Pochet, Maxime
[UCL]
The energy transition towards major renewable shares comes at many costs and challenges. One of them is the need for massive and long term electricity storage to provide power and heat at further lacking times. Hydrogen, ammonia, methane and methanol being envisioned for such storage, a fuel-flexible system is needed (0.3-3 MW). This thesis investigates the Homogeneous-Charge Compression-Ignition (HCCI) piston engine multi-electrofuel potential, while striving against the HCCI-inherent low power density and high emission of unburned fuel. A numerical and experimental preliminary study of the electrofuels is performed to investigate their required operating conditions, power density potential, and blending interests. The gained knowledge is capitalised in the making of a 23:1 compression ratio HCCI engine to allow the full ammonia-hydrogen blending range (and consequently methane and methanol). Ammonia has a 50% IMEP increase compared to hydrogen, slightly outperforming methanol and methane. Hydrogen maintained its performance compared to the usually low compression ratios, hence demonstrating the advantage of high compression ratio for these electrofuel blends. Towards the ideal design for multi-electrofuel HCCI engine, promising enhancing techniques are investigated: increased combustion temperature for minimised unburned emissions, exhaust gas recirculation to achieve stoichiometric conditions (lower NOX and possibility of three way catalysis), or water direct injection for thermal stratification and improved power density.


Bibliographic reference |
Pochet, Maxime. Use of electrofuel blends in homogeneous-charge compression-ignition engines : an experimental focus on ammonia-hydrogen. Prom. : Jeanmart, Hervé ; Contino, Francesco |
Permanent URL |
http://hdl.handle.net/2078.1/239231 |