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Ilustraciones The design of fire protection systems in underground power plants goes beyond what is solely prescriptive. This is because, in addition to the risks of the operation of rotating and electrical equipment, there is difficulty in evaluating the time required for the evacuation of personnel due to the long distances between the access portal and the power plant. Therefore, it is necessary to carry out performance-based designs to reduce the level of uncertainty left by prescriptive designs and verify that personnel can evacuate properly. In this monograph, three different physical modeling tools (PMTs) were analyzed: Fire Dynamics simulator (FDS), Consolidated Model of Fire Growth and Smoke (CFAST) and ANSYS-FLUENT, in a case of application of fire in an oil-insulated transformer with an estimate heat release rate of 8746 kW, for which five different fire scenarios were analyzed. A prescription-based approach to the characterization of a fire protection system and a fire risk analysis in hydroelectric power plants was initially undertaken. This part was particularly devoted to a fire in an electric transformer and lead to the design of a fire protection system exclusively based on prescriptive recommendations. Five fire scenarios that considered either a confined system (the transformer cell) or an unconfined system (the transformer cell and the adjacent hallway) as well as the availability of smoke evacuation and water deluge protection were then modeled with all the three PMTs. The results from all the PMTs simulations were compared, particularly those related with smoke temperature and predicted Heat Release Rate (HRR). The available evacuation times (ASET) calculated by the PMTs and associated to risks related to changes in temperature, concentration of carbon monoxide, carbon dioxide and oxygen and thermal radiation were compared with the required evacuation time (RSET) calculated by the prescriptive method. It was identified that the time required for the evacuation of personnel is less than the time available. The results of the smoke layer temperatures reported by the PMTs were compared with those calculated by the prescriptive method for the definition of the smoke extraction system. Finally, the functionality of each PMT to model the proposed fire scenarios was evaluated. FDS could be used simulate the five proposed scenarios. CFAST demanded to artificially adjust the HRR to represent the deluge extinguishing system. Even though a more detailed representation of the geometry was possible with FLUENT, only the steady-state cases could be modeled in a similar computational time frame that of FDS and with a personal computer. Even though CFAST was deemed as the easiest to use PMT, FDS was confirmed as the standard to use when modeling fires as its mathematical complexity allows for a more reliable fire representation. Although FLUENT has potential for fire simulation, its application by fire safety engineering (FSE) practitioner would be limited to steady state simulations if the simulations are to be carried out in the time frame and with the typical computational facilities available in industry. Los diseños de los sistemas de protección contra incendios en las centrales de generación subterráneas van más allá de lo netamente prescriptivo. Lo anterior se debe a que, adicional a los riesgos de la operación de los equipos rotativos y eléctricos, existe una dificultad para evaluar el tiempo necesario para la evacuación del personal debido a las largas distancias entre el portal de acceso y la casa de máquinas. Por lo tanto, se hace necesario realizar diseños basados en desempeño con el propósito de disminuir el nivel de incertidumbre que dejan los diseños prescriptivos y verificar que el personal pueda evacuar de manera adecuada. En este trabajo de grado se analizaron tres diferentes herramientas de modelación física: Fire Dynamics Simulator (FDS), Consolidated Model of Fire Growth and Smoke (CFAST) y ANSYS-FLUENT, en un caso de aplicación de un incendio de un transformador de potencia refrigerado por aceite con una tasa de liberación de calor estimada de 8746 kW, para el cual se analizaron cinco escenarios de incendios diferentes. Inicialmente se caracterizó con base en el método prescriptivo un sistema de protección y de riesgos contra incendios en centrales hidroeléctricas, específicamente en lo relacionado con el transformador eléctrico. Esta caracterización permitió el diseño de un sistema protector contra incendios a partir de recomendaciones prescriptivas. Se simularon cinco escenarios de incendios que consideraban sistemas confinados (la celda del transformador) o no confinados (la celda del transformador y el pasillo aledaño) así como la disponibilidad de extractores de humo y sistemas de diluvio. Los resultados de las simulaciones de todas las herramientas de modelación física se compararon, especialmente aquellos relacionados con la temperatura del humo y la velocidad de liberación de calor (HRR, Heat Release Rate). Inicialmente, los tiempos de evacuación disponibles (ASET) calculados por métodos computacionales para niveles de riesgo relacionados con los cambios en la temperatura, la concentración de monóxido de carbono, dióxido de carbono y oxígeno y la radiación térmica se compararon con el tiempo de evacuación requerido (RSET) calculado por método prescriptivo. Se identificó que el tiempo requerido para la evacuación del personal es menor al tiempo disponible, por lo cual, el personal puede evacuar a una zona segura. Posterior a esto, se compararon los resultados de las temperaturas de la capa de humo reportadas por las herramientas de simulación física con las calculadas por el método prescriptivo para la definición del sistema de extracción de humos. Finalmente, se evaluó la funcionalidad de cada una de las herramientas de modelación física para adaptarse a los escenarios propuestos. FDS permitió simular los cinco escenarios; con CFAST fue necesario de forma artificial ajustar la HRR para representar el sistema de extinción por diluvio. En el caso de FLUENT solo fue posible simular, dentro de un tiempo de cómputo similar al de FDS y en un computador personal, dos escenarios que se presentaban en estado estable. Si bien CFAST es la herramienta de modelación física más fácil de usar, FDS se ratificó como el estándar de uso en la simulación de incendios pues la complejidad de su desarrollo matemático le permite una mejor caracterización del incendio. Si bien FLUENT tiene potencial para simular un incendio, su aplicación por parte de profesionales especializados en el área de seguridad contra incendios se limita a simulaciones en estado estable dentro de la capacidad de cómputo normalmente disponible para este tipo de análisis en la industria. (Texto tomado de la fuente) Maestría Magister en Ingeniería Mecánica Incendios y explosiones Área Curricular de Ingeniería Mecánica

