土壤蓄热与土壤源热泵集成系统的数值模拟

结合土壤源热泵技术推广中存在的问题和地下蓄能技术的优点,提出了土壤蓄热与土壤源热泵集成系统及其地下管群换热器的布置方式。并在能量平衡的基础上建立了地下管群换热器蓄热、释热和停止运行的数学模型。通过数值模拟,分析了埋管间距对蓄热与释热的运行特性的影响。     

埋地换热器放热工况的现场运行实验研究

结合一地源热泵示范工程，建立了垂直竖井与地基桩单U型管埋地换热器联合使用的地源热泵系统的综合性能实验装置。通过对一个夏季长期间歇运行测试数据的分析，发现地下各个测点的温度上升幅度各不相同；桩埋管的热作用半径至少为2．5m，井埋管的热作用半径至少为2m；在相同的工况条件下，桩埋管的放热率大于井埋管。     

反照率影响建筑热环境的实验

针对城市建筑物外墙墙面反照率变化，建立两个建筑物理模型，在不同反照率墙面材料的条件下，对夏季建筑室内热环境进行了分析研究，验证了采用高反照率的墙面材料是一种有效的、主动的隔热节能方式；采用积分拟合方法对墙面材料的反照率进行了拟合，其结果为实际情况下城市建筑外墙墙面材料的选择及其隔热性能分析、反照率的计算及其对建筑热环境的影响评价提供了一条有效的途径。     

石灰石——石膏湿法烟气脱硫工艺不宜安装烟气换热器

近年来火电厂烟气脱硫(FGD)设施建设不断加快,目前国内外已开发的烟气脱硫技术中,研制出的石灰石—石膏烟气脱硫湿法工艺已成为我国燃煤电厂烟气脱硫的首选工艺。针对烟气脱硫湿法工艺是否需要进行烟气升温(即烟气脱硫是否需加装烟气换热器)的有关问题,文章进行了讨论并提出了建议。     

我国核裂变能可持续发展战略研究

本文从科学技术的角度,分析我国国民经济增长对核能发展的需求,探讨我国核能的近中期发展战略构想,指出为实现其发展战略目标而应重点研究的关键科学技术与问题,并提出一些相关的政策建议,为国家制定核能中长期发展规划提供参考。     

直埋热水管道和直埋蒸汽管道设计理论浅析

根据直埋热水管道和直埋蒸汽管道的不同特性 ,介绍了两种管道的应力验算及强度计算 ,并对两种直埋热力管道的敷设方式和保温结构进行了分析比较。     

Impact of the Relationship between Phase Change Temperature and Boundary Temperature on the Thermal Performance of a PCM Wall and the Presentation of PCM Thermal Performance Indexes

In the composite phase change material (PCM) building envelope, the matching relationship between the phase change temperature of the PCM and the wall's boundary temperature significantly affects the energy storage performance of the PCM building envelope. In this paper, a type of concrete hollow block with a typical structure and a common PCM were adopted to produce multiform composite PCM hollow blocks, and the temperature changing hot chamber method was performed to test the thermal performance of the hollow block walls under different temperature conditions. New indexes were proposed for the thermal performance evaluation of the PCM wall. Meanwhile, combined with experimental data, the effective heat capacity model and the enthalpy model were used to analyze the effect of correlations concerning how the relationship between phase change temperature and wall's boundary temperature influenced the thermal performance of PCM wall. Three main impact factors related to temperature were obtained through the analysis. In addition, approaches for improving the thermal performance of a composite PCM wall were put forward. This paper provides the theoretical basis, data reference and practical instruction for the proper use of a PCM wall and ways for improving the thermal performance of a composite PCM wall.     

Research on the influence of PV cell to thermal characteristics of photovoltaic/thermal solar system

In the paper, we analyzed internal thermal transmission characteristics of water‐heating photovoltaic/thermal (PV/T) solar collector covered by photovoltaic (PV) cell, established photothermal conversion model of PV/T solar system, and analyzed the influence of PV cell coverage to photothermal characteristics of PV/T solar system. Results show that the thermal efficiency of PV/T solar system by optimizing PV cells coverage can reach 68%. In addition, by designing four water‐heating PV/T solar system prototypes with PV cell coverage of 0.4, 0.56, 0.7, and 0.82, respectively, we conducted experimental researches for the four prototypes and found that the four prototypes can achieve thermal efficiencies of 58%, 51%, 64%, and 67%, respectively, in heating 250 L of water to 50°C. The experiment results are consistent with theoretical analysis results, indicating that it is feasible to improve thermal characteristics of PV/T solar system by optimizing PV cell coverage. Copyright © 2017 John Wiley & Sons, Ltd.     

A Complete Experimental Investigation on The Rheological Behavior of Silver Oil Based Nanofluid

In this study, thermo‐physical properties including thermal conductivity, viscosity, density and specific heat capacity of an oil based nanofluid including silver as to be nanoparticles have been experimentally studied. The results indicate an enhancement in thermal conductivity which was depended on bulk temperature and volume fraction of utilized nanofluids. Viscosity data show a significant increment through volume fraction increasing. In addition, the specific heat capacity and density of nanofluids were studied experimentally and it was found that, all measured rheological properties of these nanofluids, were not in agreement to published correlations.     

三相共箱式气体绝缘母线热计算方法分析

三相共箱式气体绝缘母线的热计算及散热性能研究对于其可靠性设计及在线监测具有重要意义。根据流体力学理论,采用流体多组分有限元法对三相共箱式气体绝缘母线进行热计算,利用映射网格划分实现电磁场、温度场和流体场的间隔耦合,综合考虑了母线外壳内外气体的流动和温度变化特性。采用流体单组分有限元法、流体多组分有限元法、传热学解析公式法三种方法进行计算,并对比分析了计算结果与试验结果的精度。结果表明,多组分有限元法与试验结果最为接近,为气体绝缘母线的设计及在线监测提供了理论基础。