Session: Student Poster Competition

Submission Number: 186965

Thermal Management System Optimization and Safety Assessment Analysis for Hydrogen Propulsion Systems 

The presented research, conducted by the School of Mechanical Engineering at Aristotle University of Thessaloniki, investigated the prospects of hydrogen propulsion aero engines. The study focuses on the design, optimization, and safety assessment of a novel Thermal Management System (TMS) for a hydrogen-combusting turboprop engine, aiming to maximize both performance and long-term safety. The core system architecture consists of a cryogenic tank, low and high-pressure fuel pumps, and a secondary nitrogen employing closed loop utilizing intercooling, cooled cooling air, and recuperating heat exchangers to preheat the fuel at a separate cryogenic heat exchanger. Results suggest significant performance benefits due to the secondary loop while minimizing potential operational risks.

The design and optimization process allowed for an extensive comparison between different configurations, each based on the components presented above, aiming to determine the optimal solution regarding thermal performance, total weight, complexity, and safety. The outcomes suggested that the ideal configuration employs only two of the three hot-source heat exchangers, the cooled cooling air and the recuperating heat exchangers. Optimization proved that the desired hydrogen combustion entry temperature can be achieved with relatively low weight and power demands.

Subsequently, a Safety Assessment and Failure Mode Analysis was conducted to define failure modes, effects, and system vulnerabilities. More precisely, several failure modes were thoroughly investigated, such as heat exchanger blockages and fouling formation, closed heat transfer fluid leakage and pressure reduction, tank pressure reduction and fuel mass flow rate fluctuations, and fuel supply pipe insulation decay and heat leakage. Results indicated the criticality of correct design, optimization, and control and detection systems to ensure long-term safe and stable performance, as well as acceptable tolerance regarding certain failure modes of the TMS. It is noteworthy that different flight mission phases introduced different system vulnerabilities, demanding a design process that addresses them with equal importance.

Future investigations outlined in the poster suggest higher fidelity optimization of the TMS, considering more variables and objectives to determine the best performing design and operating parameters while also accounting for turboprop engine performance. Additionally, conjugate CFD studies of the hot source heat exchangers and fuel supply pipes would allow for the determination of the risk of ice accretion and true heat leakage, respectively. Finally, transient failure mode analysis could allow for a better understanding of the system's dynamics.

Presenting Author: Kiriakos Toulgaridis Aristotle University of Thessaloniki

Presenting Author Biography: Kiriakos I. Toulgaridis is an Undergraduate Master Candidate in the School of Mechanical Engineering at the Aristotle University of Thessaloniki (AUTh). Currently working within the Laboratory of Fluid Mechanics and Turbomachines under the supervision of Prof. Anestis I. Kalfas, focused on the design, optimization, and safety assessment of thermal management systems for hydrogen-powered gas turbines.
Earlier academic background includes a student project on novel technologies for hydrogen-fueled gas turbines. Additionally, he completed an internship at Bio2CHP, a state-of-the-art spin-off project working in the development of a combined heat-power production site utilizing οrganic by-products. There he assisted in system operation, testing, and the development of operational instructions.

Authors:

Kiriakos Toulgaridis Aristotle University of Thessaloniki
Konstantinos Bollas Aristotle University of Thessaloniki
Georgios Arvithis Aristotle University of Thessaloniki
Anestis Kalfas Aristotle University of Thessaloniki