The drive to combat greenhouse gas emissions and seek eco-friendly energy solutions has led to a notable surge in the utilization of Liquid Natural Gas (LNG) in marine applications. Recognized as a sustainable fuel, LNG has gained substantial traction as a viable alternative across various commercial transport sectors, including marine and shipping. With maritime traffic accounting for an estimated 3% of global CO2 emissions, the International Maritime Organisation (IMO) aims to reduce carbon emissions. While LNG offers a more environmentally friendly alternative to highly viscous diesel fuels commonly used in cruise liners and container ships, it poses notable challenges to fuel systems and pumps due to extreme cryogenic temperatures.
Overcoming the Hurdles
When it comes to LNG pumps, bearings play a critical role, enduring extreme temperatures while fully submerged in Liquid Natural Gas ranging from (-196ºC / -320ºF) or in Liquid Hydrogen at (-253ºC / -423ºF). Carter Manufacturing Ltd., based in Oxfordshire, is a renowned global supplier of precision bearings with a 20 years-rich heritage in providing reliable bearing solutions for cryogenic applications. As fuel systems approach near-zero operating temperatures, utilizing liquid lubrication becomes increasingly challenging, necessitating the use of dry-running bearings. Conventional steel bearings, such as 52100 Chrome Steel are merely unproductive, leading to subpar performance, shorter service life, and unforeseen failures.
Apart from lubrication challenges, the material expansion and reduction within the bearing housings become crucial for optimal bearing efficiency. It is essential to carefully align the coefficient of thermal expansion with the chosen materials to ensure smooth operation.