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The structural response of industrial portal frame structures in fireWong, Shao Young January 2001 (has links)
A number of recent fires in single-storey warehouses have drawn attention to a current lack of understanding about the structural response of industrial portal frame structures to elevated temperatures. This research project has investigated the subject by conducting fire tests on a scaled model and by computer modelling using the non-linear finite element program VULCAN. This program has been developed in-house by the University of Sheffield and is capable of modelling the behaviour of three-dimensional steel and composite frames at elevated temperatures. It has been validated throughout its development. An initial investigation was conducted to validate the program for analysing inclined members, which form part of a pitched- roof portal frame, but for which it was not initially developed. Additional features were implemented into the program where necessary. A series of indicative fire tests was conducted at the Health and Safety Laboratories, Buxton. A scaled portal frame model was designed and built, and three major fire tests were conducted in this structure. In the third of these tests the heated rafters experienced a snap-through failure mechanism, in which fire hinges could clearly be identified. The experimental results were then used for validating the numerical results produced by VULCAN analyses. The correlations were relatively close, both for predictions of displacements and failure temperatures. This gave increased confidence in using VULCAN to conduct a series of parametric studies. The parametric studies included two- and three-dimensional analyses, and a number of parameters were investigated, including the effects of vertical and horizontal load, frame geometry, heating profiles and base rotational stiffness. The influence of secondary members was investigated in the three-dimensional studies using different fire scenarios. A simplified calculation method has been developed for estimating the critical temperatures of portal frames in fire. The results compare well with predictions from VULCAN. The current guidance document for portal frames in boundary conditions has been reviewed, and the concept of performance-based design for portal frame structures has been discussed.
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The safety of common steel beam/column connections in fireWang, Y.C., Davison, J.B., Burgess, I.W., Plank, R.J., Yu, H.X., Dai, Xianghe January 2010 (has links)
No / This paper summarises recent experimental research on structural steel I-section beam/column connections for fire safety, based on a programme of research on robustness of different types of steel beam/column connections, carried out in collaboration between the Universities of Sheffield and Manchester. In this research project, two series of connection tests were conducted, one on isolated connections under different combinations of axial load, shear and moment at different elevated temperatures, and one on steel beam-to-column assemblies in fire, in which the resulting connection forces were varied during the fire exposure. This paper summarises the results and the main findings of these tests, focusing on connection failure modes, tying resistance, the rotation capacity of different types of connection and their potential influences on fire resistance of the connected members. The principal objective of this paper is to discuss the implications of this research project on integrating fire resistance into the design of steel-framed structures, firstly to highlight connection characteristics which contribute most to overall robustness, and to suggest how connection detailing might change to enable connections to possess such desirable characteristics.
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The Prediction of Smoke Detector Activation Times in a Two-Storey House Fire through CFD ModellingSaunders, Julie Ann January 2010 (has links)
This report describes an investigation into the prediction of the activation times of domestic ionisation and photoelectric smoke detectors within a two storey dwelling, the work undertaken being an extension to that previously presented by Brammer (2002). Three fire scenarios are considered, each having been a real test fire undertaken at the Building Research Establishment in Cardington. These three fire scenarios all involved the flaming combustion of an upholstered armchair within the lounge on the Ground floor. During the experiments various results were recorded, including temperatures, optical densities and smoke detector activation times.
The fire scenarios where modelled using FDS, Version 5. Base parameters regarding the fuel load where defined to be 0.05kgsoot/kgfuel and 20MJ/kg. Consideration was also given to the effect varying the effective heat of combustion and defined soot yield would have on derived smoke detector activation times. Additional simulations where thus run considering soot yields of 0.04kgsoot/kgfuel and 0.10ksoot/kgfuel, and an effective heat of combustion of 25MJ/kg.
Three prediction methods where applied to the results of the FDS simulations for derivation of the activation times of smoke detectors located throughout the house. These methods where the temperature correlation method, Heskestad’s method, and Cleary’s method. The temperature correlation method considered activation criterions of 4°C, 13°C and 20°C above ambient.
