TUNNEL VENTILATION AND FIRE SAFETY

A case study ofPirpanjal Tunnel T80

0f USBRL Project-Hitesh Khanna & Sandesh SrivastvaIrcon International Limited

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PIR PANJAL TUNNEL- AN OVERVIEW• IRCON INTERNATIONAL LIMITED is the principle

execution agency for DHARAM-QAZIGUND-BARAMULLAH section of USBRL project of Northern Railway.

• Pir Panjal Tunnel, between Qazigund and Banihal, is the landmark tunnel of the project, connecting Kashmir Valley to Jammu Region.

• At 11.215 Kms., it is the LONGEST transportation tunnel in India.

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T 80 ON USBRL PROJECT

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T80 SECTION AND PLAN

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• Max Over burden 1100 mts.

• B. G. Rly. S/L Track• 3 mts. Road• 48.5 m2 X-Sec Area• Water Proof

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Ventilation Requirement•Normal Operation (Depends on Traction Mode):

– Maintain Sustainable Air Quality in side the Tunnel • Pollutant Levels• Oxygen Levels • Temperature

• Emergency Rescue Management (Depends on Fire Load):– Fire and Smoke Management to Assist Emergency

Evacuation Strategy– Fire Effect Mitigation

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• Detailed Design Consultants– M/s Geoconsult-

RITES JV– Overall Tunnel Design

and Top level Supervision, observations based On-site design with NATM approach

– Ventilation, Rescue, E&M Design

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• HBI Haerter– Ventilation

Design Proof Check

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STANDARD THRESHOLD POLLUTION LEVEL

American Conference of Governmental and Industrial Hygienists and Continuous Limit for working environment. (Ref. DPR)

1) Long Term Sustainable Threshold Values for Industrial Working Environment (8 hours working)

2) Non-Continuous Exposure, with intermittent Air Exchange3) Limits up-to 15 minutes exposure

(1) (2) (3)

CO 50 75 400

NO 25 37.5 35

NO2 5 5 5

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Design Limit

Pir PanjalCO 50 ppm 200 ppm 50 ppm

NO 25 ppm 35 ppm 90% of NOx

NO2 4 ppm 5 ppm 10% of NOx

Sum: NOx 29 ppm 40 ppm 25 ppm

CO2 5000 ppm 10000 ppm 5000ppm

SO2 5 ppm 5 ppm 5ppm

Particulates (PM)

Not defined Not defined< 0,012m -̂1 (extinction coefficient)

Temperature 40°C 50°C for a train passing, max.65°C -

Element8 Hours

Exposure15 Min. Exposure

ADOPTED THRESHOLD ENVIRONMENT PARAMETERS

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LOCO MOTIVE EXHAUST DATA

emission

g/kWh ORE UN UIC

US EPA (line haul

locomotive, Tier 0)

WDM2/ALCO 2530HP

WDM3A/ALCO 3073HP

WDM4/ALCO 4000HP

CO 3 6.7 3 6.71 0.52 0.72 0.56NOX 12 12.7 10 10.73 13.56 12.42 7.62

Particle 0.5 0.8 0.25 0.30 ??? ??? 0.39

measured emission dataStandards

What happens if a tunnel fire occurs ?

even in the upstream direction against the longitudinal velocity!!

the tunnel roof fills with smoke

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Ventilation For Fire and Smoke Management

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Ventilation For Fire and Smoke Management

• Smoke To Be Directed, to Permit Escape in other direction

• Avoid Backlayring– Critical Velocity

of Airflow to be Maintained

"BACKLAYERING

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Stratification Of Smoke

• Smoke Rises to Top– Permits Escape

Underneath in cooler air

– Flashover Control• Typically Stratification

lasts for 500-800mts– 30-40 MW fire– Tunnel Geomtry, Slope– Air Flow Conditions

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VENTILATION DESIGN INPUTS SMOKE CONTROL

• Input Parameters– What is the maximum size of any fire, which may

reasonably be expected to occur, given the use of tunnel

• (Design Fire Curve- Fire/Smoke Vs. Time)

– What Corresponding Ventilation is required to prevent smoke Backflow

• Critical Velocity to be attained

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VENTILATION SYSTEMS

• Longitudinal– Air Set in Motion along Tunnel Axis

• Portal to Portal, Same speed though out the Tunnel Length• No Division into Aerodynamic Segments• Low Cost, Does not need Transverse air Egress Points• Time to Purge Foul Air depends on Air Flow Velocity, Tunnel

Length

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VENTILATION SYSTEMS (contd.)

