低辐射能玻璃窗的节能研究

建立了低辐射能玻璃窗的物理传热模型,计算并分析了反应窗户性能的两个参数,传热系数U和太阳得热系数SHGC,着重讨论了低辐射能玻璃窗的这两个参数的特点和影响因素,找出其节能的机理,通过负荷模拟,研究了低辐射能窗户对空调能耗的影响,并在模拟结果的基础上,对我国4种典型气候下最适宜使用的低辐射能玻璃窗进行了分析。     

住宅窗户的节能研究

通过研究窗户热工参数的模拟计算方法,定义了表征窗户节能效果的两个参数：ER和ERC,并根据典型的建筑平面图,计算分析了多种因素对建筑节能的影响,得出了北京和哈尔滨两个城市的判断住宅窗户节能效果的经验回归公式,为设计人员和普通用户因地制宜地选择节能窗户提供了便捷有效的计算方法。     

遮阳型节能玻璃的全年节能评价

提出遮阳型节能玻璃的全年节能评价新方法，即太阳辐射综合节能效率SEC计算公式，将夏季遮阳节能与冬季透光节能同时考虑，不仅包含太阳辐射、建筑体形等常规建筑热工问题，而且还加入供暖空调系统设备的能效问题，该评价方法可用于全国不同地区的建筑玻璃系统选型，对建筑物冬季太阳能的合理利用具有积极意义。     

低辐射玻璃的节能性能分析

本文结合我国华北地区的气象条件对低辐射玻璃的热舒适性和节能性能进行了分析比较。计算结果表明 ,低辐射玻璃最适合于北方寒冷地区的东、西、北三个朝向的外窗 ,普通中空玻璃是建筑物冬季南向房间日照时刻的最佳节能玻璃。节能玻璃的选型不应忽视建筑物冬季太阳能的合理利用     

节能玻璃在建筑节能设计中的应用

分析了建筑节能玻璃的节能原理及传热系数U﹑可见光透射率T﹑遮阳系数Sc等三大性能指标。提出了在建筑节能设计中,节能玻璃的选择应遵循的原则。在此基础上,对影响建筑节能玻璃性能的主要因素进行了讨论,为节能玻璃在工程实践中的应用作出了指导。     

热辐射能(波)选择性强化吸收的场协同机理

从场协同原理的角度出发，分析了材料对热辐射能(波)选择性吸收过程，提出了材料对入射辐射能(波)的作用实质是材料内阻尼振子组成的力场和入射辐射场之间的相互作用；调整这两个场之间的协同关系，可以改变和改善材料的选择性热辐射性能。基于此得到了强化材料对入射热辐射能(波)选择性吸收的机理。研究表明：减弱入射辐射场与材料内阻尼振子组成的力场之间的协同关系，可以提高材料的吸收率和发射率；相反，强化这两个场之间的协同关系，可使材料表现出较高的反射率。     

全玻璃真空管太阳热水器的选购

对于消费者来说,全玻璃真空管太阳热水器的选购存在一定难度。因为它既不同于冰箱、洗衣机等早已进入千家万户、性能已被人们熟知的家电产品,也不同于家具、衣物等质量优劣较易判定的消费品。真空管太阳热水器的各项技术指标、性能及影响使用寿命的原材料质量等关键因素在初次购买时很难判别,往往在使用过程中才能慢慢体会。现在,市场上的真空管太阳热水器外观相似,但内在品质差别极大。选购一台优质高效、性能价格比合理的放心产品,可以从 8个方面进行对比： 一得热量 　　太阳热水器一年的得热量多少兆焦 (MJ)是热性能的一项主要指…     

全玻璃真空集热管热损计算与分析

根据热量传递原理,对全玻璃真空太阳集热管的热传导、对流和辐射三种传热形式进行了推导计算,其中辐射热损对真空集热管热损的贡献起主要作用,且辐射热损随温度升高而增大.根据串联电阻叠加原则得出真空集热管主体热损的计算模型,并通过该理论模型计算了全玻璃真空集热管的热损.结果表明,理论计算的热损值均小于测试的热损值,这是由于集热管的边端热损效应引起的.     

华北地区节能玻璃选型分析

本文结合我国华北地区夏季炎热冬季寒冷的气候特点 ,对遮阳型节能玻璃的热舒适性和合理选型进行了分析。建筑玻璃系统选型不应忽视冬季太阳能的利用 ,夏季遮阳节能和冬季透光节能对建筑节能而言同等重要。     

窗太阳得热系数测试设备的研发

提出了热箱法来收集并计算窗的太阳得热量.并在此基础上设计开发出测量窗太阳得热系数的实验设备.在完成测量设备标定后,对50系列塑钢推拉窗进行了重复性实验.实验结果表明,此测量设备能够稳定、准确的测定窗太阳得热系数,具有推广价值.     

