大型低温色谱柱系统的研制

低温吸附是一种有效的氢同位素分离方式,是国际热核实验堆(ITER)、聚变-裂变混合堆(FFHR)包层氚提取系统(TES)和含氚重水氚回收系统的优选方案之一.采用低温气相色谱技术研制了一套大型色谱柱系统,开展了氘-氢体系的调试实验.实验结果表明:(1)低温气相色谱柱系统的研制是成功的,实现了长期、连续、安全地运行;(2)浓缩效率高,可以将天然丰度的氘氢样品浓缩至91%以上;(3)处理容量大,对氕-氘混合原料气的处理容量达到每天200方的规模.     

氢同位素低温气相色谱分离装置的研制

低温吸附是一种有效的氢同位素分离方式,是国际热核实验堆（ITER）、聚变-裂变混合堆中包层氚提取系统和含氚重水氚回收系统的优选方案之一。课题组采用低温气相色谱技术研制了氢同位素分离装置,开展了氘-氢体系实验。实验结果表明：（1）分离装置的研制是成功的,实现了长期、连续、安全的运行;（2）分离效率高。既可以将天然丰度的氘氢样品浓缩至90％以上,也可以将氘丰度为0．08％的样品混合气分离后得到氘丰度为30％的产品,贫化部分氘丰度小于10^-5;（3）处理容量大。对氕-氘混合气的处理容量达到100m3／a的规模。     

低温色谱法制备贫氘氢样品的研究

采用无载带气的单维低温色谱分离技术,从制备流程设计出发,对分离方法、吸附材料、柱径柱长和操作参数进行了选择,并以氘丰度约为1.4×10-4的天然高纯氢为原料,在1 h之内成功制备出满足使用要求的贫氘氢样品.     

精馏过程的节能降耗

精馏过程的节能,对于减少能源消耗,降低生产成本和保护环境具有十份重要的意义。在精馏过程中可以采用最适宜回流比操作和最佳进料状态,使用中间冷凝器和中间再沸器,多效精馏技术、热泵精馏技术。合理安排多组分物料分离流程,提高过程的分离效率、提高物料回收率,进而降低能耗。并介绍我国精馏过程的节能现状与趋势。     

气相色谱法测定氘气中痕量的氧、氮

建立了测定高纯氘气中痕量氧、氮的气相色谱法.采用5A分子筛微填充石英毛细管色谱柱(30 m× 0.32 mm×30 μm),氦气作为载气,在50 ℃条件下对氘气中痕量氧、氮进行分离,以脉冲氦离子化检测器进行定性定量分析.建立的测定高纯氘气中微量氧、氮测定方法的精密度小于15%,最低检出浓度为0.5×10-6(mol/mol).     

反应堆含氚重水提氚关键技术研究进展

基于建立的年处理１０t重水的组合电解催化交换唱色谱分离（CECE-GC）实验系统,就含氘轻水提氘 演示实验及利用含氚轻水进行含氚重水提氚模拟运行做了介绍。结果表明,２４０h含氚轻水的连续运行,CECE 系统整体浓缩倍数约为４,电解池氕、氚分离因子约为１０;８m３桙d色谱分离系统运行２３h,可将１０.５m３料气的 ９０％中的氘贫化１０００倍;氚储存系统运转正常。CECE唱GC实验系统的建立,为重水提氚技术的进一步工程化提 供了研究平台。     

低温色谱分离装置的升级与优化

在总结过去多年低温色谱发展的基础上,针对现有的分离装置提出了升级与优化的方案,包括控制系统的升级、低温流路的改造、低温尾气处理系统的研制和在线监测分析系统的优化.通过该方案的实施,将提高装置的自动化水平,实现装置的闭环运行和尾气中氢氦的有效分离,加快色谱柱之间的液氮转移,大幅度降低装置的运行成本.     

低温精馏分离稳定同位素碳-13回顾与展望

概述了国际上稳定同位素碳-13的分离技术现状;分析了不同装置的技术特点;结合CO低温精馏技术关键及近年低温技术、化工技术的最新成果,从原料气制备工艺、换热器设计、新型填料设计、精馏塔结构、级联形式、能量组织利用等方面分析了低温精馏技术分离碳-13的技术创新途径.     

