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Ventilation strategies for road tunnels in different countries and consequences using Fixed Fire Fighting System (FFFS)

John Baptiste, Rohan LU (2017) VBRM05 20171
Division of Fire Safety Engineering
Abstract
A study is carried out on the ventilation strategies for road tunnels in different countries and consequences using fixed fire fighting systems (FFFS). The type of ventilation strategy for road tunnels can ensure the safety of people during the evacuation stages and protection of the rescue services during their intervention of the fire. Ventilation strategies vary from country to country and therefore it is important to get a suitable strategy which can be applied in these countries [1]. FFFS in road tunnels are defined as fire fighting equipment, which is permanently installed in the tunnel with a pipe system that water or other extinguishing agents. Usually FFFS are water spray systems and can be either high pressure or low pressure... (More)
A study is carried out on the ventilation strategies for road tunnels in different countries and consequences using fixed fire fighting systems (FFFS). The type of ventilation strategy for road tunnels can ensure the safety of people during the evacuation stages and protection of the rescue services during their intervention of the fire. Ventilation strategies vary from country to country and therefore it is important to get a suitable strategy which can be applied in these countries [1]. FFFS in road tunnels are defined as fire fighting equipment, which is permanently installed in the tunnel with a pipe system that water or other extinguishing agents. Usually FFFS are water spray systems and can be either high pressure or low pressure systems. Such systems will be able to fight fires that are relatively large and thereby potentially prevent a major disaster. In a tunnel without a fire suppression system, a slightly lower ventilation velocity is preferred to slow down the fire growth at the initial stage of evacuation. At the fire fighting stage the ventilation velocity can be adjusted up to critical velocity. In order to explore the effects of FFFS during different ventilation conditions, an analysis will be conducted on a large scale Runehamar and model scale tunnel fire experiments conducted at SP. The analysis show that the longitudinal ventilation system and FFFS will provide a tenable environment for safe evacuation. (Less)
Popular Abstract
A study is carried out on the ventilation strategies for road tunnels and consequences using fixed fire fighting systems (FFFS) in different countries. The type of ventilation strategy used for road tunnels can ensure the safety of people during the evacuation stages and protection of the rescue services during their intervention of the fire. Ventilation strategies vary from country to country and therefore it is important to get a suitable strategy which can be applied in these countries. The commonly used types in tunnels include longitudinal, transverse and semi-transverse, with and without air and smoke dampers. This study focuses on longitudinal systems.
In such systems, the longitudinal ventilation velocity selected is important to... (More)
A study is carried out on the ventilation strategies for road tunnels and consequences using fixed fire fighting systems (FFFS) in different countries. The type of ventilation strategy used for road tunnels can ensure the safety of people during the evacuation stages and protection of the rescue services during their intervention of the fire. Ventilation strategies vary from country to country and therefore it is important to get a suitable strategy which can be applied in these countries. The commonly used types in tunnels include longitudinal, transverse and semi-transverse, with and without air and smoke dampers. This study focuses on longitudinal systems.
In such systems, the longitudinal ventilation velocity selected is important to prevent the smoke back flow (backlayering) and can affect the fire in the tunnel in a positive or negative way depending on the stages of the fire. FFFS in road tunnels are defined as fire fighting equipment, which is permanently installed in the tunnel with a pipe system that water or other extinguishing agents. Usually FFFS are water spray systems and can be either high pressure (water mist) or low pressure systems (deluge system) shown in Figure 1 . Such systems will be able to fight fires that are relatively large and thereby potentially prevent a major disaster. In a tunnel without a fire suppression system, a slightly lower ventilation velocity is preferred to slow down the fire growth at the initial stage of evacuation.

Figure 1 FFFS after activation of the system
In order to explore the effects of FFFS during different ventilation conditions, an analysis will be conducted on a large scale Runehamar and model scale tunnel fire experiments conducted at SP (Statens Provningsanstalt) Technical Research Institute of Sweden. The analysis shows that the longitudinal ventilation system and FFFS will provide a tenable environment for safe evacuation. This project aims to explore the effects of the conditions inside the road tunnel with and without FFFS on evacuees form experimental data found from scale models and fullscale SP data. The thesis recommends a realistic longitudinal ventilation strategy with and without FFFS. By calculating and analyzing the concentration of the fractional effective dose or fractional incapacitating dose (FED/FID) for a free burn test and a test with a FFFS, the results at a certain distance from the fire is analyzed. The study will propose a ventilation strategy to use together with the FFFS system.
