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Fjærestad, J. S., Meraner, C., Jiang, L. & Stølen, R. (2023). Brannsikkerhet ved oppføring og rehabilitering av bygg.
Åpne denne publikasjonen i ny fane eller vindu >>Brannsikkerhet ved oppføring og rehabilitering av bygg
2023 (norsk)Rapport (Annet vitenskapelig)
Abstract [en]

Fire safety during construction and rehabilitation of buildings. This study deals with how the covering of buildings during the construction or rehabilitation of buildings affects fire safety and to what extent the regulations take this into account. The main focus has been mapping relevant requirements, recommendations, and performances related to the covering of buildings, mapping available materials, investigating the material’s fire properties, and modelling the spread of smoke within the covering. A mapping of the relevant laws and regulations applied for constructing and rehabilitating buildings has been carried out. The mapping has shown that demands are placed on owners, users, project owners, builders, businesses, employers, planners and contractors through many different laws and regulations. The people involved can have several roles, and similar roles have different names in the various regulations. For buildings in use, fire safety must be ensured for both the users and workers. It also applies that both the owner and the users are responsible for ensuring fire safety. It requires good communication and cooperation between different actors to ensure that fire safety is maintained for all involved, during the construction and rehabilitation of buildings. When covered scaffolding is used, the Regulations concerning the performance of work, use of work equipment and related technical requirements [10] require that the covering satisfy the fire requirements for materials used in escape routes (§17-20). The guideline to the Norwegian Regulations on technical requirements for construction works, TEK10, (Veiledningen til TEK10) §11-9, provides pre-accepted performance levels. For escape routes, class B-s1,d0 (In 1) is specified for walls and ceilings. There is no requirement for fire classification of the walkways in the scaffolding under the applicable laws and regulations. We believe there should be requirements for fire classification of the walkways, in the same way as for the covering, i.e., B-s1,d0 (In 1) for surfaces on walls and ceilings and Dfl-s1 (G) for surfaces on floors. The simulations of the spread of smoke from a fire inside a building during construction or rehabilitation show that the spread of smoke is affected when the scaffolding around the building is covered. Covering around the sides leads to a greater horizontal spread of smoke in the scaffolding than without covering. When the cover also has a roof, the smoke first accumulates underneath the cover's roof before it eventually also fills up with smoke down the floors of the scaffolding. The simulations showed that establishing an open field in the upper part of the cover would ventilate the smoke gases effectively, and the spread of smoke was essentially the same as for a cover without a roof. In addition, the simulation indicated that the air flow through the walkways in the scaffold could be an important factor in reducing the covering's negative effect on the spread of smoke. Of the 64 different products used for covering found in the survey, 35% had full classification according to EN 13501-1 (such as B,s1-d0). About 6% stated that the product was not flame retardant. Of the remainder, it was evenly distributed between those who stated a fire classification according to other test methods, those who did not provide any information on the fire properties and those who stated that the product was flame retardant without further specification. The mapping also indicates that the products from market leaders used by large general contractors provide products with documented fire properties. Conversations with two of Norway’s largest fire and rescue services shed light on several challenges connected to covering scaffolding and construction during firefighting activities. They pointed out that the covering could cause challenges and delays throughout their efforts. The covering gives a reduced visual overview of the spread of smoke and the location of doors and windows. This information is important for planning both extinguishing and smoke diver efforts. In addition, the covering can be an obstacle to the actual extinguishing effort, the use of an extinguishing agent and smoke divers and rescue efforts.

Publisher
s. 96
Serie
RISE Rapport ; 2023:130
Emneord
Smoke spread, CFD simulation, review of regulations, scaffolding, covering, construction, fire safety, construction site, fire and rescue service., Røykspredning, CFD-simulering, gjennomgang av regelverk, stillas, tildekking, konstruksjon, brannsikkerhet, byggeplass, brann- og redningstjeneste
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-68680 (URN)978-91-89896-17-8 (ISBN)
Merknad

Finansiert av: Direktoratet for samfunnssikkerhet og beredskap (DSB) og Direktoratet forbyggkvalitet (DiBK)

Tilgjengelig fra: 2023-12-27 Laget: 2023-12-27 Sist oppdatert: 2023-12-27bibliografisk kontrollert
Meraner, C. (2023). Car Park Fires: A Review of Fire Incidents, Progress in Research and Future Challenges.. In: Proceedings of Seventh International Conference on Fires in Vehicles: . Paper presented at Seventh International Conference on Fires in Vehicles, Stavanger, Norway, April 24-25, 2023 (pp. 7).
Åpne denne publikasjonen i ny fane eller vindu >>Car Park Fires: A Review of Fire Incidents, Progress in Research and Future Challenges.
2023 (engelsk)Inngår i: Proceedings of Seventh International Conference on Fires in Vehicles, 2023, s. 7-Konferansepaper, Publicerat paper (Fagfellevurdert)
Abstract [en]

