An Analysis of Engine Performance Between Diesel and Gas Mode of Large, 2-Stroke Marine Propulsion Engines

Abstract

Growing energy demand and increasing environmental awareness have given way to new technologies in the maritime industry. One of these technological advances is the use of liquefied natural gas (LNG) as an alternative fuel to diesel. The MV Ilshin Green Iris is South Korea's and the world's first LNG-powered bulk carrier and represents a significant shift towards realizing an era of clean energy. It utilizes a dual-fuel, high-pressure gas injection, low-speed marine engine as its source of propulsion and can operate in either a diesel mode or a gas mode. This paper aims to compare between modes to validate that dual-fuel operation is a safe and efficient alternative method to traditional marine diesel combustion. The MV Ilshin Green Iris serves as a portal to confirm that LNG is a safe, economically viable, and efficient fuel through engine performance analysis. Based on the collected data and calculations, the ME-GI engine aboard the vessel experiences about a 1.91% higher thermal efficiency and an SFOC average difference of about 16.27%, favoring gas mode. Data collected from the PMI measurements onboard prove that LNG combustion is as operationally efficient as heavy fuel oil (HFO) and that gas mode operation meets the same power requirements to that of traditional marine diesel combustion.