Large Eddy Simulations (LES) of smoke extraction duct system (SEDS) in single compartments of different volumes (i.e., 128 m(3), 512 m(3) and 2400 m(3)) with FDS 6.5.3 are presented. The required grid resolution for accurate flow inside the duct systems is discussed and the influence of different SEDS design parameters (i.e., shape and position of duct system, number and position of extraction openings) on the smoke extraction efficiency of the system is analysed. The extraction rates applied to the SEDS are determined a-priori based on simplified calculations with these estimates compared against the predicted CFD results (i.e., in terms of predicted smoke free heights inside the compartments). Overall, the numerical predictions are satisfactory (i.e., within less than 5% errors) in most of the scenarios considered, apart from the 2400 m(3) compartments, where the smoke free heights are 20% lower than expected. The analysis of the numerical simulation results reveals some important aspects, including that the use of multiple extraction openings is not efficient, in terms of smoke extraction, in the same duct of the same compartment and that the local velocities, at the level of the extraction openings, can potentially exceed the maximum allowed design values. Among the SEDS design parameters, the position and shape of the duct (i.e., rectangular or flat) as well as the position of the extraction opening(s) do not have a significant influence in terms of predicted smoke free heights.

The purpose of this paper is to present results from functional testing of ventilation systems in schools during activated fire alarm. It was investigated whether the results had coherence with the ventilation strategy in the fire safety concept and the function description for the ventilation system. Functional testing was performed at several schools in three different municipalities in Norway. Results from the preliminary mapping showed that some of the personnel responsible for maintenance of the ventilation systems lacked knowledge about the system's function during fire. Older schools often don't have a fire safety strategy at all, whereas newer schools and renovated schools normally have well documented fire safety strategies, including the ventilation system's function during fire. However, there is little or no information in the building's MOM-documentation (management, operation and maintenance) about how functional testing must be performed. The functional testing showed several incoherencies with the fire safety strategy of the school buildings.