Fires in road vehicles are common, but a large part is associated with crashes. Of all vehicle fires registered in the USA between 2013 and 2017, 16% have occurred in a parking area and only a fraction of these involved vehicles parked in car parks. Furthermore, car park fires often involve few cars only and do not lead to fatalities. However, major car park fire incidents in the last years have shown that fires can lead to significant property and environmental damage if the fire can spread to a large enough number of adjacent vehicles. Large-scale experiments conducted in the 2000-10s have shown that it can take between 10 to 20 minutes before a car fire spreads to an adjacent car. Essential factors for the fire development are ventilation conditions within the car park, air supply to the burning car’s interior (i.e., breaking windows), and fuel involvement (i.e., breaking fuel tanks, a thermal runaway in lithium-ion batteries or gas releases from pressure release devices). Recent large-scale experiments involving a battery electric vehicle showed fire spreading 5 minutes after the first car was ignited. Thus, early detection and a quick response to the fire are essential to prevent a fire from spreading to multiple cars. Modern cars have become bigger, are thus parked closer to adjacent cars and contain more combustible material, especially plastics. A larger plastic content can increase the fire size of car fires, while an increased share of combustible material on the exterior and a decreased distance between cars may aid a faster fire spread. The increasing share of alternative fuel cars introduces new fire and explosion hazards and poses challenges for extinguishing efforts. However, early detection and quick response time still play an essential role in mitigating the associated risks

Emneord
car park fires, parking garage fires, fire incidents, car fire statistics, alternative fuel vehicles.
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-71489 (URN)
Konferanse
Seventh International Conference on Fires in Vehicles, Stavanger, Norway, April 24-25, 2023
Merknad

This work was funded by European Union’s Horizon 2020 research andinnovation program through grant agreement no. 814975 as part of theinternational research project of LASH FIRE.

Tilgjengelig fra: 2024-01-26 Laget: 2024-01-26 Sist oppdatert: 2024-01-26bibliografisk kontrollert
Sarp Arsava, K., Skilbred, E. S. & Meraner, C. (2023). FRIC webinar: High-Pressure Water Mist Applications for Façade Fires.
Åpne denne publikasjonen i ny fane eller vindu >>FRIC webinar: High-Pressure Water Mist Applications for Façade Fires
2023 (engelsk)Annet (Annet vitenskapelig)
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-67561 (URN)
Merknad

ID nummer: FRIC webinar D4.1-2021.07

Tilgjengelig fra: 2023-10-25 Laget: 2023-10-25 Sist oppdatert: 2023-12-28bibliografisk kontrollert
Meraner, C., Sarp Arsava, K. & Li, T. (2023). On the effect of ventilation conditions in naturally ventilated car parks on fire safety. In: Proceedings of Seventh International Conference on Fires in Vehicles: . Paper presented at Seventh International Conference on Fires in Vehicles, Stavanger, Norway, April 24-25, 2023 (pp. 240). RISE Research Institutes of Sweden
Åpne denne publikasjonen i ny fane eller vindu >>On the effect of ventilation conditions in naturally ventilated car parks on fire safety
2023 (engelsk)Inngår i: Proceedings of Seventh International Conference on Fires in Vehicles, RISE Research Institutes of Sweden , 2023, s. 240-Konferansepaper, Publicerat paper (Fagfellevurdert)
Abstract [en]

Ventilation conditions are an essential factor in the development of car park fires. This study investigates if larger open wall areas can affect fires in naturally ventilated car parks such that a reduction of the fire resistance of the main load-bearing system is warranted. A set of ten fire simulations with different wind conditions (direction and force) were carried out. Two generic car parks were examined, one with a 21 % open area fraction and one with a 41 % open area fraction. A simplified structural analysis for all scenarios was, furthermore, conducted to investigate the effect of different open area fractions on the collapse time of individual steel beams. The results of this study indicate that the fire resistance of the main load-bearing structure should not be reduced from R30 or R60 to R15, even if the wall surfaces have a larger open area fraction.

sted, utgiver, år, opplag, sider
RISE Research Institutes of Sweden, 2023
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-71494 (URN)
Konferanse
Seventh International Conference on Fires in Vehicles, Stavanger, Norway, April 24-25, 2023
Merknad

Our gratitude goes to the Helmholtz Association for the funding of this research in the programme Materials and Technologies for the Energy Transition (MTET). 

