地下室变风量恒温恒湿空调机组的研制与性能

本文针对地下室高热高湿的环境特点,研制了变风量恒温恒湿空调机组,对样机进行了机组性能实验及模拟地下室热湿环境的机组运行实验。设计了一套智能化模拟负荷发生器,在给定热湿负荷情况下,研究机组热湿负荷独立处理能力与运行特性。结果表明:机组循环风机的变风量可以调节机组的显热与潜热处理能力,机组热湿独立处理能力较好,误差在5%左右,可以定潜热变显热和定显热变潜热运行,房间温湿度控制效果良好,温度波动±0.2℃,相对湿度波动±3%。     

新型除湿模式在国防工程中的应用

针对常规热湿联合处理技术应用于国防工程时出现的室内温湿度波动大、机组运行能效低等问题,提出利用温湿度独立控制理念构建国防工程新型除湿模式。该除湿模式由新风处理系统(全工况除湿机)和空气循环处理系统(一体化分流节能型除湿机)构成。计算分析表明与应用于常规热湿联合处理系统相比,同型号一体化分流节能型调温除湿机应用于温湿度独立控制系统(新型除湿模式构建的国防工程)时,其制冷量可增加约21.3%。     

恒温恒湿空调系统的优化控制与性能模拟

针对传统恒温恒湿空调系统表冷器采用固定露点方法导致热湿补偿损失较大的缺点,采用热湿独立控制装置和PID分程控制方法,研制了一套恒温恒湿空调系统。在实验的基础上,利用TRNSYS 16软件建模,对系统在不同热湿负荷下的运行状况及节能效果进行了模拟分析。结果表明,该系统能自动调节表冷器冷冻水流量与温度,以及加热器或加湿器的投入量,实现对空气温湿度的独立控制,并达到设定的温湿度;在设计此类表冷器时,换热面积应该以较高的冷冻水进口温度(如12℃而不是通常的7℃)来进行计算。该系统节能效果显著,比传统系统在低温高湿工况下节能30%以上;在高温低湿工况下节能50%左右。     

对温湿度独立控制空调系统的探析

为解决室内空气处理过程中显热和潜热与室内热湿负荷相匹配的问题,本文对温湿度独立控制空调系统中温度控制系统和湿度控制系统进行分析和梳理,展示了多种温湿度独立控制空调系统组合方式。通过分析研究发现,溶液除湿与毛细管辐射供冷相结合的温湿度独立控制空调系统,在节约能源和提高空气品质方面具有较高的应用价值,对降低建筑能耗具有很好的实际意义。     

焓湿向量空间及空调系统实际性能计算

针对空调系统的实际运行冷量与室内热湿负荷不匹配的问题,基于焓湿图建立了焓湿向量空间,将空调系统传统设计计算方法转化为焓湿向量计算。定义了负荷向量和空调机组函数,提出了迭代分析算法,在空调房间热湿负荷不变的前提条件下,于设计初期可理论预测出不同室外环境下空调系统的实际性能,从而省去了实验测试。并利用该算法对高温和高湿工况进行了空调实际性能计算。最后将实测数据和迭代算法计算结果作误差分析,相对误差在4%以内,验证了该算法具有较高的准确度。     

极端条件下住宅建筑辐射吊顶与独立新风复合空调系统设计

以北京某小区辐射吊顶与独立新风复合空调系统为例,对室内外极端条件下的冷负荷特性进行分析,结合新风处理机组出风温度与冷冻水入口温度所能达到的实际最大差值,讨论极端条件下新风的处理方案。认为在单位面积湿负荷小于8.4g/(h·m~2)时,可采用单独冷水盘管除湿;单位面积湿负荷在8.4～17.6g/(h·m~2)之间时,可采用冷水盘管与直膨式蒸发盘管串联除湿;单位面积湿负荷大于17.6g/(h·m~2)时,可采用加大除湿风量的方法除湿。     

大金变频控制热泵式VRV空调机组制冷运行特性的实验研究

本文对大金变频控制热泵式VRV控调系统夏季制冷运行时的节能性作了一系列实验研究,得到了VRV空调系统的夏季部分负荷运转特性,并在节能方面与普通风冷热泵冷热水机组作了比较,证明该空调机组比普通冷热水机组节能。     

用低温送风技术解决辐射供冷结露问题的研究

建立一个地板辐射供冷实验系统,进行不同空调方式结合下的实验,通过一组实验数据对地板辐射供冷初始阶段运行和持续运行时的两种结露情况进行了分析,分析结露产生的原因,得出结论：仅仅靠地板辐射供冷系统处理室内的热湿负荷时候,其供冷能力受到了结露问题的限制,亦即单靠地板辐射供冷的系统宜用于夏季冷负荷较小的地区或者是空气较干燥而不会引起结露的冷负荷较大的地区。最后通过设计计算说明采用独立新风系统与低温送风技术结合可以解决辐射地板的结露问题。     

温湿度独立控制空调系统在民用建筑中的应用

分析常规空调难以实现真正的热湿平衡的情况,并提出温湿度独立控制空调系统是解决此问题的有效方法。重点研究温湿度独立控制空调系统中新风送风参数的确定方法。指出温湿度独立控制空调系统的新风需要承担室内全部的湿负荷,新风机组的送风含湿量与新风量之间存在一定的关系,从而在一定的设计参数下可以确定新风送风参数,实现真正的热湿平衡。     

转轮除湿复合式空调系统的探讨

转轮除湿复合式空调系统利用转轮除湿处理新风用于承担室内湿负荷,室内显热冷负荷和新风显热冷负荷由干冷设备承担,可有效地控制室内温度和湿度.复合式空调系统采用热回收装置可有效地节约新风冷负荷和提高除湿能力,当新风送风温度等于室内设计温度时,系统冷水采用高温冷水(18/21℃),可有效地提高制冷机组性能系数,节约制冷能耗42.83%.但转轮除湿再生能耗过高,复合式空调系统总能耗远大于传统空调系统,降低转轮除湿再生能耗是复合式空调系统应用的关键问题.     

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.