fighting tests performed in an underground mine. A total of six different methods to fight a full scale fire in a mine tunnel were tested. The methods involved different fire-fighting equipment but were comparable regarding fundamental conditions such as length of response-route, fire-fighting set-up, and smoke and fire size. The aim was to compare different equipment and methods to reach and eventually extinguish the fire. Fire fighters using breathing apparatus (BA) were monitored regarding air consumption, movement speed and local actions and decisions. The results are presented and analyzed in respect to fire-fighting efficiency, front BA operations including moving speed and performed actions, as well as the time to successfully put out the fire. Measurements of heat release rates, temperatures and moving speeds are given in order to quantify the efficiency of the operation. Results indicate that a timespan of 15–30 min is needed for the firefighters to reach the fire source and achieve the extinguishing criteria in five of the tests. The standard equipment and nozzles shows good performance in the tests. A limiting factor on the firefighter’s endurance is the amount of air that is available. As a result from these findings the endurance of BA-teams could improve if focus is put on team organization, lightweight equipment and air supply.

  • 317. Palm, Anders
    et al.
    Kumm, Mia
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Full-scale tests of alternative methods for fire fighting in underground structures2014In: Proceedings of Sixth International Symposium on Tunnel Safety and Security., SP Sveriges Tekniska Forskningsinstitut , 2014, , p. 573-582Conference paper (Other academic)
  • 318.
    Vylund, Lotta
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research, Branddynamik.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Lönnermark, Anders
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Seminarie om räddningsinsatser under mark väckte stort intresse2014In: Brandposten, no 51, p. 36-Article in journal (Other (popular science, discussion, etc.))
  • 319.
    Wickström, Ulf
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Diskoteksbranden - Brandförloppet2000In: BrandPosten, no 22, p. 10-11Article in journal (Other (popular science, discussion, etc.))
  • 320.
    Wickström, Ulf
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Fire Research.
    Ingason, Haukur
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Sveriges tekniska forskningsinstitut, SP – Sveriges Tekniska Forskningsinstitut / Brandteknik, skydd (BRs ).
    Fires in sloping tunnels grow rapidly2000In: BrandPosten, no 23, p. 6-Article in journal (Other (popular science, discussion, etc.))
  • 321.
    Willstrand, Ola
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety. Uppsala University, Sweden.
    Pushp, Mohit
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Ingason, Haukur
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Brandell, Daniel
    Uppsala University, Sweden.
    Uncertainties in the use of oxygen consumption calorimetry for heat release measurements in lithium-ion battery fires2024In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 143, article id 104078Article in journal (Refereed)
    Abstract [en]

    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 %. 

    Download full text (pdf)
    fulltext
  • 322.
    Yao, Yongzheng
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. University of Science and Technology of China, China.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Cheng, Xudong
    University of Science and Technology of China, China.
    Scale effect of mass loss rates for pool fires in an open environment and in tunnels with wind2019In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 105, p. 41-50Article in journal (Refereed)
    Abstract [en]

    This paper investigates the influence of wind on mass loss rate per unit area (MLRPUA) of fuel-controlled pool fires both in an open environment and inside tunnels and the scale effect of pool fires is also investigated. Large pool fires with a diameter D greater than 1 m (D > 1 m) are of key concern but small pool fires (D < 1 m) are also considered for comparison. This is done by analyzing large amounts of experimental data from the literature. Results show that for small pool fires (D < 1 m) in an open environment, increasing wind speed tends to increase the MLRPUA, especially for pools with D < 0.2 m, where the MLRPUA could increase significantly with the increase of wind speed. But when small pool fires occur in tunnels, the results are more complex. When the ratio of effective tunnel height to pool diameter is less than 3, increasing wind speed tends to decrease the MLRPUA. When this ratio is greater than 3, the influence of wind on MLRPUA of pool fires in tunnels is similar to that in an open environment. The influence of wind on the MLRPUA decreases for larger pool diameters, no matter whether the pool fire occurs in an open environment or in a tunnel. For large pools with D > 1 m, the MLRPUA is not affected significantly by increasing wind speed and most likely varies within 30% for a wide range of wind speeds based on the test data collected. This influence is far less than the values concluded by previous studies based on small pool fire experiments. The outcome of this study contributes to improving the understanding of burning characteristics of pool fires under windy conditions, especially large pool fires, which are much more meaningful than small pool fires from the perspectives of fire protection engineering and fire hazard assessment.

