Kinetic and State Modelling of Cryogenic Hydrogen Mixtures Using Molecular Dynamics Simulations

September 1st, 2024

R&D Focus Areas:
Cold/cryo compressed, Computational modelling

Lead Organisation:
The University of Melbourne

Funding:
Future Energy Exports CRC (PhD Project)

Status:
Active

Start date:
2024

Completion date:
2027

Project summary description:
This PhD project focuses on the investigation of thermodynamic properties and the development of equations of state of mixed refrigerants (MR) and hydrogen-air mixtures at deep cryogenic conditions, critical for reducing hydrogen liquefaction costs and enhancing safety upon accidental hydrogen release into the environment. Outcomes include the calculation of reliable thermodynamic properties of these mixtures for the development of high-fidelity numerical tools that aim to improve the efficiency of MR cycle technologies and optimise the design of H2 liquefaction processes.

The project commences with the delivery of a simulation-based Equation of State (EoS) for H2/air mixtures and a phase change model. The initial stage focuses on creating a solid foundation for accurate simulation of hydrogen behaviour in air. The performance of this simulation based EoS will be validated and benchmarked against existing models to ensure reliability and accuracy. Following this foundational work, the developed EoS will be integrated into Computational Fluid Dynamics (CFD) simulations, introducing additional corrections that enhance the fidelity of mixture simulations. This integration aims to refine the predictive capabilities of CFD, particularly concerning hydrogen’s interaction with air.

Upon the development of a framework for the calculation of thermodynamic properties of H2/air mixtures, the framework will be employed towards the development of an EoS for H2/MR mixtures comprehensive EoS capable of predicting both the density and enthalpy of these mixtures, enabling the optimal design of MRs based on their composition. Advanced simulation phase involves determining nucleation rates and latent heat of MRs, which are key factors in optimizing the liquefaction process, which will be added in the last stage of the PhD project.

These results will offer additional physical characterization, such as the rate of energy transfer and nucleation rate in the liquefaction process, that can be leveraged to optimize the performance design of the refrigerants. Furthermore, the detailed understanding of phase change processes gained from these simulations extends beyond efficiency improvements, serving a critical role in safety measures.

Further information:
https://www.fenex.org.au/connect/

 

September 2024