hen, when a lower temperature and amount of propane cause a reduced reaction rate, the energy supplied by the heating tubes determines the temperature evolution. As a result, the temperature increases again.
The temperature distribution and energy exchange between the bed, heating tubes, and insulating wall (left). The right image shows the temperature of the reformer bed as a function of position and evaluated along the centerline.
Moving on to velocity, let’s analyze the heating and reacting gases. For the heating gas, the flow is laminar and we can clearly observe a parabolic velocity distribution. On the other hand, the reacting gas in the porous bed has a significant increase in velocity, so much so that its velocity at the outlet is around double what it was at the inlet. This increased velocity is caused by the gas expansion from the chemical reaction and the temperature increase.
Velocity field plot, depicting the heating gas in the tubes and the reacting gas in the bed.
The related density variation within the bed, which accounts for temperature and composition, shows that the density decreases through the reformer.
Gas density in the reformer bed.
The goal of this tutorial is to demonstrate that by coupling mass, energy, and flow equations in COMSOL Multiphysics, you can successfully model a steam reformer. To try this example yourself, click on the button below.
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