全回转起重船压载舱的优化探索

比较原船方案和优化方案在两种装载状态下固定起吊7500t时的数据,发现了一些问题。从而进一步分析了探讨数值分析法中所采用的优化原则的局限性。通过建立简单的数学模型,运用相关的数学软件,分析总结出压载舱分舱时的规律。比较分析几种典型的回转起吊的工况,总结出回转起吊时的一些规律。最后,归纳出如何优化设计大型起重船的压载舱。     

7500t起重船压载舱的优化研究

针对7500吨起重船的作业进行了简单的受力分析,并且对原起重船压载舱的特点进行了详细的总结。结合实际经验和相关理论,对原起重船的压载舱提出了四套改进方案,选取四种典型的工况,采用传统的多方案比较方法,从总压载量和压载水的调拨量两个主要方面进行综合评价,得出最优的压载方案。最后,总结了起重船压载舱优化的一些规律。     

超大型起重船压载调载系统研究设计

介绍了超大型起重船的发展需求及压载调载系统的作用,对2×8 000 t大型起重船的压载舱布置及调载方案进行了简要介绍,对压载泵进行了选型,对压载管系、遥控阀门、液位测量等系统进行了初步设计,并对设计方案进行了校核。结果表明该方案满足船舶各种作业需求。     

压载舱的布置对FPSO破损稳性的影响

提出了两种不同的压载舱布置方案,对某FPSO在三种不同的货油装载状态及各种初始倾斜情况时,各压载舱独立破损后的破舱稳性进行了计算研究,比较分析了FPSO压载舱的布置对其破舱稳性的影响.结果发现:在任何情况下,不论舱室大小,与首尾压载舱室破损相比,边压载舱破损将会导致更低的稳性范围;边压载舱之间或首尾压载舱之间,舱室越大,破损后,破舱稳性范围越小.进一步对边压载舱的研究发现:当舱容基本相同时,导致稳性最差的舱室与初始纵倾和压载状态有很大关系.如无纵倾、货油装载量较小时,离首部最近的边压载舱破损将出现最低的稳性范围;货油装载量很大时,将出现在离尾部最近的边压载舱.     

大型起重船典型压载系统介绍与分析

介绍了几种典型的压载系统及目前两艘大型起重船的压载系统,并分析了这些系统的优缺点和适用性。提出了新型大型起重船压载系统的设计要点,可供有关部门参考和探讨。     

压载舱流水孔面积的核算方法

绝大部分船舶采用压载水系统来保持各种装载工况下的航行性能,压载舱流水孔的面积大小对压载水系统功能的实现有着重大影响.着重介绍了一种流水孔面积的核算方法.以某12500 DWT多用途船为例,通过分析实船的排压载过程,利用流体软件FLUENT进行仿真计算,得到不同情况下压载舱流水孔附近的速度和压力分布,从而优化压载舱内流水孔的设置.     

模块运输船压载系统的设计分析

以适合北极航行的MC级模块运输船为例,对压载舱舱容和布置,压载泵的数量和容量,压载和排载时间,采用玻璃钢压载管路等问题,辅以压载管系原理分析压载管路的组成和压排原理,总结压载系统的设计特点.     

基于改进Mask RCNN的散货船压载舱裂缝检测算法

针对散货船压载舱所存在不同类型结构裂缝检测需求，基于机器视觉相关技术，探索一种应用实例分割目标检测算法（Mask RCNN）深度学习模型的裂缝识别方法。在分析散货船压载舱裂缝的图像特征的基础上，构建了基于MaskRCNN的裂缝识别深度学习模型，通过引入轻量化自底向上路径增强机制和自身特征优化模块优化检测模型，然后制作了涵盖多种类型的裂缝数据集，基于训练结果实现散货船压载舱结构裂缝图像识别，并验证了改进的MaskRCNN模型在散货船压载舱结构裂缝图像识别技术中的优越性，为压载舱自动化高效检测提供有效支撑。     

关于散货船压载/扫舱水系统的设计分析

压载/扫舱水系统是船舶上重要的保船系统。根据船型及要求不同,其选择压载/扫舱水的设计布置也不同。船企在签订散货船订单时,应充分考虑在满足规格书及有关各种规范的要求下,尽可能优化船舶设计、建造成本,而压载/扫舱水系统设计方式的不同也会影响舰船设计、建造成本。本文着重介绍大于50 000 DWT散货船不同压载/扫舱水管路系统的设计分析。     

250000DWT矿砂船压载舱的优化配置

矿砂船因其货物密度大,所需的舱容相对较小,边舱较大,所以合理配置边压载舱,减小压载舱使用量是很有必要的。应用穷举法,从1对、2对、3对压载舱同时为空舱以及前后压载舱合并的可行性出发,在保证压载状态、完整稳性及破舱稳性等影响因素的前提下,有效地减少了压载舱使用量,提高了目标船舶的经济性。     

Study on alternative approaches to corrosion protection of ballast tanks using an economic model

