Smoke Management

Spanish manufacturer Construcciones y Auxiliar de Ferrocarriles developed an innovative alternative for compartmentation, based on a smoke extraction system, to guarantee safe conditions during evacuation processes in a passenger unit. To demonstrate its performance in a train unit, a real-scale experimental programme, supported by the application of fire computer modelling, was applied in a new Construcciones y Auxiliar de Ferrocarriles’ rolling stock. The new smoke exhaust system aims to extract the smoke generated during a fire in the passenger area by exhaust fans of the heating, ventilation, and air conditioning system, allowing the ingress of fresh exterior air in the lower part of the rear ends of the car. These key elements create an air flow that evacuates the smoke to prevent people from being exposed to it. Full-scale fire tests were developed in the train unit following the Australian standard AS 4391-1999. A fire of 140 kW was used, and the smoke was generated by a clea...

This paper is concerned with enhancing fire safety of existing expanded polystyrene (EPS) based false roofing. Hotels, Hospitals, Shopping malls and offices built over a time have false roofing made of very light insulation panels within a metal framework. This is generally done to improve thermal insulation in addition to visual aesthetics by covering overhead electrical wiring that has come up arbitrarily after construction. Present investigation is on introducing a low cost in-situ fire-safety enhancement process. Experiments in 1m 3 cubic and 5 m × 8.5 m × 2.4 m rooms with low density EPS panels much like in practice were conducted at various power levels ranging from 25 to 315 kW, with gypsum coating of 2 mm over the panels only as well as over the metal framework. Safety features considered were egress time and smoke level, the former being well recognized with a 180 s value set and the latter to determine if the height available for egress is adequate for escape. Two results ...

A new type of train configuration, known as Open Wide Gangway (OWG) is becoming popular, particularly in underground environments. Previous fire modelling analysis demonstrated that the OWG configuration was considered safe as or safer than conventional configurations as it reduced the likelihood of flashover. However, these studies have ignored the impact on evacuation of the spread of fire effluent to non-fire cars. Here we explore the fire safety offered by conventional and OWG configurations using coupled fire and evacuation modelling techniques. Two tunnel train situations are considered; one in which the car side doors are available for evacuation (train in a wide tunnel) and the other in which only the end cab doors are available (train in a narrow tunnel). Two population configurations are considered, fully and half loaded. Two ignition sources are also considered, one representing an accidental fire and the other an arson fire. The analysis demonstrates that while the OWG configuration may produce improved fire performance in the car of fire origin compared to the conventional configuration, if the interaction of the fire effluent with the evacuating passengers is considered, the OWG configuration results in a significantly greater number of casualties in virtually all the scenarios considered.

In case of fire, atria constructive features favor the spread of smoke, becoming its management a challenge. Thus, the effect of different venting conditions on the dynamics of atrium fires is studied herein. Five full-scale fire experiments have been numerically analyzed to explore the influence of the make-up air. Due to the lack of experiments that exists in atria extensive modeling to extract more knowledge is required. Subsequently, 84 simulations with FDS v6 have been carried out, considering different vent areas (air velocity from 0.4 m/s to 5.3 m/s) and configurations, two Heat Release Rate values (2.5 and 5 M W), and two pan locations. It is demonstrated that make-up air velocities lower than the prescribed limit of 1 m/s may induce adverse conditions, being recommended to assess the complete fire scenario with even lower values, depending on the inlets distribution, in terms of smoke production. The results also show that asymmetric configurations are prone to induce circulation around the flame which can generate fire whirls. Thus, this numerical study links two fire types allowing the connection of pool fires to fire whirls, which completely differ in behaviour, for the sake of design of fire safety.

In case of fire, atria constructive features favor the spread of smoke, becoming its management a challenge. Thus, the effect of different venting conditions on the dynamics of atrium fires is studied herein. Five full-scale fire experiments have been numerically analyzed to explore the influence of the make-up air. Due to the lack of experiments that exists in atria extensive modeling to extract more knowledge is required. Subsequently, 84 simulations with FDS v6 have been carried out, considering different vent areas (air velocity from 0.4 m/s to 5.3 m/s) and configurations, two Heat Release Rate values (2.5 and 5 M W), and two pan locations. It is demonstrated that make-up air velocities lower than the prescribed limit of 1 m/s may induce adverse conditions, being recommended to assess the complete fire scenario with even lower values, depending on the inlets distribution, in terms of smoke production. The results also show that asymmetric configurations are prone to induce circulation around the flame which can generate fire whirls. Thus, this numerical study links two fire types allowing the connection of pool fires to fire whirls, which completely differ in behaviour, for the sake of design of fire safety.

