共查询到19条相似文献,搜索用时 125 毫秒
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热油管道输送含蜡原油的轴向温降计算 总被引:4,自引:2,他引:2
在含蜡原油热油管道输送工艺计算中,根据比热容随温度变化的趋势,得出3个不同温度区域内的比热容表达式,分别将其代入能量平衡方程中,推导出热油管道输送含蜡原油的轴向温降公式,将其与苏霍夫温降公式进行对比。结果表明:应用该公式能更精确的计算出热站间距、出站温度,减少不必要的损失。 相似文献
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地震时,考虑海底管道与土介质的相互作用,对将跨断层海底管道作为薄壳结构时的断层位错反应进行分析计算.利用Ansys分析软件,将管道模型简化为四节点薄壳单元结构, 土介质简化为弹塑性弹簧,建立管土相互作用的有限元分析模型,进行分析计算.根据计算结果以及海底管道屈曲校核准则描绘出管道破坏等级范围分布图.最终得出结论:地震时在大位移断层运动作用下,海底管道存在明显的屈曲变形,在屈曲变形较大处,海底管道发生断裂. 相似文献
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天然气管网的初始流量分配 总被引:3,自引:1,他引:2
在对天然气管网进行离线数值模拟计算时,需要给各管段分配初始流量,作为迭代计算的初始值。根据管道的流动状态多在阻力平方区的特点,建立初始流量分配的数学模型,用C 语言编制出计算程序。对实例进行计算和分析,表明用最小平方和法求解各管段初始流量时,不需手工预分初始流量,也不需预先确定各管段流体流动方向,求解所得初始值接近真实值,使数值计算的收敛速度大大提高。 相似文献
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根据自流装车管路系统中鹤管流量不同的工艺特点,建立了自流装车管路系统水力计算和装车时间计算的严格模型,讨论了自流装车管路系统水力计算的数值求解方法和基本思路,应用弦截法求解管路系统水力计算方程,求出在一定液位上集油管、鹤管段的流量。采用龙贝格数值积分法求解装车时间,应用VC 6.0高级语言编制了自流装车管路系统计算程序,应用该程序可快速进行工艺设计计算和模拟计算。计算表明:操作的鹤管数越多,各鹤管的流量差别就越大。 相似文献
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Wang Z.Zhuang X. 《现代隧道技术》2018,(5):33-44
In the whole process of survey, construction and operation of rock tunnels, hydraulic fracturing is a mechanical mechanism that needs to be focused. In this paper, numerical simulation for fracture damage constitutive model and analytical formula were used to study the hydraulic fracturing of stratified sedimentary rocks. Based on multi-field coupling finite element analysis software, and combining the linear elastic fracture criterion with the damage constitutive model, a seepage-stress-rock damage coupling model is redeveloped, in which micro cracks can be characterized, and applied to study the hydraulic fracturing of rock mass in the saturated seepage process. By introducing dispersed parallel micro cracks for simulating the beddings of sedimentary rocks, the sedimentary rock cylinder model was established to simulate the hydraulic fracturing behaviors under injecting water into apertures and acting of confining pressure, in order to study the fracturing failure modes and seepage distribution patterns. In addition, the quantitative relationship between the critical water pressure for initial cracking and the confining pressure, the pore diameter of specimens was discussed by changing the pore diameter and confining pressure. In order to verify the cracking initiation pressure law obtained by numerical simulation, based on the seepage theory and the basic equation of elastic mechanics, and combined with the tensile failure mode obtained in the simulation, the formula of critical water pressure for cracking initiation in the rock cylinder with uniform linear elastic seepage was derived. The results of analytical solution and numerical calculation show that the cracking initiation pressure obtained by the two methods is in good agreement with the deviation within 3%. The larger the confining pressure, the larger the cracking initiation pressure, with the approximate linear relationship. The smaller the aperture, the larger the cracking initiation pressure, with the approximate negative slope linear relationship in a certain range. At the same time, the cracking initiation pressure by the analytical solution is always slightly greater than that of the numerical solution, which reflects the impact caused by the difference of the basic material hypothesis between the analytical method and the numerical method. When the material property parameters are consistent, the cracking initiation pressure based on the assumption of ideal linear elastomer will be greater than that of the material introduced into the initial damage bedding. © 2018, Editorial Office of "Modern Tunnelling Technology". All right reserved. 相似文献
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文章通过对大气-热管-土体耦合传热模型进行分析简化,采用ANSYS有限元分析系统建立了热管路基三维传热模型,并以青藏铁路北麓河地区气候条件和地质条件为背景,对普通路基和热管路基进行了模拟计算与对比分析,得到了两种冻土路基不同时刻的路基温度场变化规律。 相似文献
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基于有限容积法,建立伴热稠油管道停输过程的非稳态传热模型,采用"焓-多孔度"技术,利用FLUENT软件,分别对伴热管与稠油管同时停输及稠油管道单独停输两种情况进行了数值模拟,并考虑了析蜡潜热对温降的影响,得出了不同时刻管内原油凝固区、混合区、液油区的位置及温度场的分布。结果表明:两种情况下,稠油固化过程基本相同。稠油管道单独停输时,管内原油温降速率比双管同停温降速率略慢,但在一定时间内相差不大。随着停输时间的延长,两种情况下管内稠油温降速率变化明显,说明伴热管对稠油管道短期停输影响不大。文中给出安全停输时间,为工程设计提供一定指导。 相似文献