基于两相流的无损储存系统仿真与实验研究
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摘要
研究了无损储存(Zero Boil-Off,ZBO)储罐内低温液体流场的变化情况,针对液氮无损储存储罐建立二维轴对称模型,以UDF程序定义蒸发冷凝模型,分别对制冷机关闭和开启两种工况下储罐内部温度场、速度场进行数值仿真计算,得到了液氮储罐内流体流动、传热等规律。结果表明:制冷机关闭工况下,氮气温度从边界到储罐中心逐渐降低,液氮在储罐漏热作用下产生涡旋,温度逐渐趋于一致;制冷机开启工况下,模拟初始阶段储罐内流场与制冷机关闭工况基本一致,后期氮气温度降低至77 K,制冷量对液氮流场影响较小。搭建液氮储罐实验平台对模拟结果进行验证,仿真计算结果与实验结果对比表明:两者结果较为吻合。
In order to study the variation of cryogenic liquid flow field in the Zero Boil-Off( ZBO) storage tank,a two-dimensional axial symmetric numerical model of liquid nitrogen storage tank was built,and the evaporation-condensation model was defined by the User Defined Function( UDF),the temperature and velocity fields in the storage tank were simulated when the refrigerator is turned off and on,and the laws of fluid flow and heat transfer in the liquid nitrogen storage tank were obtained. It is indicated that when the refrigerator is turned off,the temperature of nitrogen is stable and shows gradually decreases from the boundary to the center of the tank,vortex was developed in the liquid nitrogen under the effect of heat leakage of the tank,the liquid nitrogen temperature gradually becomes identical; in the initial stage when the refrigerator is turned on,the flow field in the tank is basically the same as the condition when the refrigerator is turned off,in the later stage of the simulation,the temperature of nitrogen is reduced to 77 K,and the cooling capacity has little effect on liquid nitrogen flow field. The liquid nitrogen storage tank experimental platform was established to verify the simulation results. The comparison between the simulation results and the experimental results shows that both are in good agreement.
In order to study the variation of cryogenic liquid flow field in the Zero Boil-Off( ZBO) storage tank,a two-dimensional axial symmetric numerical model of liquid nitrogen storage tank was built,and the evaporation-condensation model was defined by the User Defined Function( UDF),the temperature and velocity fields in the storage tank were simulated when the refrigerator is turned off and on,and the laws of fluid flow and heat transfer in the liquid nitrogen storage tank were obtained. It is indicated that when the refrigerator is turned off,the temperature of nitrogen is stable and shows gradually decreases from the boundary to the center of the tank,vortex was developed in the liquid nitrogen under the effect of heat leakage of the tank,the liquid nitrogen temperature gradually becomes identical; in the initial stage when the refrigerator is turned on,the flow field in the tank is basically the same as the condition when the refrigerator is turned off,in the later stage of the simulation,the temperature of nitrogen is reduced to 77 K,and the cooling capacity has little effect on liquid nitrogen flow field. The liquid nitrogen storage tank experimental platform was established to verify the simulation results. The comparison between the simulation results and the experimental results shows that both are in good agreement.
引文
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6 任金平.基于高真空VD-MLI技术的低温容器传热及结构分析[D].兰州:兰州理工大学,2015.Ren Jinping. Thermal and structure analysis of cryogenic vessels adopting high vacuum VD-MLI technology[D]. Lanzhou:Lanzhou University of Technology,2015.
7 祝铁军.小型撬装式BOG再液化装置的研发与实验测试[D].上海:上海交通大学:2015.Zhu Tiejun. Design and experimental test of a small scale BOG re-liquefaction systemin skid-mounted package[D]. Shanghai:Shanghai Jiaotong University:2015.
8 GB/T18443. 5-2010.真空绝热深冷设备性能试验方法-第5部分:静态蒸发率测量[S].北京:中国标准出版社,2010.GB/T18443. 5-2010. Testing method of performance for vacuum insulation cryogenic equipment-Part 5:Static evaporation rate measurement[S]. Beijing:Standards Press of China,2010.
2 程进杰,朱建炳,冶文莲,等.基于ZBO存储的低温储箱漏热分析[J].低温工程,2012(6):46-50.Cheng Jinjie,Zhu Jianbing,Ye Wenlian,et al. Heat leakage analysis of cryogenic tank based on ZBO storage[J]. Cryogenics,2012(6):46-50.
3 陈亮,梁国柱,魏一,等.低温推进剂贮箱压力变化的CFD仿真[J].航空动力学报,2015,30(6):1470-1477.Chen Liang,Liang Guozhu,Wei Yi,et al. CFD simulation of cryogenic propellant tank pressure variation[J]. Journal of Aerospace Power,2015,30(6):1470-1477.
4 冶文莲,王丽红,王田刚,等.低温制冷机与ZBO存储系统耦合数值模拟[J].低温与超导,2013,41(8):19-23.Ye Wenlian,Wang Lihong,Wang Tiangang,et al. Numerical simulation of cryocooler and zero boil-off storage system coupling[J]. Cryogenics and Superconductivity,2013,41(8):19-23.
5 李玉星,王武昌,乔国发,等.密闭LNG储罐内的压力和蒸发率[J].化工学报,2010(5):1241-1246.Li Yuxing,Wang Wuchang,Qiao Guofa,et al. Pressure and evaporation rate in a closed LNG tank[J]. Journal of Chemical Industry and Engineering,2010(5):1241-1246.
6 任金平.基于高真空VD-MLI技术的低温容器传热及结构分析[D].兰州:兰州理工大学,2015.Ren Jinping. Thermal and structure analysis of cryogenic vessels adopting high vacuum VD-MLI technology[D]. Lanzhou:Lanzhou University of Technology,2015.
7 祝铁军.小型撬装式BOG再液化装置的研发与实验测试[D].上海:上海交通大学:2015.Zhu Tiejun. Design and experimental test of a small scale BOG re-liquefaction systemin skid-mounted package[D]. Shanghai:Shanghai Jiaotong University:2015.
8 GB/T18443. 5-2010.真空绝热深冷设备性能试验方法-第5部分:静态蒸发率测量[S].北京:中国标准出版社,2010.GB/T18443. 5-2010. Testing method of performance for vacuum insulation cryogenic equipment-Part 5:Static evaporation rate measurement[S]. Beijing:Standards Press of China,2010.