A First For Screw Compressors: Marine Dual Fuel Engines

    Image courtesy of Kobe Steel

    Kobe Steel Ltd. has received an order for two screw compressors for use with marine dual fuel engines. According to the company, this is the first time that screw compressors will be used to supply fuel to marine dual fuel engines. Plans call for Kobe Steel to deliver the compressors to South Korea’s Daewoo Shipbuilding & Marine Engineering Co. Ltd. in August 2017.

    The vessel, scheduled to enter service in 2018, will transport LNG from a shale gas liquefying plant in North America to Europe and other destinations around the world.

    The market size of nonstandard compressors for marine dual fuel engines is forecast to total over US$190 million in the next five years, according to Kobe Steel. Kobe Steel is targeting to gain over 50% of the market by 2020.

    Nonstandard compressors for marine dual fuel engines are generally used to compress vaporized LNG, namely boil-off gas (BOG), which is then sent to the engines. To date, marine dual fuel engines have been of the middle speed, four-stroke type and been driven predominantly by low gas pressure. To date, according to Kobe Steel, only centrifugal compressors have been used for these engines.

    In recent years, due to the need to save energy in ship operation and comply with stricter environmental regulations, dual fuel, low speed, two stroke engines that offer high efficiency with a 10% improvement in fuel consumption have entered the market. In the future, this type of engine will become the norm as its adoption is being considered for nearly all new vessels, Kobe Steel said.

    Marine dual fuel, low speed, two-stroke engines require relatively high gas pressure, making centrifugal compressors less efficient, according to Kobe Steel. These engines need to have their fuel gas pressure controlled within the allowable level of the load percentage of the engines. Screw compressors are highly suitable for these engines, which need to have their fuel gas pressure controlled within the allowable level the load percentage of the engines, as they can keep pace with load fluctuations and operate most efficiently in the medium- to high-pressure range, the company said.

    Kobe Steel, which manufactures screw, reciprocating, and centrifugal compressors, has received an additional order for one reciprocating compressor for BOG reliquefaction, which will be installed in the same vessel.