Heterogeneous reaction rate data pertaining to microchannel methanol steam reforming reactor systems at different temperatures
Description
To obtain the solution of the heterogeneous reaction rate problem, numerical simulations are performed using fluid mechanics. Methanol is combusted catalytically with air, and the heat released is used to heat the reactor. The energy which is released during catalytic oxidation is necessary for the endothermic steam reformation taking place simultaneously. Water steam is converted into hydrogen-rich gas using methanol in an endothermic reaction on a catalyst. There is even less need for mass and volume storage capacity, since the same alcohol fuel is used for the endothermic and exothermic processes. An array of channels operating in parallel is used, and the inside of the channels is coated. All channels are of the same cross-section and length. Additionally, there are equal numbers of oxidation and reforming channels, which are arranged in an alternating pattern. The wall of each channel is composed of a substrate coated with a catalyst. The substrate is preferably metal, and most preferably stainless-steel sheet. The design increases the number of boundary layers between a fluid and a reactor wall by a factor of one hundred or more, and boundary layers are known to impede heat transfer. However, relatively high heat transfer is provided. To facilitate computational modeling of transport phenomena and chemical kinetics in the flowing system of complex chemical reactions involving gas-phase and surface species, steady-state analyses are performed. The problem is solved using structured meshes. The mesh is refined in the computational domains of the catalytically active layers. A mesh independence study is carried out. The solution is independent of the mesh resolution. Boundary conditions are specified and physical properties are defined for the fluids, solids, and mixtures. Physical properties depend on temperature and composition. A piecewise-polynomial function is specified for the temperature dependence. To define composition-dependent properties for the mixtures, the mass-weighted-mixing-law is applied. Contributor: Junjie Chen, E-mail address: koncjj@gmail.com, ORCID: 0000-0002-5022-6863, Department of Energy and Power Engineering, School of Mechanical and Power Engineering, Henan Polytechnic University, 2000 Century Avenue, Jiaozuo, Henan, 454000, P.R. China
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Steps to reproduce
The mathematical formalism developed to describe transport phenomena and chemical kinetics is implemented into ANSYS FLUENT. The computer code and its usage are fully documented. More specifically, ANSYS FLUENT is applied to define the terms in the equations relating to conservation, thermodynamics, chemical production rates, and equation of state, and then combine the results to define the problem involving surface chemistry. The governing equations are solved numerically for the conservation of mass and momentum and for energy and species. The governing equations are discretized in space, and the second-order upwind discretization scheme is used. The under-relaxation factors are reduced for all variables.