fire safety engineering methodology - transfeu · fire safety engineering methodology introduction...

Fire safety

engineering

methodology

Heinz Reimann

Senior Engineer

Bombardier Transportation

> EC TRANSFEU Project

> Final Conference

Hotel Marivaux, Brussels

25th September 2012

Fire safety engineering methodology

Content

Introduction

Definitions

Presentation of general Fire safety

engineering (FSE) methodology

Fire safety objectives and performance

criteria

Methods and tools for fire performance

and passenger evacuation

2


Introduction

Transfeu is using for fire safety engineering International

and European Standards where applicable.

Transfeu development results shall guide future Standard

development

The definition of Fire safety engineering according

ISO 13943;2000 is the following:

Application of engineering methods based on

scientific principles to the development or

assessment of designs in the built environment

through the analysis of specific fire scenarios or

through the quantification of risk for a group of fire

scenarios

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Definitions

RSET Time required for escape

The term RSET is defined in Definition in (ISO13571, 2007) as

“Calculated time required for occupants to travel from their

location at the time of ignition to a place of safe refuge”.

Definition for use of Transfeu

Estimated time required for passenger and staff to escape

from their location at time of ignition to a safe area in the

train.

Note : Transfeu do not consider the safety of passenger in the

safe refuge. (Safe area outside a train.)

4


Definitions (continue)

ASET Available safe escape time

Definition according (ISO13571, 2007)

For an individual occupant, the calculated time interval

between the time of ignition and the time at which conditions

become such that the occupant is estimated to be

incapacitated, i.e. unable to take effective action to escape to

a safe refuge or place of safety.

NOTE 1 The time of ignition may be known, e.g. in the case of a fire model or a fire test, or it

may be assumed, e.g. it may be based upon an estimate working back from the time of

detection. It is necessary to state the basis on which the time of ignition is determined.

NOTE 2 This definition equates incapacitation with failure to escape. Other criteria for ASET

are possible. It is necessary to state if an alternative criterion is selected.

NOTE 3 Each occupant may have a different value of ASET, depending on that occupant’s

personal characteristic

5



Safe area outside a train

A safe area outside a train is a survivable space, inside or

outside the tunnel, for passengers and staff to find refuge after

they have evacuated from a train.

A passenger station (in a tunnel or at the surface) can be a

safe area if it meets the requirements of paragraph 4.2.1.5. of

TSI SRT.

Note: Definition out of the revision of TSI SRT V2.0

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Safe area in the train

A safe area in a Train for passengers and staff area is the

passenger’s area on board a train of operation category B,

where the passengers and or the staff have shelter from the

immediate effects of a fire, such as heat exposure, smoke

opacity and toxic gases during a minimum time of 15 minutes.

Note: Protected by fire barriers according (prEN 45545-3,

2012) with the IE test criteria’s. The effects of smoke transfer

are considered minimal if the integrity requirements of (prEN

45545-3, 2012) are respected.

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General methodology for FSE

● Definition of fire safety objective and associatedcriteria of performance and acceptance

● Fire risk analysis and design fire scenarios

● Choice of numerical simulation tools for theevaluation of fire performance

● Input data to use in the numerical simulation tools


Fire safety objectives

The fire safety objectives are identical for Passenger Railway

vehicles, Passenger buses and Passenger ships.

The performance criteria’s are different according the different

hazards.

The following objectives shall be taken in account:

Prevent occurrence of fire

Protect passenger and staff in the event of a fire on

board

Provide means of escape for passenger and staff

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Fire safety performance criteria

For technical areas in Passenger ships

The following areas are considered as technical areas:

Cabinets for Electrical -, Control - and Auxiliary equipment

Diesel engine area.

These technical areas shall be protected with fire barrier having

a separation. The following requirements are for duration of 60

minutes according to EN 1363-1 and the heat curve of ISO 834.

