Concept Design of a Bulk Carrier Retrofit with LNG Fuel

Abstract

This report showed a case study of a mini-cape size bulk carrier of being retrofitted for Liquefied Natural Gas (LNG) fuel and the selection of its new fuel tanks to meet the stringent emissions requirement. The vessel was equipped with a dual fuel ready (DFR) engine before the retrofit. Engine manufacturer will supply and replace engine parts for LNG fueled operations with no significant modification of the engine structure required. The detailed engineering design considerations were studied with cost reduction and minimum downtime set as ultimate objectives. Top-down and bottom-up approaches for cost estimation are used in this analysis. The analysis was determined by life cycle cost and management costs. The cost analysis showed the payback period of an LNG fueled ship retrofit is 4.5 years against a 0.5%S compliant fueled vessel. The payback period is considered reasonable and it shows retrofitting vessels for LNG fuel as an attractive option in meeting new regulation for ship-owners. If the shipyard standardizes the tank construction including outfitting, the specified cost may even go lower. A further reduction is also anticipated with repeating orders of similar vessels.

Case Studies of Single Nitrogen Expander Liquefaction for FLNG

“…Exergy for process calculation can be done by the equation for the state to state as equation (11) e=(h-T 0 s) T,P -(h-T 0 s) T 0 P 0 (11) where T0 and P0 are at ambient conditions, and e is exergy.…”