This thesis work presents deals with the issue of fire safety consideration in naturally ventilated buildings. The particular case of the interaction between the wind and hot smoke movement is pinpointed. In the first chapter, basics of natural ventilation mechanisms are shown. Then, the analysis of building’s regulations, relating to fire safety and thermal comfort, allows to highlight potential conflicts and normative gaps. Theses gaps and conflicts are illustrated through real buildings feedbacks. The challenge of indoor flow pattern studies for safety purpose is hence underline. In the second chapter, scientific’s barriers in relation with the transitions between existing flow pattern, when wind and buoyancy are opposed, are identified thought a literature review. A scaled experiment is proposed in the third chapter, using density difference between air and helium, to identify internal flow pattern when wind opposes buoyancy. Three stable internal flow patterns are identified. A power law characterizing the transitions between identified flow pattern, involving source Froude number and dynamic pressure ratio between source jet and wind, is found. In the fourth chapter, the identified flow pattern are observed when the tested volume is emptied, and a relation between the initial Richardson number Ri and the characteristic emptied time θ is found. Furthermore, specific behaviour of internal flow, when the volume is emptied, is quantitatively study thanks to a numerical model. In the last part of this thesis, transitions law between internal flow patterns allows to introduce a new wind dependent fire safety index. A methodology is then proposed to both analyse fire safety and thermal comfort in building. The presented method gives the opportunity to avoid conception conflicts underlined in the first chapter of the present work.; Ces travaux de thèse, répondent à la problématique liée à la sécurité incendie des bâtiments ventilés naturellement, et notamment au comportement des fumées chaudes lorsqu’elles interagissent avec le vent. Le premier chapitre concerne la mise en exergue de la problématique bâtimentaire, au travers de la présentation des moteurs de la ventilation naturelle, d’une analyse règlementaire croisée sécurité incendie / confort thermique, et de multiples retours d’expériences. La nécessité d’étudier les régimes d’écoulement interne lorsque le vent interagit avec la fumée est mise en évidence. Ainsi, dans le second chapitre, les verrous scientifiques, associés à l’identification des régimes d’écoulement en convection mixte, sont soulevés à l’aide d’une analyse de la littérature. Dans le troisième chapitre, nous nous intéressons à la caractérisation des régimes d’écoulement internes lorsque le vent oppose le tirage thermique dans un volume contenant une source constante générant les forces de flottabilité. Une expérimentation densimétrique, air/hélium, à échelle réduite est proposée. Trois régimes d’écoulement internes stables sont mis en évidence. Les transitions entre ces régimes sont caractérisées par une loi puissance, mettant en jeu le nombre de Froude, relatif à la source générant les forces de flottabilité, et le rapport entre la pression dynamique de la source et celle du vent. Dans le quatrième chapitre, ces régimes sont également identifiés, expérimentalement et numériquement, lors de la vidange de fluide léger lorsque le vent oppose le tirage thermique. Une relation entre le nombre de Richardson et un temps de vidange caractéristique est identifiée. L’étude numérique nous permet d’analyser des dynamiques particulières de vidange de manière quantitative. Dans la dernière partie, les lois de transitions entre régimes d’écoulement permettent d’introduire un indicateur de sécurité dépendant des conditions de vent. Une méthode d’analyse, qui considère à la fois la sécurité et le confort, est alors proposée pour éviter les conflits mis en avant dans les retours d’expériences du chapitre 1.

This thesis work presents deals with the issue of fire safety consideration in naturally ventilated buildings. The particular case of the interaction between the wind and hot smoke movement is pinpointed. In the first chapter, basics of natural ventilation mechanisms are shown. Then, the analysis of building’s regulations, relating to fire safety and thermal comfort, allows to highlight potential conflicts and normative gaps. Theses gaps and conflicts are illustrated through real buildings feedbacks. The challenge of indoor flow pattern studies for safety purpose is hence underline. In the second chapter, scientific’s barriers in relation with the transitions between existing flow pattern, when wind and buoyancy are opposed, are identified thought a literature review. A scaled experiment is proposed in the third chapter, using density difference between air and helium, to identify internal flow pattern when wind opposes buoyancy. Three stable internal flow patterns are identified. A power law characterizing the transitions between identified flow pattern, involving source Froude number and dynamic pressure ratio between source jet and wind, is found. In the fourth chapter, the identified flow pattern are observed when the tested volume is emptied, and a relation between the initial Richardson number Ri and the characteristic emptied time θ is found. Furthermore, specific behaviour of internal flow, when the volume is emptied, is quantitatively study thanks to a numerical model. In the last part of this thesis, transitions law between internal flow patterns allows to introduce a new wind dependent fire safety index. A methodology is then proposed to both analyse fire safety and thermal comfort in building. The presented method gives the opportunity to avoid conception conflicts underlined in the first chapter of the present work., Ces travaux de thèse, répondent à la problématique liée à la sécurité incendie des bâtiments ventilés naturellement, et notamment au comportement des fumées chaudes lorsqu’elles interagissent avec le vent. Le premier chapitre concerne la mise en exergue de la problématique bâtimentaire, au travers de la présentation des moteurs de la ventilation naturelle, d’une analyse règlementaire croisée sécurité incendie / confort thermique, et de multiples retours d’expériences. La nécessité d’étudier les régimes d’écoulement interne lorsque le vent interagit avec la fumée est mise en évidence. Ainsi, dans le second chapitre, les verrous scientifiques, associés à l’identification des régimes d’écoulement en convection mixte, sont soulevés à l’aide d’une analyse de la littérature. Dans le troisième chapitre, nous nous intéressons à la caractérisation des régimes d’écoulement internes lorsque le vent oppose le tirage thermique dans un volume contenant une source constante générant les forces de flottabilité. Une expérimentation densimétrique, air/hélium, à échelle réduite est proposée. Trois régimes d’écoulement internes stables sont mis en évidence. Les transitions entre ces régimes sont caractérisées par une loi puissance, mettant en jeu le nombre de Froude, relatif à la source générant les forces de flottabilité, et le rapport entre la pression dynamique de la source et celle du vent. Dans le quatrième chapitre, ces régimes sont également identifiés, expérimentalement et numériquement, lors de la vidange de fluide léger lorsque le vent oppose le tirage thermique. Une relation entre le nombre de Richardson et un temps de vidange caractéristique est identifiée. L’étude numérique nous permet d’analyser des dynamiques particulières de vidange de manière quantitative. Dans la dernière partie, les lois de transitions entre régimes d’écoulement permettent d’introduire un indicateur de sécurité dépendant des conditions de vent. Une méthode d’analyse, qui considère à la fois la sécurité et le confort, est alors proposée pour éviter les conflits mis en avant dans les retours d’expériences du chapitre 1.