E Integrity

I Insulation

S Smoke leakage (Preventing smoke passage)

The diesel engine area shall be protected with a fire fighting

system

10



Fire effluents which reduces the mobility for evacuation

Heat exposure

For evacuation of the passenger and staff, the heat exposure

anywhere on the evacuation path out of the danger zone shall

not be bigger than as a heat dose max 60 kJ/m2 over the energy

from heat flux level of 1 kW/m2; heat flux max 2.5 kW/m2

Reference: (The Swedish National Board of Housing, Building

and Planning – BOVERKET: Guidance on performance-based

design of buildings (2011))

Temperature exposure

For evacuation of the passenger and staff, the maximal

temperature in the evacuation environment shall be 80 °C.

11




Smoke optical density

During evacuation time out of the danger zone the passenger

and staff in passenger vehicles and ships shall have visibility of

the escape route of a length of 16 m within a height of 1.5 m.

In passenger buses the visibility of the escape route of a length

of 5 m within a height of 1,5 m from the floor level.

For passenger ships the escape ways shall be guided in

accordance with ISO 15370

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Toxic effect of fire gasesUsing the FED/FEC concept described in ISO 13571 provides a calculation

method for estimating the time available for occupants to escape from a fire

(i.e. ASET). The method examines both the asphyxiant effect (based on an

FED calculation) and the irritant effect (based on an FEC calculation) of fire

gases. The time available for escape depends on which effect is predicted to

occur first.

Estimation of the minimum required ASET Railway vehicles Operation category 1 4.5 Minutes

Railway vehicles Operation category 2,3 7.5 Minutes

Railway vehicles Operation category 4 20 Minutes

Passenger buses 4.5 Minutes

Passenger ships 20 Minutes

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Fire risk analysis and Design Fire Scenario

Risk analysisbased on the following investigations:Analysis of accidental fires with regard to ignition sources, type,

intensity and location.Identification of fire hazards (different procedures will be used to

identify the hazards; HAZOP, PHA, FMEA etc.)

Design fire scenariowill take into account:Vehicle geometry (train, ship, bus), ventilation, passive fire protection (reaction to fire performance of materials

and products) fire resistance of structures, escape routes active fire prevention (detection, smoke extraction, extinguishing).

will define the design fire


Result of the fire risk analyse


Design fire scenario

● Scenario 2A and 2B

● Scenario 1 A and 1B


Fire ignition source

Ignition source for the passenger area for

Railway vehicles and ShipsThe maximum ignition source of interiors is a piece of burning luggage and

this can be considered equivalent to model 5 described in Annex A of

prEN 45545-1. (75kW during 2 minutes and 150KW during 8 minutes)

This luggage can be placed by accident in front of or above a seat. A 100 g

UIC 564-2 – paper cushion (newspapers) is of equivalent effect to primary

ignition.

This ignition source is identical with the design fire for full-scale and real-scale

test and was validated during the risk analyse in Task 4.2

Note: Any volume used for the placement of luggage in accordance with the

operational protocol which is less than 0,55m x 0,35m x 0,25m in any

orientation shall not be considered as a location of a burning luggage

(model 5 ignition source).

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Ignition source for technical areas for Railway vehicles

●Technical areas with High voltage circuits, which are directly

linked with the catenary line and those containing Diesel

engines are protected with fire barriers and the ignition source

is considered to be equivalent to model 5 described in Annex

A of pr EN 45545-1.

(75kW during 2 minutes and 150KW during 8 minutes).

●Technical areas with electrical circuits which are electrically

protected, the ignition source is considered to be equivalent to

model 2 according Annex A of pr EN 45545-1

(A radiant flux of nominal value 25 kWm-2 applied to an area

of 0,1 m2.)

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Ignition source for the passenger area for buses

The primary ignition source should be equal to a paper cushion

and similar to the ignition source 1 as defined in Annex A of pr

EN 45545.

There is no possibility of starting a fire from luggage in the

passenger area; luggage shall be placed in a special luggage

compartment.

Ignition source for technical area for buses

For diesel engines placed in the engine bay model 5 according

Annex A of pr EN 45545-1is applicable.

(75kW during 2 minutes and 150KW during 8 minutes)19




Introduction and objectives

Existing numerical simulations tools are principally developed

for building applications but surface transport investigations do

pose specific implications with regard to the influence of

different parameters on the fire and smoke development.