A correlation between normal and hemispherical emissivity of low-emissivity coatings on glass

Transparent low-emissivity coatings are commonly used to reduce the thermal conductance of windows. It is important to be able to characterize and compare the wide variety of these coatings that are now available. The property that best describes the effectiveness of a coating in suppressing radiative heat transfer is the total hemispherical emissivity. It is much simpler, however, to measure the normal emissivity. This paper shows that a correspondence exists between these two properties which applies to most types of low-emissivity composite coatings. An empirical expression for this correspondence is provided.     

Thermal emissivity of materials

In this paper we present a macroscopic theory of thermal emissivity of materials incorporating the effect of the extinction coefficient on the intensity transmission coefficient and the critical angle. Results have been presented for the emissivity of various materials (e.g. silver, aluminium, glass and water) for both Gardon's theory and the present theory. It is seen that the present theory successfully explains the observed thermal emissivity of metals (Al and Ag) as well as non-metals (glass and water).     

Investigation of steel emissivity behaviors: Examination of Multispectral Radiation Thermometry (MRT) emissivity models

Steel emissivity behaviors were investigated in this study. Experiments were conducted to measure emissivity. Six emissivity models were then applied to examine Multispectral Radiation Thermometry (MRT) on inferring surface temperature. The data show that emissivity decreases with increasing wavelength. For steel containing high chromium, emissivity is usually lower than others because of the chromium oxide protection layer. Two emissivity models provide the best overall compensation for different alloys, number of wavelengths, and temperatures. The results reveal that if the emissivity model can well represent the real emissivity behaviors, the more accurate inferred temperature can be achieved.     

Electrochromic emissivity modulator for spacecraft thermal management

A novel electrochromic device (ECD) working in mid- to long-wave infrared (IR) region is presented, comprising of a solid-state monolithic thin film system for adjusting heat rejection/receiving levels on attached surfaces. The system is an electrically controllable active emissivity modulator. EclipseVED™, variable-emissivity ECD, is designed for satellite and spacecraft thermal control, using an active ECD system for long-wave infrared (LWIR) modulation and a passive cold mirror for solar rejection. Emissivity modulation of the system is 0.8 for 7–12 μm region while average solar rejection is 80% in the vis–NIR region. Device properties and initial space test results are also presented.     

New formulae for the equivalent night sky emissivity

The knowledge of the equivalent sky emissivity is important in computations of radiation cooling systems, as well as in the evaluation of the thermal losses in solar collectors. A new empirical formula has been developed which permits the determination of the equivalent nocturnal sky emissivity as a function of the site's altitude, the ambient temperature, the relative humidity and the degree of cloudiness, of mist or of haze present at the time. The formula has been found to agree well with the equivalent nocturnal sky temperature values measured at various Venezuelan sites and other places. Comparison is made with formulae from other investigators. A modification of Brunt's. Elsasser's and Angström's formulae for clear nocturnal sky is also suggested.     

Effect of water emissivity on solar still efficiency

The proper installation of a solar still can reduce the heat loss from the basin to ambient and significantly increase the still efficiency. In this case, the use of a dye resulted in minimal improvement in still efficiency. The reduction in the water emissivity will reduce the radiation heat transfer from water to glass. This resulted in a substantial improvement in still efficiency and offers great potential for solar still usage. The two methods above are mutually exclusive and could be used concurrently for best results. The numerical predictions reported agree favorably with the most recently published experimental work in a similar configuration.     

等温黑体空腔积分发射率的计算

黑体空腔积分发射率的计算对辐射测温黑体空腔的设计非常重要,不同计算方法之间的互相校验是保证计算准确的重要手段。提出了一种基于有限元的计算方法,计算了等温轴对称黑体空腔的积分发射率,结果与Monte Carlo法的平均相对偏差为0.000 9,表明该方法准确可靠。在此基础上,对等温非轴对称黑体空腔的积分发射率进行了计算,结果与Monte Carlo法的平均相对偏差为0.000 5,表明能够有效计算非轴对称黑体空腔积分发射率。     

气体热辐射机理的研究与热辐射特性的计算

从对气体热辐射的微观机理的研究出发，利用谐振子模型对气体燃烧产物的热辐射特性进行了研究与计算，结果表明：气体的热辐射波谱取决于气体分子的固有振动频率、等离子体频率、阻尼系数以及气层厚度，提高压力、气层厚度和降低温度可以有效地改善气体热辐射的选择性。     

Clear sky emissivity as a function of the zenith direction

Using the Bliss's theory [1] which assimilates the atmosphere as a column constituted of plane and parallel layers, the expression of the clear sky emissivity as a function of the zenithal direction is established. Other relations as the mean emissivity and the temperature of a part of the celestial vault are also established. The power emitted by some parts of the sky are calculated. Experiments have been conducted. This paper describes the study and presents the results.