Numerical study of non-premixed hydrogen combustion in an argon power-cycle engine
Year: 2025
Type: article
Abstract: The hydrogen-fueled direct-injection (DI) compression-ignition (CI) argon power cycle (APC) is a highly efficient and emission-free energy conversion system that relies on the low specific heat capacity of the working fluid argon. Compared to conventional internal combustion engines, the DI CI APC allows to freely adjust the oxygen level of the charge. Besides, the engine operating pressure can be increased at virtually no cost from a theoretical perspective. In this study, we systematically investigate how to take advantage of these two benefits by varying the intake pressure and oxygen mole fraction using a validated Reynolds-averaged numerical simulation environment. It is found that the optimal amount of oxygen is a trade-off between burn duration and specific heat ratio of the charge. Provided that the oxygen mole fraction is high enough to achieve complete combustion, the sensitivity of the thermal efficiency to the oxygen content is relatively low. Increasing the intake pressure for a fixed oxygen level leads to shorter burn durations and less heat loss, thereby significantly increasing thermal efficiency. Flame-wall interaction is a dominant factor that negatively impacts the engine performance, and should therefore be minimized. The highest obtained thermal efficiency is 70%, which is comparable to efficiencies of state-of-the-art hydrogen fuel cells. The DI CI APC has therefore potential to overcome challenges of conventional engines, without penalizing its strengths.
Authors: N. Diepstraten, L.M.T. Somers, J.A. van Oijen
Institution: Eindhoven University of Technology
Language: English
Subfield: Fluid Flow and Transfer Processes
Field: Chemical Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,910
Awards: G1248366388, Argon Power Cycle
OpenAlex ID: W7106239083