JULY 5, 2012 — Mitsubishi Heavy Industries, Ltd. (MHI) will begin developing low-speed, dual-fuel, marine diesel engines capable of using not only conventional heavy oil but also natural gas as fuel.
Designated the "UEC-LSGi," the new engine will be added to the lineup of the Mitsubishi UEC Engine Series and is scheduled to be launched onto the market in 2015.
For the new engine, MHI will engage in the development of new components required for dual-fuel use, including a new direct fuel injection system, a gas-fuel supply system and control system.
MHI plans to complete preliminary testing by a single cylinder test engine by the end of March 2014. The company will then conduct verification tests for full-scale engines with dual-fuel use capability and bring an 11,000 – 18,000 kW class power output UEC-LSGi engine with a cylinder bore of 600 mm onto the market.
The engine]will use the diffusional combustion method, in which high-pressure gas, about 300 bar, is injected in the air compressed by the cylinder stroke and ignited by a pilot flame using a very small amount of fuel oil. The method excels in responsiveness for changes in gas fuel composition and sudden changes in engine load, compared with the pre-mixed combustion method, in which low-pressure gas is mixed with air and then compressed. Leveraging this feature, MHI will develop the engine with high combustion stability.
The UEC-LSGi will also be designed to be capable to operate with heavy fuel only to100 percent engine load, which enables it to meet various operational needs. For NOx (nitrogen oxide), natural gas is slightly advantageous compared with conventionally used heavy oil. MHI will apply its EGR (exhaust gas recirculation) technology, currently in development, and others for the new engine to comply with IMO rules.