  • 323.
    Yao, Yongzheng
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. University of Science and Technology of China, China.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Cheng, Xudong
    University of Science and Technology of China, China.
    The characteristics of under-ventilated pool fires in both model and medium-scale tunnels2019In: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 87, p. 27-40Article in journal (Refereed)
    Abstract [en]

    This paper investigates the characteristics of under-ventilated fires in tunnels. This was done by using both model and medium-scale tunnels. The fuels used were heptane and xylene. The mass loss rates per unit area, ventilation rates from tunnel inlet, flame characteristics, O 2 , CO and CO 2 concentrations, optical densities and heat release rates were measured and recorded. Results show that the fire behaviors in under-ventilated tunnel fires are different from that in well-ventilated fires. In under-ventilated fires, the mass loss rate per unit area is found to decrease during identical periods due to the low oxygen concentration resulting from the low ventilation rate and vitiation, meanwhile the flame size dramatically reduces with a lifted and fluttering flame. This was clearly observed in model-scale tests, but due to limited optical view there was no possibility to observe this in the medium-scale tests. As a result, the ventilation rate approaches the amount required for complete combustion of vaporized fuel. This indicates that the combustion has converted from ventilation-controlled to fuel-controlled. No significant increase in CO production is observed in under-ventilated fires. Besides, the equivalence ratio and combustion efficiency were analyzed in order to judge whether the combustion is fuel-controlled or ventilation-controlled. This study provides new experimental information that contributes to improving the understanding of characteristics of under-ventilated fires in tunnel and can help firefighters to make right judgements and take related protective measures during the rescue processes.

  • 324.
    Yao, Yongzheng
    et al.
    RISE Research Institutes of Sweden. China University of Mining and Technology, China.
    Li, Ying Zhen
    RISE Research Institutes of Sweden, Safety and Transport, Safety Research.
    Ingason, Haukur
    RISE Research Institutes of Sweden, Safety and Transport, Safety Research.
    Cheng, Xudong
    University of Science and Technology of China, China.
    Zhang, Heping
    University of Science and Technology of China, China.
    Theoretical and numerical study on influence of wind on mass loss rates of heptane pool fires at different scales2021In: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 120, article id 103048Article in journal (Refereed)
    Abstract [en]

    The paper presents an investigation of the influence of wind on the mass loss rate per unit area (MLRPUA) of heptane pool fires at different scales. This work was done by a theoretical analysis and numerical simulations. Correlations are developed to show how results from a small-scale pool fire might be used to estimate MLRPUA for a large-scale pool fire. The calculated results demonstrate that in the presence of wind, the MLRPUA in large-scale pool fires (side length>1 m) does not increase several times as the small-scale tests have revealed, and the 1.5 m heptane square pool fire only varies within a range of −20% and 30% of that in the free burn. Numerous heptane pool fires with different pool scales and wind speeds were simulated using FDS (Fire Dynamics Simulator). Results indicate that within a certain range of Froude number (0–2.5), the overall variation trend of MLRPUA with wind speed varies from increasing significantly to decreasing as the pool scale increases gradually (0.15 m–6 m). For large-scale heptane pool fires, the MLRPUA most likely fluctuates within ±40% for a wide range of Froude number. The outcomes of this study could contribute to improving the understanding of burning characteristics of different scales of pool fires under windy conditions in an open environment. 

