Development of a Hydrogen Engine for Light Commercial Vehicles

Ryosuke Matsui (Toyota Motor)

To promote hydrogen adoption, we developed a hydrogen engine for light commercial vehicles. Based on a V6 3.5L turbocharged gasoline engine, over 90% of parts were reused while achieving 40% thermal efficiency and meeting Euro 7 emission standards. This presentation will address technical challenges such as abnormal combustion caused by hydrogen and the solutions implemented.

Transient NOx reduction for lean burn SI H2-ICE by water injection utilizing water recovered from exhaust gasses

Xander Seykens･Jinlin Han･Erik Doosje (TNO)

The hydrogen internal combustion engine (H2-ICE) is a promising pathway for complying with heavy-duty CO2 regulations. The lean burn SI H2-ICE is characterized by its ultra-low engine-out NOx potential in steady-state operation. The main source of engine-out NOx is thermal NO formed during dynamic engine operation when in-cylinder air-excess ratio momentarily drops due to insufficient supply of air. In this paper, a proof-of-concept for transient NOx reduction is provided. In this proof-of-concept NOx emissions during dynamic engine operation (step loads) are effectively reduced by the application of port water injection. The utilized water is recovered from the exhaust gases, making the NOx reduction a self-sustaining process.

Development of ammonia/hydrogen SI engine (Third Report)
-Investigation into the Application of Port Fuel Injection in Ammonia/Hydrogen Engines and Evaluation of Its Effects on Engine Performance-

Naoki Muta･Kosuke Kusaba･Hiroaki Masatsuki･Tomohiro Nishihashi･Tomonori Kuroki･Yukihide Nagano･Masato Sawashita･Yuta Shima･Kazuya Naito･Tatsuya Ehara (Daihatsu Motor)

The ammonia/hydrogen spark ignition engine will be developed as one of the engines using the carbon-neutral fuel. This study aims to evaluate the impact of adopting a port fuel injection (PFI) system for the supply of an ammonia/hydrogen mixture on engine performance. Building upon the direct-injection (DI) hydrogen jet model developed in our previous work, a new PFI jet model was formulated. Engine simulations and performance assessments were conducted for the PFI-based supply system.

Combustion System Design Study for a Commercial Vehicle Hydrogen Engine Application

Thomas Briggs･Daniel Ryan Williams (Southwest Research Institute)･Tomoyuki Itou (Isuzu Motors)

A pent-roof combustion chamber design was adapted from a previous natural gas engine demonstration to allow for single-cylinder engine combustion studies on PFI and LPDI hydrogen operation. Comparisons were made of the impact of tumble and injector type on the efficiency and performance of this engine. The results demonstrated an improvement in efficiency for LPDI relative to PFI and that tumble ratio did not have a strong impact on hydrogen combustion. Peak net indicated thermal efficiency of 46% was measured, with engine-out NOX emissions and engine out exhaust temperature at levels which are compatible with standard lean-NOX aftertreatment solutions.