The Heskestad and Cleary methods were found to derive comparable activation times for each detector location. None of the prediction algorithms where however found to predict activation times consistently comparable to the test data. Rather, it was determined that for an appropriate prediction method to be adopted for accurate assessment of a given fire scenario, consideration must be given to the:
• type of detector being assessed;
• location of the detector relative to the fire;
• mode of combustion (i.e. flaming or smouldering); and the
• growth rate of the fire.
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The Kiruna town move : Unearthing the possibilities for full-scale fire testsPettersson, Henrik, Thörn, Adam January 2021 (has links)
The work with this thesis started during the last semester at the Fire Protection Engineering program at Luleå University of Technology. Kiruna has relied on the iron ore resources of Luossavaara and Kiirunavaara since the creation of the town. The iron ore stretches underneath the current city center. Therefore, some of the housings have to move northwest. The consequences of the town move are that some of the current housings will be demolished after the government owned mining company LKAB has bought the estates. This thesis aims to research the possibilities of performing fire tests in theses abandoned housings. Full-scale fire tests are usually expensive and therefore it is of substantial importance that the performed tests are meaningful. A meaningful full-scale fire test, in the author’s opinion, is defined as: The goal has to be well defined with a structured definition of what should be achieved. The test should aim at over-bridging knowledge gaps in the fire engineering science. The test should not be suitable executing for a laboratory environment. Earlier performed fire tests and scientific papers where studied to identify possible knowledge gaps. Four main topics where identified: FDS validation and computer modeling Passive fire protection system in old buildings Load bearing systems Façades and exterior claddings Two field inventories were conducted during 2016-2017. Some objects had a cultural value and were therefore excluded. The authors have decided to only include objects deemed interesting. However, these objects are just a small amount of the buildings affected by the move. The majority of the buildings identified as suitable for fire tests are high-rise residential buildings. These were found suitable for most of the identified topics. The number of buildings with large open spaces, large ceiling heights and atriums was small. The environmental requirements and permits required for performing fire tests were studied as a part of the thesis. The County administration of Norrbotten is in charge of these legal matters. The authors conclude that the authorization process may be lengthy and complicated but feasible. The authors’ conclusion is that the probability of performing full-scale fire tests are low. The lack of complex buildings, difficulty in extracting accurate, reliable data and high costs are some of the reasons. / Detta examensarbete påbörjades under den sista terminen vid brandingenjörsprogrammet på Luleå tekniska universitet, höstterminen 2017. Kiruna har sedan staden grundades alltid varit beroende av de järnmalmsfyndigheter som finns Loussavaara och Kiirunavaara. Den järnmalmsåder som löper från Kiirunavaara sträcker sig under stadens befintliga stadskärna. Delar av staden kommer därför att flyttas i nordvästlig riktning. Stadsflytten medför att delar av stadens bebyggelse kommer att köpas upp av det statliga gruvdriftsbolaget LKAB som sedan river fastigheterna. Arbetet syftar till att undersöka möjligheten att utföra brandförsök i dessa tomma fastigheter. Försök i full skala är mycket kostsamma vilket medför att det är eftersträvansvärt om brandförsöket är meningsfullt. Ett meningsfullt brandtest i full skala definierades av författarna som följande: Målet som försöket ska uppnå och vad som ska mätas är tydligt definierat Försöket ska överbrygga eller syfta till att överbrygga kunskapsglapp inom brandforskningen Försöket ska inte vara lämpligt att utföra in en laboratoriemiljö För att uppnå kravet avseende kunskapsglappet undersöktes tidigare brandförsök och vetenskapliga tidskrifter. Fyra huvudspår identifierades: FDS validering och datormodellering Passivt byggnadstekniskt brandskydd i äldre byggnader Lastbärande system Fasader och fasadbeklädnader Inventeringen gjordes i två omgångar under 2016 och 2017. Vissa objekt sållades bort på grund av dess kulturhistoriska värde. Inventeringen visar de objekt som författarna finner intressanta sett till ovanstående men representerar bara ett urval av alla de byggnader som evakueras i samband med flytten. Sett till de byggnader som under inventeringen identifierades som lämpliga för brandförsök utgörs de flesta av höga bostadshus. De höga bostadshusen bedömdes som lämpliga för samtliga identifierade huvudspår. Byggnader med stora öppna ytor, höga takhöjder eller atrium förekom ej förutom i ett fåtal fall. Som en del i arbetet undersöktes de miljötillstånd som krävs. Länsstyrelsen i Norrbotten som är den instans som beviljar eller avslår tillstånd. Författarna bedömer processen som omfattande men genomförbar. Sannolikheten för försök i full skala i samband med stadsflytten bedöms som låga. Bristen på komplexa byggnader, svårigheten i att extrahera exakta och tillförlitliga mätvärden samt den höga kostnaden medför att det är svårt att driva projektet så långt att det leder till försök i full skala.
