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液氢缩比贮箱蒸发特性数值模拟及实验验证 被引量:5
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作者 王舜浩 朱文俐 +4 位作者 胡正根 周芮 余柳 王彬 张小斌 《化工学报》 EI CAS CSCD 北大核心 2019年第3期840-849,共10页
地面缩比贮箱用来模拟箭载液氢贮箱热物理过程及运行特性,包括筒段和壳段,壳段用于支撑筒段。筒段和部分壳段使用泡沫绝热,壳段结构部分裸露在环境中,成为液氢贮箱的主要漏热源。基于计算流体力学方法数值研究了液氢缩比贮箱蒸发特性,... 地面缩比贮箱用来模拟箭载液氢贮箱热物理过程及运行特性,包括筒段和壳段,壳段用于支撑筒段。筒段和部分壳段使用泡沫绝热,壳段结构部分裸露在环境中,成为液氢贮箱的主要漏热源。基于计算流体力学方法数值研究了液氢缩比贮箱蒸发特性,构建了基于VOF两相流模型以及Level-set界面跟踪方法的贮箱两相氢流动和相变传热传质数学框架,其中气液界面传质率基于Lee模型计算。框架中的系数、边界条件等作如下考虑:Lee模型中的液化/蒸发系数通过与实验数据对比获得;通过理论分析低温面有/无泡沫保温层的结冰特性,对暴露在环境的泡沫和铝壳表面施加对流换热或常热流边界条件;当贮箱压力达到约2个大气压(0.2 MPa)时,安全阀打开放气保持内部压力不变,基于自定义函数方法模拟阀门开闭实现控制贮箱压力的目的。与实验测量的液位下降速率和气相温度非稳态变化对比表明,构建的数值模型能够较好地模拟液氢贮箱自增压过程的复杂流动、相变传热传质特性。为模拟真实箭载液氢贮箱停放阶段的热物理过程打下基础。 展开更多
关键词 缩比贮箱 自增压 相变 CFD
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西班牙洗缩联合机的消化吸收
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作者 陈丽星 张贵杰 龚晓玲 《毛纺科技》 CAS 北大核心 2000年第2期59-61,共3页
介绍了西班牙洗缩联合机的机构组成 ,特别是结合缩呢效果 ,分析了缩箱的结构与功能。联系实例从加工产品的产质量优势上突出了该设备的优良性能 ,并与其它同类设备做了比较 ,提高了企业的经济效益。
关键词 毛染整 洗缩联合机 缩箱 缩绒 设备
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Study on Position Control System with Programmable Logic Controller
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作者 唐海燕 卢仁军 郝云鹏 《Journal of China University of Mining and Technology》 2003年第1期108-112,共5页
To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a math... To solve the problems of mechanical cam, tracking in an automatic welding machine, a new method of programmable logic controller ( PLC) tracking is presented. Based on analyzing the forming of welding tracking, a mathematical model of position control is set up. The experiments show that using a modified machine, PLC makes little welding positional error and can meet the product requirements. 展开更多
关键词 elliptical tracking position control mathematical model PLC
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Application of Aspen to Lithium Bromide Refrigerator
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作者 Xinli Wei Wenrui Mao 《International Journal of Technology Management》 2013年第1期115-117,共3页
By transforming the original interstage compression cooling system of nitrogen fertilizer plant and adding lithium bromide refrigerator, the paper designs a new compressor interstage cooling system which leads interst... By transforming the original interstage compression cooling system of nitrogen fertilizer plant and adding lithium bromide refrigerator, the paper designs a new compressor interstage cooling system which leads interstage heat in lithium bromide refrigerator and uses the obtained cooling capacity to reduce the temperature of compressed gas. And aspen is used to simulate the new process. Lastly, the paper makes economical and feasible conclusion. 展开更多
关键词 ASPEN lithium bromide refrigerator synthesis ammonia
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Small Scale Refrigerators and Freezers: Thermal Improvements in the Envelope
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作者 Clito Afonso Joaquim Gabriel 《Journal of Environmental Science and Engineering(A)》 2017年第1期1-14,共14页
Like in other sectors of activity, the sustainability in refrigeration systems is a mandatory goal to achieve, namely at house holdings, bars and restaurants, where small-scale refrigerators and freezers are widely us... Like in other sectors of activity, the sustainability in refrigeration systems is a mandatory goal to achieve, namely at house holdings, bars and restaurants, where small-scale refrigerators and freezers are widely used. The aim of this work is to demonstrate experimentally, trough measurements carried out in these equipments, the improvement that can be achieved if several modifications are implemented in traditional household refrigeration systems. In addition, it was also simulated and analysed experimentally a slightly different equipment, a refrigeration system used for draught beverages. Both systems work on a single vapour compression refrigeration with R-134a as working fluid. In the end, by implemented the modifications tested in the virtual model, it was possible to improve their thermal behaviour, a decrease in electrical energy consumption, as well as, the associated CO2 emissions reduction can be attained. In this project, the CFD (Computational Fluid Dynamics) soffware--ANSYS Fluent was used to simulate the ambient temperature and velocity fields inside the refrigerator and in that way to validate the measured results. 展开更多
关键词 Small scalerefrigerators/freezer thermal efficiency air infiltration SUSTAINABILITY CO2 emissions reduction.
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