低温低压下工业铁粉的干燥特性及传热传质分析

本文通过搭建低温低压热泵干燥装置,研究了工业铁粉在不同低压下的干燥效果并分析了低温低压干燥过程中的传热与传质。结果表明:降低干燥环境压力会增大湿铁粉的除湿量,当环境压力从101 kPa降至10 kPa,除湿量增加2.5倍,且在10 kPa压力下铁粉含湿量能降至1%以下。当干燥空气为50℃,风速为0.5 m/s时,随着压力从101 kPa逐渐降至10 kPa,传质系数降低28.1%,传热系数降低68.4%,因此表征传热传质相对强度的刘易斯因子LF随着环境压力的降低而降低。当环境压力为10 kPa、风温为50℃时,流速从0.2 m/s增至2.0 m/s时,传质系数增加32.9%,传热系数增加67.8%,表明低压环境抑制了风速对传质系数的强化作用,因此LF随着风速的增加而增加。在10 kPa环境压力下,LF低至0.5~0.6,表明低压环境中质量扩散与热量扩散存在明显区别。     

三氟化氮萃取精馏工艺研究

高纯度的三氟化氮是微电子工业中一种优良的等离子蚀刻气体,是半导体与LCD产业制造过程中必备的材料。针对NF3气体中CF4杂质采用常规方法难以分离的特点,提出一种新的纯化工艺——低温萃取精馏纯化法,对低温萃取精馏生产高纯NF3过程的工艺流程进行了研究,并采用AspenPlus在广泛操作条件下对精馏过程进行了精馏模拟计算。通过工艺试验,找到适合于本物系的精馏运行参数,优化了生产流程,稳定了工艺系统运行,三氟化氮纯度达到了99．999％以上,产品中的CF4杂质含量低于10×10^-6（V／V）。     

Automated cryogenic valves

This article presents a guide to the popular value types and how they are automated for remote on-off control and flow modulation.     

Development of a miniature cryogenic fluid circuit and a cryogenic micropump

This article presents the development of a miniaturized cryogenic fluid circuit for distributed cooling of low-temperature tracking detectors in high-energy physics (HEP). The heart of the circuit is a prototype cryogenic micropump. This volumetric pump is compatible with cooling powers of about 10-100 W, and capable of producing pressure heads of up to around 0.3 MPa. Besides detector and electronics cooling in HEP, potential applications are found in the field of superconductor technology.     

Time to cool a cryogenic object by a gaseous cryogenic agent

Dependences to compute the cooling time of a single-channel object are obtained theoretically and confirmed experimentally.Notation D mass of helium in the channel - M mass of metal of the channel wall - G mass flow rate of the cryogenic agent - G_equ equivalent mass flow rate - c_p, c_m mean integrated specific heat of the cryogenic agent and the channel wall material - U perimeter - cooling time - ₁ time of the first cooling period - T₂ time of the second cooling period - channel wall temperature - T flow temperature - T_o initial flow temperature - T_in flow temperature at the channel input - W flow velocity - L channel length - L_in, L_out lengths of the delivery and removal pipelines - F, F_in, F_out cross-sectional areas of the channel being cooled, and of the delivery and removal pipelines - F_s total heat-transfer surface - d channel inner diameter - d_in, d_out inner delivery and removal pipeline diameters - P flow pressure - P flow pressure at the input to the element - P_out flow pressure at the output from the element - G_o, G₁ initial and final flow rates of the cryogenic agent - z a coordinate - ¯z=z/L a dimensionless coordinate - dimensionless channel length - dimensionless cooling time - V₁ dimensionless temperature - k_G,a, k _u , f, m, , g parameters - A, B constants - Re Reynolds number - R gas constant - coefficient of dynamic viscosity - hydraulic drag coefficient - coefficient of heat elimination Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 39, No. 4, pp. 629–635, October, 1980.     

TSAG-based cryogenic Faraday isolator

Thermooptical and magnetooptical properties of novel magnetoactive crystal terbium–scandium aluminum garnet were investigated at temperature range 80–300 K. It is shown that Verdet constant increases inversely proportional to temperature, and thermally induced depolarization, and the optical power of the thermal lens is reduced significantly with cooling from 290 K to 80 K. According to estimates, TSAG crystals in [1 1 1] orientation allow to create a cryogenic Faraday isolator provides a degree of isolation of 30 dB with the laser power exceeds ∼6 kW, it is estimated that the transition to the [0 0 1] orientation allows to provide degree of isolation of 30 dB at a laser power higher than 400 kW.     

Applications of cryogenic containers

The advantages of the storage and handling of atmospheric gases in liquid form are universally appreciated, but their realization depends on the economic justification.The considerable advance made in the design and production of cryogenic containers, particularly using “wrapped insulation” has resulted in greatly improved liquid conservation, longer service life and reliability, and lower capital cost.Many applications using cryogenic liquids have now become economically and operationally acceptable on a worldwide basis, and this review examines the development and interdependence of the equipment and the application.