污氦气配气系统研制和实验研究

为了研究氦基混合气体在氦液化器中内纯化器里的分凝分离纯化机理,同时积累更多的内纯化器设计、研制和性能提高的相关实验数据,需要开展氦基混合气体在低温下纯化实验研究。因此,搭建了内纯化器实验平台,配气系统装置是内纯化器实验平台的重要组成部分。配气系统可以实现不同组分的氦基两元混合气体的配比,通过对配气系统配置的气体进行分析检测,测量结果与理论计算的误差在5%范围内。最终配气实验的结果表明配气系统能满足内纯化实验对氦基混合气体的要求。     

国外部分

91072 利用膜分离和PSA法的常温氦纯化装置神户制钢技报,1989,39(3),37～40 为了回收和再利用,研制了在常温下能操作的新的氦纯化装置。本装置是由可达到高纯度的PSA装置、高回收率的分离模件及氟里昂制冷机构成。纯化后的氦纯度为99.999％,回收率为99％以上。由于可在常温下纯化氦,所以,容易操作和维修,运转成本低。     

氦制冷机和液化器中的纯化系统

主要介绍了氦制冷机和氦液化器中应用的几种典型的氦纯化器的工作原理，主要工作程序和优缺点，并介绍了讨论了几种氦纯化器的设计方案，吸附量和计算以及可用于氦纯化器的工程设计。     

工业规模等温吸附法分离氖氦

我厂氖氦分离,过去一直采用液氢冷凝法及活性炭低温吸附法相结合的生产工艺。液氢冷凝法是使氖氦混合气中的氖气在液氢温度下连续液化排放,所得的氖气质量较好。但由于液氢冷凝分离设备年久失修,氖氦分离效果差,氦气纯度特别低,仅达60%左右,提取率在70%以下。由于氦气纯度差,故增加了后一道工艺——低温吸附的处理量,造成空分塔收集的原料气来不及处理,液氮消耗大,生产一立方米氦气需要大约340升左右液氮。     

等温吸附法分离氖-氦-氮混合气试验技术总结报告

一、前 言我国五十年代末到六十年代中期,先后建立了吸附法、冷凝法以及冷冻法的的氖一氦分离装置,并投入了工业生产。它对满足生产和科研以及国防建设提出的纯氖、纯氦要求作出     

氖气的液化与氖氦气体的分离

介绍用液氖冷凝法分离纯氖氦混合气的工艺流程与工艺过程,并对原林德公司的工艺进行了改进,加快了氖、氦气的分离速度,提高了氖、氦气的纯度。图2。     

真空自由燃烧氦电弧温度场的数值模拟研究

对蒸发冷凝法制备纳米粉体装置的加热源——真空自由燃烧氦电弧进行了研究。阐述了电弧的构造及电位分布，介绍了电弧产热的机理。在满足一定基本假设的前提下，文中给出了电弧的控制方程。运用有限元理论，构建了自由燃烧电弧的计算模型，运用ANSYS8．0对电弧的温度场进行了模拟，并应用类比法验证了本文构建的计算模型及模拟结果的正确性。     

HL-2M氦回收纯化系统建设

核工业西南物理研究院正在建设的HL-2M托卡马克液氦低温系统中低温用户每周实验需消耗约16m~3液氦,所以设计了一套氦回收纯化系统,此系统包含了回收、储存、纯化三个部分。回收系统由两台流量分别为50m~3/h和100m~3/h高压活塞压缩机组成;储存系统由中高压储罐及气囊组成,最大存储能力6000m~3,其中4800m3高纯氦及1200m~3非高纯氦;纯化系统核心设备为纯化器,纯化器出口的氦气纯度达到99.999%以上。系统建成后最大氦气回收速率为150m~3/h。     

大型氦低温系统中的杂质净化

EAST是一个全超导的托卡马克核聚变实验装置,磁体采用超临界氦迫流冷却.磁体在降温过程中对氦气的纯度有很高的要求,净化系统是整个低温系统的重要环节之一,以防各种杂质气体在低温下凝结固化威胁低温系统的稳定可靠运行.理论分析了氦气纯化的基本原理及固定床吸附器的吸附机理,对低温纯化器的运行进行了阐述,并介绍了杂质成分检测系统,以对净化效果进行评估,实验得知氦气净化系统能满足低温系统氦气高纯度的要求.     

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。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.