半潜维修船上浮工况多功能浮力舱配置优化

Size optimization of multi-functional buoyancy tanks of semi-submersible repair vessels in floating conditions

为了解决半潜维修船在海上开展维修作业时,通常将故障船舶或大型海洋工程设备浮装在维修甲板上。若其携带的维修设备较重,可能导致举力不足或难以安全托举故障船舶或设备出水的问题。依据船舶安全知识,以初稳性高度值为目标函数,建立了半潜维修船上浮工况多功能浮力舱配置及压载优化模型,并设计了2阶段方法实现对模型的求解。以半潜维修船携带维修设备的同时浮装3万t故障大型海洋工程设备为例,求得安全可行的多功能浮力舱配置及其相应的船舶压载最优方案,证明了模型的有效性,并通过变参数分析法总结了维修设备重量系数与故障船舶或设备装载位置对初稳性的影响规律。该方法可为解决半潜维修船携带维修设备浮装故障船舶或大型海洋工程设备的安全问题提供理论指导。

When a semi-submersible repair vessel carries heavy maintenance equipment,it may not be able to safely lift a nonfunctioning ship or very large marine engineering equipment out of the water. To address this safety problem,we established a multi-functional buoyancy tanks size and ballast optimization model for semi-submersible repair vessels in floating conditions,with the objective function of the initial metacentric height based on the theory of ship safety. Then,we designed a two-stage method for solving this model. Finally,taking as an example the semisubmersible repair vessels lifting 30 000 t of nonfunctioning equipment along with a certain amount of maintenance equipment,we provide a safe and feasible solution for an optimal multi-functional buoyancy-tank size and a relevant ballast plan,which confirm the validity of this model. Moreover,using a variable parameter control technique,we analyze the effects on the initial metacentric height of a weight coefficient of the maintenance equipment and position of the nonfunctioning ship or equipment on the maintenance deck. Our results indicate that reducing the weight of the maintenance equipment is beneficial to the initial metacentric height. There is also an optimal loading area.When the gravity center of a nonfunctioning ship or equipment is located in this area,the initial metacentric height is greater. When outside this area,the initial metacentric height is lower. Our proposed method provides theoretical guidance for resolving the safety problems associated with semi-submersible repair vessels with maintenance equipment in floating conditions.