One of the most relevant problems in ship construction and maintenance nowadays is corrosion in ballast tanks of modern merchant vessels. On the one hand, there is a general consensus that the economic lifespan of such a vessel depends, to a large degree, upon the corrosion state of its ballast tanks, while on the other hand these ballast tanks, located between the outer hull and the cargo tanks, makes routine inspection and maintenance a difficult task.Today, ship's ballast tanks are usually constructed in steel and protected with an epoxy coating backed up by sacrificial zinc anodes. Such a construction has been applied without significant alterations for many years. The objective of this economic study is to compare this construction method with some potential alternatives. The considered alternatives are: (1) an increase in structural scantlings, eliminating the necessity to replace corroded at a cost of real cargo carrying capacity of the ship, (2) application of the novel and more durable TSCF₂₅ coating (3), the use of corrosion resistant steel in ship construction and (4) a standard PSPC₁₅ coating combined with lifetime lasting aluminum sacrificial anodes. A cost model was used to evaluate these alternative options together with sensitivity analysis. It is concluded that the durable coating and the use of lifetime lasting aluminum anodes are bound to improve the actual basic tank concept. Corrosion resistant steel becomes attractive when the steel price becomes competitive.     

Reducing the cost of ballast tank corrosion: an economic modeling approach

One of the most relevant problems in ship construction and maintenance nowadays concerns the corrosion in the double hull space ballast tanks of modern merchant vessels. On the one hand, there is a general consensus that the economic life span of such a vessel depends primarily upon the corrosion state of its ballast tanks, while on the other hand, the position of these tanks, squeezed between the outer hull and the loading tanks, makes routine inspection and maintenance almost impossible.Today, ship's ballast tanks are usually constructed in grade A steel and protected with a standard epoxy coating, backed up with sacrificial zinc anodes. Such a construction has been applied without significant alterations for many years. However, the objective of this economic study is to compare this construction method with some feasible alternatives. The considered alternatives are: (1) an increase of the scantlings, eliminating the necessity to replace corroded steel but diminishing the cargo carrying capacity of the ship, (2) application of the novel and more durable TSCF₂₅ coating (3), the use of corrosion resistant steel in ship construction or (4) a standard PSPC₁₅ coating combined with lifetime lasting aluminum sacrificial anodes. After running each alternative through a cost model including an extensive sensitivity analysis, it is concluded that the durable coating and the use of lifetime lasting aluminum anodes are bound to improve the actual basic tank concept. Corrosion resistant steel becomes attractive depending upon the evolution of the international steel market.     

基于CFD的潜艇高压气吹除主压载水舱系统模拟

高压气吹除主压载水舱是潜艇舱室进水情况下最有效的应急挽回手段之一.由于高压气吹除时压载水舱中剧烈的气液混合流动,导致建立的理论模型有一定局限性.本文通过CFD中两相流VOF模型对高压气吹除压载水舱的动态过程进行仿真,分析吹除过程中压载水舱中气-液混合现象、压力变化情况及压载水舱排水速率等特点,以验证高压气吹除压载水舱的理论模型.     

特殊用途浮船坞作业控制系统研究

供舰船上排、下水用的浮船坞，是一种特殊用途的浮船坞，控制系统必须按其用途要求进行特殊设计。现介绍该特殊用途浮船坞作业控制系统的几个主要方面，包括：手动控制、计算机辅助手动控制、压载舱群液位计算机控制、配载计算及联机控制等。利用计算机实现对浮船坞的作业控制在国内尚无成功的先例，实现对压载舱群液位的控制、配载计算及联机控制等功能更是一次有益的探索。     

Optimal ballast water exchange sequence design using symmetrical multitank strategy

The quality of the ballast water exchange scheme affects many aspects of a ship, including intact stability, structural strength, building and operational expenses, etc. This paper focuses on developing an optimization methodology for large-scale sequential ballast water exchange. The method of transversely symmetrical ballast water tanks being exchanged simultaneously is adopted, and the potentials of multiple tanks being exchanged at a time are explored. The mathematical model for the symmetrical ballast water exchange problem is built by minimizing the occurred maximum trims, maximum hull girder bending moments, and shearing forces as objectives, and the related safety assessment criteria as constraints. A multiobjective genetic algorithm with some operators specially designed for the problem is presented to obtain a set of approximate Pareto-optimal solutions for engineers to choose from. Finally, a real case study on the symmetrical ballast water exchange of a 176,000 DWT bulk carrier is conducted to illustrate the effectiveness of the proposed approach.     

压载水舱泥沙淤积原因和冲淤新方法

东海海水含沙量较高,船舶压载水舱等部位易形成泥沙沉积,增加船舶负重及油耗等运营费用。文章分析了船舶压载水舱泥沙淤积原因,模拟研究了泥沙沉降特征,提出了基于气动冲淤方式的压载水舱泥沙治理新方法。     

适应共同结构规范的30．8万t VLCC船型开发

708研究所以“经济、安全、环保”（ESE）为宗旨，开发了适应双壳油船共同结构规范（CSR）的30．8万t VLCC船型。文中介绍了CSR对结构设计的关键要求以及对总体设计的部分要求，并着重对VLCC总强度储备、中剖面设计和粗网格有限元分析等关键技术进行了分析，以期初步阐明CSR对VLCC结构设计的影响。     

晃荡要求对散货船压载舱结构的影响探讨

协调版共同结构规范（CSR-H）对散货船液舱的晃荡强度提出新的要求。针对散货船专用压载舱,通过对晃荡载荷的规范计算,并结合实船统计数据对比,探讨了基于CSR-H的晃荡要求对散货船专用压载舱结构设计的影响,包括有效晃荡长度、有效晃荡宽度和构件尺寸等。