PS Ventilatio n - Smoke extraction -
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E. Da Riva, S. E. Wojnarska 1 2013-02-12 PS Ventilation - Smoke extraction -
description
PS Ventilatio n - Smoke extraction -. Air inlets. Boundary conditions / assumptions:. Only SEVS system Extraction in TR3-TR8, 30 000 m3/h each Air inlets in the galleries corresponding to TR1 and T2 Two cases! With 25 000 m3/h injection in the center and without. Smoke extractors. - PowerPoint PPT Presentation
Transcript of PS Ventilatio n - Smoke extraction -
E. Da Riva, S. E. Wojnarska 12013-02-12
PS Ventilation- Smoke extraction -
E. Da Riva, S. E. Wojnarska 22013-02-12
Boundary conditions / assumptions: Only SEVS system Extraction in TR3-TR8, 30 000 m3/h each Air inlets in the galleries corresponding to TR1 and T2 Two cases! With 25 000 m3/h injection in the center and without
Air inlets
Smoke extractors
E. Da Riva, S. E. Wojnarska 32013-02-12
Boundary conditions / assumptions: Extraction: velocity ~5m/s, area 1,7m2 (velocity inlets) Inlets: TR1: 3,0m X 3,4 m; TR2: 1,2m X 2,0m (pressure inlets), central – velocity inlet 1,3m X
0,55m Tunnel leak tight
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Results
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Conventions
“r45” means flow rate in the tunnel between the technical room 4 and 5. Flow rate in tunnels (r12, r23, etc.) is positive when counter-clockwise. Flow rate in galleries is positive when moving radially from the ring center to the outside.
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Velocity in the tunnel (m/s)With air injection in the centerNormal
0.760.79
1.3
0.56
0.38
0.87
0.99
1.38
0.05
0.27
0.70.43
1.14
0.43
0.35
0.74
0.85
1.19
0.07
0.23
3.43
0.68
3.96
0.76
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Air flow rates in the tunnel
r12 r23 r34 r45 r56 r67 r78 r81
-150000
-100000
-50000
0
50000
100000
150000NormalWith central inletSeries3
Air
Flow
Rat
e [m
3/h]
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Air flow rates in the galleries
gallery1 gallery2 gallery3 gallery4 gallery5 gallery6 gallery7 gallery8
-10000
-5000
0
5000
10000
15000
20000NormalWith central inletSeries3
Air
Flo
w R
ate
[m3/
h]
Even galleries have smaller cross section The flow rate values are taken in the center of the gallery (50 meter from the center of the ring)
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Velocity in the galleries
gallery1 gallery2 gallery3 gallery4 gallery5 gallery6 gallery7 gallery80.0000
0.1000
0.2000
0.3000
0.4000
0.5000
0.6000
0.7000
0.8000
0.9000NormalWith central inletSeries3
Air
Vel
ocity
[m/s
]
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Path linesWith air injection in the centerNormal
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Model of the fire Fire will be modelled as an mass inflow No combustion process in the simulation Power of the fire - 5MW
𝐶𝐻 4+2𝑂2→𝐶𝑂2+2𝐻 2𝑂16𝑘𝑔+44,8𝑚3→22,4𝑚3+44,8𝑚3
𝑣𝑎𝑖𝑟=𝑣𝑂2
0,209=13,37 𝑚3𝑎𝑖𝑟
𝑘𝑔𝐶𝐻 4
𝑣2=𝑇 2
𝑇 1𝑣1=
1400300
∙11,96=55,81𝑚3𝑠𝑚𝑜𝑘𝑒𝑘𝑔𝐶𝐻 4
h𝑒𝑎𝑡 𝑜𝑓 𝑐𝑜𝑚𝑏𝑢𝑠𝑡𝑖𝑜𝑛�̇�=5𝑀𝑊
5 ∙107 𝐽𝑘𝑔
=0,1 𝑘𝑔𝑠
˙𝒗 𝒔𝒎𝒐𝒌𝒆=𝟎 ,𝟏𝒌𝒈𝒔 ∙𝟓𝟓 ,𝟖𝟏𝒎
𝟑
𝒌𝒈=𝟓 ,𝟓𝟖𝒎𝟑
𝒔
Reaction (in normal conditions):
Volume of the smoke:
Volumetric flow rate:
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Conclusions and suggestions: Central inlet reduces air going from the ring to the galleries More flow in the center will improve the results Flushing of smoke will be the worst in r56 due to very low flow rate Openings can significantly change the results – they should be taken into account Efficiency of smoke extraction depends on the position of the fire Smoke modelled as inlfow (with volumetric flow rate) may change the results With air injection in the center, less air is taken from two main inlets
Conclusions
To be discussed: Position and size of the fire Openings – size and position Increasing the flow in the central room
E. Da Riva, S. E. Wojnarska 132013-02-12
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