• Journal of the Society of Naval Architects of Korea
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• v.51 no.6
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• pp.451-458
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• 2014

The purpose of this study is to compare the economics between a diesel propulsion vessel and a LNG fuel propulsion vessel through the analysis of the present value using the LCC(Life Cycle Cost) method. This study is also to judge the economics for long-term operation of a LNG fuel propulsion vessel as a result of analysis about the equivalent uniform annual cost. In particular, LCC method was strengthened by sensitivity analysis based on combined interest rate which is considering discount rate and inflation rate simultaneously.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.3
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• pp.352-359
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• 2018

As a fuel for ship propulsion, liquefied natural gas (LNG) is currently considered a proven and reasonable solution for meeting the IMO emission regulations, with gas engines for the LNG-fueled ship covering a broad range of power outputs. For an LNG-fueled ship, the LNG bunkering process is different from the HFO bunkering process, in the sense that the cryogenic liquid transfer generates a considerable amount of boil-off gas (BOG). This study investigated the effect of the temperature difference on boil-off gas (BOG) production during ship-to-ship (STS) LNG bunkering to the receiving tank of the LNG-fueled ship. A concept design was resumed for the cargo/fuel tanks in the LNG bunkering vessel and the receiving vessel, as well as for LNG handling systems. Subsequently, the storage tank capacities of the LNG were $4,500m^3$ for the bunkering vessel and $700m^3$ for the receiving vessel. Process dynamic simulations by Aspen HYSYS were performed under several bunkering scenarios, which demonstrated that the boil-off gas and resulting pressure buildup in the receiving vessel were mainly determined by the temperature difference between bunkering and the receiving tank, pressure of the receiving tank, and amount of remaining LNG.