Tilgjengelig fra: 2024-01-26 Laget: 2024-01-26 Sist oppdatert: 2024-01-26bibliografisk kontrollert
Reitan, N. K., Fjærestad, J. S., Fjellgaard Mikalsen, R., Skilbred, E. S., Meraner, C. & Aamodt, E. (2023). RISE Fire Research sitt høst-webinar [RISE Fire Research’s autumn webinar]: 17 november 2023.
Åpne denne publikasjonen i ny fane eller vindu >>RISE Fire Research sitt høst-webinar [RISE Fire Research’s autumn webinar]: 17 november 2023
Vise andre…
2023 (norsk)Annet (Annet vitenskapelig)
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-67880 (URN)
Merknad

RISE Fire Research sitt høst-webinar ble arrangert 17 november, kl 9-11. Her finner du opptak fra webinaret.

Du kan lære om nye forskningsfunn innen blant annet: batteribrann og rømningsveier, brannfarlig julepynt, dødsbranner i Norge, samt brannsikkerhet ved oppføring eller rehabilitering av bygg. Forskningen er finansiert av Direktoratet for samfunnsikkerhet og beredskap (DSB) og Direktoratet for byggkvalitet (DiBK).

Viktige tidspunkt i videofila: 

00:00:00 Velkommen ved CEO – Nina Kristine Reitan, adm.dir. RISE Fire Research

00:02:57 Kunnskapsbehov innen brannfaget – Johan Marius Ly, avd.dir. Brann og redning, Direktoratet for samfunnssikkerhet og beredskap (DSB)

00:05:37 Kort info om semi-automatiske parkeringsanlegg (publisert rapport) – Nina Kristine Reitan

00:06:45 Kort info om veileder om silobrann (publisert rapport) – Nina Kristine Reitan

00:07:42 Kort info om feiing av ildsteder (pågående prosjekt) – Nina Kristine Reitan

00:09:07 Rømning ved brann i litium-ion batteri i elsparkesykkel (publisert rapport) - Janne Siren Fjærestad og Ragni Fjellgaard Mikalsen

00:39:39 Brann til jul (pågående prosjekt)– Ellen Synnøve Skilbred

01:04:42 Brannsikkerhet ved oppføring og rehabilitering av bygg (pågående prosjekt)– Janne Siren Fjærestad og Christoph Meraner

01:34:55 Analyse av dødsbranner i Norge i perioden 2015-2020 (pågående prosjekt)– Edvard Aamodt og Ellen Synnøve Skilbred

01:58:24 Oppsummering og avslutning – Nina Kristine Reitan

Tilgjengelig fra: 2023-11-20 Laget: 2023-11-20 Sist oppdatert: 2023-11-21bibliografisk kontrollert
Fjærestad, J. S., Fjellgaard Mikalsen, R. & Meraner, C. (2023). Rømning ved brann i litium-ion batteri i elsparkesykkel.
Åpne denne publikasjonen i ny fane eller vindu >>Rømning ved brann i litium-ion batteri i elsparkesykkel
2023 (norsk)Rapport (Annet vitenskapelig)
Abstract [en]

Fire evacuation during lithium-ion battery fires in electric scooters

This study deals with escape in the event of a lithium-ion battery fire. The study is funded by the Norwegian Directorate for Civil Protection (DSB) and the Norwegian Building Authority (DiBK). The main objective is to evaluate the consequences of a thermal runaway in an electric scooter in an enclosed space in terms of the spread of gas and smoke from the battery and the potential to prevent escape via escape routes. The scenarios examined are representative of public buildings, schools, office buildings, and other buildings that require many people to escape via large open spaces (e.g., classrooms, open-plan offices) and corridors (escape routes). In addition to the experimental study, information about incidents involving fires in electric scooters in Bergen in recent years has been collected, and the Bergen Fire Service’s experiences from these incidents are presented. A total of 6 large-scale experiments were carried out with a fire in an electric scooter, 3 of the experiments were carried out in a 55 m2 large room corresponding to a classroom, and 3 of the experiments were carried out in a 15 m long corridor (38 m2 ). The ceiling height in the building was around 3 m. The concentrations of the gases CO2, CO, O2, HCl, HF, HCN, SO2, CH2O, NO and NO2 were measured in the experiments. The measurements are used to establish an experimental basis for evaluating whether and when critical gas values (according to ISO 13571:2012 "Lifethreatening components of fire") are achieved and thus lead to reduced ability to escape. The temperature change caused by the fire was measured at different heights in the room. In addition, video documentation is used to assess how the spread of smoke affects escape in a situation where there is a fire in an electric scooter in an escape route. The study has shown that a thermal runaway in a lithium-ion battery leads to a rapid fire development where the battery essentially bursts into flames, with jet fires and potential ejections of burning battery cells far away from where the fire started. The duration of this fire behavior with jet fires and flying debris was between 3 and 7 minutes. In the fire experiments, the emitted energy was not high enough to raise the room temperature to a critical level. Near the fire, however, there is a hazard of fire spread to other combustible materials in the room due to the behavior of the fire and high temperature of the jet flame. Ejection of burning battery cells poses a hazard of fire spread even to areas far away from the start location. Fires in an electric scooter battery or similar lithium-ion batteries can cause a rapid spread of smoke to the entire room. In the conducted experiments, the fire room was no longer smoke-free at the height of 1.9 m already after 1-2 minutes. Due to this rapid spread of smoke, visibility in the room will be affected after a short time and make escape more difficult. In the corridor, the smoke spread was relatively evenly distributed in height, while the smoke in the large room ("classroom") spread in a layer under the roof. Both forms of dispersion are thus possible, depending on the room and ventilation configuration. The gas measurements in the fire experiments detected both asphyxiant and irritant gases. Due to the battery size, which affects how much gas is formed, in relation to room size and ventilation conditions, the calculated FEC, i.e., the critical concentration of irritant gases, was below the selected limit value of 0.1 in all experiments. Although the FEC value was below 0.1 in all the experiments, people in the fire room would have begun to feel an effect from some of the toxic gases. However, this effect would not have been disabling. The FED, that is, the critical dose for asphyxiant gases, was only obtained after 23 to 30 minutes. It is important to remember that the concentration of toxic gases in a room due to a fire in a lithium-ion battery depends on the ratio of battery size, room size, and ventilation conditions. This means the limit values could have been exceeded for a larger battery or in a smaller room. The most important recommendation from this study is: Avoid storing and charging electric scooters and similar in living areas and escape routes. Chapter 7 also presents 8 tips and recommendations for the population, as well as 1 for the building owner and 1 for the fire service.