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Development of non-destructive test methods for assessment of in-use fire fighter's protective clothingThorpe, Peter A 31 May 2004
The very nature of the fire fighting environment makes thermal degradation of turnout gear inevitable. Standards that are currently in place to ensure that new gear performs adequately for the protection of the fire fighter do not provide a quantitative measure for assessing this gear once it is in service. When the performance of the gear is compromised due to degradation, it could put the fire fighter wearing the gear at unnecessary risk. A non-destructive test that indicates the end of the useable service of the garment would be a benefit to the fire service.
Full scale fire tests were conducted to suggest a range of heat fluxes that turnout gear specimens should be subjected to in order to simulate degradation caused by in-field use of the gear. A series of destructive tests were conducted on exposed specimens. A number of non-destructive tests were performed on the same specimens. The results of destructive and non-destructive tests were compared.
This research explored some options for non-destructive tests of turnout gear. Digital image analysis and colorimetry were both offered as possibilities for a diagnostic test of this gear. Correlations between destructive performance tests and the colour changes of the outer shell fabric could be used to develop non-destructive tests to evaluate every garment owned by a department. More work is required to improve these test methods, but the door has been opened to better testing for in-use gear, and ultimately to provide better protection for the fire fighters who use this clothing.
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Development of non-destructive test methods for assessment of in-use fire fighter's protective clothingThorpe, Peter A 31 May 2004 (has links)
The very nature of the fire fighting environment makes thermal degradation of turnout gear inevitable. Standards that are currently in place to ensure that new gear performs adequately for the protection of the fire fighter do not provide a quantitative measure for assessing this gear once it is in service. When the performance of the gear is compromised due to degradation, it could put the fire fighter wearing the gear at unnecessary risk. A non-destructive test that indicates the end of the useable service of the garment would be a benefit to the fire service.
Full scale fire tests were conducted to suggest a range of heat fluxes that turnout gear specimens should be subjected to in order to simulate degradation caused by in-field use of the gear. A series of destructive tests were conducted on exposed specimens. A number of non-destructive tests were performed on the same specimens. The results of destructive and non-destructive tests were compared.
This research explored some options for non-destructive tests of turnout gear. Digital image analysis and colorimetry were both offered as possibilities for a diagnostic test of this gear. Correlations between destructive performance tests and the colour changes of the outer shell fabric could be used to develop non-destructive tests to evaluate every garment owned by a department. More work is required to improve these test methods, but the door has been opened to better testing for in-use gear, and ultimately to provide better protection for the fire fighters who use this clothing.
