Multi-objective optimization of liquid hydrogen FPSO at the conceptual design stage

A conceptual design of a liquid hydrogen FPSO was developed in this research, and its hull dimensions were optimized under the environment at the Donghae gas field in South Korea. During the conceptual design stage, a process of production, storage, and offloading of liquid hydrogen was studied, and the topside and hull layouts for the liquid hydrogen FPSO were proposed. The capacities of each module were determined based on the operation scenario. The corresponding required areas and weight of each module were estimated from the literature review and the data from the ongoing project (KRISO, 2022). The optimized hull dimensions were presented by a Multi-Objective Evolutionary Algorithm (MOEA) with two objectives, minimization of the hull steel weight and the motion level considering the constraints related to geometry, stability, and hydrodynamic performances. The obtained Pareto set shows three classified solution types depending on the active constraints, which is able to propose a wide range of design alternatives for the liquid hydrogen FPSO with unique constraints compared to general ships.