Specialists rely on side-fired steam methane reforming (SMR) furnaces for the production of hydrogen and syngas. These furnaces take catalytic reforming of natural gas to create a mixture of hydrogen and carbon monoxide. These furnaces work at elevated temperatures and use a catalyst to speed up the reaction between steam and methane (the main component of natural gas) to generate hydrogen and carbon monoxide. Side-fired SMR furnaces are frequently used in many industries to produce hydrogen. Here are some typical applications: Refining, Chemical processes, Electronics, and power generation. In this project, a side-fired steam methane reforming furnace is simulated through a 3-dimensional concept using ANSYS Fluent software. It is aimed to investigate hydrodynamic and thermal conditions of it. To give credit to the CFD simulation, a numerical paper titled “Optimal Tube Bundle Arrangements in Side-Fired Methane Steam Reforming Furnaces [1]” is considered the basic assumption.

• 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

In this project, a side-fired steam methane reforming furnace is simulated through a 3-dimensional concept using ANSYS Fluent software. It is aimed to investigate hydrodynamic and thermal conditions of it. To give credit to the CFD simulation, a numerical paper titled “Optimal Tube Bundle Arrangements in Side-Fired Methane Steam Reforming Furnaces” is considered the basic assumption.

Simulation Process

In the initial step, the geometrical data extracted from the reference paper and design B is drawn using the ANSYS Design Modeler software, shown below. It consists of a tube bundle with a specific design and array in the middle of the furnace. Figure 2 shows it.

Then, it is meshed in ICEM software with the aim of producing a structured grid. Consequently, 4012428 elements are generated.

Figure 2- Furnace geometry design in Design Modeler software

The most notable settings of the solver is dedicated to the radiation effects and species used in the simulation. Thus, the Discrete Ordinates radiation along with Species Transport module are activated. The absorption coefficients of the pure substances are temperature-dependent. The mixture species cosnist of h2o, o2, co2 and n2. Additionaly, the furnace walls are considered adiabatic, gray, homogeneous and diffuse emitters.

Post-processing

The CFD analysis of the side-fired steam methane reforming (SMR) furnace explains important hydrodynamic and thermal properties via full velocity and temperature distributions. ANSYS 3D Fluent simulation shows velocity magnitudes that vary from stagnation points (about 0 m/s) in the inter-tube sections to maximum velocities of 17.5 m/s in the flue gas inlet zone. The study of thermal-fluid behavior indicates that careful positioning of tubes along the upper and right furnace walls maximizes exposure to the main hot gas flow, dramatically improving heat transfer efficiency. The temperature distribution pattern, along with the velocity field, displays a dominant radiative heat transfer mechanism, essential for optimizing SMR furnace performance and enhancing hydrogen production efficiency.

Figure 3- Velocity and Temperature distribution around the tube bundle

The streamline visualization and flow field analysis shows interesting fluid dynamics patterns within the tube bundle arrangement. The increased distance between central tubes stimulates improved fluid circulation; However, the main heat transfer method continues to be driven by radiation due to the higher working temperatures. The finding aligns with industrial SMR furnace design concepts, wherein oxygen-enriched combustion technology can significantly enhance radiative heat transfer by elevating concentrations of radiatively involved species (CO2 and H2O). The CFD results indicate that the configuration of the tube bundle markedly affects the overall efficiency of the furnace, temperature uniformity, and reaction kinetics in hydrogen production processes.

Figure 4- 2D streamlines around the tube bundle