Yanmar to launch dual-fuel genset
Yanmar is stepping up its efforts in the dual-fuel arena with the launch of a six-cylinder, 260mm bore genset
Japanese engine maker Yanmar is to add a dual-fuel genset to its range of four-stroke engines.
The six-cylinder, 260mm bore EY26DF is already available as a propulsion engine – to be installed on the gas-fuelled tug boat being built for Mitsui OSK Line – and its genset counterpart, boasting an output of 1,533kW, will be released shortly.
The company claims that an innovative air flow control system – with waste gate valves controlling inlet air according to cylinder pressure – not only prevents knocking and misfiring, but also enables owners to install smaller engines.
Jelle Westerhof, area manager – commercial marine, Yanmar Europe, explained that the air flow control system means that the engine’s power does not drop when it uses gas with a low calorific value (a methane number of less than 80). Instead the engine reduces the amount of air in the mix.
“The fuel to air ratio is changed automaticaly, which is the reason you can maintain the power of your engine,” Westerhof said. “With other engines, you would need to build in more power to account for this – for example if you needed output of 1,500kW you may need a 1,650kW engine.”
Compared to the EY26 diesel engine, the 6EY26DF delivers 84% NOx, 25% CO2, and 99% Sox and PM reductions, meeting IMO’s Tier III NOx limits. In gas mode the new engine exceeds Yanmar’s current diesel engine thermal efficiency ratios, at 46.8%.
An eight-cylinder version of the EY26 engine is under development, and Yanmar noted in a press release that it would “continue its efforts towards expanding its dual-fuel engine line-up”.
Yanmar has capacity to build 2,500 engines a year from its factory in Japan, where all Yanmar engines are built. Between 70-80% of the factory’s output are gensets, with around half of those destined for the Japanese market in containerships, tankers and bulk carriers.