大型LNG船玻璃钢压载水管道应力校核方法

玻璃钢管作为大型液化天然气(LNG)船压载水管道,在其应用过程中易出现部分管道破裂以及管道支架损坏的问题,针对该问题,以某大型LNG船为例,采用管道应力分析软件CAESARII建立压载水系统玻璃钢管道有限元模型。根据实际建造营运方式,考虑船舶运动加速度、船体变形、温度和压力等载荷,确定能覆盖所有建造运营条件的载荷工况。采用ISO 14692标准作为大型LNG船玻璃钢压载水管应力校核设计的标准,分析压载水管道的应力水平以及作用在管道支架上的负荷,对应力超标处的管道进行优化布置,对承受大负荷的管道支架进行结构加强设计。实船应用结果表明,该方法的应用效果良好,可推广到其他类型船舶的玻璃钢压载水管道系统的设计中。

Study of Stress Analysis method for GRP Ballast Water System Pipeline of a Large LNG Carrier

Abstract: GRP pipes have excellent corrosion resistance, hydraulic properties and small specific gravity, and have been gradually applied to marine and offshore engineering Domain. There are still phenomena of pipe rupture and support damage in GRP Ballast Water System Pipeline of a Large LNG carrier. This paper takes ballast water system GRP pipe of a large LNG vessel as the research object. Firstly, pipeline finite element model is established by using CAESARII which is a professional pipeline stress analysis software. Secondly, based on the actual construction and operation mode, load cases are formulated considering temperature, pressure, hull deformation and motion acceleration loads. Finally, ISO 14692 is adopted as the code for stress checking design of GRP ballast pipes of large LNG vessel. According to analysis result, piping arrangement is optimized for the stress exceeding the standard and the structural reinforcement is designed for the bracket subjected to the large load, which shows a good performance in the ship operation. The design method of this paper can be further extended to the design of GRP ballast water pipe system for various types of vessels.