Introduction to Side-Fired Steam Methane Reforming CFD Simulation

This project presents a steam methane reforming CFD Simulation of a side-fired furnace, a vital technology for producing hydrogen. For making hydrogen and syngas, experts often use a steam methane reforming CFD approach to study side-fired furnaces. These furnaces use a special process with a catalyst to change natural gas into hydrogen and carbon monoxide. An SMR CFD model is needed because these furnaces operate at very high temperatures. Also, they use a catalyst to make the reaction between steam and methane happen faster. This steam methane Reforming Fluent simulation shows how this reaction creates hydrogen. Because of this, side-fired furnaces are very common in industries like refining, chemical plants, and electronics for hydrogen production.

In this project, a steam methane CFD simulation of a side-fired furnace is done in full 3D using ANSYS Fluent. The main goal is to use SMR Fluent to study the flow and heat conditions inside the furnace. To make sure our steam methane reforming CFD simulation is reliable, we used a scientific paper called “Optimal Tube Bundle Arrangements in Side-Fired Methane Steam Reforming Furnaces [1]” as a guide for our work.

• Reference [1]: Engel, Sebastian, et al. “Optimal tube bundle arrangements in side-fired methane steam reforming furnaces.” Frontiers in Energy Research8 (2020): 583346.

Figure 1- Sketch of a radiation-based and CFD-based furnace model extracted from the paper mentioned in the following

Simulation Process (SMR Fluent Setup: 3D Furnace Modeling )

First, for this SMR CFD project, we created the 3D geometry using ANSYS Design Modeler. The measurements for this shape came from “design B” in the reference paper. The design of our steam methane CFD model includes a group of tubes arranged in a special way inside the furnace. Then, we used ANSYS ICEM software to create a structured mesh for the SMR Fluent simulation. As a result, a high-quality mesh with 4,012,428 elements was made. This is very important for getting correct results from a steam methane reforming CFD simulation.Next, we configured the solver settings in ANSYS Fluent for this steam methane Fluent analysis. The most important settings are for radiation and the different gases in the simulation. Therefore, we activated the Discrete Ordinates (DO) radiation model and the Species Transport module. Using these models is necessary to correctly capture the flow and heat transfer in our steam methane reforming CFD study. In this model, the ability of the pure gases to absorb heat changes with temperature. The gas mixture in our SMR CFD analysis includes H2O, O2, CO2, and N2. Finally, we set the furnace walls to be adiabatic, gray, and diffuse for the radiation calculations.

Figure 2- Furnace geometry design in Design Modeler software

Post-processing (Steam Methane Reforming CFD Analysis)

The SMR CFD analysis of this furnace gives us important details about its flow and heat properties. The 3D steam methane Fluent simulation shows how the gas velocity is distributed. Specifically, the results show that the velocity changes from stagnation points (about 0 m/s) between the tubes to maximum velocities of 17.5 m/s where the hot gas enters. Our steam methane CFD study also indicates that the placement of the tubes near the top and right walls is very important. This positioning increases their exposure to the hot gas, which significantly improves heat transfer. Moreover, looking at the temperature distribution from our SMR Fluent model, we can confirm that there is a dominant radiative heat transfer mechanism. Understanding this is essential for making the furnace work better for hydrogen production.

Figure 3- Velocity and Temperature distribution around the tube bundle

By visualizing the streamlines, our steam methane CFD simulation shows interesting flow patterns around the tube bundle. A key finding is that the increased distance between central tubes stimulates improved fluid circulation. However, the analysis also confirms that because of the very high working temperatures, the main way heat moves is still through radiation. This result from our steam methane reforming CFD work matches real industrial furnace designs. For example, in real furnaces, more oxygen is sometimes used to increase the amount of CO2 and H2O, which boosts radiative heat transfer. In conclusion, the SMR CFD results clearly demonstrate that the configuration of the tube bundle markedly affects the overall efficiency of the furnace, temperature uniformity, and reaction kinetics in the hydrogen production process.Figure 4- 2D streamlines around the tube bundle

Figure 4- 2D streamlines around the tube bundle