Publisher
s. 79
Serie
RISE Rapport ; 2023:32
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-64169 (URN)978-91-89757-78-3 (ISBN)
Tilgjengelig fra: 2023-03-07 Laget: 2023-03-07 Sist oppdatert: 2023-06-29bibliografisk kontrollert
Meraner, C. & Sarp Arsava, K. (2022). Brannsikkerhet i naturlig ventilerte parkeringshus.
Åpne denne publikasjonen i ny fane eller vindu >>Brannsikkerhet i naturlig ventilerte parkeringshus
2022 (norsk)Rapport (Annet vitenskapelig)
Abstract [en]

Fire safety in naturally ventilated car parks This study investigates fires in car parks, and is financed by the Norwegian Directorate for CivilProtection (DSB) and the Norwegian Building Authority (DiBK).The main objective of the study is to collect knowledge in order to evaluate whether it is safe to reducethe fire resistance of main load-bearing systems in car parks in fire classes 1 and 2 to R 15 A2-s1,d0[incombustible material], provided that more than 1/3 of the wall area is open and that the buildingdesign is such that good ventilation is ensured. Reduced fire resistance is indicated as a pre-acceptedsolution in the guideline to the Regulations on technical requirements for construction works(TEK17).The results of this study indicate that the fire resistance of the load-bearing structures shouldnot be reduced from R30 - R60 to R15, even if the wall surfaces have more than 1/3 open areafraction.Relevant regulations in Norway, Sweden, Denmark and Finland have been surveyed. The followingmain rules apply to load-bearing systems in car parks in these Nordic countries:• Car park with two floors : R 30 – R 60• Car park with three and four floors : R 60• Car park with more than four floors : R 60 – R 90 – R 120In Norway and Sweden, subject to different prerequisites, the fire resistance may be reduced to R 15.In Denmark and Finland, however, the use of R 15 for the load-bearing system in car parks is notallowed. Sweden and Finland require the installation of an automatic sprinkler system if the fireresistance is reduced. This requirement applies to car parks with two floors in Sweden (from R 30 toR 15 with sprinklers) and for car parks with a height above 28 m, which is around eight floors, (fromR 120 A2-s1,d0 to R 90 A2-s1,d0 with sprinklers). Of the four Nordic countries, only Norway uses theopen area fraction in wall surfaces as a basis for reducing the fire resistance.Under the pre-accepted solutions in the guideline to TEK17, car parks with open wall surfaces will inpractice often need to have sprinkler systems, either because each floor is defined as a separate firecell, or because the total gross area in a fire cell with open connection across several floors exceeds800 m2, or because the fire section size demands it. In these cases, the design will be morecommensurable with Sweden, i.e. a reduction in fire resistance, but with the installation of a sprinklersystem.In order to be able to assess the effect of wall surfaces with a different open area fraction, a total of tenfire simulations with different wind conditions (direction and force) were carried out. Two generic carparks, one with 21 % open area fraction and one with 41 % open area fraction, were examined. Thecar parks have one floor and a floor area of 1 797 m2, three «open» sides and one side closed by afirewall.It is emphasized that the CFD simulations and structural analysis involve a number of uncertaintiesand limitations. Absolute values for fire spread and collapse time therefore only provide some2© RISE Research Institutes of Swedenindications and no final answers. The focus is therefore on a comparison of car parks with a differentopen area fraction.In a car park with 41 % open area fraction, i.e. more than 1/3 open wall area, the main load-bearingsystem may under certain conditions be constructed with a fire resistance of minimum R 15 A2-s1,d0[incombustible material]. For a car park with 21 % open area fraction, the fire resistance must beminimum R 30 or R 60 depending on the number of floors.In this study, only one floor was simulated. The fire simulations are based on a simple spreadingmodel and are well suited for a comparative study. Owing to model uncertainty, spreading progresscannot be directly used for the analysis of other car parks.The fire simulations have shown that a larger open area fraction, and thus better ventilation, can limitthe extent of fire spread, i.e. the number of cars to which the fire spreads.The difference between a closed (less than 1/3 open area fraction) and an open (more than 1/3 openarea fraction) car park in terms of the number of cars that are burning, is most visible after 40 minutes– 60 minutes, when the fire has reached a certain size. This is because the difference in the time ittakes the fire to spread between cars is accumulated over time, and because the ventilation conditionsassume greater importance when the fire becomes so large as to make it ventilation controlled.For very high wind velocities (e.g. 11 m/s), the open area fraction plays a smaller role, since this leadsto good ventilation also when the open area fraction is lower (21 % in this study).Increased ventilation and thus increased wind velocity in car parks, leads to the fire spreading faster inthe wind direction, downstream of cars that are already burning. This is because the fire and smoke aredriven to one side, and thus closer to adjacent cars. In major fires, increased ventilation will also givethe fire increased access to oxygen.A faster spread of fire in the wind direction may result in more cars burning simultaneously, comparedwith a more closed car park, where the flow rate is lower. Several cars burning simultaneously maycause greater thermal stress on the support system, and potentially an earlier collapse of the structure.The extent of stress will depend significantly on the wind direction, layout of the car park, location ofthe fire start relative to the location of other cars, and so on.A simplified structural analysis showed that an increased open area fraction both entails a positive anda negative effect on the structure’s load-bearing ability in a fire, depending on whether windconditions are favorable or not.Regardless of wind conditions, the structural analysis showed that expanding the open area fractionfrom 21 % (i.e. less than 1/3) to 41 % (more than 1/3), has a smaller effect on the collapse time thanreducing the fire resistance from R 30 to R 15. The difference is even more pronounced in a reductionfrom R 60 to R 15. By using R 60 none of the beams collapsed. The results of this study indicatetherefore that the fire resistance for load-bearing structures should not be reduced even if the wallsurfaces have more than 1/3 open area fraction.For all the fire simulations visibility conditions were examined after 15 minutes. For very low or veryhigh wind velocities little difference in visibility conditions is expected, depending on the open areafraction. At moderate wind velocities, statistically the most common, it turned out

