Yuchai, a major supplier of diesel and methane heavy-duty engines, launched China’s first hydrogen-fuelled medium-duty engine for city bus, refuse and distribution tasks at the end of last year. Power output of the YCK05H was unstated, but the manufacturer claimed successful application of technologies including high-pressure multiport direct fuel-injection, low-inertia turbocharging and lean-burn combustion. The base diesel engine design was adapted to overcome hydrogen-specific problems including backfiring and ‘knock’.
The big YCK16H engine adopts advanced high-pressure common rail, direct injection technology and dual-channel turbocharging, which can allow homogeneous or stratified combustion in the cylinder as required, giving stronger power performance, higher thermal efficiency and better stability.
Yuchai claims the 15.93-litre platform has high adaptability to fuel of varying purity and can be adjusted to run on grey or green hydrogen. “The fuel supply can be freely combined according to user needs and the basic conditions of fuel production, storage and transportation, which is a highly adaptable, flexible and controllable zero-carbon/low-carbon power solution,” the company says.
A multi-fuel capability has also been developed. An intelligent control system and high-efficiency air management system, which can realise both equivalent ratio combustion and lean combustion, can adjust the injection fuel pressure and air intake volume according to different fuels.
Yuchai says: “The application of ammonia fuel and methanol is also one of the highlights of this engine platform. Compared with hydrogen, ammonia fuel and methanol feature lower preparation cost, easier storage, wide application and less environmental impact. Based on the above advantages, ammonia-fuelled internal combustion engines and methanol-fuelled internal combustion engines have a broader development prospect. The development of YCK16H provides a good technical platform for the application of single fuel of ammonia or methanol, ammonia-hydrogen blended fuel and diesel-methanol blended fuel, and lays a technical foundation for China to develop zero-carbon emission internal combustion engines.”
Yuchai’s launch of its hydrogen engines reflects similar technical advances by Cummins, DAF and JCB in Europe and North America, and indicates that the future of long-haul trucking may not be dominated by heavy and expensive battery-powered solutions. The Cummins engine, in particular, is of a similar displacement and output to the Yuchai unit.