L形高真空多层绝热低温管道热-结构耦合分析

发布时间：2018-01-29 01:44

本文关键词： 液化天然气高真空多层绝热低温管道波纹管绝热支撑热-结构耦合有限元方法应力漏热量　出处：《天然气工业》2017年03期 　论文类型：期刊论文

【摘要】：用于输送LNG等低温介质的高真空多层绝热(HV-MLI)低温管道常处于深冷环境且要承受流体内压,在热-结构耦合作用下的受力较为复杂。为了研究HV-MLI低温管道各部件在复杂载荷作用下的响应状况,以某水平—竖直走向的L形HV-MLI低温管道为例,建立了热-结构耦合分析有限元模型,计算得出了不同工况下的管道温度场分布情况,以及管道中内管、外管、热桥、波纹管和绝热支撑上的应力及应力随各载荷的变化关系。分析结果表明:(1)绝热支撑和热桥是影响管道漏热量的主要部件,以输送LN_2为例,通过上述两个部件的漏热量分别占管道总漏热量的49.07%和49.32%;(2)内管、外管、弯头及热桥等部件应力较小且低于材料屈服极限,实际使用过程中不易发生危险;(3)波纹管应力随输送介质温度的降低和补偿内管长度的增加而增大,水平管段波纹管的应力较高,是管道中的危险部件;(4)内管所受内压是影响绝热支撑应力的主要因素,随内管内压的增大,水平管段与竖直管段中离弯头最近的绝热支撑应力大幅增加,而远离弯头的其他位置处的绝热支撑应力变化不大,因而可适当增加离弯头最近的绝热支撑厚度,同时减少远离弯头处支撑的厚度,以便在保证强度的同时减少漏热量。
[Abstract]:High vacuum multilayer adiabatic HV-MLI pipes used to transport low temperature medium such as LNG are usually in cryogenic environment and have to bear internal pressure of fluid. In order to study the response of each component of HV-MLI cryogenic pipeline under complex load, the force under thermal-structural coupling is more complex. Taking a horizontal vertical HV-MLI cryogenic pipeline as an example, the thermal-structural coupling analysis finite element model is established, and the temperature distribution of the pipeline under different working conditions is calculated. The stress and stress of inner pipe, outer pipe, thermal bridge, corrugated pipe and adiabatic support vary with each load. The results show that the adiabatic support and thermal bridge are the main components that affect the heat leakage of pipeline. Taking conveying LN_2 as an example, the heat leakage through the two parts above accounts for 49.07% and 49.32 percent of the total heat leakage of the pipeline, respectively. (2) the stress of inner pipe, outer pipe, elbow and hot bridge is smaller and lower than the yield limit of material, so it is not easy to occur danger in practical use; (3) the stress of bellows increases with the decrease of the temperature of the conveying medium and the increase of the length of the compensated inner pipe, and the stress of the bellows in the horizontal section is higher, which is a dangerous part in the pipeline. The internal pressure of the inner pipe is the main factor affecting the adiabatic support stress. With the increase of the internal pressure, the adiabatic support stress near the elbow in the horizontal and vertical pipe increases significantly. However, the adiabatic support stress at other locations away from the elbow has little change, so the thickness of the adiabatic support near the elbow can be increased appropriately, and the thickness of the support far away from the elbow can be reduced at the same time. In order to ensure strength while reducing heat leakage.
【作者单位】：兰州理工大学石油化工学院;甘肃蓝科石化高新装备股份有限公司;中国科学院近代物理研究所;
【基金】：甘肃省科技重大专项“大型LNG储罐研发”(编号:1203GKDA001)
【分类号】：TE973
【正文快照】： 0引言随着我国液化天然气(LNG)产量、进口量和使用量的持续增加,输送LNG用的高真空多层(HV-MLI)绝热管道的使用量也日益增加。由于此类管道具有优异的绝热性能,在天然气液化站、LNG加气站、LNG接收站、液氢(LH2)、液氧(LO2)等航天燃料输送以及低温超导行业中都得到了广泛应用[

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