In what way open wall surfaces impact a car park fire is highly dependent on the fire scenario andwind conditions. These two factors cannot be controlled. Dimensioning the fire resistance to the mainload-bearing system in a car park based on the open area fraction of wall surfaces (more than 1/3 ofthe area) is therefore considered unreliable. Open wall surfaces contribute in some cases to improvingvisibility conditions in car parks, which may extend the available escape time. For this reason, openwall constructions are nevertheless considered advantageous.This study did not examine the effect of sprinkler systems in combination with a reduction in fireresistance, such as is allowed in Sweden. Nevertheless, a sprinkler system, which is little affected bywind conditions, is generally considered better suited as a compensatory measure if the fire resistanceis reduced.It is, therefore, our recommendation that the possibility of reducing the fire resistance in open carparks in fire classes 1 and 2 be reconsidered. This option should be considered removed, or othercriteria could be employed to reduce the fire resistance, such as e.g. sprinkler systems (as in Sweden).Sprinkler systems are considered better suited as a compensatory measure if the fire resistance isreduced.As a basis for such reassessment experiments (fire tests) should be carried out. This is becauseCFD simulations have some limitations, especially regarding the interaction between sprinkler/dropsof water and solid fuel.In addition to the wall design, other factors may also impact the spread of fire, such as e.g. ceilingheight, the design of the floor slab, and the distance between cars. These factors were not examined inthis study. E.g., simulations show that a ribbed floor slab (floor slab with underlaying beams) mayhave a large impact on local flow conditions and thus the spread of fire. To examine these parametersit is recommended that the existing fire spreading model be used, and if relevant validated throughexperimental research.

Publisher
s. 60
Serie
RISE Rapport ; 2022:95
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-62515 (URN)978-91-89711-35-8 (ISBN)
Merknad

Dette prosjektet er finansiert av Direktoratet for samfunnssikkerhet og beredskap (DSB) ogDirektoratet for byggkvalitet (DiBK), og er utført som en del av prosjektporteføljen underforskningsavtalen mellom DSB og RISE Fire Research. Prosjektets bakgrunn og målsetting erbeskrevet i kapittel 1.

