Advantages of a Combined System for Metering and Regulating Heat Consumption

Advantages are considered for a combined system for metering and regulating heat consumption, and data are given on the reduction in heat consumption without deterioration in conditions in such a system.     

在福州地区以天然能源为热泵冷热源的应用前景

以夏热冬暖地区城市-福州的气候、水文条件为基础，结合一住宅全年空调负荷的DOE-2．1模拟结果，分析在福州采用天然能源作为热泵的冷热源的应用前景，结果表明：（1）全年绝大部分时间内适合利用空气作为冷、热源；（2）闽江、内河周边的用户适合采用水源热泵；（3）温泉聚集地区不适合采用地下水和岩土作为冷源；（4）夏季适合联合使用岩土和辅助散热装置作冷源，冬季只使用岩土作热源。     

附加物对材料低温比热测量精度的影响

介绍了真空绝热法测量材料低温比热的原理及方法。考虑到测量系统中样品架、加热器及温度计等附加物引入的热容因素，建立了比热测量误差的传递关系式，并给出了分析数据。对具体测量中有关精度的问题进行了探讨。     

湖南某地表水源热泵水温调查与扩容方案分析

对湖南某湖水源热泵系统的水温进行多点连续监测并对监测数据进行分析,提出几种空调扩容方案,并分析各方案的优劣与可行性,其中多冷热源方案在一定程度上能够起到为空调系统增效的作用。在进行类似地表水源热泵系统扩容改造时,本文的实测数据与扩容方案可作为参考与借鉴。     

Heat capacity of fcc calcium

The lattice entropy derived from the measured heat capacity at intermediate and high temperatures is analyzed to yield a weakly temperature dependent entropy Debye temperature. An unusual temperature dependence of this quantity may be a sign of error in the heat capacity data. When this analysis is applied to heat capacity data recommended by Hultgren et al. (1973) for 20 nontransition metals, the result for fcc Ca stands out as anomalous. We have reconsidered heat capacity data of fcc Ca and find that measurements by Eastman et al. (1924), which were given little weight by Hultgren et al., are consistent with a normal behavior of the entropy Debye temperature up to 450 K.     

Localized States in Melts of Light Rare-Earth Metals

Based on the results of analysis of the data of optical experiment, equations are suggested for the estimation of the values of electron components of surface energy and of melting heat of metal systems. The results of calculation of these components for light rare-earth metals in the liquid state are given.     

Specific Heat Measurements by a Thermal Relaxation Method: Influence of Convection and Conduction

This paper involves the well-known thermal relaxation method for measurement of the specific heat (c) of thin solid samples. Although this method was applied successfully in recent years for the characterization of different materials, in this work some aspects that must be taken into account in order to avoid problems based on satisfying the required experimental conditions of heat flux imposed by the physical model used for data analysis and processing will be discussed. For this purpose, for a given experimental geometry, the heat diffusion equation will be solved in order to obtain the sample’s requirements for reliable measurements of c, regarding its thickness and thermal conductivity. An experimental device is described that can be used for the study of the influence of heat dissipation by convection on the method. A computer simulation was performed for comparing the simple model with one that takes to in account the gradient of temperature inside the sample. The results of measurements are presented.Paper presented at the Seventeenth European Conference on Thermophysical Properties, September 5–8, 2005, Bratislava, Slovak Republic.Part of this work was performed when the author was at Universidad de La Habana, Facultad de Física, San Lázaro y L, Vedado 10400, La Habana, Cuba.     

冷却塔复合式地源热泵系统在西安某办公建筑中的应用

结合复合式地源热泵系统在西安某办公楼项目中应用的实例,从地质条件、热响应试验、冬夏季土壤的热平衡及运行情况等方面进行详细介绍,针对地源热泵系统的设计及使用提出一些参考建议.     

套管换热器传热过程强化实验系统的研制

多套管式换热器结构简单,清洗、维修方便,易实现加工制作,提出多套管式换热器对套管换热器进行传热强化.在设定条件下编写程序,对多套管换热器进行优化设计,计算显示在相同条件下多套管式换热器与单套管换热器相比传热系数有较大的提高.系统中设置回热器,有效节约能源.该系统在有余热、废热可以利用的场合节能效果更加显著.     

大型公共建筑采暖耗热量测试分析

参考《居住建筑节能检验标准》、依据《公共建筑节能设计标准》和传热学相关知识,对某大型公共建筑进行采暖耗热量测试,给出数据采集及处理方法,并对测试结果进行分析评价。     

U形地埋管地源热泵系统动态性能数值模拟

地源热泵系统全年动态性能模拟对系统方案设计具有重要意义。基于一维非稳态传热数值模型,给出了U形地埋管地源热泵耦合模拟算法。根据建筑逐时负荷、地质情况以及热泵机组性能等条件,耦合模拟方法能够给出长期地温、水温以及系统能耗信息,为方案评估提供依据。与基于解析模型的模拟算法进行了交叉比较,表明数值模型计算准确,计算速度快,具有工程实用性。对某案例进行全年逐时分析,根据模拟结果对钻孔数目及钻孔间距的选择提出相应的建议。     

