LNG船货物机械室穿舱件温度场研究

Research on the Temperature Field of Penetration Pieces in Cargo Machinery Room of LNG Carrier

货物机械室是大型液化天然气(Liquefied Natural Gas,LNG)船液货系统的重要组成部分,是维持货舱及管路稳定压力、液货输送及驳运的核心区域。对某大型LNG船货物机械室的穿舱件及其周围的温度场进行研究,使用有限元法计算不同材料以及环境因素下的温度场,分析各影响因素的重要性及温度场状态形成原因。通过分析计算不同材料在低温下的性能及温度场分布,确定温度场中材料较脆弱、需要加强的区域,根据计算结果综合评估需要加强的材料面积。通过研究发现,越靠近低温管,温度梯度越大,温度下降得也越快,如果采用普通碳钢,低温面积约为管子截面积的4倍,而不锈钢材料可有效地减小低温面积。研究结果可为施工和甲板的稳定性设计提供理论依据,是设计优化的有效支撑。

Cargo machinery room is an important part of the liquid cargo system on the large liquefied Natural Gas(LNG) carrier. It is the core sector to maintain stable pressure in the pipelines and to carry out liquid cargo delivery andtransfer. This paper studies the penetration pieces and its surrounding temperature field of the cargo machinery room onthe large LNG carrier, where the finite element method is used to calculate the temperature field corresponding todifferent material and environmental factors, and to analyze the significance of each influencing factor and the formationof the temperature field. The weak regions that need to be reinforced are identified through analyzing both theperformance and the temperature field distribution of different materials, and the size to be reinforced is comprehensivelyevaluated based on the calculation results. Through the study, it is found that the temperature gradient is larger in theregion closer to the low temperature tube where the temperature drop is also faster. If ordinary steel is used, the lowtemperature area is about 4 times the section of the tube. However, stainless steel material can effectively reduce the lowtemperature area. This study provides some theoretical basis for construction and deck stability design, and is helpful fordesign optimization.