Tilgjengelig fra: 2023-01-11 Laget: 2023-01-11 Sist oppdatert: 2023-04-19bibliografisk kontrollert
Yang, A., Aamodt, A., Samuelsen, P. H., Olsø, B. G., Haukø, A.-M. -. & Meraner, C. (2022). Fire safety of ventilation systems and fire incidence reports in Norwegian schools. In: ROOMVENT 2022: . Paper presented at 16th ROOMVENT Conference, ROOMVENT 2022, 16 September 2022 through 19 September 2022. EDP Sciences
Åpne denne publikasjonen i ny fane eller vindu >>Fire safety of ventilation systems and fire incidence reports in Norwegian schools
Vise andre…
2022 (engelsk)Inngår i: ROOMVENT 2022, EDP Sciences , 2022Konferansepaper, Publicerat paper (Fagfellevurdert)
Abstract [en]

School fires are causes of concern in many countries. Although most of these fires are minor in terms of heat release rate, the amount of smoke produced can be substantial and cause significant damage beyond the room of origin. Currently, Norwegian schools have a wide spread of different ventilation strategies and systems, and building owners struggle with how to test, maintain and keep them fire safe. A systematic survey of fire incidences and ventilation strategies in schools for three municipalities in Norway was done to gain better insights into fire safety in schools. The results indicated that the place of origin is often in locker rooms/toilets, kitchen, or outdoors, and the fires were usually deliberately set. For non-arson fires, electrical failure was the most common cause. The majority of the fire incidences were small but would often result in smoke damage and spread of soot in the building, leading to high restoration costs for the local municipality. A lack of documentation of the fire safety and the function of the ventilation system was also identified, indicating a need for improved routines and systems for registering fire incidences and documentation of the technical systems. © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/)

sted, utgiver, år, opplag, sider
EDP Sciences, 2022
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-64017 (URN)10.1051/e3sconf/202235602001 (DOI)2-s2.0-85146866131 (Scopus ID)
Konferanse
16th ROOMVENT Conference, ROOMVENT 2022, 16 September 2022 through 19 September 2022
Merknad

Funding details: Norges Forskningsråd, 321099; Funding text 1: This study is a part of the project "BRAVENT – Efficient smoke ventilation of small fires", and is funded by the Research Council of Norway, grant no. 321099.

Tilgjengelig fra: 2023-02-22 Laget: 2023-02-22 Sist oppdatert: 2023-02-22bibliografisk kontrollert
Meraner, C., Li, T. & Sanfeliu Meliá, C. (2021). Avgassing fra litium-ion batterier i hjemmet.
Åpne denne publikasjonen i ny fane eller vindu >>Avgassing fra litium-ion batterier i hjemmet
2021 (norsk)Rapport (Annet vitenskapelig)
Abstract [en]

