高温气冷堆氦气透平循环流动阻力特性分析

采用更加真实的阻力模型分析了流动阻力对10MW高温气冷堆(HTR-10)氦气透平循环特性的影响规律。分析结果表明,高温气冷堆氦气透平循环的压力损失主要由局部阻力和摩擦阻力组成。10MW高温气冷堆闭式氦气透平循环(HTR-10GT)发电系统在实际充装量调节及额定工况下,氦气在部件连接管道的局部压降占82.4%,沿程阻力压降占17.6%。氦气充装量减小时,局部压损系数不变而沿程阻力系数增大,导致循环效率降低;当充装量由100%降低到30%,连接管道的局部压降份额下降约20%,系统效率下降15%左右。随着充装量的减小,做功部件的进出口压力随充装量的变化线性变化,压气机的压比略有增大,透平的膨胀比有较大幅度的非线性增大。     

空气化工将在韩国建造新装置

正根据最近投资计划显示,空气化工产品公司将在韩国建造全新的特种气体装置以及氦气输送和充装设备。公司于近日在一则新闻中提到,其位于忠清北道梧仓邑的"转填"装置,将有能力产出包括氦气在内的多种高纯度特种气体,但并未透露相关财务信     

电气设备中保护气体监测用SO2F2气体标准物质研制

介绍了钢瓶装氦气中氟化硫酰（SO₂F₂）气体标准物质的研制过程。标准混合气是通过将SO₂F₂和氦气充装到钢瓶中制备而成,研究了气瓶内压力和保存时间对混合气稳定性的影响。对混合气配制的一致性进行了考察,并对引入的不确定度进行了评估,由结果可以看出,每个摩尔分数点混合气的量值一致性均较好。通过对称量法配气与稳定性导致的不确定度的评价,结果显示利用称量法制备的氦气中SO₂F₂气体标准物质在6个月内的稳定性良好,其相对扩展不确定度不大于2%。     

气体工业名词术语

充装压力 ( Filling Pressure)永久气体的充装量以在基准温度下的充装压力限定值来表示。对于氧气、空气、氮气、氢气、甲烷、一氧化碳、氩气、氦气、氖气的充装压力可查阅《气瓶安全监察规程》( 1 989)或由国家技术监督局批准的相应国家标准。间歇吹洗 ( Intermittence Purging)是一种吹洗或置换系统的有效方法。将纯气或样品气充入系统 ,充入的压力不可与钢瓶的压力相等 ,以避免钢瓶阀和减压器的加压侧中的残余气体和湿气与纯气或标准气混合 ,然后将系统压力泄至接近常压 ,反复升压、降压数次 ,即反复稀释数次 ,即可将系统吹洗或置换干…     

液氯钢瓶充装改造中的定量控制和联锁控制技术应用

液氯钢瓶的充装有严格规定,在充装过程中严禁过量充装,通过智能定量充装技术的应用,实现了液氯钢瓶定量充装,杜绝生产过程中的超量充装,同时又实现了液氯钢瓶的计算机档案管理,提高钢瓶充装过程的安全可靠性,提高生产效率和安全生产管理水平。     

液氩槽车充装技术:高压充装 尾气回收

低温液体充装前,槽车、联接软管的预冷及充装中贮槽必须的升压、低温液体的复热蒸发等,均不可避免地造成产品液氩的汽化损失。文章从生产实际中总结出“低压充装、尾气放空”、“高压充装”、“高压充装,尾气回收”三种充装方法,并一一对比。向同行推荐一种快速、低消耗的低温液氩槽车充装技术——“高压充装,尾气回收”。该方法同样适用于其它低温液体充装。图2表3参1。     

林德气体(宁波)将建立一体化供气网络

<正>2015年10月27日,林德气体(宁波)有限公司(以下简称:林德气体〔宁波〕)气体充装项目进入调试阶段,正式投产后将提供压缩空气、氢气、氮气、氧气、一氧化碳、二氧化碳、氦气、氪气以及氙气等50多种工业气体,市场范围覆盖全宁波。结合此前拥有的管道输气和槽罐液态供气模式,林德将建立从大批量用户到小用量客户的一     

北京航天试验技术研究所低温技术事业部

正北京航天试验技术研究所低温技术事业部是专业从事深冷介质(LH_2、LN_2、LO_2)应用技术研究、开发、试验和各类低温深冷液、气体的生产、贮存、转注、运输、销售与品质检测的航天高科技单位,在氢能综合开发与应用领域处于技术领先地位,是规模化、工业化自行生产和安全应用液氢的单位,拥有北京市氢气、氦气、氮气、氧气、氩气充装、运输资     