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Reaction to fire performance of wood and other building productsTsantaridis, Lazaros January 2003 (has links)
<p>The theme of this thesis is the reaction to fire performanceof wood and other building products, andparticularly thematerial fire properties time to ignition, rate of heat releaseand smoke production. These properties have been measured by asmall-scale fire test method, the Cone Calorimeter, andpresented for different types of building products.</p><p>Uncertainty analysis, included instrument and assumptionuncertainty, has been performed for the case that both O2 andCO2 are measured for calculation of the rate of heat release inthe Cone Calorimeter. The partial derivatives for theuncertainty analysis are given. The relative uncertainty forthe rate of heat release measurements in the Cone Calorimeteris between ±5% to ±10% for rate of heat releasevalues larger than about 50 kW/m2.</p><p>The time to ignition in the Cone Calorimeter is compatiblewith the time to ignition in the ISO Ignitability test, whichis the main test method for measuring time to ignition. Thetime to ignition is an increasing linear function of density.The rate of heat release in the Cone Calorimeter is dependentof material thickness and of use of retainer frame. Thematerial thickness gives the heat release curve duration andshape. Thin materials have short burning time and two maximumvalues. Thick materials have long burning time and when thematerial is thicker than about 35 mm no second maximum appears.When the retainer frame is used the actual exposed surface isreduced from 0.01 m2 to 0.0088 m2, the rate of heat release isreduced and the burning time is increased. A comparison ofresults with and without use of the retainer frame gives thenequal results when the exposed area is set to 0.0088 m2 in thecase of using the retainer frame.</p><p>The time to flashover in the full-scale room corner test waspredicted on the basis of Cone Calorimeter data at 50 kW/m2 bya power law of ignition time, the total heat release calculatedover 300 s after ignition and the density of the product. Therelation gives a simple relation to evaluate if a productreaches flashover in the room corner test.</p><p>The smoke production has also been measured in the ConeCalorimeter. The white light and the laser smoke measurementsystems have shown similar results. There is a correlationbetween Cone Calorimeter and room corner test smoke productionwhen the products are divided into groups: those that reachflashover in the room corner test in less than 10 min and thosethat have more than 10 min to flashover. Temperature profilesin wood have been measured in the Cone Calorimeter by a simpletechnique. The effect of fire protective gypsum plasterboardson the charring of wood frame members has been determined andcompared with fullscale furnace wall tests. The protectiveeffects of twenty different boards have been presented. ConeCalorimeter and furnace tests show similar charring of wooduntil the boards fall down in furnace tests. After that, thecharring of wood is higher in the furnace, because the wood isexposed directly to the fire.</p><p><b>Keywords:</b>building products, charring of wood, ConeCalorimeter, fire retardant treated wood, fire tests,ignitability, mass loss, rate of heat release, reaction tofire, smoke production, wood products</p>
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Reaction to fire performance of wood and other building productsTsantaridis, Lazaros January 2003 (has links)
The theme of this thesis is the reaction to fire performanceof wood and other building products, andparticularly thematerial fire properties time to ignition, rate of heat releaseand smoke production. These properties have been measured by asmall-scale fire test method, the Cone Calorimeter, andpresented for different types of building products. Uncertainty analysis, included instrument and assumptionuncertainty, has been performed for the case that both O2 andCO2 are measured for calculation of the rate of heat release inthe Cone Calorimeter. The partial derivatives for theuncertainty analysis are given. The relative uncertainty forthe rate of heat release measurements in the Cone Calorimeteris between ±5% to ±10% for rate of heat releasevalues larger than about 50 kW/m2. The time to ignition in the Cone Calorimeter is compatiblewith the time to ignition in the ISO Ignitability test, whichis the main test method for measuring time to ignition. Thetime to ignition is an increasing linear function of density.The rate of heat release in the Cone Calorimeter is dependentof material thickness and of use of retainer frame. Thematerial