Доступ предоставлен для: Guest

ISSN Online: 2377-424X

ISBN CD: 1-56700-226-9

ISBN Online: 1-56700-225-0

International Heat Transfer Conference 13
August, 13-18, 2006, Sydney, Australia

NUMERICAL STUDY OF THE AUTO-IGNITION PROCESS IN METHANE-AIR MIXTURES AT ELEVATED PRESSURES

Get access (open in a dialog) DOI: 10.1615/IHTC13.p26.120
11 pages

Аннотация

This study describes the modelling of the auto-ignition of methane/air-mixtures at elevated pressures up to 5 MPa based on detailed chemical kinetics and different heat transfer models. At first a zero-dimensional approach is adopted, based upon the model of Semenov. The chemistry is based upon a detailed reaction mechanism. Four different reaction mechanisms are considered. A reduced methane reaction mechanism of the British Gas Corporation shows the best agreement with the experimental results. To take thermal and mass diffusion into account a one-dimensional model is built including an adapted kinetic mechanism. The results of this model do not agree with the experimental auto-ignition limits. This discrepancy is caused by not taking into account the additional heat losses due to natural convection inside the vessel. Therefore, a CFD-model is used to compute the heat transfer and the buoyant flows inside the vessel. The coupling of the reduced reaction mechanism to this model results in an accurate prediction of the auto-ignition process. It is believed that this CFD-kinetics coupling is very promising for the modelling of the auto-ignition risk under realistic process conditions.