• Transverse– Two Independent Ducts (Fresh Air Inflow and Exhaust

air exit)• Can create Aero dynamic Sections (In case of Fire)• May Need Transverse Exit Routes (Low Overburden Ventilation

Shafts, Stations in Metros• Costlier to Install, and operate (More Aerodynamic Losses)

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VENTILATION SYSTEMS (contd.)

• Semi-Transverse– Combination of Longitudinal and Transversal System:

• Separation of Fresh and Exhaust air• Reversible-

• Fire Case Fresh Air through Portal, Exhaust through Ventilation Stack, Permitting Aerodynamic Separation

• Normally, Fresh air Through Ventilation Stacks• Larger Tunnel X-Section

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VENTILATION SYSTEMS (contd.)• Considering the merits and demerits of each

ventilation system and since there is no station and stop in pir-panjal tunnel; longitudinal ventilation system has been considered fit to apply in this tunnel & worldwide also, only longitudinal ventilation is applied to rail/road tunnel or underground projects. Only in underground stations and stops, transversal and semi transversal might be applied.

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Boundary Conditions (Geometric Data)

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Boundary Condns. (Geometry)

Description DetailsTunnel length 11.215 mLength from Banihal Station to South portal

1450 m

Length from North Portal to Qazigund Section

4774 m

Finished cross section 48.50 m2

Average elevation above sea level 1734.75 m

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Thermo Dynamic DataITEM REFERENCE

Geothermal Heat Input Depending on Parent Rock Temperature and Temp. Gradient to Tunnel Rock Surface

Para 3.2.2

Temperature, Pressure and Density Gradient of Air Inside the Tunnel

Para 3.2.2.1

Portal Meteorological Data Para 3.2.3

Portal Temperature, Wind Pressure, Natural Buoyancy Pressure and Pressure Differential between the Portals

Para 3.2.3.1, 3.2.3.2, 3.2.3.3, 3.2.3.4

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Aero Dynamic DataITEM REFERENCE

Tunnel Characteristics:Portal Losses, Tunnel Wall Friction, Wind Velocity at PortalsAir Pressure and TemperatureAir Density

Para 3.4

Critical VelocityCritical Froude NumberTemperature Near The Fire Scene

Critical Velocity to prevent Back LayeringConstant Air flow to Blow the Smoke away from Passengers Exiting in Other Direction, Drive HC Vapours Away from Fire Source to avoid Flash Over

Jet Fan Installation Factor & Piston Effect Of The Train and Train Data

Para 3.5 & 3.6

THERMODYNAMICS...buoyancy…

temperature rise leads to lower density of airwarm mass of rock

heat of train

…. and to longitudinal velocity - chimney effect

a thermodynamic effect

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...wind pressure and meteorological effects...

T u n n e lwind pressure effect depends on:

- meteorological situation

- tunnel data wind pressure

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AERODYNAMICS...piston effect …

T u n n e ldepends on:

for the Pir Panjal tunnel

the piston effect leads to:

• longitudinal velocity of about 5.34 m/s

• fresh air of about 241 m3/s

- ratio between tunnel and train cross section area

- tunnel resistance: length of tunnel, wall friction and others

- speed of train and aerodynamic drag

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Calculation Of Fresh Air Flow• Para 3.6.2

– Fresh Air Demand due to Gaseous Emissions– Fresh Air Demand due to Particulate Emissions– Fresh Air Demand oxygen Depletion (Diesel Engine)– Normalization Of Temperature (Below 40 deg. C)

after passage of 5000T train Uphill• Ventilation Design (Normal Case) Para 4.0

– Time to restore Safe Conditions Inside the Tunnel– Waiting Time for Next Train to enter (after exit of

