LNG储罐内罐小孔泄漏工况下温度场数值模拟
Numerical Simulation of Temperature Distribution Under Small Hole Leakage at the Inner Wall of LNG Tank
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- 引用格式:
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张,娜,李兆慈,郭志超.LNG储罐内罐小孔泄漏工况下温度场数值模拟[J].天然气与石油,2020,38(3):7-12.doi:
Zhang Na, Li Zhaoci, Guo Zhichao.Numerical Simulation of Temperature Distribution Under Small Hole Leakage at the Inner Wall of LNG Tank[J].Natural Gas and Oil,2020,38(3):7-12.doi:
- DOI:
- 作者:
- 张 娜 李兆慈 郭志超
Zhang Na, Li Zhaoci, Guo Zhichao
- 作者单位:
- 中国石油大学(北京)油气管道输送安全国家工程实验室/城市油气输配技术北京市重点实验室
National Engineering Laboratory for Pipeline Safety/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, China University of Petroleum, Beijing, 102200, China
- 关键词:
- LNG储罐;小孔泄漏;温度场;数值模拟
LNG tank; Small hole leakage; Temperature field; Numerical simulation
- 摘要:
LNG储罐是接收站核心设备,内罐泄漏会造成夹层绝热结构和外罐的破坏。针对LNG双金属全容罐内罐小孔泄漏,通过设置热边界条件和绝热层的物性参数,划分内壁和绝热层网格数,模拟得到内罐壁稳态温度分布;分析泄漏点处的对流换热,建立二维非稳态渗流方程,计算得到漏液在罐壁绝热层内的流场分布;将求得的速度分布作为对流扩散项添加到二维非稳态对流换热方程中,完成速度场和温度场的耦合,得到内罐壁绝热层的温度分布。LNG内罐发生泄漏时,漏液先向下聚集,靠近泄漏源处的弹性毡首先降温到LNG温度,且此处的温度梯度较大,而后沿罐底逐渐渗透到膨胀珍珠岩绝热层。由此，为内罐泄漏事故的救援和事故分析提供了理论依据和科学指导,以最大限度地减少泄漏事故造成的危害。
The LNG storage tank is the core equipment of the receiving station,and the inner wall leakage causes the destruction of the insulation layer and the outer wall.This paper is aimed at the small hole leakage at the inner wall of bimetal full containment LNG tank.By setting the thermal boundary conditions and the physical properties of the insulation layer, the number of inner wall grids is divided and the steady temperature distribution of the inner tank wall is simulated.By analyzing the convective heat transfer at the leak point, a two-dimensional unsteady seepage equation is established to calculate the flow field distribution of the leaking liquid in the insulation layer of the tank.The obtained velocity distribution is added as a convection diffusion term to the two-dimensional unsteady convective heat transfer equationso as to complete the coupling of velocity field and temperature field, and obtain the temperature distribution of insulation layer of the inner wall.When leakage occurs to LNG inner tank, the leaking liquid first gathered downward,and the elastic felt near the leak source first cooled to the LNG temperature.And the temperature gradient here is large.Then, it gradually penetrates into the expanded perlite insulation layer along the bottom of the tank,which provides theoretical basis and scientific guidance for the rescue and accident analysis of the inner tank leakage, so as to minimize the hazard caused by the leakage.