This is why adapted simulation tools will be developed in the

WP5, which will be validated by tests on real trains in the

WP6.

However, many conditions which are considered in the train

are similar for other surface transportation vehicles.

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Numerical simulation tools for a FSE study

Calculation tools, to evaluate the following performances:

Fire growth, smoke movements (FDS)

Thermal transfer, heat fluxes

Structural behaviour in case of fire

Atmospheric dispersion

Simulation of product reaction or resistance to fire

Toxicity effect




Simulation tool of fire effluents

Transfeu partners agreed to work with computer codes

designed for fire:

A general fire modelling code, Fire Dynamics Simulator (FDS)

version 5.5, developed in partnership between NIST (USA)

and VTT (Transfeu partner).

Simulation tool for passenger evacuation

We decided to use FDS + Evac, because it is inside fire

simulation model FDS, which is used for trains in TRANSFEU

project.

Tool for assessing fire barriers during design

Assessment of fire barrier design with cone-calorimeter test

22


Development plan for the use the FDS for Fire

safety engineering

Request for Transfeu

The project was to develop new simulation tools for trains in

order to predict the ASET (Available Safe Escape Time) in

simulating the different following effects on passenger and

staff:

Visibility (due to smoke)

Incapacitation (due to toxic gas)

Tenability (Temperature, radiation)

23


Development plan for the use the FDS for Fire

safety engineering

Three methods have been developed in order to model the fire

source from the simplest one (prescribed source method to the

most complex one (calculated pyrolysis rate method).

Method 1 Simply yield (Prescribed HRR and burnt area)

Method 2 Kinetic yield (Prescribed HRR and thermal properties)

Method 3 Detailed yield (Pyrolysis calculated)

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Input data for validation of

the numerical simulation tools

Types of data:

Thermal physical and chemical data

Resistance and reaction to fire small scale tests

Full & Real scale tests for validation of the

numerical simulation tools using the

Thermal, physical and chemical data;

small scale test results.


Reaction to fire Small scale tests

Heat release Spread of flame

Opacity of smoke

+ FTIR Gas cell

ISO 5660-1 ISO 5658-2

ISO 5659-2

FTIR Gas cell++


Large & real experiments for validation of the

numerical simulation tools Small Scale fire

Tests on material

Real scale Fire test

on product in

vehicle

Small scale fire

models

Full scale fire

test on product

Full scale fire

models

Fire growth, smoke movements

models in vehicle

validation

validation

Pyrolysis Inputs

ISO 5660-1


The use of Simulation tools for

Fire safety engineering

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Transfeu Task Validation results with full & real scale tests

Use for fire safety engineering

Develop new simulation tools for trains taken into account in order to predict the ASET (Available Safe Escape Time) in simulating the different following effects on passenger and staff:

Visibility (due to smoke)

Incapacitation (due to toxic gas)

Tenability (Temperature, radiation)

For the multi-scale methodology

The validation of Full scale and Real scale test are in progress.

The simulation of production of opaque smoke needs additional investigations.

The model of the ignition source with different heat density zones shall be done more intensive to predict the burnt area of the impacted combustible material

It seems that the use of model 1 have finally the most benefit for simulation of the complete passenger area. The model 2 and 3 can be used for detail study Additional consideration will be made during FDS simulation that the burned area taken in account in a realistic way.


The use of Simulation tools for

Fire safety engineering

29

Transfeu Task Validation results with full & real scale tests

Use for fire safety engineering

Completed FDS + EVAC tool for passenger evacuation in Railway vehicles

Validation of the different scenario according the actual knowledge was successful

The simulation tool was used to calculate the minimum requested time for ASET

FDS tool for the assessment of fire barrier during design with the cone calorimeter

The simulation results using Cone-calorimeter results were validated with medium size furnaces successful.

Furthermore, cone calorimeter experiments together with FDS simulations can be used to define real scale fire separating performance for assumed fire exposures.


Thank You very much for Your attention !

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