thickness gives the heat release curve duration andshape. Thin materials have short burning time and two maximumvalues. Thick materials have long burning time and when thematerial is thicker than about 35 mm no second maximum appears.When the retainer frame is used the actual exposed surface isreduced from 0.01 m2 to 0.0088 m2, the rate of heat release isreduced and the burning time is increased. A comparison ofresults with and without use of the retainer frame gives thenequal results when the exposed area is set to 0.0088 m2 in thecase of using the retainer frame. The time to flashover in the full-scale room corner test waspredicted on the basis of Cone Calorimeter data at 50 kW/m2 bya power law of ignition time, the total heat release calculatedover 300 s after ignition and the density of the product. Therelation gives a simple relation to evaluate if a productreaches flashover in the room corner test. The smoke production has also been measured in the ConeCalorimeter. The white light and the laser smoke measurementsystems have shown similar results. There is a correlationbetween Cone Calorimeter and room corner test smoke productionwhen the products are divided into groups: those that reachflashover in the room corner test in less than 10 min and thosethat have more than 10 min to flashover. Temperature profilesin wood have been measured in the Cone Calorimeter by a simpletechnique. The effect of fire protective gypsum plasterboardson the charring of wood frame members has been determined andcompared with fullscale furnace wall tests. The protectiveeffects of twenty different boards have been presented. ConeCalorimeter and furnace tests show similar charring of wooduntil the boards fall down in furnace tests. After that, thecharring of wood is higher in the furnace, because the wood isexposed directly to the fire. Keywords:building products, charring of wood, ConeCalorimeter, fire retardant treated wood, fire tests,ignitability, mass loss, rate of heat release, reaction tofire, smoke production, wood products / <p>NR 20140805</p>
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Temperature distribution and charring penetrations in timber assemblies exposed to parametric fire curves : Comparisons between tests and TASEF predictionsAndersson, Isac, Ek, Niklas January 2017 (has links)
Four furnace tests have been performed using two different parametric fire curves and the results are compared with computer simulations and Eurocode calculations. What differentiates the parametric fire curve from other fire curves is in particular the cooling phase, something that has proven to be hard to model for timber structures. A literature study and computer simulations were followed by experimental work performed at SP Wood Building Technology in Stockholm. The computer simulations were performed using the computer code TASEF. The predictions from TASEF were compared with measurements from the fire tests to evaluate how well the program can predict temperature distribution using a parametric fire curve. The four fire tests were executed at SP Wood Building Technology, glued laminated timber beams were used in all tests. When preparing the test specimens thermocouples were installed to measure temperature distribution, the thermocouples were installed in drilled holes. A deviation study regarding these drill-holes was performed as a part of the preparations. The temperature distributions measured during the tests were compared with the temperature distribution predicted by TASEF. Charring rate and charring depth were obtained from the fire tests, from the TASEF simulations but also by using equations given in the Eurocode. Since TASEF simulates temperature distribution and not charring depth, the 300 °C isotherm was assumed to represent the charring depth. The results from all three methods were compared and evaluated. The agreement between experiments and TASEF predictions regarding temperature distribution and charring depth were in general very good. Parametric fire curves with opening factors of 0.02 m1/2 and 0.04 m1/2 were used in four fire tests. TASEF performed more accurate predictions regarding the temperature distribution for the small opening factor but looking at the charring depth the predictions were better for the bigger opening factor. It is recommended to perform further studies and find out the reason for this behaviour. Comparing the charring depths measured at the tests with values calculated using Eurocode 5 there were some differences in charring depths. Charring depths for the horizontal direction of the beams were much alike, but when comparing the charring depths for the vertical direction there is a significant