Exploring various sizes of liquefied gas carriers by an optimisation approach to early-stage project

Abstract

The present work aims to provide a comprehensive approach to assist within the early-stage project of ship energy systems. This integrated approach enables the optimisation of design, synthesis and operation, considering economic and technical aspects, as well as route weather. A Differential Evolution optimisation algorithm is used to maximise the net present value of the system. Constraints are considered to avoid propellers presenting strength, cavitation and vibration concerns. The case study is designed using three liquefied natural gas carriers of different cargo capacities sailing between Lake Charles and Tokyo Bay, via Panama Canal. The approach is shown to be effective to find optimal solution quickly and highlights the need for employing constraints to avoid future technical concerns. The approach also succeeded to quantify the gain of the net present value using the economy of scale, i.e. using bigger ships, and higher service speeds.