The study of an integrated energy system is presented in this article that will cover all types of energy loads (mechanical, electrical, thermal) on a Very Large Crude Carrier (VLCC) with the maximum technically possible and economically feasible exploitation of fuel energy, thus reducing the operating cost and environmental footprint of the ship. There may be a large variety of configurations, design specifications and operating states that can cover the loads, making it necessary to apply synthesis, design and operation optimization of the system. The net present value of the system is selected as the objective function. For this purpose, a superconfiguration of the system is considered, which includes a number of Diesel engines adapted for possible operation in a combined Diesel and Rankine cycle, heat recovery steam generators producing high and low pressure steam, steam turbines that can contribute to propulsion and/or to the electricity production, an exhaust gas boiler and auxiliary boilers, as well as Diesel-generator sets. The synthesis of the system, that is, the components that will finally exist in the system, and their interconnections, the design specification of the components and the operating properties at characteristic operating states of the ship are not predetermined, but they are the result of formal, mathematical optimization. In addition, the speed of the vessel in each state, an important operational variable that has a crucial effect on the propulsion power and thus on the fuel consumption, is also determined by the optimization. The hull characteristics, the loading condition and the weather state are taken into account for the calculation of the propulsion power. For the optimization, proper models of the various components have been developed and the optimization problem is solved by addressing the three levels (synthesis, design, and operation) at a single computational step. The benefits of optimization, as well as the conditions that make the combined cycle economically justified, are demonstrated through an application example. The numerical solution is obtained for various values of fuel price and freight rate, so that the effects of these two crucial parameters on the optimal solution are assessed.

中文翻译：

---

联合循环综合能源系统的合成、设计和运行优化，包括 VLCC 季节性速度的优化

本文介绍了综合能源系统的研究，该系统将涵盖超大型原油运输船 (VLCC) 上的所有类型的能源负荷（机械、电力、热力），并在技术上和经济上最大限度地利用燃料能源，从而降低船舶的运营成本和环境足迹。可能有多种配置、设计规范和操作状态可以覆盖负载，因此有必要应用系统的综合、设计和操作优化。选择系统的净现值作为目标函数。为此，考虑了系统的超配置，其中包括许多柴油发动机，适用于在组合柴油和兰金循环中的可能操作，产生高压和低压蒸汽的热回收蒸汽发生器、可用于推进和/或发电的蒸汽轮机、废气锅炉和辅助锅炉，以及柴油发电机组。系统的综合，即最终将存在于系统中的部件及其互连、部件的设计规范和船舶特征运行状态下的运行特性不是预先确定的，而是由以下因素决定的：正式的数学优化。此外，每个状态下的船舶速度是一个重要的操作变量，对推进功率和燃料消耗具有至关重要的影响，也由优化决定。船体特点，计算推进功率时考虑了装载条件和天气状况。对于优化，已经开发了各种组件的适当模型，并且通过在单个计算步骤中解决三个层次（合成、设计和操作）来解决优化问题。优化的好处，以及使联合循环在经济上合理的条件，通过一个应用示例得到了证明。获得了燃料价格和运费的各种值的数值解，以便评估这两个关键参数对最优解的影响。已经开发了各种组件的适当模型，并且通过在单个计算步骤中解决三个层次（合成、设计和操作）来解决优化问题。优化的好处，以及使联合循环在经济上合理的条件，通过一个应用示例得到了证明。获得了燃料价格和运费的各种值的数值解，以便评估这两个关键参数对最优解的影响。已经开发了各种组件的适当模型，并且通过在单个计算步骤中解决三个层次（合成、设计和操作）来解决优化问题。优化的好处，以及使联合循环在经济上合理的条件，通过一个应用示例得到了证明。获得了燃料价格和运费的各种值的数值解，以便评估这两个关键参数对最优解的影响。