difference. The equations regarding charring depth for wood exposed to parametric fire curves in Eurocode 5 underestimate the charring depth. It is recommended to evaluate these equations further. For one of the timber beams delamination occurred, this has previously been assumed not to occur to glued laminated beams. More studies should be performed regarding delamination of glued laminated beams exposed to fire. / Fyra brandtester i en brandprovningsugn har genomförts med två olika parametriska brandkurvor och resultatet har jämförts med datorsimuleringar och Eurocode-beräkningar. Det som särskiljer parametriska brandkurvor från andra brandkurvor är nedkylningsfasen, något som har visat sig svårt att modellera för träkonstruktioner. Litteraturstudier och datorsimuleringar följdes av experimentellt arbete som utfördes vid SP Träbyggande och Boende i Stockholm. Datorsimuleringarna har utförts med datorkoden TASEF. Simuleringsresultat från TASEF jämfördes med mätningar från brandtesterna för att utvärdera hur bra TASEF kan förutse temperaturdistributionen då en parametrisk brandkurva används. De fyra brandtesterna förbereddes och utfördes på SP Träbyggande och Boende, limträbalkar användes i samtliga tester. När testbalkarna förbereddes inför brandtesterna installerades termoelement för att mäta temperaturdistributionen. Termoelementen installerades i borrhål. Som en del av förberedelserna gjordes en avvikelsestudie för dessa borrhål. Temperaturdistributionen som uppmättes under testerna jämfördes med temperaturdistributionen från TASEF-simuleringar. Från brandtester, TASEF-simuleringar och från ekvationer i Eurocode erhölls förkolningshastighet och förkolningsdjup. Eftersom TASEF simulerar temperaturer och inte förkolningsdjup användes 300 °C isotermen som då antogs representera förkolningsdjupet. Resultatet från alla tre metoder jämfördes och utvärderades. Generellt stämde temperaturdistributionen och förkolningsdjupen från TASEF-simuleringarna väldigt bra överens med de experimentella resultaten. Under testerna användes parametriska brandkurvor med öppningsfaktorer av 0.02 m1/2 och 0.04 m1/2. TASEF simulerade mer noggranna resultat gällande temperaturdistributionen för kurvan med den lägre öppningsfaktorn medan simuleringar för kurvan med den högre öppningsfaktorn gav bättre resultat för förkolningsdjupet. Det rekommenderas att göra fler studier för att ta reda på anledningen till detta beteende. Genom att jämföra förkolningsdjup som uppmättes efter brandtesterna med beräknade värden från Eurocode förekom vissa skillnader. Förkolningsdjup för bredden av balkarna var likartade, medan förkolningsdjupet för höjden av balkarna hade en signifikant skillnad. Ekvationerna i Eurocode underskattade förkolningsdjupet, det rekommenderas därför att utvärdera dessa ekvationer ytterligare. För en av limträbalkarna inträffade delaminering, detta har tidigare antagits vara osannolikt för limträbalkar. Fler studier borde utföras angående delaminering av limträbalkar exponerade för parametriska brandkurvor.
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Småskalig släckning av konstruktionsbränderPaulusson, Herman, Larsson, Caroline January 2018 (has links)
Konstruktionsbränder kan idag orsaka stora problem för räddningstjänsten. Släckningsarbeten vid konstruktionsbränder brukar idag involvera släckmedel som bygger på vattenbaserade medel. Detta medför att primära skador kan begränsas, men istället uppstår problemet med sekundära skador som mögel eller vattenskador. Idag finns det flertalet släckmedel som används men det finns inga dokumenterade tillfällen där flytande kväve och/eller koldioxid används vid konstruktionsbränder. Branschen har istället funnit användningsområden för flytande kväve vid gruvbränder med flertalet lyckade insatser. Flytande kväve och koldioxidsläckare är båda kylande släckmedel som vid användning uppnår mycket låga temperaturer. Släckmedlen släcker på liknande sätt, båda kyler till en viss del, men den primära släckkällan är kvävning. Flytande kväve får en avsevärd volymutveckling vid fasövergång från flytande till gas. Gasen tränger undan syret i den brandhärjade konstruktionen och kan därmed släcka branden. Koldioxid verkar på samma sätt, kvävande, men i detta fall övergår den kondenserade gasen till fast fas (torr-is) vid aktivering som sedan sublimerar till gas och kväver branden. För att undersöka släckmedlens förmåga att bekämpa konstruktionsbränder samt återantändningsskyddet vid användning, har åtta konstruktioner byggts. De fristående konstruktionerna ska efterlikna ett regelfack från en väggkonstruktion. Vid försöken har fyra konstruktioner använts till att undersöka flytande kväve och fyra