Thermoeconomic Analysis of the Marine Energy System
of a QC-max LNG Carrier

Μαχαίρα, Αικατερίνη; Machaira, Aikaterini

dc.contributor.author	Μαχαίρα, Αικατερίνη	el
dc.contributor.author	Machaira, Aikaterini	en
dc.date.accessioned	2025-11-28T08:04:50Z
dc.date.available	2025-11-28T08:04:50Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/62944
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.30640
dc.rights	Αναφορά Δημιουργού-Μη Εμπορική Χρήση-Όχι Παράγωγα Έργα 3.0 Ελλάδα	*
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/gr/	*
dc.subject	LNG Carrier	en
dc.subject	Integrated marine energy systems	en
dc.subject	Reliquefaction	en
dc.subject	Voyage Plan	en
dc.subject	Energy saving devices (ESDs)	el
dc.title	Thermoeconomic Analysis of the Marine Energy System of a QC-max LNG Carrier	en
dc.contributor.department	Laboratory of Marine Engineering	el
heal.type	bachelorThesis
heal.classification	Marine energy systems	en
heal.language	en
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2025-06-19
heal.abstract	The maritime sector is undergoing a transformative shift driven by escalating global energy demands and increasingly stringent environmental regulations. Liquefied Natural Gas (LNG) carriers have become a central component of this shift, with the global orderbook for LNG vessels expanding steadily to meet both environmental and logistical demands. This thesis examines the energy system of a QC-Max LNG carrier, one of the most technologically advanced vessel types in terms of cargo capacity and engineering sophistication. These vessels incorporate complex configurations such as dual-fuel low-speed engines and advanced boil-off gas (BOG) management systems, which introduce challenges in energy modeling, simulation, and performance assessment. To address these complexities, a mathematical model of the vessel's integrated energy system was developed using the gPROMS platform. Key performance indicators—such as fuel consumption, specific energy consumption, and operational expenditure—are analyzed to assess the impact of various design and operational strategies. Particular emphasis is placed on the contribution of Energy Saving Devices (ESDs), including shaft generators, the air lubrication system, and the reliquefaction unit. These technologies are evaluated in terms of their effectiveness in improving energy efficiency and reducing cargo boil-off consumption and, consequently, emissions. Additionally, the thesis considers the operational perspective of charterers, emphasizing the importance of maximizing energy performance relative to delivered cargo. The operational analysis is based on two actual voyages, incorporating real navigational constraints and ship-specific conditions to enable realistic and practical performance assessments. The study aims to maximize the amount of cargo delivered at the end of the voyage by maintaining constant cargo tank pressure, thereby ensuring efficient cargo management. Through a holistic and systems-based approach, this research contributes to the ongoing effort to optimize LNG carrier operations in the context of the energy transition. By bridging theoretical modeling with practical applications, the thesis offers strategic recommendations for achieving sustainable and economically efficient LNG transport.	en
heal.advisorName	Dimopoulos, George
heal.committeeMemberName	Λυρίδης, Δημητριος	el
heal.committeeMemberName	Προυσαλίδης, Ιωάννης	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Ναυπηγών Μηχανολόγων Μηχανικών. Τομέας Ναυτικής Μηχανολογίας. Εργαστήριο Ναυτικής Μηχανολογίας	el
heal.academicPublisherID	ntua
heal.numberOfPages	114
heal.fullTextAvailability	false