【作者】 周昊；

【导师】 冯武文；

【作者基本信息】 北京化工大学 ， 化工过程机械， 2006， 硕士

【摘要】 LNG(液化天然气)船是一种国际上公认的高技术、高难度、高附加值的复杂船型。本文所研究的是一艘138000m~3的LNG船，该船的热维护系统十分复杂，对其进行温度场分析是一项有意义的工作。为了准确计算出LNG船的温度场，研究LNG船封闭腔室对流系数是极其重要的。 本文对LNG船体模型进行了简化，分别讨论了LNG船封闭腔室内热传导、热对流、热辐射对热量传递的影响程度，从理论上推导出LNG船舱中的对流系数关系。 使用ANSYS有限元程序，采用热分析单元，建立了138000m~3 LNG船1／4船舱的三维有限元模型，根据理论公式，用APDL语言编制迭代程序，计算出LNG船在8种工况下各腔室的对流系数，进而得出LNG船的温度场及日蒸发率。 根据本文建立的模型计算得到的日蒸发率与国外实测资料一致，证明了计算对流换热的方法是有效的。 通过对LNG运输船温度场的分析，为我国独立研制或改进LNG船液货舱热维护系统打下了良好的基础。更多还原

【Abstract】 In this thesis, Deep discussion was made on the temperature field of the heat maintenance system a 138000 m~3 of LNG (liquefied natural gas) Ship, which is recognized as a kind of complex ship with high tech, high difficulty and high appended value. In order to compute accurately the temperature field of LNG Ship, the work described in this paper is very important and meaningful. The main contributions of this thesis are as follows:In this thesis, the LNG ship model was simplified. The heat conduct, heat convection, heat radiation’s influence on the LNG ship’s cavity were discussed respectively. Furthermore, the theoretical convection formula of the LNG Ship’s cavity was obtained.A three-dimensional finite element model for the 138,000 m~3 LNG carrier was built by applying thermal element of ANSYS code. The iterative algorithms using the APDL language was drawn up according to the theories formula. The convection coefficient in LNG ship’s cavity are calculated under eight kinds of load cases, then thetemperature field of LNG ship and BOR (boil off rate) have been also performed.According to the model, the calculating results of BOR coincide with experimental date from abroad. It showed that the method of calculating convection coefficient is correct.By analyzing LNG ship’s temperature field, it will lay a good foundation for our country to develop and improve LNG ship’s heat maintenance system independently.更多还原