This study evaluates venting from lithium-ion batteries in homes and is commissioned by the Norwegian Directorate for Civil Protection (DSB) and the Norwegian Building Authority (DiBK). The main objective is to study the extent to which venting from a battery in a dwelling can pose a risk for people, focusing on the consequences associated with venting. The Norwegian fire statistics database BRIS was used to identify relevant scenarios. Based on these scenarios, a total of nine numerical simulations of gas dispersion in a generic dwelling were carried out. Boundary conditions, such as gas quantity and composition, were based on a literature study. The simulations were used to evaluate the potential for accumulation of an explosive gas mixture, exposure to toxicity-related gases (both asphyxiants and irritants) and the possibility of detection of carbon monoxide (CO). Electric car batteries, electric bikes, electric scooters, electric hoverboards and larger, stationary battery energy storage systems are found to be the lithium-ion batteries with the highest energy content, which are most common in homes. Other electrical appliances – consumer products make up a larger share in the fire statistics, but these have a lower energy content and thus less potential to pose a major risk for people. Electric cars that are charged in the garage and larger batteries used for energy storage contain the most energy and therefore have the potential for the most severe consequences. However, these batteries are not stored or charged/discharged in living areas, while electric bikes/ scooters/ balancing boards are often stored and charged in the living room, hallway and bedroom. Electric bikes and similar batteries are also subjected to more mechanical and thermal loads compared with battery energy storage systems. It is therefore assumed that the frequency of incidents involving these batteries will be larger than the frequency of incidents involving battery energy storage systems. Therefore, the simulations in this study focused on venting from an electric bike battery (from a single cell and from an entire pack) in the hallway to a generic dwelling. A quantitative risk analysis of the risk associated with electric bike batteries compared with the risk associated with battery energy storage systems was not carried out. Lithium-ion batteries undergoing a thermal event typically emits 1-3 litres of gas per ampere-hour (Ah) at 26 °C and 3.7 volts (V), depending on battery chemistry and state of charge (SOC). Venting from lithium-ion batteries contains carbon dioxide, flammable components such as carbon monoxide, various hydrocarbons, methanol and hydrogen, as well as toxic components such as hydrogen fluoride, hydrogen chloride and hydrogen cyanide. The relatively large proportion of flammable gases (e.g. around 30% hydrogen) makes venting from lithium-ion batteries an explosion hazard. Although batteries with a low state of charge emit less gas than batteries with a high state of charge, the risk of explosion of batteries with a low state of charge may be larger, since the likelihood of late ignition is larger. There are many different types of lithium-ion batteries on the market and several methods for battery safety tests. Today, there is no unified, public system or database with an overview of data for venting from thermal events in lithium-ion batteries. Such a system would be useful, to cover knowledge gaps and to provide data that can be used in risk evaluations. The results show that the largest amount of flammable gas mixture, 26 litres, was accumulated by venting from a 400 watt-hour (Wh) electric bike battery pack, which was placed on a shelf in a small hallway of 3.5 square meters. When the thermal event was limited to a single battery cell, 3.6 litres of flammable gas were formed. Moreover, the results show that the location of the battery plays an important role in the accumulation of flammable gas. When the battery is stored in a partially enclosed area, such as a shelf, the gas can accumulate. The results also show that, especially for venting from a battery pack, it is best to store the batteries in large and wellventilated rooms. No explosion risk analysis was performed related to the accumulated flammable gas clouds. Fire gases from lithium-ion battery fires are generally not significantly more toxic compared with comparable plastic fires, but have the potential for low concentrations of more harmful gases, such as hydrogen fluoride (HF), to be released. The results of the simulations carried out in this study show that the limits for health-hazardous or fatal gas concentrations are exceeded by a thermal event in a lithium-ion battery. Toxic gases can have an asphyxiating and an irritating effect on humans. The results show that the critical value of irritating gases obtained before the limit value of asphyxiating gases. Hydrogen chloride (HCl) and hydrogen fluoride (HF) reached most rapidly health-hazardous or fatal gas concentrations, and these gases also spread most in the room. Furthermore, the results show that risks for people associated with exposure to toxic gases are primarily relevant when the entire battery pack is involved in the thermal event. When the thermal event is limited to a single cell, the simulations show that critical gas concentrations are reached only nearby the battery. If, on the other hand, a thermal event spreads to the entire battery pack, it leads to critical levels of toxic gases throughout the room after about 1 minute for a small room (3.5 m2 ), and in the entire upper half of a large room (43.5 m2 ) after about 4 minutes. To reduce the risk of toxic gas venting, the same measures are recommended as for the reduction of the risk of accumulated flammable gas. Larger lithium-ion batteries should be charged and stored in well-ventilated rooms that are not living areas or part of the escape route, ideally in external buildings. This is consistent with NELFO's recommendations for battery energy storage systems in residential buildings. However, costs/ benefits must be considered, especially for electric bikes and smaller batteries containing less energy than battery energy storage systems. Furthermore, closed doors are good physical barriers to prevent or delay gas and smoke spread in the dwelling. Another important barrier recommended to reduce the risk associated with venting from or fire in a lithium-ion battery is early detection. It is especially important since a thermal runaway develops very quickly, compared with, for example, a fire that starts as a smouldering fire. In this study, only a coarse analysis of the possibility of early detection of increased concentration of carbon monoxide was carried out. The results suggest that combination detectors near the battery may be a good measure to ensure early detection. Recommendations for further work identified in this study are the validation of the simulations by conducting battery fire tests of relevant electric bike batteries and conducting large-scale experiments for validation of gas dispersion and detection. It is also recommended to evaluate the potential overpressure that a delayed ignition (explosion) of gas can generate. Furthermore, it should be considered conducting a similar study for battery energy storage systems or other scenarios with significantly higher energy content than electric bike batteries.

Publisher
s. 90
Serie
RISE Rapport ; 2021:17
Emneord
Lihium-ion batteries, Li-ion batteries, e-bike, BESS, thermal runaway, venting, explosion risk, toxic gas, exposure, dwelling, numerical simulation, CFD. Litium-ion batterier, Li-ion batterier, elsykkel, energilagringssystem, termisk hendelse, avgassing, eksplosjons risiko, giftig gas, eksponering, bolig, numerisk simulering.
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-53489 (URN)978-91-89385-01-6 (ISBN)
Tilgjengelig fra: 2021-06-08 Laget: 2021-06-08 Sist oppdatert: 2023-06-08bibliografisk kontrollert
Meraner, C., Aamodt, E., Storesund, K., Wingdahl, T. & Holmvaag, O. A. (2021). Effektiv, skånsom og miljøvennlig slokking av brann i mindre bygningsenheter.
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2021 (norsk)Rapport (Annet vitenskapelig)
Abstract [en]

