Computational Modeling for Power Generation Systems

The ability to adapt technology design early in the development process is critical to controlling costs and reducing risks. Innovative energy technologies face a lengthy journey from the laboratory bench through commercial deployment that could take up to 15 years for pre-deployment and another 20 to 30 years for widespread industrial-scale deployment. Additionally, it’s estimated that 75 percent of the cost of manufacturing occurs at the conceptual design stage. Computational modeling is the key to controlling costs and risks in a timely fashion.

Reducing CO2 emissions and improving the performance of fossil fuel-based energy systems is a key mission of NETL. Computational tools and models that help identify, design, scale up, and optimize promising technology concepts play a pivotal role. Computational modeling, coupled with high-performance computing, is used to simulate and study the behavior of complex systems and allows scientists and engineers to conduct thousands of simulated experiments using multiple variables. A multiscale modeling approach allows the evaluation of system components at various scales, ultimately leading to a better understanding and optimization of a complete, integrated system. The results of modeling help researchers make predictions about what will happen in the real system in response to changing conditions.

At NETL, computational tools are used to simulate interacting phenomena associated with fossil fuel-based energy systems, providing vital data about physical properties, thermodynamics, chemical reactivity, heat transfer, hydrodynamics, mass transfer, and other aspects of the device or processes. Two examples of these tools are Modeling of Solid Oxide Fuel Cells and Multiphase Flow with Interphase eXchange.

A rendering from MFix-TFM (Two-Fluid Model), the most mature MFIX model, capable of modeling multiphase reactors ranging in size from benchtop to industry-scale.

Modeling Solid Oxide Fuel Cells (SOFCs)

SOFCs are electrochemical devices that convert the chemical energy of a fuel (methane or syngas) and an oxidant (air or oxygen) directly into electrical energy. Because SOFCs produce electricity through an electrochemical reaction instead of a combustion process, they are much more efficient and environmentally benign than conventional electric power generation processes. Their inherent characteristics make them uniquely suitable to address the environmental and water concerns associated with fossil fuel-based electric power generation.

Modeling SOFCs ranges from the nanometer scale to the utility scale. At the nanoscale, electrochemical phenomena and surface reconstruction are modeled to understand electrode performance and material degradation. At intermediate scales, detailed cell and stack performance models yield predictions of performance, degradation, fuel consumption, thermal stresses, and other phenomena. These detailed models are used to create SOFC models that are integrated into chemical process simulators to demonstrate performance and identify costs of utility-scale power generation plants.

Multiphase Flow with Interphase eXchange (MFiX)

Computational modeling can be used to simulate complex power systems and components like gasifiers and carbon capture reactors allowing for a better understanding of performance prior to finalizing technology design features. Models that quantify uncertainty are important for reducing the cost and time required for developing zero-emission fossil fuel conversion processes and systems.

Multiphase flows—the simultaneous flow of materials of different phases (gas, liquid, or solid)—are encountered in most commercial energy and environmental processes. Understanding the interaction between these phases is critical to understanding and predicting the performance of energy system devices that employ multiphase flows. NETL is a recognized world leader in developing and applying computational fluid dynamic models of multiphase flow reactors.

Information generated using these models is far more extensive than data generated by experiments alone. The models can integrate experimental and computational results to provide unique insights. MFiX, a suite of the computational fluid dynamics codes developed specifically for modeling reacting multiphase systems, is central to the process at NETL. This open-source software has more than two decades of development history and 4,000 registered users worldwide. MFiX has become the standard for comparing, implementing, and evaluating multiphase flow models. Researchers at NETL use MFiX to perform basic and applied research on advanced fossil energy technologies including gasification, coal combustion, gas cleanup, and CO2 capture.