金沢大学理工研究域機械工学系, 延長が500m以下の船底型をした都市内道路トンネルを対象に，自動車火災が発生した場合の換気施設による排煙の有効性について検討した．検討には煙挙動CFD数値シミュレーションと避難数値シミュレーションを用いた．トンネル内に1.2m/sの自然風を有していると煙が拡がり，換気施設による排煙を行わない場合は10名を超える利用者が煙に暴露され避難が困難な状況となる．一方，換気施設による排煙を行った場合，自然風が存在する状況下においても0.3m3/s·m以上の排煙量を確保すると煙の拡がりは抑制され，煙に暴露される利用者は3名から0名程度に減少した．このことから，延長が短い場合でも利用者の避難時の安全性を確保するためには，換気施設による排煙が必要であることを確認した．\n The present paper indicates that effects of smoke extraction by ventilation system in road tunnel fires, which model tunnels adopted urban U-shaped tunnels shorter than 500 m length. The investigation used smoke CFD simulation and evacuation simulation. In the case with natural ventilation velocity 1.2 m/s, the situation where it difficult for over 10 users to evacuate due to exposure by smoke occurred with no smoke extraction by ventilation facilities. Meanwhile in the case with over 0.3 m3/s·m of smoke extraction by ventilation facilities, smoke propagation can be controlled even with natural ventilation existing, the number of users exposed by smoke decreased from 3 persons to 0. Hence, it was confirmed that even in short tunnels smoke extraction by ventilation facilities was necessary to keep the users' evacuation safety in tunnel fires.

Submitted to Energy and Buildings; Safety performance is one of the most important considerations in building design. Moreover, new environmental building design allows construction to have a sustainable relationship with the outdoor climate, especially in tropical context. This paper aims at evaluating how conception that allows natural ventilation by mean of passive strategies, affects fire safety performance in buildings. A methodology, combining safety and comfort through a global index, is proposed in order to understand how the consideration of fire safety can affect initial passive design. The use of dynamic thermal simulation associated with fire simulation gives the opportunity to quantify fire performance annually. Sensitivity analysis is performed by using delta moment index. This allows to evaluate the absolute impact of input parameter on both fire safety and thermal comfort outputs. A refined study is then performed by the use of conditional output distribution. It takes into account the relative importance given to fire Safety or thermal comfort concerns. The strong dependence of fire safety, in terms of smoke extraction, on weather conditions, building orientation, occupation profiles and seasons, is demonstrated in naturally ventilated buildings.

