A dynamic model for liquefied natural gas evaporation during marine transportation

Dimopoulos, GG; Frangopoulos, CA

dc.contributor.author	Dimopoulos, GG	en
dc.contributor.author	Frangopoulos, CA	en
dc.date.accessioned	2014-03-01T01:57:05Z
dc.date.available	2014-03-01T01:57:05Z
dc.date.issued	2008	en
dc.identifier.issn	13019724	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/28335
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-56849087887&partnerID=40&md5=d22d9b66c3a481c9cdfe6ec718fa3332	en
dc.subject	Boil-off gas	en
dc.subject	Dynamic simulation	en
dc.subject	Liquefied natural gas	en
dc.subject	Vapor-liquid equilibrium	en
dc.subject.other	Gas fuel purification	en
dc.subject.other	Gas industry	en
dc.subject.other	Gases	en
dc.subject.other	Landforms	en
dc.subject.other	Liquefied gases	en
dc.subject.other	Liquefied natural gas	en
dc.subject.other	Natural gas	en
dc.subject.other	Phase equilibria	en
dc.subject.other	Thermodynamic properties	en
dc.subject.other	Thermodynamics	en
dc.subject.other	Vapors	en
dc.subject.other	Waterway transportation	en
dc.subject.other	Wetlands	en
dc.subject.other	Boil-off gas	en
dc.subject.other	Case studies	en
dc.subject.other	Conservation equations	en
dc.subject.other	Cryogenic tanks	en
dc.subject.other	Dynamic simulation	en
dc.subject.other	Economic assessments	en
dc.subject.other	Energy systems	en
dc.subject.other	External-	en
dc.subject.other	Global energy markets	en
dc.subject.other	Liquid phase equilibriums	en
dc.subject.other	Marine energies	en
dc.subject.other	Marine transportations	en
dc.subject.other	Marine transports	en
dc.subject.other	Mass flows	en
dc.subject.other	Off gasses	en
dc.subject.other	Operation modes	en
dc.subject.other	Significant impacts	en
dc.subject.other	Solution accuracies	en
dc.subject.other	Time discretization	en
dc.subject.other	Variations of	en
dc.subject.other	Vessel operations	en
dc.subject.other	Natural gas transportation	en
dc.title	A dynamic model for liquefied natural gas evaporation during marine transportation	en
heal.type	journalArticle	en
heal.publicationDate	2008	en
heal.abstract	Marine transport of natural gas, predominately in the form of Liquefied Natural Gas (LNG), is of growing importance in the global energy markets. LNG is transported with vessels having cryogenic tanks without any means of external refrigeration. Hence, a significant fraction of the cargo LNG volume evaporates during voyage, which is usually called Boil-Off Gas (BOG). According to the type of the energy system, BOG can be utilized as fuel, reliquefied or burned in an oxidizer. The handling of the boil-off gas during the LNG vessel operation and the assessment of its thermodynamic properties are key issues in the technical and economic assessment of the complete marine energy systems of LNG vessels. A detailed dynamic boil-off model has been developed, which accounts for the variation of BOG mass flow, composition and thermodynamic properties during voyage. The model employs coupled non-linear vapor - liquid phase equilibrium thermodynamic equations and differential conservation equations describing the evolution of LNG quantity and composition with time. Various solution and time discretization schemes have been tested to assess the solution accuracy and stability. The model has been used to investigate the variation of the LNG and BOG quantity, composition and thermodynamic properties during typical voyage profiles of a case study LNG vessel. Variations of the thermodynamic properties and of the quantity of BOG in the range of 6 to 10% during voyage have been found, having a significant impact in operation modes and fuel consumption of the energy system. Results have been also compared with the traditional approaches used in the marine technical practice.	en
heal.journalName	International Journal of Thermodynamics	en
dc.identifier.volume	11	en
dc.identifier.issue	3	en
dc.identifier.spage	123	en
dc.identifier.epage	131	en