konstruktioner för att undersöka koldioxid. Av dessa åtta användes två som testkonstruktioner i syftet att bestämma metod för applicering av släckmedel och anläggning av brand i konstruktionen. För att anlägga en brand i konstruktionerna antändes de i det nedre högra hörnet med hjälp av en propanbrännare. Vid fyra försök applicerades släckmedlen i mitten av konstruktionen i ett hål som borrats för att nå innandömet. Vid de andra två konstruktionerna applicerades släckmedlen vid hålet där branden anlades. För att mäta de temperaturer som uppstod i konstruktionerna placerades fem termoelement i varje konstruktion. I de tre försök där flytande kväve applicerades sjönk temperaturen drastiskt och efter en timme, när försöken avslutades, registrerade inget termoelement temperaturer höga nog för att en återantändning skulle kunna ske. I de tre försök där koldioxid applicerades släcktes två av tre konstruktioner och den tredje återantändes. Fem av sex försök uppvisades en trend där temperaturen låg mellan 12 – 56 °C när försöken avslutades och där temperaturen fortfarande sjönk. En trend påvisades för bägge släckmedlen, där de dröjde kvar i konstruktionen när försöken avslutades, efter cirka en timme. Släckmedlen kunde därmed under en lång tid förångas och påverka den brandhärjade konstruktionen och motverka återantändning. Slutsatsen av detta projekt är att flytande kväve och koldioxid verkar lovande som släckmedel vid konstruktionsbränder. Fler försök bör dock utföras för att styrka resultatet innan ett välgrundat uttalande kan göras. / Today structural fires can cause big problems for the rescue services. Extinguishing structural fires usually depends on methods involving water based extinguishers. These methods entails that the primary damages can be limited although secondary damages like mold or water damage may arise. Today there are several fire extinguishers that are used in the industry but few documented occasions have been found where liquid nitrogen or carbon dioxide is used on structural fires. Liquid nitrogen has long been used for mining fires with success. What liquid nitrogen and carbon dioxide in extinguishers have in common is that they are both cooling agents which upon activation reach very low temperatures. These extinguishing agents both put out a fire in a similar way, they both chill when applied, but that is not the primary source. The primary source of extinguishing comes by suffocating the fire by removing all the surrounding oxygen. The volumetric growth of gas between phase transitions displaces the oxygen present in the fire ravaged construction and thereby extinguishes the fire. Eight constructions were built to test these extinguishing agents and their potential for extinguishing construction fires. The purpose of these constructions was to simulate one part of an entire wall. To perform these tests, four out of the eight constructions were used to examine liquid nitrogen and the other four were used for carbon dioxide fire extinguishers. Two constructions were used as test constructions with the purpose to test different methods for the extinguishing agents as well as setting fire to the construction. A propane burner was used in the lower right corner of the construction to ignite it. The extinguishing agents were applied to the center of the constructions in four tests. In two tests the extinguishing agents were directed at the base of the fire in the lower right corner. A total of thirty thermocouples were used, divided evenly among the six tests that recorded data, with five thermocouples being placed in each construction. In the three tests with liquid nitrogen as extinguishing agent, the temperature dropped drastically. The temperatures registered in the wall by the thermocouples were not high enough to pose any risks for a fire to resurface at the end of the tests. In the tests using carbon dioxide as an extinguishing agent the fire managed to resurface in one out of three tests. In five out of six tests the thermocouples registered temperatures in the range of 12 – 56 °C and continually declining. Both of the extinguishers displayed similar behavior when observed, namely that the extinguishing medias could be observed remaining in the constructions long after the tests ended. This means that the extinguishing agents could evaporate during an extended period of time and counteract any flames from resurfacing. To conclude this report, the good qualities these extinguisher agents exhibit implies that they work well as extinguishing agents to combat construction fires. More experiments should be performed to strengthen the results from this project.
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