This report has been made after a 3 months internship within the design office Lombardi Lyon. The aim here is to show the need to improve fire risk culture and management. Therefore, a survey has been answered by 431 French people. This survey deals with the reaction in case of fire, in several situations. Then, two measures for the minimization on the consequences of a fire are displayed : the feedback or project post-mortem principle for tunnel fires and a casework of smoke extraction engineering for building fires. Although big progresses have been made in France since the early 2000s in the field on fire risk prevention, there is still much to be done, both at the technical level and the cultural level within the population., Ce rapport résulte d’un stage de trois mois dans les locaux du bureau d’études Lombardi Ingénierie à Lyon. L’objectif est ici de mettre en lumière la nécessité d’améliorer la culture du risque incendie en France. Pour ce faire, un sondage est réalisé au sein de la population française afin d’appréhender les connaissances des Français en matière de réaction face à un incendie dans diverses situations. Dans la suite du rapport, des dispositifs de minimisation des conséquences des incendies dans les tunnels et les établissements recevant du public sont exposés. Pour les incendies en tunnel, le principe du retour d’expérience est détaillé avec un exemple concret. Pour les incendies dans les établissements recevant du public, une étude de cas d’ingénierie du désenfumage est menée. Bien que d’énormes progrès aient été réalisés en France dans le domaine de la prévention du risque incendie, il reste encore aujourd’hui beaucoup à faire, tant au niveau technique qu’au niveau de la culture du risque au sein de la population.

Life safety is one of the objectives of fire engineering design for road tunnels. Fire engineering design requires maintaining a tenable condition for a period of time to allow occupants to evacuate to safety. This will be achieved by controlling the smoke under credible design fire scenarios in a tunnel. The critical location in a tunnel fire emergency condition is the tunnel region upstream of the fire, where occupants are most likely to reside as traffic jam can usually be created by the fire incident. Tenability for the downstream region of fire is not the main focus of this research because vehicles can generally drive out of the tunnel at a higher speed than that of the smoke flow, and local damper smoke extraction can help keep a tenable condition in the downstream region beyond the local fire zone, in case there is a congestion in the downstream region of the fire. To maintain a tenable condition in the upstream tunnel region from the fire incident, the required minimum longitudinal flow velocity to prevent smoke backlayering can be calculated based on NFPA 502 recommendations. This critical velocity takes no credit of the smoke extraction or active overhead fixed fire suppression effects. Smoke extraction with a dedicated smoke duct along the entire length of the tunnel is gaining popularity because of its efficiency and robustness in providing a tenable environment in the tunnel with unknown upstream and downstream traffic conditions. In this paper, a modified critical velocity to control smoke back-layering while smoke extraction and fire suppression systems are operating has been analyzed. This modified critical velocity is approximately 20% lower than the critical velocity that is recommended in NFPA 502. This allows significant savings on ventilation capacity for road tunnels which have a local smoke exhaust capability using a dedicated smoke duct. It is concluded that the smoke extraction performance is similar whether using ceiling dampers or vertical wall-mounted dampers for smoke capture to maintain tunnel tenability. However, tunnel gradients play a major role on the modified critical velocity for a nominated design fire and the required smoke extraction rate.

