PhD defence by Ruixue Li

Abstract

Safety is a cornerstone of modern industry, where the complexity of systems and their interdependencies continue to grow. From offshore oil platforms to renewable energy systems like hydrogen refueling stations, the ability to identify hazards and manage risks is crucial to prevent accidents and ensure reliable operations. Traditional safety methods, such as HAZOP and FMEA, have served well but struggle to keep pace with the demands of increasingly complex and dynamic systems.

In this PhD project, I explore a cutting-edge approach called Model-Based Safety Assessment (MBSA) to address these challenges. Using a method called Multilevel Flow Modelling (MFM), I developed a new framework to systematically analyze safety risks. MFM focuses on how energy, mass, and control information flow within systems, enabling a deeper understanding of how failures propagate across interconnected components.

By combining MFM with advanced tools like Bayesian Networks, I introduced a way to quantify risk scenarios, rank their severity, and verify potential failures. The research demonstrates how this approach can be applied to various industrial systems, showing its adaptability from traditional oil and gas operations to emerging renewable energy technologies. The results highlight the potential of model-based methods to make safety assessments more precise, scalable, and proactive.

This work opens the door to safer and more efficient industrial systems, providing tools that can help engineers and decision-makers better understand and mitigate risks in a rapidly evolving technological landscape.

Supervisors

• Main supervisor: Associate Professor Xinxin Zhang, Department of Electrical and Photonics Engineering, DTU
• Co-supervisor: Professor Ole Ravn, Department of Electrical and Photonics Engineering, DTU

External examiners

• Professor Maureen Hassall, The University of Queensland, Australia
• Professor Yiliu Liu, Norwegian University of Science and Technology, Norway

Chair of assessment committee

• Associate Professor Hans Henrik Niemann, Department of Electrical and Photonics Engineering, DTU

Master of the Ceremony

• Associate Professor Søren Hansen, Department of Electrical and Photonics Engineering, DTU