Dual Reutilization of LNG Cryogenic Energy and Thermal Waste Energy with Organic Rankine Cycle in Marine Applications

Abstract

LNG is a promising alternative fuel at competitive price [1]. The LNG market is set to increase by 50% between 2017 and 2020. The worldwide fleet of LNG powered vessels is now expanding rapidly and the increasing number of LNG terminals are planned and constructed at major ports around the world. This study proposes a new Organic Rankine Cycle (ORC) with LNG Direct Expansion (DE) for the reutilization of the cryogenic energy within LNG storage tanks and potential waste thermal energy from various sources in the marine context. The proposed ORC system is designed in terms of the field testing data from a real marine application and analysed through dynamic simulation using Siemens LMS Imagine.Lab AMESim. Three optimal working fluids are examined on high vacuum and above atmospheric condensing pressures in the temperature range of -110˚C and 300˚C. The proposed ORC system is characterized by a significant improvement in thermal efficiency and power production in comparison of the existing ORC systems driven by waste thermal energy.