Magistrsko delo na celovit način obravnava požarno varnost v visokih stavbah. Analiza požarne varnosti je narejena na primeru stolpnice Kristalna palača, ki je danes z 89 metri najvišja stavba v Sloveniji (2016). Izdelan je model BIM (Archicad), uporabljen v programu za požarno (PyroSim) in evakuacijsko analizo (Pathfinder). Pri tem je model BIM optimiziran do te mere, da je lahko neposredno uporaben v programih za požarno in evakuacijsko analizo. Študija požarne varnosti Kristalne palače je izdelana na podlagi zadnje veljavne slovenske zakonodaje in tehnične smernice TSG-1-001:2010 ter smernice za visoke stavbe MHHR (Muster-Hochhaus-Richtlinie, 2008). Prikazana je primerjava v tem delu izdelane študije z obstoječo študijo, ki je bila narejena na podlagi švicarske smernice VKF. Na podlagi študije je izdelan tudi izkaz požarne varnosti za obravnavano stavbo. Pri požarni analizi so v računalniškem programu PyroSim analizirane tri ključne (referenčne) etaže. Pri tem so v modelu vključeni in analizirani vsi požarni sistemi, ki se nahajajo v analiziranih požarnih sektorjih (etažah), in sicer: sistem avtomatskega odkrivanja in javljanja požara, sprinklerski sistem, mehanski odvod dima in toplote ter naravni odvod dima in toplote. Rezultati širjenja dima po etaži so upoštevani pri analizi evakuacije v računalniškem programu Pathfinder, kjer je analizirana hitrost evakuacije iz stavbe. Podrobno pa je predstavljen (analiziran) tudi pomen dvigala za gasilce. Na koncu je prikazana še analiza varnostne razsvetljave v referenčni etaži, narejena v računalniškem programu DIALux. Za potrebe predstavitve ključnih rezultatov analiz je bila v računalniškem programu Lumion narejena tudi video animacija. This master's thesis comprehensively explores fire safety in high-rise buildings. A fire safety analysis was performed on a model of the Crystal Palace skyscraper, which, at 89 meters, is the tallest building in Slovenia today (2016). A BIM model of the entire building was generated (Archicad) to be used with the software for fire (PyroSim) and evacuation analysis (Pathfinder). The BIM model of the building was optimized in a way it could be directly imported into the software for fire and evacuation analysis. The fire safety analysis of the Crystal Palace was performed in line with the most recent applicable Slovenian laws, and technical guidelines TSG-1-001:2010 and MHHR (Muster-Hochhaus-Richtlinie, 2008). Furthermore, a comparison of the fire study performed as a part of this thesis and an existing study that was carried out in accordance with the Swiss VKF guidelines is presented. The study data were also used to prepare a fire safety statement for the concerned building. In the scope of the fire analysis,three key (reference) floors were analyzed using PyroSim software. All fire systems which are located in the studied fire compartments (floors) were taken into account in the numerical model, i.e. the automatic fire detection and fire alarm system, fire sprinkler system, mechanical smoke extraction system and natural smoke and heat extraction system. The results of the spread of smoke over the floor were taken into account in the evacuation analysis in Pathfinder which was used to analyze the speed of evacuation from the building. Furthermore, the importance of the fireman’s elevator is also presented (analysed) in the numerical studies. The last part of the thesis is dedicated to the analysis of the security lighting on the reference floor which was performed in DIALux. In order to present the key results of the analyses, a video animation was created in Lumion.

With the aim of evaluating capabilities of a ventilation system to control the spread of smoke in the emergency operating mode, thereby providing conditions for safe evacuation of people from a fire-struck area, computational fluid dynamics simulation of a fire in a semi-bedded garage was conducted. Using the experimental results of combustion dynamics of a passenger car on fire, optimal positions of ventilation openings were determined. According to recommendations by DIN EN 12101 standard, the operating modes of a ventilation system were verified and optimal start time of the smoke extraction system was defined.

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica O presente trabalho consiste na análise do funcionamento dos sistemas automáticos de detecção e extinção de incêndios de uma unidade industrial e dos sistemas de ventilação mais apropriados à protecção contra incêndios. São abordados os conceitos de fogo e de incêndio, nomeadamente a fenomenologia do fogo e os seus constituintes, passando pela caracterização da combustão e culminando nas fases de um incêndio. A temática da protecção contra incêndios, os meios de segurança activa e os métodos de extinção de incêndios são igualmente abordados, assim como a regulamentação em vigor que define os parâmetros em que um sistema de protecção contra incêndios é dimensionado. Os equipamentos de detecção e extinção de incêndios, em geral, bem como os detectores ópticos de fumo e por aspiração, os sistemas automáticos de extinção por água, a redes de incêndios armada (RIA) e os sistemas de abastecimento e bombagem de água para incêndios, em particular, foram analisados os seus dimensionamentos face à legislação vigente. A aplicação dos conceitos estudados a um caso de estudo é efectuada para o caso de uma unidade industrial, permitindo efectuar o dimensionamento de todos os sistemas que, de acordo com a legislação, seriam necessárias à respectiva protecção contra incêndio. Abstract: The present work consists in the analysis of the functioning of automatic fire detection and extinguishing fires of an industrial unit and ventilation systems most suitable to fire protection. Are approached concepts of heat and fire, in particular the phenomenology of fire and its constituents, the characterization of combustion and culminating in the stages of a fire. The issue of the fire protection, the active safety measures and methods of extinguishing fires are also discussed, as well as current regulations that define the parameters in which a fire protection system is dimensioned. Detection equipment and fire extinguishing, in general, as well as optical and vacuum smoke detectors, automatic fire extinguishing water systems, fire networks (RIA) and supply and water pumping systems for fire, in particular, were addressed and analyzed their sizing under the current legislation. The application of the studied concepts in a case study is carried out for a case of na industrial unit, allowing the design of all systems that according to the legislation would be necessary for its protection against fire.