For the general public, healthcare facilities are always a safe and secure place for treatment. Generally, healthcare institutions are equipped to deal with exterior interruptions, but circumstances brought on by internal risks are more serious and frequently require an emergency evacuation of the facility. An incident happened at the radiodiagnostic setup of a tertiary care institute in North India. This fire incident created panic among staff and patients. At the place of casualty, there were around 150 persons, including staff, patients, and their attendants. Immediately after the confirmation of the fire incident, the fire department and security department took action in the form of fire control and smoke evacuation. Though six fire handling staff required minor emergency services for asphyxia due to smoke inhalation and were cured by oxygen support only, none of the patients was affected due to timely smoke evacuation. Most often, smoke management techniques implemented are compartmentation, pressurization, dilution, ventilation, buoyancy, and airflow. So, we concluded that the step of timely smoke evacuation and preventing the spread of smoke by various methods help to reduce fatality due to smoke. The training programs and mock drills give stakeholders the needed knowledge, skills, and practice they need to safeguard patients and employees.

SUMMARYThe development of fire‐safety measures for high‐speed passenger trains has been focused on preventing fire initiation or delaying fire growth and spread through small‐scale tests of the materials used in trains. However, new fire‐safety approaches for trains consider a systemic approach. This approach considers numerous global factors that influence fire dynamics, such as the influence of vehicle design, selection of materials, and active and passive protection systems installed. In the present paper, the results of small‐scale and full‐scale tests carried out on the new generation of high‐speed trains operating in Spain are presented. This rolling stock is classified as category B according to the Technical Specification for Interoperability and Operation Category 3 according to EN 45545–1. The results confirmed good fire behaviour using both approaches (small and full‐scale tests). Additionally, several analyses have been performed, including an analysis of the quality of ...

Smoke is the most deadly factor in vehicular tunnels fire since smoke spreads in heading harmonize with passenger's evacuation way. It reduces visibility and can cause fatalities by suffocation. This paper presents a numerical study of the effect of extracting the smoke by different system of ventilation on smoke spread inside the vehicular tunnel, like (water mist system with transverse ventilation and longitudinal system with jet fans and solid curtain with transverse system and semi transverse system) Also tenable conditions were checked at human level. FDS 6.5.1 ver. was used to predict the various parameters of temperature, and visibility and Co concentration. Eight cases were conducted; Cases 1, 2, 3 and 7 were done to compare between four different ventilation systems at 30 MW. Case 4, 5, 6 and 8 were done to compare between three different ventilation systems at 100 MW.

The development of fire-safety measures for high-speed passenger trains has been focused on preventing fire initiation or delaying fire growth and spread through small-scale tests of the materials used in trains. However, new fire-safety approaches for trains consider a systemic approach. This approach considers numerous global factors that influence fire dynamics, such as the influence of vehicle design, selection of materials, and active and passive protection systems installed. In the present paper, the results of small-scale and full-scale tests carried out on the new generation of high-speed trains operating in Spain are presented. This rolling stock is classified as category B according to the Technical Specification for Interoperability and Operation Category 3 according to EN 45545-1. The results confirmed good fire behaviour using both approaches (small and full-scale tests). Additionally, several analyses have been performed, including an analysis of the quality of materials used for making different components of the passenger compartment and the influence of ignition source position on fire development.

In case of fire, atria constructive features favor the spread of smoke, becoming its management a challenge. Thus, the effect of different venting conditions on the dynamics of atrium fires is studied herein. Five full-scale fire experiments have been numerically analyzed to explore the influence of the make-up air. Due to the lack of experiments that exists in atria extensive modeling to extract more knowledge is required. Subsequently, 84 simulations with FDS v6 have been carried out, considering different vent areas (air velocity from 0.4 m/s to 5.3 m/s) and configurations, two Heat Release Rate values (2.5 and 5 M W), and two pan locations. It is demonstrated that make-up air velocities lower than the prescribed limit of 1 m/s may induce adverse conditions, being recommended to assess the complete fire scenario with even lower values, depending on the inlets distribution, in terms of smoke production. The results also show that asymmetric configurations are prone to induce circulation around the flame which can generate fire whirls. Thus, this numerical study links two fire types allowing the connection of pool fires to fire whirls, which completely differ in behaviour, for the sake of design of fire safety.