The study of the test data shows that the use of FFFS decreased the temperatures in the tunnels and was not affected by the different velocities. In the experiments, the longitudinal ventilation velocity was set at 3 m/s, which prevented backlayering of smoke during the test, thus proving effective during the evacuation process. The longitudinal ventilation velocity of 2 m/s used in the Runehamar tunnel 2016 test can be used to prevent long backlayering. The study confirmed that at the initial stages of the fire that a velocity of 2 m/s be used and after the FFFS is initiated the velocity can be increased to 3 m/s. At a distance of 42 m away from the fire, the model scale test showed that the longitudinal ventilation velocities can increase the temperature in the free burn test. However, FED heat conv will not affect the people.
The study of the test show in the cases of the Runehamar test it can be concluded that people at a distance of 1000 m away from the fire will be safe with and without FFFS for test conducted 2016, however in the full scale test of 2013 due to failure of the FFFS people are affected by the concentration of FED asphyxia of 0.3 is obtained after 44.95 minutes of exposure time. This will although be dependent on the type of material burning. The calculated concentration for FED heat conv. of 0.3741 was obtained after 30 minutes of exposure time was found in the model scale. The early activation of the FFFS reduces the concentration significantly. The different longitudinal ventilation velocities used in the test namely: 2 m/s, 3 m/s and 6 m/s has shown to be effective in controlling the fire at both distances and providing a safe environment for people. It was shown that the most effective of the three velocities was 3m/s when FFFS is operating. The early activation of the FFFS made a difference in controlling the fire thus it’s recommended for use in road tunnels. The results of the study support the idea that although people will be safe in the road tunnels, the first few minutes are important during a tunnel fire for the ability of people in the tunnel to escape. (Less)
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author
John Baptiste, Rohan LU
supervisor
organization
course
VBRM05 20171
year
type
H2 - Master's Degree (Two Years)
subject
keywords
Longitudinal ventilation, fixed fire fighting system (FFFS), fractional effective dose (FED)
report number
5548
other publication id
LUTVDG/TVBB-5548-SE
language
English
id
8915119
date added to LUP
2017-07-05 08:49:28
date last changed
2017-07-05 08:49:28
@misc{8915119,
  abstract     = {A study is carried out on the ventilation strategies for road tunnels in different countries and consequences using fixed fire fighting systems (FFFS). The type of ventilation strategy for road tunnels can ensure the safety of people during the evacuation stages and protection of the rescue services during their intervention of the fire. Ventilation strategies vary from country to country and therefore it is important to get a suitable strategy which can be applied in these countries [1]. FFFS in road tunnels are defined as fire fighting equipment, which is permanently installed in the tunnel with a pipe system that water or other extinguishing agents. Usually FFFS are water spray systems and can be either high pressure or low pressure systems. Such systems will be able to fight fires that are relatively large and thereby potentially prevent a major disaster. In a tunnel without a fire suppression system, a slightly lower ventilation velocity is preferred to slow down the fire growth at the initial stage of evacuation. At the fire fighting stage the ventilation velocity can be adjusted up to critical velocity. In order to explore the effects of FFFS during different ventilation conditions, an analysis will be conducted on a large scale Runehamar and model scale tunnel fire experiments conducted at SP. The analysis show that the longitudinal ventilation system and FFFS will provide a tenable environment for safe evacuation.},
  author       = {John Baptiste, Rohan},
  keyword      = {Longitudinal ventilation,fixed fire fighting system (FFFS),fractional effective dose (FED)},
  language     = {eng},
  note         = {Student Paper},
  title        = {Ventilation strategies for road tunnels in different countries and consequences using Fixed Fire Fighting System (FFFS)},
  year         = {2017},
}