气瓶安全与检验问答(十二)

问 :铳有下列原始标志的气瓶是盛装何种气体的 ?其工作压力为 1 6.8MPa( 2 4 0 0× 0 .0 0 7) ,为什么又打上“2 0 0 AT” ( 2 0 .0 MPa)的工作压力 ?OTC　 5 0 - 472 2 0AGA　 HELIUM　 2 4 0 0　 PSI2 0 0 AT　 U.S.　TEST　 40 0 0答 :铳有上列原始标志的气瓶是盛装氦气的。该瓶设计工作压力为 2 4 0 0 psi (注 :1 psi=6.89k Pa) ,换算为工程大气压为 2 4 0 0× 0 .0 70 3=1 68.72 kgf/cm2 。原始标志处打铳的“2 0 0 AT”是国外充装单位打铳的 ,不是气瓶制造厂打铳的。充装单位打铳“2 0 0 AT”的目的 ,是为了避免充装气…     

瓶装压缩气体充装速度浅析

在分析瓶装气体充装速度的基础上研究了国家标准对气体充装过程中速度的规定,探讨并计算了气瓶(以40L氧气瓶为例)由0.05 MPa余压分别充装到12、13、14、15 MPa所需充装时间,为气瓶充装单位提供技术参考。     

发射场氦气现场提纯技术

液氢贮箱在加注液氢前首先进行氮气置换 ,合格后再进行氦气置换 ,置换后排出的氮氦混合气混合贮存 ,混合气中He纯度为 91 6 6 % ,其余主要为氮气。结合中心现有条件 ,提出了利用高压低温冷凝法和低温吸附法相结合的方法对回收的氦气进行现场提纯 ,可以生产纯度大于 99 995 %的氦气。     

超临界氦的储存及排放

叙述了超临界氦储存过程中存在的热分层现象,研究了超临界氦储槽的有效容积,日蒸发率,填充率对储槽气枕空间内压力和温度变化的影响,给出了估算增压排放液氦所需气量的方法和实例。     

The sensitivity of thermomechanical reading of data

The size of elements of modern thermomechanical data storage devices approaches the length of molecular free path for gas at room temperature and atmospheric pressure. In such devices, the heat transfer by gas molecules is the main factor defining the sensitivity of thermomechanical reading of data. This paper deals with heat transfer in devices with hardly any collisions between gas molecules. The developed mathematical model and numerical codes are used to estimate the sensitivity of thermomechanical reading of data with the device structure filled with various inert gases such as helium, neon, and argon. It is demonstrated that filling with helium makes it possible to significantly increase this sensitivity. The simulation and estimation results demonstrate that the sensitivity of the existing method of thermomechanical reading of data is not reduced catastrophically when the dimensions of reading cell are reduced at least to dimensions somewhat smaller than the molecular free path for gas.     

液氦温区VM-PT制冷机气量分配特性研究

VM气耦合脉冲管制冷机(VM-PT)是一种新型的液氦温区制冷机,为探索两级气耦合复杂的机理,本文采用Sage软件构建了低温调相VM-PT制冷机的整机模拟程序,研究了运行频率、平均压力、毛细管长度以及Er3Ni填充长度等参数对两级气量分配的影响。数值结果表明运行频率、平均圧力、毛细管长度以及Er3Ni填充长度均会影响两级质量流的分配,进而影响制冷机的最低温度,权衡工质的做工能力以及蓄冷器损失两方面因素,该四个参数均存在一个最佳值。搭建了实验平台并对数值模拟进行了验证。在实验中通过优化毛细管和蓄冷器,在运行频率1.6 Hz、平均压力1.4 MPa、压比1.6的情况下得到了3.86 K的无负荷制冷温度,在4.2 K可提供约10 mW的制冷量。     

An efficient helium circulation system with small GM cryocoolers

We developed a helium circulating system that re-liquefies all the evaporating helium gas and consumes far less power than conventional systems, because warm helium gas at about 40 K collected high above the surface of the liquid helium in the Dewar is used to keep the Dewar cold, and because cold helium gas just above the liquid helium surface is collected and re-liquefied while still cold. A special transfer tube with multi-concentric pipes was developed to make the system operate efficiently. The system can produce up to 35.5 l/D of liquid helium from the evaporated helium using two 1.5 W@4.2 K GM cryocoolers.     

