集成一体化干湿球温湿度传感器的研究

温湿度传感器发展的历史很悠久,同时也出现了很多新型温湿度传感器。本文重点在干湿球理论的基础上,设计了干湿球温湿度传感器的数据采集系统硬件电路。为了保证温湿度测量精度,对硬件电路进行了误差分析,并且提出了系统误差的改善方法。     

变速直膨式空调系统运行特性的稳态ANN模型

在假设系统输出显、潜冷量的相对值在不同的蒸发器入口空气状态下不发生明显变化的前提下,本文针对实验用变速直膨式空调系统建立了稳态人工神经网络(ANN)模型,预测其在不同压缩机、风机转速组合下的系统输出,利用输出显、潜冷量的相对值可以消除室内空气状态对系统输出的影响。通过稳态实验获得数据训练、检测并验证ANN模型预测变速直膨式系统运行特性的准确性,并通过非训练状态点下的稳态实验验证所提出假设与ANN模型的适用性。ANN模型的训练、检测以及验证实验结果的最大误差均小于5%,平均误差均小于3%,表明该稳态ANN模型可以在训练状态点以及非训练状态点较为准确地预测变速直膨式系统的运行特性。     

基于对角矩阵法解耦的温湿度自适应控制研究

针对海洋计量校准实验室温湿度控制中存在的耦合作用,本文提出了一种基于对角矩阵法解耦的神经元自适应PID控制方法。通过对恒温恒湿控制系统的深入研究,构建了海洋计量校准实验室恒温恒湿系统的测量模型,并在采用相对湿度与绝对湿度的转换和对角矩阵法实现恒温恒湿系统模型解耦的基础上,本文应用设计的神经元自适应PID方法对温湿度进行了控制仿真实验。实验结果显示,应用神经元自适应PID算法的温度控制的最大超调为2℃,相对湿度控制的最大超调为13%,并在1200s左右就能达到温湿度设定值且保持稳定。这表明基于对角矩阵法解耦的神经元自适应PID控制方法能实现计量校准实验室更高的温湿度控制精度和更好的稳定性。     

干湿球系数影响因素分析与试验研究

采用传热传质理论结合相对湿度试验分析干湿球系数的影响因素和变化规律。结果表明,干湿球系数主要受对流传热和传质特性的影响,是温度和风速的函数,且随温度的升高或速度的减小而增大。湿度查算表和史密森气象用表适用于20℃～40℃、2. 5m/s～5m/s环境;常用经验式和Huang拟合式可在0. 1m/s～5m/s风速范围内使用,但前者适用于常温(20℃～40℃)环境,后者适用于高温(60℃～80℃)环境。通过非线性回归构建干湿球系数模型,模型预测干湿球系数在0. 1m/s～5m/s、20℃～80℃范围内的误差1. 5%。     

关于JJG205—2005的几点思考

一、检定干湿球温湿度计时是否应同时检定干球、湿球温度计示值误差？ 结合JJG205—2005《机械式温湿度计》检定规程7．3．2．2温度示值误差检定、7．3．2．3湿度示值误差检定以及附录A中的“检定记录格式”来看,笔者认为,JJG205—2005对于干湿球温湿度计来说,只是规定了其十球温度计的温度示值误差检定,而没有规定在温度示值误差检定时要同时检定湿球温度计。     

干湿球温度在国标允差内变化对风管送风式热泵性能影响的实验研究

为分析现行国标规定的干湿球温度允差对空调机组能效的影响,采用空气焓差性能测试方法,控制环境干湿球温度在GB/T 17758—2010规定的读数允差±1℃/±0.5℃内波动,测定风管送风式热泵实验样机的制冷量与能效比。实验结果表明,室内外侧干球温度达允差下限-1℃,室内外侧湿球温度达允差上限+0.5℃时,机组处于最佳制冷工况,EER为2.80,高于标准工况测量值达3.26%。室内侧湿球温度对EER影响最为显著,影响系数为0.0464;其次是室外侧干球温度,对EER的影响系数为-0.0340。将干湿球温度允差严格为±0.3℃/±0.1℃,EER测定误差将由±3.5%降低至±1%,可更准确评定机组的能效等级。     

离心-温度复合装置的自学习切换控制方法研究

针对惯性仪表的复合校准问题,设计了基于离心-温度复合装置的自学习切换控制方法,实现了高精度、高均匀性的温度场控制。根据离心机不同工况下的温度箱控制系统结构不同,切换控制方案可满足系统在高低温下的精度要求,自学习PID控制算法解决了控制过程中存在的温度波动问题。离心机旋转状态下和非旋转状态下的实验结果表明：该控制系统性能良好,在-55～80℃内的温度控制误差在±0.1℃之内。     

纯电动汽车冷媒直冷电池热管理系统的实验研究

针对电动汽车动力电池能量密度逐渐上升及快充过程中电池发热量大的问题,本文提出采用蜂窝型单面吹胀铝板作为电池冷板的一种新型冷媒直冷电池热管理系统,充分利用制冷剂在流道内的高沸腾传热潜热处理动力电池热负荷。为了研究此冷媒直冷热管理系统的运行性能,构建了新型直冷系统的实验测试装置,并在UDDS标准工况下进行实验研究。测试结果表明:在6 k W下的最大设计发热量下,系统在150 s左右可快速响应热管理需求,具有较快的温度响应特性;电池冷板表面平均温度可控制在15～20℃的最佳温度区间,并达到温差小于4℃的良好均温性,且系统COP稳定在2. 8以上。     

太阳能-空气能双源直膨式热泵系统夏季冷热电性能研究

本文设计了一种基于微热管阵列的太阳能-空气能双源集热蒸发(冷凝)器及双源直膨式热泵系统,该系统可有效降低光伏组件温度提升光伏发电效率,同时可实现制热和制冷功能,是一种多能互补可满足多种用能需求的新型建筑供能系统形式。搭建了太阳能-空气能双源直膨式热泵系统实验台,并对系统在夏季典型工况下的发电、供冷与提供生活热水性能进行实验测试与分析,结果表明,双源直膨式热泵系统制热运行时,PV/T组件工作对光伏组件起到了显著降温作用,相比于热泵不运行工况,组件光电功率提高56.43%,光电效率提升53.15%;双源直膨式热泵系统将180 L水由20℃加热至50℃的制热过程,系统平均制热COP为4.59,集热功率为3.20 kW,总发电量为1.43 kW·h,总耗电量为1.36 kW·h;由12℃冷却至7℃的制冷过程,系统平均EER为2.29。     

用干、湿球法测量相对湿度结果的不确定度分析

给出了用干湿球法测量相对湿度的数学公式,并对公式进行了推导,求出了该公式的灵敏度系数和方差.使用德国富琪温湿度环境试验箱构成实验环境,在温度变化为±0.15℃范围内对各项不确定度进行了分析,用干湿球法测量相对湿度结果的不确定度≤1.5%.并提出干湿球法测量相对湿度应注意的事项.     

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.……     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.……     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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