An approach of Computational Fluid Dynamic (CFD) modelling in fire safety strategy has gained a good result recognised by researchers and professional engineer. This paper describes the analysis of CO2 and temperature distribution inside the multipurpose hall. A

Longitudinal ventilation systems are commonly installed in new tunnels in big cities of the Far East including Mainland China, Hong Kong and Taiwan. Many tunnels are found and some of them are inclined at an angle to the horizontal. However, smoke movement in those tilted tunnels is not fully understood. Some longitudinal ventilation was designed based on presumed smoke movement pattern without experimental demonstration. Smoke movement pattern in a tilted tunnel model was studied by scale modeling technique. A 1/25 tunnel model of length 2 m with adjustable angle to the horizontal was constructed by transparent acrylic plastics. A small pool fire was put in with smoke generated by burning smoke pellets. Longitudinal ventilation was set up by a fan at one end. Different ventilation rates were adjusted by a transformer on controlling input to the fan motor. Experiments were performed with the tunnel angle varying up to 30 o to the horizontal. Observed smoke movement patterns indicated that the shape of the buoyant plume inside the tunnel depends on the tilted angle. Smoke would flow along the tunnel floor due to gravity. The bending angle of the plume depends on the tunnel angle. Tunnel inclined with higher angles to the horizontal would give larger amount of smoke flow. All results will be reported in this paper.

Spanish manufacturer Construcciones y Auxiliar de Ferrocarriles developed an innovative alternative for compartmentation, based on a smoke extraction system, to guarantee safe conditions during evacuation processes in a passenger unit. To demonstrate its performance in a train unit, a real-scale experimental programme, supported by the application of fire computer modelling, was applied in a new Construcciones y Auxiliar de Ferrocarriles’ rolling stock. The new smoke exhaust system aims to extract the smoke generated during a fire in the passenger area by exhaust fans of the heating, ventilation, and air conditioning system, allowing the ingress of fresh exterior air in the lower part of the rear ends of the car. These key elements create an air flow that evacuates the smoke to prevent people from being exposed to it. Full-scale fire tests were developed in the train unit following the Australian standard AS 4391-1999. A fire of 140 kW was used, and the smoke was generated by a clea...

During building fires, the most lethal factor affecting the occupants is the spread of smoke and toxic gases in the compartment, adjacent spaces, evacuation routes, and locations that are remote from the fire origin threatening life and damage to the property of the facility. Smoke and heat control in building fires is a major challenge for the egress of occupants as well as the fire-fighting operations. This paper provides an insight into risks due to the failure of smoke control and ventilation systems. Life and fire safety in and outside the building must also be analyzed in order to limit the spread of fire and control the spread of smoke thereby, offering adequate time and structural stability for the evacuation process as well as firefighting operations. This paper focuses on the identification of factors to establish the critical risk and reliability of the smoke control and exhaust systems in the buildings in an event of a fire.

Soot is perhaps the most harmful element in vehicle tunnels fire as smoke moves harmonize with the way passengers flee. It decreases visibility and can cause suffocation fatalities. This paper presents an empirical analysis on the effect of removing smoke through different ventilation systems on smoke distribution inside the vehicle tunnel, such as water mist system with transverse ventilation with several extractions of exhaust fans   Sustainable human conditions were also tested. FDS 2019 ver. was used to predict temperature, visibility, and concentration of co. Motivation/Background: Present work to investigate the effect of extracting the smoke by different system of ventilation on smoke spread inside the vehicular tunnel. Method: By FDS 2019 that used governing equations and naver-stocks equations. Results: We predicted in this paper smoke spread, temperature distribution, co concentration distribution and visibility. Conclusions: This study looks at the importance of smoke con...

This paper applies a novel and fast multiscale approach to model ventilation flows and fires in tunnels. The complexity and high cost of full CFD models and the inaccuracies of simplistic zone or analytical models are avoided by efficiently combining mono-dimensional (1-D) and CFD (3-D) modeling techniques. The multiscale model couples a 3-D CFD solver with a simple 1-D model allowing for a more rational use of the computational resources. The 1-D network models tunnel regions where the flow is fully developed (far field), and detailed CFD is used where flow conditions require 3-D resolution (near field). The multiscale method has been applied to model steady-state fires and tunnel ventilation systems, including jet fans, vertical shafts and portals, and it is applied here to study the transient flow interactions in a modern tunnel of 7 m diameter section and 1.2 km in length. Different ventilation scenarios are investigated to provide the timing to reach the critical velocity conditions at the seat of the fire and to remove the upstream back layering. The much lower computational cost is of great value, especially for parametric and sensitivity studies required in the design or assessment of real ventilation and fire safety systems. This is the first time that a comprehensive analysis of the transient fire and ventilation flow scenarios in a long tunnel is conducted.

