Graphite oxidation modeling for application in MELCOR.

Gelbard, Fred

Sandia National Laboratories

关键词: Numerical Solution;    Oxidation;    Oxidation.;    Graphite Moderated Reactors;    37 Inorganic, Organic, Physical And Analytical Chemistry;   

DOI  :  10.2172/947293
RP-ID  :  SAND2008-7852
RP-ID  :  AC04-94AL85000
RP-ID  :  947293

美国|英语

来源: UNT Digital Library

【 摘 要 】

The Arrhenius parameters for graphite oxidation in air are reviewed and compared. One-dimensional models of graphite oxidation coupled with mass transfer of oxidant are presented in dimensionless form for rectangular and spherical geometries. A single dimensionless group is shown to encapsulate the coupled phenomena, and is used to determine the effective reaction rate when mass transfer can impede the oxidation process. For integer reaction order kinetics, analytical expressions are presented for the effective reaction rate. For noninteger reaction orders, a numerical solution is developed and compared to data for oxidation of a graphite sphere in air. Very good agreement is obtained with the data without any adjustable parameters. An analytical model for surface burn-off is also presented, and results from the model are within an order of magnitude of the measurements of burn-off in air and in steam.