Client
Hyradix
Project Objectives
- The reactant injection system of the auto-thermal reformer mixes high temperature steam, ambient temperature natural gas, and ambient temperature air
- The steam, natural gas, and air mix in the injection system and are then delivered through a manifold to the catalytic reactor
- The main objectives of the simulation were as follows:
- Simulate the mixing or mixture fraction of each reactant component throughout the injection system
- Simulate the temperature distribution of the reactants throughout the injection system
- Simulate the temperature distribution throughout the injection system hardware
- The temperature distribution in the reactor manifold is very important. The high temperatures that are currently found in the manifold force Hyradix to purchase an extremely expensive manifold that is made of expensive materials, and involves a costly manufacturing process. By using numerical simulations it is hoped that a different injection system can be found that reduces the temperature of the manifold. A standard inexpensive manifold can then be purchased for the reactor.
- The temperature and mixture fraction distribution throughout the reactants is very important because it determines where coking of the natural gas will occur. Coking is a very serious problem because it can drastically reduce the conversion efficiency of the reformer. Expensive cleaning and repairs are then required to get the reformer to operate properly.
Summary of Project and Results (Non-Confidential)
- The first step of the project was to build the solid model of the injection system. The multi-physics simulation software ANSYS was used to perform the analysis.
- Material components and properties were defined as well as fluid components and properties
- The boundary conditions to the model were defined and included the steam, natural gas, and air injection temperature, velocity, and mixture fraction. The reactor exit product temperature, velocity, and mixture fraction were prescribed.
- The solid model and fluid volumes were meshed with a fine distribution of elements to capture the complex physics that occurs in the injection process
- Solid elements were chosen to simulate the heat transfer that occurs throughout the hardware of the system
- Fluid elements were chosen to simulate the turbulent flow that occurs as the reactants propagate through the system. The heat transfer that occurs during the mixing process in the reactants was simulated. The heat transfer that occurs from the reactants to the hardware was simulated. The mixing of the reactants as tracked by a mixture fraction for each reactant was simulated.
- The fluid mechanical/thermal/mixing simulation in the reactant flow elements was coupled to the thermal simulation in the hardware elements
- The entire simulation was iterated many times until the simulation converged appropriately
- Various configurations of the injection system design were simulated to examine the effect on hardware/manifold temperature distribution, and coking probability in the system