硼硅玻璃3.3：全玻璃真空太阳集热管用玻璃

硼硅玻璃３３———全玻璃真空太阳集热管用玻璃沈长治傅延龄１９９６年瑞士Ｒａｐｐｅｒｓｗｉｌ太阳能检测和研究中心测试了我国清华大学太阳能电子厂的全玻璃真空管太阳集热器，其瞬时效率截距超过了欧洲最佳产品。这种真空太阳集热管使用的玻璃管由北京玻璃仪器厂生...     

全玻璃真空太阳集热管规模生产的质量管理

全玻璃真空太阳集热管规模生产的质量管理严锡元牛传瑾全玻璃真空太阳集热管（以下简称集热管）的生产，在我国，从清华大学殷志强教授等研制出第一支集热管开始，仅有十多年历史，至于大批量生产，则是最近二、三年的事．清华大学太阳能电子厂于１９９４年建成一条年产１...     

太阳能真空集热管的结构种类与特点

太阳能真空集热管按真空封装结构可分为两大类：全玻璃真空集热管和玻璃－金属真空集热管,从取热方式、使用温度和性能要求的不同又有各种不同的内部结构。本文对国内外一些有代表性的太阳能真空集热管的结构种类和特点做了综述。     

国家标准《全玻璃真空太阳集热管》修订审定会召开

国家标准GB／T17049-1997《全玻璃真空太阳集热管》修订审定会于2004年9月23日在云南省丽江市召开。本标准修订的主要内容为：1．适当提高全玻璃真空太阳集热管及其材料的光一热性能参数；2．增加罩玻璃管直径Ф58mm为全玻璃真空太阳集热管；3．增加全玻璃真空太阳集热管的真空品质检测；4．增加了采用钢球进行机械冲击试验的内容。     

全玻璃真空集热管的热损

对一种具有溅射Ａｌ－Ｎ／Ａｌ吸收表面的全玻璃真空集热管的辐射热损进行了测量。在氦对所用硼硅玻璃渗透１３．５年实验的基础上，考虑了渗氦对集热管真空度的影响。分析和比较了辐射热损与气体导热热损的大小，在集热管真空度Ｐ≤６．７×１０－３Ｐａ时，辐射热损比气体导热热损约大２—３个数量级；集热管在整个使用期间直至２０年，通常辐射热损始终占热损的最主要部份。提出了为降低热损，在生产中应注意的若干问题。本文还报道了一种简单易行的非稳态卡计法测试与计算整管在１００℃以下的总热损与等效发射率的方法并给出了实例。     

全玻璃真空管太阳热水器框架的设计

全玻璃真空管太阳热水器框架的设计徐秉业沈新普邱纯一全玻璃真空管太阳热水器主要由全玻璃真空集热管、框架及管道系统组成。由于玻璃管内工作压力较高（设计压力最大为０４５ＭＰａ，即４５个大气压），所以对框架的力学性能有较高的要求。此外，框架的经济性、抗腐...     

全玻璃真空太阳集热管光-热性能检测

全玻璃真空太阳集热管光热性能检测殷志强一、引言经国家经贸委资源节约综合利用司提出，全国能源基础与管理标准化委员会归口，清华大学、中国标准化与信息分类编码研究所负责，由殷志强、薛祖庆、贾铁鹰、沈长治、严习元编写的《全玻璃真空太阳集热管》国家标准，经国...     

太阳热水器的新起点--全玻璃热管真空集热管研制成功

为了降低成本，解决直接走水的真空管太阳热水器在玻璃管内结垢、管子易炸裂及在严寒地区使用会冻结的问题，北京清华索兰环能技术研究所在１９９８年成功地研制出热管与玻璃真空管合为一体的全玻璃热管真空集热管，用该管可以替代金属热管真空集热管。其外径与一般玻璃真...     

室温对全玻璃真空太阳集热管平均热损系数的影响

引言 平均热损系数（ULI）是判定全玻璃真空太阳集热管热性能的一个重要技术指标。它是指在无太阳辐照条件下，全玻璃真空太阳集热管内充满80℃热水时，通过真空集热管向周围环境传递热能，水温下降，管内平均水温与环境温度相差1℃时，吸热体单位表面积散失的功率。全玻璃真空太阳集热管的热损系数取决于选择性吸收表面的发射比大小和真空夹层内的气体压强，因此热损系数的大小可以综合地反映吸收表面发射比和夹层的真空度好坏，较主要地决定着真空集热管的高温性能。     

全玻璃同轴型真空管太阳集热器的热性能

全玻璃同轴型真空管太阳集热器的热性能殷志强Ｇ．Ｌ．Ｈａｒｄｉｎｇ（澳）Ｒ．Ｅ．Ｃｏｌｉｎｓ（澳）一引言集热器的光学效率ηＯＰＴ取决于真空集热管的光学参数：选择性吸收涂层的太阳吸收比、玻璃罩管的太阳透射比、集热管之间距离、集热管与其背后的反射器距离和反...     