In case of fire in an atrium, a smoke and heat control (SHC) system can be designed to improve safety inside the atrium. An important design criterion is the smoke free height in the atrium. This smoke free height is the result of a number of parameters, of which the fire heat release rate (HRR), the SHC extraction mass flow rate, the position of the extraction device or opening and the size and position of openings for make-up air are of primary importance. In the present paper, an extensive numerical study, based on computational fluid dynamics (CFD), is presented in which these parameters are varied. The presence of a downstand or balcony is not covered in the study at hand. From the results, a correlation is presented for adhered spill plumes in atria without downstand, relating the smoke extraction rate to the smoke free height in the atrium. The smoke layer in the atrium is illustrated to become multi-dimensional beyond a certain threshold value of the smoke extraction rate and existing correlations, which do not take this phenomenon into account, are not conservative. The position and exact size of the make-up air inlet openings are shown not to affect the observations, as long as the openings are sufficiently large.

Full-scale and reduced-scale measurements along with numerical simulations have been carried out in order to increase fire safety in car parks, with particular focus on the smoke back-layering (SBL). SBL is the distance covered by the smoke upstream of the ventilation flow with respect to the fire source. It has been measured in both full- and reduced-scales and the results are compared to the literature. The investigated car park (full- and reduced-scale) has been simplified: ceiling and walls are plain and the final layout is similar to a very wide road tunnel. Horizontal and vertical beams supporting the ceiling are not considered. Therefore the results obtained are only valid for large closed parks with a flat ceiling and uni-directional smoke and ventilation patterns within the investigated heat release rate range. The study serves double purposes: Empirical formulae can be obtained and the best model for SBL can be chosen from the existing correlations for road tunnel fires to be applied to car parks with the above described simplified geometries. If the results of the reduced-scale car park model are in accordance with the full-scale ones, the reduced-scale model can be used for more complex car park layouts, which is a very favorable solution in terms of both time and costs. In addition to the SBL investigation, unexpected flow phenomena at the entrance and extractors, respectively, are also explained by reduced-scale trials.

Wanneer brand uitbreekt in complexe gebouwen met binnenin een grote open ruimte, kan de gevormde rook zich doorheen die hele ruimte verspreiden. Om dit tegen te gaan, worden rookafvoersystemen geïnstalleerd. In het bijzonder in grote atria – denk aan een winkelcentrum of hotellobby – en grote gesloten parkeergarages is een dergelijk systeem essentieel voor de brandveiligheid. Voor het ontwerp van ventilatiesystemen wordt vaak een beroep gedaan op bestaande formules. Deze zijn echter niet altijd toereikend. Voor parkeergarages zijn geen formules beschikbaar, en worden formules gebruikt die ontwikkeld werden voor tunnels. In atria worden formules gebruikt die opgesteld zijn op basis van kleinschalige modellen en met beperkte geldigheid. Het is de vraag in hoeverre die formules bruikbaar zijn. Op deze vraag wordt in dit werk een antwoord gegeven. Gebruikmakend van computermodellen die de brand en rookbeweging simuleren, worden zowel in parkeergarages als in atria honderden simulaties verricht, waarbij een aantal verschillende parametervariaties – zoals het brandvermogen en de afmetingen van de ruimte – bestudeerd worden. Op basis van deze simulaties wordt ten eerste aangetoond dat kleinschalige experimenten onder bepaalde voorwaarden representatief zijn voor reële configuraties. Daarnaast worden ook nieuwe formules opgesteld voor het ontwerp van de rookafvoersystemen in parkeergarages en atria.

Brandrauch ist bei Gebäudebränden die Hauptursache für Todesfälle. Entsprechend wichtig ist es im Brandfall, den entstehenden Rauch kontrolliert abzuführen und Rettungswege für eine ausreichende Zeit rauchfrei zu halten. Architektonisch anspruchsvolle Gebäude und Zentren mit viel Publikumsverkehr erfordern oft maßgeschneiderte Konzepte, um die Schutzziele erfüllen zu können. Für die Wirksamkeit dieser Konzepte wird zunehmend der Nachweis durch praktische Überprüfungen gefordert. In diesem Beitrag werden Grundlagen der Entstehung, Ausbreitung und Beherrschung von Brandrauch beschrieben sowie Grundsätze für die praktische Überprüfung von Entrauchungskonzepten und -anlagen dargestellt. Anhand von Praxis-Beispielen werden Erfahrungen aus zahlreichen durchgeführten Rauchversuchen geschildert und Verbesserungsmöglichkeiten aufgezeigt.