Nippon Yusen Kaisha (NYK) will install a variable compression ratio (VCR) system on two large LNG-powered coal vessels built at Oshima Shipbuilding Co., Ltd. are to be built. The ships are scheduled for delivery by the end of 2025. This will be the first time VCR systems will be installed on ships, including existing ships that use heavy fuel oil as their main fuel.
The VCR system can adjust the air compression ratio in the engine combustion chamber to an optimal balance depending on engine performance and LNG fuel properties. This optimal adjustment improves fuel efficiency by about 3% during operation in LNG gas mode and by about 6% in diesel oil mode.
The system is also expected to play an important role in reducing greenhouse gas emissions from existing ships and improving engine efficiency as decarbonized fuels are introduced.
Based on its technology and experience in large, low-speed marine engines, Mitsui E&S DU Co., Ltd. together with Winterthur Gas & Diesel Ltd, a Swiss engine licensor, developed the VCR system.
NYK strives to deepen its partnerships with companies that are actively adopting and developing greenhouse gas reduction technologies and contributing to greenhouse gas reduction in the maritime shipping business.