Underground metro networks are expanding rapidly in all around the world and during the last few decades, tunnel fire accidents with severe casualties occurred in various countries. The frequency of the tunnel fire incidents will be increasing due to the increased amount of underground transportation routes in the upcoming years. In order to prevent the loss of lives in tunnel fires, accurate design of Tunnel Ventilation Systems is crucial. This research thesis presents the simulation of a mid-train fire scenario in the tunnel of the Marmaray Metro Line by the use of Fire Dynamics Simulator (FDS) Computational Fluid Dynamics (CFD) Software. The main goal of the simulation is to determine the efficiency of the emergency ventilation system in case of a mid-train fire in the metro tunnels and investigate the ways to increase the safety degrees in underground metro tunnels. Since mid-train fires are not widely studied, one purpose of this thesis is to attract attention to the risks asso...

An approach of Computational Fluid Dynamic (CFD) modelling in fire safety strategy has gained a good result recognised by researchers and professional engineer. This paper describes the analysis of CO2 and temperature distribution inside the multipurpose hall. A

Soot is perhaps the most harmful element in vehicle tunnels fire as smoke moves harmonize with the way passengers flee. It decreases visibility and can cause suffocation fatalities. This paper presents an empirical analysis on the effect of removing smoke through different ventilation systems on smoke distribution inside the vehicle tunnel, such as water mist system with transverse ventilation with several extractions of exhaust fans Sustainable human conditions were also tested. FDS 2019 ver. was used to predict temperature, visibility, and concentration of co. Motivation/Background: Present work to investigate the effect of extracting the smoke by different system of ventilation on smoke spread inside the vehicular tunnel. Method: By FDS 2019 that used governing equations and naver-stocks equations. Results: We predicted in this paper smoke spread, temperature distribution, co concentration distribution and visibility. Conclusions: This study looks at the importance of smoke contr...

In vehicular tunnel fire safety design, very low design fires [1] were adopted as reported [2,3] years ago. This assumption has to be reviewed because the style of living, the traffic flow, passenger loading, the amount of combustibles carried by cars, cargo vans or light goods vehicles (LGV) and heavy goods vehicles (HGV), and the expectations of citizens have drastically changed. Therefore, all these changes pose great challenges to the fire safety provisions for vehicular tunnels. Further, fire technology has improved significantly in the past decades, making it easier to put out big fires. This is the right time to review the fire safety provisions for both existing tunnels and the forthcoming tunnel projects. Note that there are urban traffic link tunnels (UTLT) [4] in China. Some identified problems can also be solved by using the new experimental data on heat release rate upon burning different types of vehicles. In 2011, the design fire was increased to 100 MW for HGVs in NFPA 502 [5].

Many big public transport terminals in the Far East including the airport and many subway stations [1] in Hong Kong are not fully covered by fire suppression and smoke exhaust systems. Only the cabin concept [2-4] was used in many big halls, but mostly protecting some areas for retail and catering. Apart from the hard efforts of the author and his students [5-19], very few systematic experimental studies were reported to demonstrate that the design [20-23] can control the heat release rate to a certain value, nor smoke would not spread to the entire big hall. Heat removed by operating the sprinklers in a cabin was not measured, but only presumed to be controlled within a small value such as 2 MW. Almost no full-scale burning tests appeared in the literature to demonstrate that the cabin concept would work as expected [24], particularly in the Far East, where social responsibility and education of citizens are very different from those in advanced countries. Taking the Hong Kong airport terminal as an example, it was observed that combustibles (apart from luggage) are always placed outside the cabin! Research results compiled in advanced countries might not be applicable to such developing areas [7]. Strong justification with full-scale burning tests is needed on watching flashover in a cabin fire as proposed [25,26].

Soot is perhaps the most harmful element in vehicle tunnels fire as smoke moves harmonize with the way passengers flee. It decreases visibility and can cause suffocation fatalities. This paper presents an empirical analysis on the effect of removing smoke through different ventilation systems on smoke distribution inside the vehicle tunnel, such as water mist system with transverse ventilation with several extractions of exhaust fans Sustainable human conditions were also tested. FDS 2019 ver. was used to predict temperature, visibility, and concentration of co. Motivation/Background: Present work to investigate the effect of extracting the smoke by different system of ventilation on smoke spread inside the vehicular tunnel. Method: By FDS 2019 that used governing equations and naver-stocks equations. Results: We predicted in this paper smoke spread, temperature distribution, co concentration distribution and visibility. Conclusions: This study looks at the importance of smoke control generally as well as the smoke control criteria in the automotive tunnel configuration which acknowledged them. Because the smoke barrier water mist screen with a transverse ventilation device improves the smoke removal technique. FDS is a valuable method for simulating smoke diffusion as well as other effects.