This study evaluates efficient, low-exposure and environmentally friendly extinguishing of fires in small building units and is commissioned by the Norwegian Directorate for Civil Protection (DSB) and the Norwegian Building Authority (DiBK). The main objective is to increase the knowledge on how to extinguish fires in smaller building units efficiently in terms of time and water amount, with minimal exposure of the fire service to smoke, heat and direct contact with soot, as well as minimal environmental exposure in case of extinguishing water run-off. For a holistic evaluation of firefighting methods, the tactical assessments and priorities of the fire service were also studied. In total seven medium-scale fire tests were carried out in a 13.5 m2 compartment with a ceiling height of 2.4 m, a ventilation opening of 0.54 m2 and an adjacent corridor. The fuel in the experiments consisted mainly of a sofa with mattresses according to specifications given in the "open space" test specified in the standard IMO Resolution 265 (84) and walls clad with OSB boards. One experiment was carried out with real furniture. The study focuses on indirect extinguishing (i.e., cooling of the fire gases) with four different extinguishing methods, which are: • Coldcut cobra cutting extinguisher and water, • Spray nozzle and water, • Spray nozzle and foam, • Fognail extinguishing spear and water. The extinguishing was started based on a temperature criterion of 350°C, 80 cm below the ceiling. The water consumption during extinguishing, the fire compartment temperature, as well as the particle and the gas concentration (CO, CO2, etc.), were measured during the experiments. Measuring devices for temperature, polycyclic aromatic hydrocarbons (PAHs) in particulate phase and volatile organic compounds (VOCs) were attached to a firefighter’s jacket to measure exposure. The firefighters stayed, during all experiments, for at least 1.5 minutes in the fire compartment to ensure a measurable PAH and VOC exposure. The experiments were furthermore documented with video recordings from several angles and infrared video of the fire compartment. After four of the trials, interviews with the fire service were conducted to evaluate the tactical assessments made during the firefighting effort. In the experiments, all extinguishing methods caused the temperature in the smoke layer to drop below 150°C within 2.5 minutes and the flaming fire was extinguished. The fire re-ignited in all experiments approx. 6 minutes after the start of the experiment, except for experiment F4, extinguishing with foam, where there was re-ignition after approx. 4 minutes. The experiments showed that the cutting extinguisher and Fognail have a good effect, even under "artificial" limitations in the experiments (duration and direction of the extinguishment). Both of these extinguishing methods used approximately the same amount of water. As the purchase costs for a Fognail are significantly less than for a cutting extinguisher, the Fognail has been found to be not only an efficient extinguishing method but also beneficial from a cost/benefit perspective. Purchasing costs are important for the fire service, especially for smaller fire services. Foam had the poorest cooling effect in the experiments and led to the fastest re-ignition. It was therefore concluded that foam is at high temperatures the least suited extinguishing method to reduce the temperature in the fire compartment. However, it is important that the use of foam is considered depending on the given fire scenario since the present study did not evaluate all properties and possible benefits of foam (such as the ability to cover flammable liquid). Furthermore, it can be assumed that foam can have a better effect when the temperature in the fire compartment is first lowered by using an external extinguishing method. The combination of foam and external extinguishing methods was not investigated in the present study. It is therefore recommended to evaluate this combination in future studies. To use an external extinguishing method (cutting extinguisher or Fognail) as an immediate measure in advance of internal firefighting gives the following advantages compared with smoke diving without the use of an external extinguishing method: • less soot and less explosive/toxic fire gases in the fire compartment, • better effect of the secondary internal extinguishing agent, • faster reduction of the temperature in the fire compartment, • less sauna effect (high humidity can cause heat to penetrate the clothes of the firefighters, which in turn can lead to injuries and that the smoke divers must retreat). The measurements during the experiments show that the use of cutting extinguishers or extinguishing spears can reduce exposure to the fire brigade with regard to heat and contact with particles. It was not possible to identify a clear trend for exposure to the carcinogens (PAH and VOC) measured at the firefighter’s jacket, by comparing the different extinguishing methods in the experiments. The experiments and interviews with the fire service further showed that the firefighter underestimated the negative ejector effect that ventilation openings into the fire compartment have. That is, placing a nozzle near an opening can lead to more oxygen being supplied to the fire which aggravates the situation. The video recordings from the experiments are published together with this report and will be a good learning tool for the fire service.

Publisher
s. 104
Serie
RISE Rapport ; 2021:73
Emneord
Slokking, skjærslokker, brannvesenet, brannforsøk, utvendig slokkemetoder
HSV kategori
Identifikatorer
urn:nbn:se:ri:diva-56637 (URN)978-91-89385-63-4 (ISBN)
Tilgjengelig fra: 2021-09-21 Laget: 2021-09-21 Sist oppdatert: 2023-03-02bibliografisk kontrollert
Organisasjoner
Identifikatorer
ORCID-id: ORCID iD iconorcid.org/0000-0002-3445-8074
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