  • 325.
    Yao, Yongzheng
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. University of Science and Technology of China, China.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Lönnermark, Anders
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Cheng, Xudong
    University of Science and Technology of China, China.
    Study of tunnel fires during construction using a model scale tunnel2019In: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 89, p. 50-67Article in journal (Refereed)
    Abstract [en]

    The paper presents a study on the characteristics of tunnel fires during construction. A model-scale tunnel was built and fire tests were conducted. The tunnel consists of an inclined access tunnel and a horizontal main tunnel. The main tunnel has two dead ends (excavation faces) and the only opening is from one side of the access tunnel. Propane gas burner and the fibre board soaked with the heptane were used as fuels. The flame characteristics, O 2 and CO volume fraction and gas temperature were measured and recorded. Two typical characteristics of self-extinguishment and smoke spread were found in the tunnel fires during construction. Results indicate that when a fire occurs in the horizontal main tunnel, the critical equivalence ratio for the occurrence of self-extinguishment is within 0.28–1.38 for the propane gas burner and 1.11–3.6 for the fibre board soaked with heptane. The difference is related to the burning behavior of the different fuels used. The fire location in the horizontal tunnel also has a significant influence on the fire development. A well-ventilated fire at the center of the horizontal tunnel becomes under-ventilated due to vitiation when it is located at the closed end of the horizontal tunnel. Besides, when a fire occurs at the closed end of the horizontal main tunnel, the stratification of smoke is destroyed after hitting the closed end, and then the smoke seems to spread over the entire cross section of the tunnel. The smoke spread velocity is found to be proportional to the ventilation rate. However, when a fire occurs at the closed end of the inclined access tunnel (lower end), the fire does not self-extinguish, even when the ventilation rate is 0 m 3 /s. The corresponding smoke spread velocity is higher than that in the horizontal main tunnel. The outcomes of this study provide new experimental information that contributes to improve the understanding of characteristics of tunnel fires during construction and can help firefighters to make better decisions during the rescue processes.

  • 326.
    Yao, Yongzhenh
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. University of Science and Technology of China, China.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Cheng, X.
    University of Science and Technology of China, China.
    Numerical study on overall smoke control using naturally ventilated shafts during fires in a road tunnel2019In: International journal of thermal sciences, ISSN 1290-0729, E-ISSN 1778-4166, Vol. 140, p. 491-504Article in journal (Refereed)
    Abstract [en]

    This paper studies the overall smoke control of natural ventilation systems with vertical shafts during fires in a common road tunnel by numerical modelling. The variables studied include the heat release rate, longitudinal fire location along the tunnel, length of shafts and the interval between two shafts. Simulation results indicate that the total smoke spread length on both sides of fire source is closely independent of the heat release rate and longitudinal fire locations. For a given dimensionless shaft interval (the ratio of the shaft interval to shaft length), with the increase of shaft length, the smoke spread length firstly increases, reaching a maximum at 12 m, and then decreases significantly until 18 m. For a fire less than 30 MW, the first shaft pair on both sides of fire source prevents the critical-temperature smoke (270 °C) from spreading beyond this shaft. For a 100 MW fire, in the cases with shorter shaft lengths (L shaft ≤9 m), the critical-temperature smoke can't be controlled between the first shaft pair. The gas temperature at human height (1.8 m) is less than 60 °C in all cases with shafts. Downdraught occurs when the smoke front stabilizes at the bottom of a shaft and the buoyancy force could be too low to overcome the kinetic pressure of the air flow flowing into this shaft, consequently destroying the structure of smoke layer. In most scenarios, the total exhaust area of shafts that is required to exhaust all the smoke is about 100 m 2 . The first shaft pair plays a critical role to exhaust the smoke, and its exhaust efficiency is also affected significantly by the shaft length. This study investigates how to control the smoke by using vertical shafts in a road tunnel fire and the conclusions are useful to tunnel fire protection engineering.

