Design Fires in Road Tunnels (2011) / Chapter Skim
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Pages 28-39
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From page 28... ...
The main large-scale test programs that have been performed follow. Ofenegg Tunnel Tests To gain at least a general impression of the temperature conditions and the amount of smoke to be expected from a gasoline fire, evaluations of the performance of the fixed fire suppression system tests were performed in the Swiss Ofenegg Tunnel and in the Zwenberg Tunnel in Austria.
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From page 29... ...
Benelux Tunnel Tests In the Benelux Tunnel, 14 fire tests were used to determine the benefits of fitting large drop sprinklers. These sprinklers were selected so that the large droplets would penetrate the powerful fire plumes and not be swept away by the tunnel ventilation.
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From page 30... ...
• Partial Transverse Ventilation -- Either supply air or exhaust air, but not both, is uniformly delivered or extracted throughout the entire length of a tunnel. • Partial Transverse with Single-Point Extraction -- A series of large, normally closed exhaust ports distributed over the length of the tunnel to extract smoke at a point closest to the fire.
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From page 31... ...
fire positioned at different locations along the length of the tunnel. Runehamar Tunnel Tests The Runehamar Tunnel fire tests were initiated, planned, and performed by the Swedish National Testing and Research Institute from 2001 to 2003 as a part of the Swedish National Research program and in collaboration with the European UPTUN project led by TNO (The Netherlands)
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From page 32... ...
Runehamar Test Series, Test 3, u = 3 m/s 152 119 10 1281 Ingason and Loˇnnermark A Trailer Mock-up with 3.1 Ton Corrugated Paper Cartons Filled with Plastic Cups (19%) , Runehamar Test Series, Test 4, u = 3 m/s 67 67 14 1305 Ingason and TABLE 6 LARGE-SCALE EXPERIMENTAL DATA RESULTS FROM UPTUN TESTS (continued on next page)
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From page 33... ...
The qualification of a simulation tool must follow several rules: • Thematic: a reference experiment must deal with fires in tunnels. Cold smoke tests cannot represent fire behavior.
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From page 34... ...
were observed, but they did not last long. The Puymorens and Chamoise Tunnel tests have been based on heptane pool fires (21)
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From page 35... ...
. FIGURE 10 Plabutch Tunnel Fire Test sponsored by Graz University of Technology.
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From page 36... ...
For example, the Grashof number is a combination of the Reynolds and the Richardson numbers: The Reynolds condition is generally limited to checking that the Reynolds numbers in the model are sufficient to ensure the turbulent character of the longitudinal airflow. The thermal exchanges with the walls are difficult to model exactly as they would appear in an actual tunnel.
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From page 37... ...
Numerical modeling has become a tool of choice for design engineers modeling tunnel fires. Designers need to select appropriate physical models and boundary conditions to model fire events.
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From page 38... ...
Tests were performed with various ventilation systems including: – Full-transverse ventilation – Partial transverse – Single-point extraction – Oversized exhaust – Natural ventilation – Longitudinal ventilation with jet fans. Tests concluded that a longitudinal ventilation system employing jet fans is highly effective in managing the direction of the spread of smoke for fire sizes up to 100 MW in a 3.2% grade tunnel, which allowed for its application in the United States.
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From page 39... ...
Advantages: - Direct interpretation Disadvantages: - Cost - Limited number of tests Conclusions: - Unrealistic if not associated with other objectives Tunnel Fire Tests Before or Under Operation (aimed at optimizing ventilation responses in fire event) Advantages: - Partial results with full- scale facilities - Numerous different situations Disadvantages: - Lack of information due to the limited number of sensors Conclusions: - Useful but partial results Advantages: - Accumulation of experience useful to choose a system - Test performed with real ventilation systems Disadvantages: - Limited number of tests Conclusions: - Useful Advantages: - Shows operators how the ventilation reacts - Fire departments are very interested in expected situation Disadvantages: - No operation possible during the tests Conclusions: - Well suited Tunnel Fire Tests Before or Under Operation (aimed at operators and fire department training)
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