Rail tank cars exposed to fires: experimental analyses of thermal conditions imposed to a railcar engulfed in crude oil fires (Series 1-3 Tests)
Notice bibliographique
Résumé
A series of 2-m pool fire experiments were performed to better evaluate the comparative thermal hazard between different crude oils as a result of pool fires, which could occur as a consequence of an accident in the land transport of crude oils. In order to assess the thermal conditions to which a rail tank car could be exposed, a calorimeter designed to simulate a 1/10th scale tank car was placed above a 2-m diameter pool fire fueled by heptane in Series 1 tests, Bakken crude oil from North Dakota in Series 2 tests and diluted bitumen (dilbit) crude oil from Alberta in Series 3 tests. The calorimeter was instrumented to measure the total heat flux at various locations along its surface. The crude oils used in the testing program were specially handled to ensure no change in its composition over the course of the testing program, from the time of fuel acquisition to the time of fire testing. In conjunction with the fire testing, a fuel characterization study was conducted to enable the study of fire effects in relation to fuel properties. The burning behaviours of the fuels were observed by measuring the burning rate, flame height and heat release rate (HRR), the flame surface emissive powers (SEP) and the incident heat fluxes away from the fire. Overall, the Bakken crude oil and heptane fires displayed continuous steady burning throughout the test while the dilbit crude oil fires displayed unsteady burning behaviour, which was mainly caused by the fuel composition containing a larger fraction of heavy end hydrocarbons than the Bakken crude oil and heptane. The total heat flux measured by the calorimeter indicated that the measurements were uneven around the circumference of the calorimeter. The average heat flux to the calorimeter from the Bakken and dilbit crude oil fires was higher than that from the heptane fires although the measured HRRs of the Bakken and dilbit crude oil pool fires were less than those of the heptane pool fires. The main reason for the increased heating of the object in particular by the Bakken and dilbit crude oil fires is that the total heat flux to the object is mostly affected by radiative heat exposure from the flame, and the Bakken and dilbit crude oil fires have higher radiative heat fraction. The study also investigated the effects of test parameters on fire characteristics. These parameters include the effect of fuel types, the presence and placement of a calorimeter engulfed in the fire, fuel feed temperature, and allowing the fuel to burn down. The results indicate that there was no significant effect of “fuel supply temperature” and “fuel to burn down (i.e., non-continuous fuel feed)”. The higher fuel supply temperature increased the burn rate by about 10% for the heptane and Bakken crude oil tests. For the dilbit crude oil fires, due to the non-steady burning behaviour, the impact of the calorimeter was difficult to capture. Allowing the fuel to burn down, rather than maintaining a constant fuel level in the pool pan, resulted in minimal effect on average values of the mass burning rate and general fire characteristics of the Bakken crude oil pool fires. For the dilbit crude oil, the fuel compositional effect on the burning behaviour was observed in both continuous and non-continuous fuel feeding. The non-uniform burning behaviour became easier to discern when there was no continuous fuel feed into the fuel pan.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,001 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».