Transient heat pump behaviour: a theoretical investigationComportement de la pompe à chaleur en régime transitoire: recherche théorique

A detailed mathematical model of vapour compression heat pumps is described. Model equations of the various heat pump components are given. The component models include the condenser, evaporator, accumulator, expansion device, and compressor. A brief discussion of the modelling techniques is presented, as is the solution methodology. Preliminary simulation results are also illustrated. The model developed predicts the spatial values of temperature and enthalpy as functions of time for the two heat exchangers. The temperatures and enthalpies in the accumulator, compressor and expansion device are modelled in lumped-parameter fashion. Pressure responses are determined by using continuity satisfying models for both the condenser and evaporator. The summary provides a list of future work anticipated in the area of dynamic heat pump modelling.     

Transient heat pump behaviour: a theoretical investigation

A detailed mathematical model of vapour compression heat pumps is described. Model equations of the various heat pump components are given. The component models include the condenser, evaporator, accumulator, expansion device, and compressor. A brief discussion of the modelling techniques is presented, as is the solution methodology. Preliminary simulation results are also illustrated. The model developed predicts the spatial values of temperature and enthalpy as functions of time for the two heat exchangers. The temperatures and enthalpies in the accumulator, compressor and expansion device are modelled in lumped-parameter fashion. Pressure responses are determined by using continuity satisfying models for both the condenser and evaporator. The summary provides a list of future work anticipated in the area of dynamic heat pump modelling.     

An investigation of the balance method of measuring unsteady heat flux

A method of measuring unsteady heat flow, based on the balance equation of heat flows at the entrance and inside the object, is described. The theoretical principles for obtaining formulas and results of investigations on a thermal model are presented. Diagrams of a heat meter and of a measuring system are given. __________ Translated from Izmeritel’naya Tekhnika, No. 12, pp. 37–41, December, 2006.     

土壤源热泵地下垂直埋管换热器常用传热模型的研究

本文介绍了土壤源热泵的国内外研究现状以及三种常用的埋管换热器传热模型,分析了这三种模型各自具有的特点和适用条件.并对传热模型的选取提出了自己的观点,为特定条件下如何选取合适的模型提供了一定参考.     

一种新型立式真空热处理炉

介绍了炉子的用途、性能、结构特点并列举了不同规格、型号金属材料的固溶、调质、退火等热处理测试数据图表及1Cr18Ni9Ti管件固熔处理工艺曲线示意图，由于本炉具备堆装及吊装两种不同的装料方式，因此，可适用于各种形状金属材料的热处理，尤其是对超长管、杆件金属材料的处理是本炉所解决的关键所在。     

地源热泵系统在夏热冬冷地区别墅项目中的应用

通过对某别墅项目中地源热泵系统应用的介绍,给出了此类项目中生活热水和空调及采暖系统相结合的形式及水系统设置中采取的节能措施,并对该类型建筑中,地源热泵系统应用形式进行了初步探讨,希望对今后地源热泵技术在这类项目中的应用起到一定的借鉴作用。     

Effect of fin spacing on the heat transfer and pressure drop of a two-row plate fin and tube heat exchanger

The analogy between heat and mass transfer (using the naphthalene sublimation technique to measure the mass transfer coefficient) was used to investigate the heat transfer capabilities of various two-row plate fin and tube heat exchanger configurations. Average transfer coefficients were determined from measurements of the mass transferred in an analogical system consisting of a pair of naphthalene plates and an array of spacer discs. The analogical system modelled a typical heat exchanger flow passage. Special attention was given to the effect of fin spacing on heat transfer capabilities. A physical interpretation of the experimental data has been given and new conclusions have been drawn. The pressure drop of the heat exchanger configurations has also been investigated.     

Selecting Meters for Water-Based Heat Supply Systems

Basic criteria are considered for selecting meters for open and closed water-based heat supply systems. Results are given from an independent questionnaire concerned with the ranking of selection criteria and preferences for types of meter present on the Russian market, as well as the technical characteristics and services provided by meters made by the Teplocom company in St. Petersburg.     

Multivariate numerical derivative by solving an inverse heat source problem

A method for approximating multivariate numerical derivatives is presented from multidimensional noise data in this paper. Starting from solving a direct heat conduction problem using the multidimensional noise data as an initial condition, we conclude estimations of the partial derivatives by solving an inverse heat source problem with an over-specified condition, which is the difference of the solution to the direct problem and the given noise data. Then, solvability and conditional stability of the proposed method are discussed for multivariate numerical derivatives, and a regularized optimization is adopted for overcoming instability of the inverse heat source problem. For achieving partial derivatives successfully and saving amount of computation, we reduce the multidimensional problem to a one-dimensional case, and give a corresponding algorithm with a posterior strategy for choosing regularization parameters. Finally, numerical examples show that the proposed method is feasible and stable to noise data.