江水源热泵系统适宜性指标研究

近年来水源热泵空调技术的大力发展,越来越多的工程采用水源热泵空调系统形式,尤其是长江流域因地理位置的优越性,很多城市将其列为可再生能源应用加以推广。但由于江水源热泵系统取水输配能耗较高,导致系统能效降低,通过对传统冷水机组冷却塔制冷系统能效比进行研究,得到适合工程应用的江水源热泵系统适宜性评价方法。     

大型风冷冷水机组性能评价系统节能性研究

针对大型风冷冷水机组性能评价系统能耗高的现状,分析评价系统的主要能耗构成,指出传统大型风冷冷水机组性能评价系统的高能耗成因,提出一种新型变容量全回收风冷冷水机组性能评价系统。新型评价系统省去样机恒温水箱、冷冻水箱和换热水泵,将变容量水冷乙二醇冷冻机组与经济器(冷却塔协同功能板换)串入闭式回路实现一级温控,结合变频泵与调节阀实现二级温控。实证表明:相比传统评价系统,应用双级温控的新型评价系统相近工况过渡耗时减少为前者的70%,综合能耗降为传统的75%,运行稳定性良好,节能效果显著。     

江水源热泵在上海地区应用的可行性分析

对江水源热泵在上海地区的应用进行可行性分析,讨论黄浦江水文特点,冷却水排放问题,系统与江水间的相互影响等,并对江水源热泵实施案例进行分析。     

办公楼变频空气源热泵序列优化控制

为了满足公共建筑中空调系统部分负荷下的节能运行调节需求,制冷机房经常配置多台冷水机组。空调系统中冷水机组能耗占比较高,而机组序列控制在系统满足室内负荷需求与节能中运行起关键作用。为了提高热泵机组的运行能效,本文提出一种空气源热泵机组的序列优化控制方法。首先建立变频空气源热泵机组模型,然后建立多台同型号机组序列优化控制目标函数,同时给出实时建筑负荷下求解机组最佳运行序列组合的算法与步骤。以某工程为例,利用e QUEST软件分析了办公楼全年的空调负荷变化,并在夏季、冬季典型日负荷基础上,对比分析了热泵机组序列优化控制策略与传统策略。结果表明:与传统策略相比,在10%~100%的系统部分负荷范围内,采用序列优化控制策略的机组能耗平均降低13.4%。在夏季典型日,热泵机组能耗降低14.5%;在冬季典型日,热泵机组能耗降低12.3%;在过渡季典型日,热泵机组能耗降低3.3%。在供冷季,采用机组序列优化控制策略能耗降低14.1%;在供热季能耗降低9.0%。热泵机组的序列优化控制策略具有明显的节能效果。     

“闭式冷却塔+磁悬浮冷水机组”用于数据中心空调系统的节能设计

论文介绍了某高性能数据中心空调系统采用闭式冷却塔+水冷磁悬浮冷水机组的设计方案以及节能运行模式,并给出了运行模式间转换温度的确定方法。研究表明:采用此方案后,可充分利用自然冷源,减少压缩机运行时间,节省能耗。与传统风冷直膨式空调能耗对比,年节省能耗达46.9%。     

某地铁车站中蒸发冷凝式冷水机组的应用分析

目前，地铁地下车站的空调冷源系统通常采用水冷冷水机组+冷却塔的组合方式。在实际工程中，冷却塔在室外地面的安装位置存在用地困难、景观难以协调以及运行噪声投诉等问题。结合重庆某地铁车站的实际案例，分析具体存在的问题，采用整体蒸发冷凝式冷水机组替代传统的水冷冷水机组和冷却塔，较好地解决车站空调冷源的问题，并从占地面积、投资费用、节能、节水方面进行了方案比较，分析了蒸发冷凝式冷水机组在地铁工程中应用的适用性。     

江水源热泵区域供能系统成本分析

目前对区域供能的研究基本上是着眼于建筑能量消耗的多少而忽略了所消耗能源的品质,实际建筑的耗能与能量的品质关系密切,基于热力学第二定律的分析方法能更好地反映区域系统的耗能状况。在对分析和经济学研究的基础上,利用成本分析方法,建立江水源热泵区域功能系统成本分析模型。以实际的区域供能项目为背景,对江水源热泵热泵区域供能系统和常规水冷机组加锅炉系统进行成本对比分析,对江水源热泵区域供能系统的应用起到了指导意义。     

水源热泵在某办公楼的可行性研究及能耗分析

根据项目办公楼所在地的水文地质及相关资料,应用层次分析法建立地下水源热泵系统和土壤源热泵系统的评价体系模型并计算二者的适宜性指数,得出两种系统均适宜项目所在区域。综合分析两种系统的经济性、环境影响及地下水源热泵的回灌方式,比较确定地下水源热泵系统方案。利用DEST软件模拟结合负荷频率法计算年运行能耗,利用概算指标计算初投资并与传统系统进行对比。得出该办公楼地下水源热泵系统的费用年值比采用冷水机组+燃煤锅炉方案节省18%。对于地下水源热泵系统的设计及方案的选择具有很好的借鉴意义。     

开式江水源热泵系统在重庆地区的适用性分析

在总结前人研究的基础上,综述了开式地表水源热泵系统方案设计要求,认为可以从技术、经济和环保性三方面分析江水源热泵的可行性。重庆江水水量、水温等水质参数完全满足机组要求,为了确保江水源热泵在重庆地区的技术适用性,重点在于寻找解决含砂量过高的技术方案。同时,合理设计的水源热泵系统具有较好的经济性能,尾水排放对江水的污染较小,满足经济环保性要求。认为江水源热泵系统在重庆地区具有较强的可行性及适用性。     

蒸发冷却技术在数据中心液冷系统中的应用探讨

数据中心内空调水冷系统能耗是除IT设备能耗外第一大能耗,在国内数据中心,大多采用风冷或水冷的散热方式进行降温,而液冷散热是比风冷或水冷散热更直接效率更高的散热方式.现常采用的冷却塔与液冷技术相结合,由于冷却塔内发生的是直接蒸发冷却过程出水温度在进口空气湿球温度之上.而间接预冷式蒸发冷却冷水机组通过预冷段对进口空气进行预...     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。