船舶全寿命期腐蚀防护设计研究

发布时间：2018-11-17 07:04

【摘要】：随着船舶朝着大型化和复杂化的发展趋势,船舶的安全问题变得更加重要。船舶在其全寿命期内都面临着腐蚀问题,腐蚀可能造成严重的事故。船舶的腐蚀防护方法主要有防腐涂层和阴极保护。船舶涂层防腐性能会随着船舶服役时间的增长而逐渐恶化,导致防腐效果弱化。在传统的阴极保护设计中,大多采用经验公式来设计阴极保护参数。这种方法不能根据船舶在不同时期下防腐涂层状态的变化,采取灵活可靠的应对方案。因此,针对船舶进行全寿命期内的腐蚀防护进行科学有效的设计具有重要意义。本文研究了涂层的防腐机理和船舶常用涂料,针对目标船设计了防腐涂层方案,并结合阴极保护对涂装的要求,设计了阴极保护系统涂装方案。根据目标船的特点,设计了外加电流阴极保护系统。该阴极保护系统由保护及控制系统和监测系统两部分组成。控制系统可以通过反馈控制机制自动调节电源输出,从而将保护电位控制在合理范围内。通过监测系统可以获得监测点处的实时保护电位,能够清晰、直观地掌握阴极保护效果。通过缩比模型试验,验证了阴极保护系统的可靠性,并发现了涂层破损率变化对阴极保护的影响。最后,采用数值模拟方法,设计船舶全寿命期的阴极保护方案。通过船舶涂层破损率的变化考虑船舶在不同时期的涂层防腐状态。初步设计采用单独外加电流阴极保护的方式,但是出现了严重的保护电位分布不均匀现象。优化设计采用牺牲阳极阴极保护联合外加电流阴极保护的方式,取得了经济有效的阴极保护效果。
[Abstract]:With the development of large-scale and complicated ships, the safety of ships becomes more and more important. Ships are faced with corrosion problems in their lifetime, corrosion may cause serious accidents. The corrosion protection methods of ships are mainly anticorrosive coating and cathodic protection. The anticorrosion performance of ship coating will deteriorate gradually with the increase of ship service time, which leads to the weakening of anticorrosion effect. In the traditional cathodic protection design, the empirical formula is used to design the cathodic protection parameters. This method can not be flexible and reliable according to the state of anticorrosion coating under different periods of time. Therefore, it is of great significance to carry out scientific and effective design for the corrosion protection of ships during their lifetime. In this paper, the anticorrosive mechanism of the coating and the common coatings of the ship are studied. The anticorrosive coating scheme is designed for the target ship, and the coating scheme of the cathodic protection system is designed according to the requirements of the cathodic protection for the coating. According to the characteristics of the target ship, the applied current cathodic protection system is designed. The cathodic protection system consists of protection and control system and monitoring system. The control system can automatically adjust the output of power supply by feedback control mechanism, so that the protection potential can be controlled within a reasonable range. Through the monitoring system, the real time protection potential of the monitoring point can be obtained, and the cathodic protection effect can be grasped clearly and intuitively. The reliability of the cathodic protection system is verified by the scaling model test, and the influence of the damage rate of the coating on the cathodic protection is found. Finally, the cathodic protection scheme for the whole life of ship is designed by using numerical simulation method. The anticorrosion state of ship coating in different periods is considered by changing the damage rate of ship coating. The primary design adopts the method of single applied current cathodic protection, but the distribution of protection potential is not uniform. The optimal design adopts sacrificial anode cathodic protection combined with applied current cathodic protection to obtain economical and effective cathodic protection effect.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U662

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