Uphill Loaded Train)

Train with 40 km/h needs about 17 min to pass tunnel

l o n

g i

t u d

i n

a l

v e

l o

c i t

y

longitudinal velocity

-5,00

-4,00

-3,00

-2,00

-1,00

0,00

1,00

2,00

3,00

4,00

5,00

0 60 120 180 240 300

time [min]

[m/s

]

TRAIN SIMULATION TO ASSESS VENTILATION NEED

For normal operatrion

No artificial ventilation is needed

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Ventilation Design ApproachNatural velocity achieved inside tunnel :

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• Select Design Fire Load:Investigations were performed by Deutsche Bahn AG – Diesel Loco → Peak 20

MW– Electric Loco → Peak 12

MW– Passenger train → Peak 25

MW– Freight train → Peak 8-52

MW (depending on load)• Design Fire Adopted 40

MW (Two Dsl. Loco in Tandem)

Emergency Ventilation Design Fire

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TEMPERATURE / SMOKE PROGRESSION ALONG THE LENGTH HEIGHTComputation fluid dynamics (camatt)

– Design Fire– Tunnel Geometry– Fan design &

Configuration – Thermo Dynamics– Fluid Dynamics

Emergency Ventilation Design Approach:

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TEMPERATURE / SMOKE PROGRESSION ALONG THE LENGTH HEIGHT BY NEAR FIRE CONDITIONS BY 3DCFDObjective:-

– To clarify condition d/s of fire– Influence of longitudinal flow

velocity on the tenability d/s from fire

– Design Fire load 25 MW– Smoke plum should remain

2.5m above rail level during self evacuation time

– Use of Deutsche Bahn Fire curve for smoke release rate and critical velocity

Emergency Ventilation Design Approach:

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Ventilation Requirement with Electric Traction

► No ventilation required for regular operation

► Fire load for electric locomotives < Diesel powered ones

►

According to design procedure and UIC → fire load depends on type of train→ typical criteria *: ● Diesel → Peak 20 MW● Electric → Peak 12 MW● Passenger train → Peak 25 MW● Freight train → Peak 8-52 MW (depending on load)

► Chosen design criteria → 40 MW

► Electric traction does not impact ventilation design

* According to Deutsche Bahn AG

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FINAL VENTILATION DESIGN

Jet Fan (Main Tunnel)

Jet Fan (Access Tunnel)

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Proposed E&M System Outline

Redundant Power Supply ~ I-67, I-65

CCTV System I-68

Emergency and Service Phone System I-42

Tunnel Radio System I-66, I-2

Public Address System (Speaker System) ~Fire Detection System Fire Fighting System (Water Line,

Extinguishers) I-24, I-64

Ventilation System I-25

Emergency Lighting I-41

Control Centre ~

World Standard Pir Panjal CommentsUIC

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FUNCTIONAL X-SECTION OF T80

E&M System

Consists of the following 433/250V – 50 Hz Power SupplyEmergency Power SupplyEarthing & Potential Equalisation

SystemTunnel LightingTunnel FittingsFire Detection SystemBuilding Power & Lighting Installations Room Ventilation & Air Conditioning

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Ventilation Control Eqpmnts Visibility detection Airflow measurement Automatic operation Basic ventilation

Visibility dataAirflow directionWind speed

Fire VentilationFire AlarmVisibility dataAirflow directionWind Speed 38

VENTILATION CONTROL STRATEGYREQUIREMENTS TO THE STAFF (NORMAL

OPERATION)Train staff

►Report about type and direction of train entering the tunnel

►Break down: Report the location of the break down

Control center staff

►Know about train type and direction

►Monitor emission levels in the tunnel

►Monitor appropriate operation of ventilation

►Instruct the train driver to shut down engines (if necessary) 39

Ventilation Control Strategy

Requirements to the staff (emergency operation)

Train staff

►Guide passengers in the right direction

►Communicate and Local Guidance for Passenger Rescue

Control center staff

►Select and confirm the appropriate mode of operation

►Monitor the appropriate mode of ventilation

►Support rescue operation (e.g. coordinate the rescue train)

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THANK YOU