新型太阳能冷管吸附制冷的实验研究

根据固体吸附式制冷原理,利用太阳光作为热源,对一种新型太阳能冷管的制冷性能进行试验研究。该冷管冷凝器采用薄壁不锈钢材料,利用沸石分子筛—水作为吸附工质对。实验结果表明:在太阳辐射强度为21.01~22.90MJ/m2,室外环境温度最高为31℃时,该太阳能冷管的单支制冷量大约为145k J,制冷温度为11℃,制冷系数约为0.118。     

新型太阳能吸附制冷系统性能实验研究

采用新型吸附床结构建立一套太阳能固体吸附式制冷系统,利用ZSM-5沸石分子筛-水作为工质对进行空调应用领域吸附脱附制冷性能研究。通过实验测得吸附床内温度可达130℃,与太阳辐照度有密切的关联,床内沿轴线有温差分布,周向温度分布均匀。吸附过程沿制冷剂进口方向有时滞后,吸附床温度对吸附过程有影响,实验系统COP变化范围为0.02~0.05之间。     

吸附制冷用吸附剂性能测试及实验研究

研究吸附工质对的性能对于吸附式干燥、除湿、制冷具有重要作用,而吸附剂的吸附量、导热系数和吸附材料的性质、温度、压力等许多因素有关,因此用实验来测定就变得十分的有必要。本文以3A作为吸附剂,水作为制冷剂,组成吸附式制冷工质对,通过液位法对工质对的吸附制冷性能进行了研究。结果表明:它的最大吸附量为24.5g,最大吸附率为0.112g/g。本实验吸附床中3A沸石分子筛的量为218.5g,在脱附温度为260℃,吸附环境温度为25℃时,根据已有的对太阳能冷管的改进实验,选用同样材料的太阳能冷管计算时,可得其制冷量为147.864J,制冷系数COP为0.116。     

ZSM-5沸石在空调应用中的吸附脱附性能研究

针对固体吸附式制冷在空调领域的应用,建立了一套采用ZSM-5沸石-水作为吸附工质对的实验研究系统,对其吸附脱附性能进行了实验研究,得到了吸附脱附性能曲线。比较了不同吸附床温度以及吸附床有无保温情况下,ZSM-5沸石分子筛对水的吸附情况:低温情况对水蒸气的吸附量随吸附时间明显增加,但吸附率逐渐变慢;床温升高,吸附剂达到吸附平衡所需时间缩短,平衡吸附量则有所降低。     

以膨胀硫化石墨为基质的氯化钙/氯化钡-氨两级复合吸附式制冷循环实验研究

相对于单级吸附式制冷,两级吸附式制冷对热源温度和环境冷却温度适用范围更广。本文采用膨胀硫化石墨为基质,研制了氯化钙/氯化钡-氨两级吸附式制冷系统并进行了实验研究。吸附床采用传热传质强化后的新型固化吸附剂,利用新型非翅片式填充方式,有效降低了吸附系统的质量,增加了紧凑性。结果表明:两级吸附式制冷系统可以很好地适应热源温度低于100℃的工况,其性能在多数工况下高于单级吸附式制冷,系统COP与SCP随氯化钙解吸时间先增加后减小,COP最大可达0.27,SCP最大可达132.5 W/kg。     

低温热源驱动的二级吸附冷冻循环实验研究与性能分析

在冷冻应用方面,传统的吸附式制冷工质对在热源温度低于90℃、冷凝温度高于25℃的条件下,很难实现-10℃以下的冷冻。为了实现100℃以下的太阳能或废热利用,这里提出了二级吸附式制冷循环,建立了性能测试实验台。采用CaCl2-BaCl2-NH3作为工质对,利用85℃热源驱动,测试不同蒸发温度与冷凝温度下吸附剂的吸附与解吸性能。结果表明,二级吸附式制冷能够实现-20℃下的冷量输出,同时,冷却水温度为25℃时,氯化钙的循环吸附量、二级吸附式制冷COP与SCP分别为0.598kg/kg,0.24,106.6W/kg。     

沸石分子筛吸附式制冷 Ⅰ.沸石分子筛体系的选择

用高真空吸附重量法测定了水和乙醇在 NaY、13X、5A 等沸石分子筛上的吸附等温线,吸附温度范围从25℃到300℃。阐述了沸石分子筛用于吸附式制冷的吸附理论基础,根据液-气-沸石的稳态平衡方程对液体-沸石吸附体系制冷的物理化学性质进行了描述。按照不同用途的制冷要求对吸附体系进行了选择。发现乙醇液体-沸石体系(如乙醇-5A 体系)可用于小循环量的低温制冷如制冰、冷冻机等,而水-沸石体系(如水-NaY 体系)可用于大循环量的制冷如空调、冰箱等。     

燃料电池汽车余热驱动的吸附式制冷系统结构设计

为了有效利用燃料电池汽车的余热,本文建立了燃料电池汽车余热驱动的吸附式制冷系统.该吸附式制冷系统由三个主要的回路构成:吸附床加热冷却回路、吸附质循环回路以及热水循环回路.针对吸附式制冷系统的核心部件吸附床,在分析比较了各主要吸附床结构的前提下,最终确定采用单元吸附管组合结构,并进行了相应的设计计算.本文的研究结果对于低温热源驱动吸附式制冷的研究起到一定的指导作用.     

太阳能连续吸附式冷藏室的试验性能研究

太阳能吸附式制冷作为一种无氟制冷技术及利用低品位热源的有效工具,越来越受到重视。同时,使用环保型工质和节能是制冷技术发展的的必然趋势。以一太阳能连续吸附式冷藏室为例,对其进行试验研究,得出吸附床的厚度和太阳能集热器的出水温度对制冷系统性能的影响最大,对今后系统的设计改进和试验具有一定指导意义。     

浅析热源温度对硅胶-水制冷机性能的影响

通过实验研究热媒水温度对某型硅胶-水吸附式制冷机性能的影响,发现随着热媒水温度的升高,制冷机的制冷量增加但在不同温度区间内的增幅不一致;COP随热媒水温度升高成波浪形变化,形成两个波峰和两个波谷.结合对硅胶物理结构和吸附过程的研究,通过对实验现象做定性分析后认为:硅胶的"墨水瓶"形微孔结构是形成此现象的主要因素.在设计和评价硅胶水制冷机应充分考虑此因素对制冷机性能的影响,尤其是设计时应根据热源温度选择合适孔径的硅胶或根据硅胶孔径选择合适的热源温度.     

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.     

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.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to