In this paper, an LNG BOG re-liquefaction system operating according to the Claude refrigeration cycle using oxygen as refrigerant is analysed. It includes a comprehensive exergy analysis of a BOG reliquefaction system installed onboard an LNG carrier. Commonly operating data have been used to carry out a thermodynamic analysis of the system. The system is basically made of two parts: Oxygen cy...

A. 1 ohansson and P. Lundqvist Dept. of Energy Technology Div. of Applied Thennodynamics and Refrigeration The Royal Institute of Technology, KTH Stockholm, Sweden Test results from field retrofit situations, where R22 has been changed to Isceon 59 1 and R407C in two identical chillers, shows that both substitutes require more subcooling than R22 to give the system a satisfying performance. It ...

Two-phase ejectors are devices capable of improving the performance of refrigeration and air conditioning cycles by means of expansion work recovery. Ejector studies often focus on the design and performance of the two-phase ejector and the effect it can have on the performance of the ejector cycle. However, the ejector is not the only component of the system that can have a significant influen...

Heat exchangers are important units in most industrial processes. They involve physical phenomena such as condensation and evaporation including several boiling regimes. Different types of heat exchangers constructed for different applications may differ much in geometrical design. This work explains and demonstrates a modelling framework which is capable of handling a multitude of geometries a...

Vapor refrigerant injection cycle with a flash tank has proven to be effective in improving system performance significantly at extremely low and high ambient temperatures. However, the control strategy of operating the system is still unclear. There is no open publication on the comprehensive study of the vapor injection cycle control strategy to date. This paper presents the experimental inve...

The transition from CFC-12 (GWP=10,900) to HFC-134a (GWP=1,430) in the 1990’s in new vehicle air conditioners eliminated the contribution to ozone depletion potential (ODP) from new vehicles and reduced the direct Global Warming Potential (GWP) by over 80%. One proposed alternative is HFC-1234yf (GWP=4). Despite the phase-in success of HFC-134a as a zero ODP automotive refrigerant it is still a...