Progress Report on the Cooperation Between NMIJ and PTB on Zinc Point Cells

The National Metrology Institute of Japan (NMIJ) and Physikalisch-Technische Bundesanstalt (PTB) have agreed to conduct a collaborative study on zinc point cells. An open-type zinc cell was prepared to act as a transfer cell in this collaboration, and cells were prepared for both institutes to perform experiments using a common cell during the collaboration. The experiments reflect concerns that both institutes have been studying independently over the past several years using an open-type cell. The concerns include the impurity effect, stability of the realized temperature, and the difference in the heat flux due to a change in the filling gas. A part of the zinc sample extracted during the fabrication of this cell was analyzed, and for the purpose of confirmation, the initial sample taken from the same lot as that used in the transfer cell was also analyzed. The stability of the transfer was evaluated from cell comparisons performed by NMIJ before and after the air transportation between PTB and NMIJ. PTB and NMIJ demonstrated an increase in temperature at the zinc point due to a change in the filling gas from argon to helium. The improvement using helium gas was found strongly to depend on the construction of the cell and the fixed-point furnace design. The analysis of the zinc sample confirmed a strong inhomogeneity of Pb and a contamination by some elements. Careful analysis for estimating the impurity effect on the temperature realized using the transfer cell was also conducted based on the latest studies to avoid an improper application of fixed-point correction.     

Defect-sealing synthesis of vertically oriented ordered mesoporous silica membranes

Vertically oriented ordered mesoporous silica membranes have been successfully synthesized in our laboratory in the form of silica plugs filling the macron-sized straight pores of hydrophobic track-etched polycarbonate membrane support. However, these membranes have shown gaps between the plugs and support pore wall which make the membranes unfeasible for use. This paper reports on techniques of synthesis of defect-free ordered mesoporous silica membranes by filling the gaps with microporous silica. Here, the elimination of defects is achieved by filling the membrane gaps with an alkoxysilane followed by exposure to humid air to allow controlled hydrolysis and condensation resulting in the formation of microporous silica within the gaps. Molecular probing gas permeation and helium/nitrogen (or oxygen) binary separation tests, coupled with surface characterization methods, show that the final membranes contain ordered mesopores of about 2.7 nm pore diameter, running through the membrane, with gaps sealed by microporous silica having a pore size <0.55 nm.     

Helium detection in gas mixtures by laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy (LIBS) has been evaluated as a tool for monitoring trace levels of helium in gas mixtures consisting mostly of hydrogen. Calibration data for helium in hydrogen was investigated at different helium concentration levels. At high concentrations of helium (>7.25%), the LIBS signal is quenched due to Penning ionization. The hydrogen alpha line (656.28 nm) was observed to broaden as the concentration of helium impurities in the hydrogen gas mixture increased. The helium line at 587.56 nm was selected as the analyte line for helium impurity detection. The effects of laser energy, the delay time between the laser pulse and data acquisition, and the gas pressure on the LIBS signal of helium were investigated to determine the optimum conditions for helium detection. The LIBS signal from the helium line at 587.56 nm shows good linear correlation with helium concentration for He concentrations below 1%. Thus, LIBS can be reliably used to detect the low levels of helium. The limit of detection for helium was found to be 78 ppm.     

BEPC-Ⅱ低温系统的氦气净化技术

氦气净化技术是国家大科学工程北京正负电子对撞机重大改造(BEPC-Ⅱ)中低温系统的关键技术之一.在充分调研国内外大型低温系统氦气净化技术的基础上,结合自身情况,创造性提出氦气储罐内部处理及真空置换方案,一次性充入氦气,将储罐内氦气不纯度控制在40 vpm之内,同时辅之以80 K外置低温吸附器对氦气储罐内以及冷箱和超导设备端的氦气进行净化.高效而又经济的解决了BEPC-Ⅱ低温系统中的氦气纯度问题,成功地进行了制冷机的验收测试和超导设备的调试及运行.     

A liquid hydrogen-deuterium target

The design of a liquid hydrogen-deuterium target is described in which the gas is liquefied at the expense of boiling off liquid He-vapour. A closed gas circulation system is used in the target; this increases the safety of operation and makes it easy to replace H₂ by D₂. The target design allows the use of detachable heads appropriate to the requirements of a specific experiment. The working time obtainable from one filling of helium is 80h for a liquid hydrogen target, (LHT) and 60 h for a liquid deuterium target (LDT). 2.85 I of liquid He are required to liquefy 1 I of H₂ and 3.8 l for 1 of D₂