  • 327.
    Zhao, Shengzhong
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. Chongqing University, China.
    Li, Y. Z.
    Chongqing University, China.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Liu, F.
    Chongqing University, China.
    A theoretical and experimental study on the buoyancy-driven smoke flow in a tunnel with vertical shafts2019In: International journal of thermal sciences, ISSN 1290-0729, E-ISSN 1778-4166, Vol. 141, p. 33-46Article in journal (Refereed)
    Abstract [en]

    In this study, a series of small-scale experiments was carried out in a model scale tunnel with dimensions of 20 m (Length) × 2 m (Width) × 1 m (Height) to investigate the characteristics of buoyancy-driven smoke flow in a tunnel with vertical shafts. Different shaft settings and four different longitudinal ventilation velocities were tested in the experiments. A theoretical model for the mass flow rate of buoyancy-driven smoke flow in the shaft was developed and validated. The gas temperature along the tunnel ceiling and smoke stratification were subsequently analyzed and discussed. The results showed that more shafts, greater shaft heights and greater shaft cross sectional areas can significantly increase the smoke extraction rate, and the total smoke mass flow rate in the shafts increases with the increasing ventilation velocity. The local pressure loss coefficient at the shaft inlet may not be a fixed value. An average value of 1.0 for this coefficient was recommended for engineering estimation and design of rectangular-shaped natural shafts. The presence of vertical shaft is beneficial to the smoke stratification and could increase the height of the smoke layer interface, especially for the downstream of the shaft.

  • 328.
    Zhao, Shengzhong
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety. Chongqing University, China.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Kumm, Mia
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Liu, Fang
    Chongqing University, China.
    Re-direction of smoke flow in inclined tunnel fires2019In: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 86, p. 113-127Article in journal (Refereed)
    Abstract [en]

    The re-direction of smoke flow in inclined tunnel fires refers to the phenomenon that the smoke flow direction suddenly changes due to the changes of thermal buoyancy or outside pressure or the activation of fans. This poses special risk for fire rescue services fighting fires in tunnels. Both small-scale tunnel fire tests (28 scenarios) and numerical simulations of full-scale tunnel fires (31 scenarios) were conducted to study this special phenomenon. A one-dimensional model was used to predict the flow velocity in the inclined tunnels, based on two different methods for calculating the mean smoke temperature (Method I and Method II, respectively). Results show that the smoke flow direction could be well predicted by the model with Method II. When the ventilation velocity is relatively large and the flow tends to be one dimensional, both methods produce similar results. Further, the influences of important factors on the re-direction of smoke flows were systematically analyzed. These factors include heat release rate, tunnel slope, tunnel length, friction factor, tunnel cross sectional area and fire source location.

  • 329.
    Zhao, Shengzhong
    et al.
    Shandong Jianzhu University, China.
    Yang, Haoran
    Shandong Jianzhu University, China.
    Li, Ying Zhen
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Ingason, Haukur
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Liu, Fang
    Chongqing University, China.
    Theoretical and numerical study on smoke descent during tunnel fires under natural ventilation condition2023In: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 142, article id 105414Article in journal (Refereed)
    Abstract [en]

    The smoke stratification and the smoke descent along a tunnel are of the utmost importance for personnel evacuation. The paper investigates the smoke descent along a tunnel during a naturally ventilated tunnel fire. A theoretical model is developed to predict the smoke depth below the ceiling along the tunnel. A series of numerical simulations of full-scale tunnel fires are conducted to compare with the developed model, and some coefficients such as the entrainment coefficient are determined from the simulation results. The concepts of critical moment and critical distance are proposed to characterize the smoke descent along the tunnel. The results show that as the smoke spreads longitudinally, the smoke depth below the tunnel ceiling continuously increases. The temperature decay along the tunnel due to heat losses and air entrainment at the smoke layer interface is considered as the main parameter for the smoke descent. After the vitiated air returns back to the fire source, the smoke stratification in the entire tunnel will be significantly reduced. The smoke layer depth along the tunnel based on the temperature distribution is relatively stable in the process of smoke development, which is not sensitive to the HRR, but influenced by the tunnel width, and this method could only be used before the critical moment. The outcomes of this study could provide references for a better understanding of smoke movement in naturally ventilated tunnels and provide technical guidelines for fire safety designers.

4567 301 - 329 of 329
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf