Overview of the PRISME project Technical Description and...

Overview of the PRISME project

OECD – PRISME Project on Fire Propagation

Final Seminar

PRISME Project: Fires in Confined and Ventilated nuclear-type multi-compartments

Audouin L., Rigollet L., Pretrel H., Le Saux W.

IRSN / ETIC

Technical Descriptionand Main Outcomes

Summary

(1) Context & Objectives

(2) Description of Experimental Facilities


(3) Description of Experimental Campaigns

(4) Some Outstanding Results

(2) Description of Experimental Facilities

(5) Conclusion

1 – Context & Objectives

PRISME Project: Program overview

(1) Context: the PRISME fire research program (2006-2011) wasconducted in an international framework (Project Secretariat:OECD/NEA ; Operating agent: IRSN)

(2) 20 partners from 12 countries: Belgium (TRACTEBEL-Suez,BEL_V), Canada (AECL), Finland (STUK, VTT), France (IRSN, EdF,


BEL_V), Canada (AECL), Finland (STUK, VTT), France (IRSN, EdF,DGA/IUSTI), Germany (GRS, iBMB, BfS), Japan (JNES), Korea(KINS), Spain (CSN), Sweden (Vattenfall Ringhals), UK (HSE), TheNetherlands (VROM-KFD, NRG), and USA (NRC).

(3) Main objectives: Investigate smoke and heat propagation mechanisms in multi-compartment fire scenarios and assess the consequences of fire on targets of interest (thermal stress on electrical cables and their potential malfunction).

2 – Description of Experimental Facilities

Description of DIVA facility(1) 5 compartments (4 rooms and 1 corridor).

(2) Rooms 1 to 3 (120 m3), room 4 (180 m3) and corridor (160 m3).

(3) Each room is connected with a mechanical ventilation system by means of inlet and outlet duct.

(4) Each room can be connected with its


(4) Each room can be connected with its adjacent rooms through doorway and/or simple openings.

(5) Instrumentation: up to 800 possible measurement channels on the data acquisition system.

(6) Measurements: Fuel mass, temper., gas (CO, CO2, O2 and HCT) and soot concentrations, heat fluxes, pressures, flow rates in all compartments and in ventilation network, video.0

ROOM 1ROOM 1

CORRIDOR

CORRIDOR

ROOM 2ROOM 2

ROOM 3ROOM 3

ROOM 4ROOM 4

4 m

4 m

5 m

5 m

5 m 6 m

2.5 mROOM 1ROOM 1

CORRIDOR

CORRIDOR

ROOM 2ROOM 2

ROOM 3ROOM 3

ROOM 4ROOM 4

4 m

4 m

5 m

5 m

5 m 6 m

2.5 m

2 – Description of Experimental Facilities

Description of SATURNE calorimeter

(1) Hood: 3 m in diameter.

(2) For these PRISME support tests, the height between the floor and the bottom rim of the hood was about 4 m.

(3) The smoke exhaust system is connected to a ventilation network. Its exhaust flow rate can be ranged from 10,000 to

3 m


rate can be ranged from 10,000 to 25,000m3/h.

(4) This calorimeter is designed for studying fire source up to nearly 1.5 MW.

(5) Measurements: Pressures, gas flow rates, temperatures, gas concentrations (O2, CO, CO2 and HCT) and soot concentration, heat fluxes, video (.

4.2

m

Summary of fire tests carried out during the PRISME project

3 – Description of Experimental Campaigns


Description of PRISME Source campaign

PRISME Source

(1) Objective: Fire behavior of HTP pool fire (HTP=Hydrogenated Tetra-Propylene, C12H26) in open atmosphere.

(2) Parameters: pool area (0.1 to 0.4 m²).

3 – Description of Experimental CampaignsFree Atm

osphere

(=> no air viciation)


(2) Parameters: pool area (0.1 to 0.4 m²).

(=> no air viciation)

Confined and Ventilated

Rooms (=> vitiated envir.)

Single Compartment(PRISME Source)

Name D1 D2 D3 D4 D5 D5a D6 D6a

S (m2) 0.4 0.4 0.4 0.4 0.2 0.2 0.4 0.4

Tr (h-) 4.7 8.4 1.5 4.7 4.6(2)

1.6 4.7 1.7

Inlet H H H H H H B B

Description of PRISME Door campaign

PRISME Door

(1) Objective: The spread of smoke and hot gases through open doors for two and three rooms + Heat transfer to surrogate and real cables + Effect of oxygen depletion on fire source.



(2) Parameters: Pool area, the initial massof fuel (HTP), ventilation flow rate,number of compartments and locationof air inlet.Two and Three Compartments

(PRISME Door) Name PRS_D3 PRS_D2 PRS_D1 PRS_D4 PRS_D5 PRS_D6

S (m2) 0.4 0.4 0.4 0.4 1 1

Tr 4.7 1.5 0 8.6 4.7 4.7

Nb of room 2 2 2 2 2 3


Description of PRISME Leak campaign

PRISME Leak

(1) Objectives:

+ Propagation of smoke and hot gases through leakages (Leak 1 to 3)

+ thermal transfer on a duct crossing the fire room and flowing in the


the fire room and flowing in the adjacent room (Leak 4)

+ Cable performance tests (fire thermal stress, T>430°C nearby upper cables).

(2) Parameters: Fuel (HTP, 0.6m²), type of leakages (3), duct or not.

3 – Description of Experimental CampaignsDescription of PRISME Integral campaign (open)

(1) Objectives:

• The propagation of smoke and hot gases

through doorways (more than 300° in L3);

• The effect of the number of adjacent rooms onthe propagation through doorways;

• The effect of sprinkler activation;

• The effect of fire damper closure;

L1 L2 L3

L0

3100 m3/h

3100 m3/h

PRS_INT_2

Inlet

Exhaust


• The behaviors of cable & cabinet fires inconfined and ventilated fire scenarios.

(2) Parameters: Fuels (TPH, cabinet, cables), 3

or 4 rooms connected by doorways, firedampers and a deluge system (sprinklers).

L1 L2 L3

L0

2600m 3/h

3100m3/h

500m3/h

PRS_INT_5

Inl et

Ex haust

4 – Experimental Results: Pressure effect induced by fires in forced ventilated enclosuresPressure and ventilation system

(1) Pressure time history: A typical behavior that consists in an over-pressure peak at ignition (possible others peaks of pressure during the combustion phase) and a low-pressure peak at extinction.

(2) Background: The pressure variation isthe result of the energy balance within


the result of the energy balance withincompartment, which includes the fireHRR, the energy dissipating throughwall’s enclosure and the net balancethrough the ventilation branches.

(3) Ventilation network: A directconsequence of the pressure peaks isthe variation of air flow in theventilation system. Reverse flows canoccur at fire ignition (inlet) and at fireextinction (outlet).

4 – Experimental Results: Effect of oxygendepletion on fuel mass loss rate

Oxygen depletion and fuel MLR in fire compartment

(1) Air vitiation: The combustion products fill up quickly the fire compartment involving the oxygen depletion in it (under-ventilated condition).

(2) Effect of oxygen depletion on MLR: Thefire duration can be either shorterbecause extinction occurs quickly bylack of oxygen, either drastically longer

S=0,4 m2

2

4

6

8

10

12

14

16

18

20dm/dt (g/s)

Free (S4)

Free (S3)

Tr=8,3 (D2)

Tr=4,7 (D6)

Tr=4,7 (D1)

Tr=1,7 (D6a)

Tr=1,5 (D3)

Source


lack of oxygen, either drastically longerbecause the decrease of MLR understeady state condition involves moretime to burn all the mass of fuelavailable in the pan.

(3) Effect of oxygen depletion on fireduration: The fire duration for a RR of4.7 (Source, D1) is around 2.5 timeslonger compared with the same pool firein free atmosphere. The same behavioris observed in Door tests.

0

2

0 600 1200 1800 2400 3000t (s)

Tr=1,7 (D6a)

0.0

0.2

0.4

0.6

0.8

1.0

1.2

0 300 600 900 1200 1500 1800 2100t (s)

dm/dt * (-)

Free atm.

2R_Tr=0

2R_Tr=1.5

2R_Tr=4.7

2R_Tr=8.6

Tr=1.5

Free atm.Tr=4.7

Tr=8.6

Tr=0

Door

Quick description

(1) The effects of the ventilation rate and the fire HRR on the velocity profiles are analyzed to quantify the natural vs forced flows during the steady state regime.

(2) The forced flow is induced by the ventilation network as initial condition with the air flowing from the room 1 to the room 3.

4 – Experimental Results: Effect of ventilationon the velocity profile through the doorways


L0

hN23hN12

qv

Q

∆∆∆∆P12 ∆∆∆∆P23

D12 D23

L1

L2

L3

Integral

Results and discussion

Effect of flow rate: The main effect of the forced ventilation is to shift significantly the value of the inflow. At the upstream doorway (D12), the rise of the ventilation flow rate increases the inflow velocity. Inversely, at the downstream doorway (D23), the flow rate increase contributes to reduce the inflow until completely disappears (forced ventilation with one-way flow).

=> the ventilation network could promote significantly the propagation of hot gas to preferential neighboring compartments.

4 – Experimental Results: Effect of ventilationon the velocity profile through the doorways


preferential neighboring compartments.

0

1

-0,6 -0,4 -0,2 0,0 0,2 0,4 0,6

U*

z*

qv- 700m3/hqv- 3100m3/h

Doorway D12 - HRR=100kW

0

1

-0,6 -0,4 -0,2 0,0 0,2 0,4 0,6

U*

z*

qv- 700m3/h

qv- 3100m3/h

Doorway D23 - HRR=100kW

4 – Experimental Results: Cable performance testingElectrical malfunction of cables due to fire thermal stress

(1) IRMS system (Sandia): The Insulation Resistance Measurement System (IRMS) monitors conductor-to-conductor and conductor-to-ground insulation resistance for various conductor pairs.

(2) SCDU system (Sandia): The Surrogate Circuit Diagnostic Unit (SCDU) is nominally configured to simulate a

Leak


nominally configured to simulate a typical motor operated valve (MOV) control circuit (specific conductors were electrically energized and various modes of cable failure monitored).

(3) Main outcomes: The results provide therelationship between outside gastemperature and cable electricalfailures. These data were in closeaccordance with those obtained inlaboratory tests under controlledradiative heat sources.

5 – ConclusionPRISME experimental campaigns:

An improvement of fire modeling and a experimental database (more than 35

large-scale fire tests) used to validate fire safety codes (as zone modeling,

lumped parameter approach and CFD)

Benchmarking Group:� Comparisons of various fire codes (two-zone, lumped parameter, CFD)

� Development of validation strategy (multi-metrics)

� Sensitivity analysis on fire codes


� Sensitivity analysis on fire codes

� Flow rates through doorways

Opening of PRISME Tests Results2 tests on the IRSN Website (July 2012):

PRISME Source D1 & PRISME Door D3

All experimental measurements

Tests reports

Photos and films

Special Issue of Fire Safety Journal

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