In order to achieve a low-carbon and carbon-neutral society, Mitsubishi Heavy Industries Engine & Turbocharger, Ltd. (MHIET) is developing reciprocating engines that use hydrogen and ammonia as fuel. For hydrogen/natural gas mixed combustion engines, we verified with actual equipment the combustion characteristics when the ratio of hydrogen mixed with natural gas is increased to 35 vol%, and have clarified the conditions for avoiding abnormal combustion such as knocking and pre-ignition and determined specifications for future commercialization of the engine. For hydrogen combustion engines, we conducted numerical simulation and verification using a single cylinder testing engine to select operating conditions and component specifications that will achieve high power output and high efficiency while avoiding abnormal combustion, and are currently promoting the multi-cylinder engine design by developing the selected conditions and specifications. For ammonia/diesel oil mixed combustion engines to be used in marine engines, we researched for an appropriate combustion system that can significantly reduce greenhouse gases including N2O by using numerical simulation, and have confirmed an 82% reduction compared to conventional engines through verification using a small test engine.