Experimental verification of thermal remote sensing method for recovering temperature distribution in glass

The thermal remote sensing method for recovering the temperature distribution in glass from spectral emission data is examined experimentally. An analytical model is formulated and the desired temperature distribution is obtained using an optimization scheme which determines the temperature profile in the form of a polynomial or a set of discrete points. In order to evaluate the accuracy and validity of the thermal remote sensing method, the recovered temperatures are compared with independent measurements using surface thermocouples and a Mach-Zehnder interferometer. Experimental results are reported for fused silica (Corning Code 7940) glass samples using a Perkin-Elmer spectrometer to measure the spectral radiant energy emerging from the layer of glass. Opaque (high and low emittance) boundary conditions at the heated surface of the glass were considered. Temperatures in the range from 500 to about 900 K were examined. Spectral emission data between 3.3 and 4.8 μm were used in recovering the temperature distribution in the glass samples. The results showed that the recovered and interferometrically measured temperature profiles agreed well, with the maximum deviation never exceeding approximately 2 per cent.     

Effects of composite fiber orientation on wind turbine blade buckling resistance

This paper utilized the inherent directional properties of composite materials to increase the critical buckling load of a 70 m carbon/glass hybrid wind turbine blade. The effect of changing the fiber orientations of the less stiff, off‐axis glass fiber plies (referred to as stability plies in this paper) was studied via nonlinear finite element buckling simulations. The orientation of the stability plies was found to influence the onset of the Brazier effect, which further influenced blade stability and buckling failure location. Although both blade weight and laminate thickness remained constant, an increase in critical buckling load of 8% was achieved with a negligible change in bending stiffness. The more stable blade allowed for removal of material leading to a decrease in maximum laminate thickness and a drop in blade mass of 3.3%. Modifications to the ply stacking sequence and carbon fiber usage were also considered and were found to affect the buckling load but not necessarily the optimum fiber orientation of the stability plies. Copyright © 2013 John Wiley & Sons, Ltd.     

Visualization and mechanical strength of glass seal in planar type solid oxide fuel cells

This study evaluated the mechanical reliability of glass seal in planar type solid oxide fuel cells and clarified the relationship between glass wettability and the mechanical reliability of glass seal. A visualization experiment was developed to observe a specific model seal in a furnace subjected to temperature variation and the relationship between the glass wettability and the seal shape was measured. The seal model consists of glass (G018-311, Schott, Germany) and interconnectors (Crofer 22 APU, VDM Metals GmbH, Germany). The visualization experiment and analysis were based on the sessile drop method to quantify glass surface tension and contact angle between glass and interconnector. The equation balance of forces with these surface properties succeeded to reproduce the seal shape observed in the visualization. Subsequently, the seal stress field was numerically solved, and the mechanical strength of the seal was quantitatively evaluated using the stress intensity factor. The analyses concluded that the stress intensity factor is 1.5 times higher than its minimum value as the contact angle raised from 90 to 130° and glass wettability decreased.     

Towards green buildings: Glass as a building element—the use and misuse in the gulf region

The recent economic growth in the Gulf region notably in Dubai, United Arab Emirates (UAE) has led to a colossal number of buildings that has been constructed in the past 5 years. In the last decade, a total glazed building's façades became the icon of Dubai. This large area of glazing in each façade needs protection against overheating and sun glare in summer. According to leader in energy and environmental design (LEED) glass selection becomes a main element in this equation to contribute towards achieving a green building. The aim of this paper is to investigate the problems associated with misuse of glass, as a building element in UAE particularly in Dubai. Inadequate design with ill-selected glass/glazing type may lead not only to poor daylighting in building interiors but also contribute significantly to fatigue, insomnia, seasonal affective disorder (SAD) and above all increase CO₂ emission.The purpose of the study is to specify the required improvements to permit natural, ‘free’ daylight to filter through the building façade into interior space, especially with the right type of glass. This paper examines the status of buildings in Dubai in terms of glass type, visible light transmittance, reflection (out/in) and relative heat gain. A quantitative analysis is conducted to assess the impact of glass on the building users' performance in terms of daylight environment. A recent built high-rise office building was selected in the investigation to asses whether selected glass provide the recommended daylight factor (DF) and daylight level (DL) according to IES standards. The results revealed that most the glass/glazing was misused in 70% of buildings in intermediate and low performance groups. The DF and DD in the selected office building were unexpectedly tremendous and found far beyond the recommended level due to the use of spectrally selective glazing (clear on both sides).     

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。     

浅谈对玻璃电熔窑设计的一些看法

简述了玻璃电熔窑的优点，分析了小型电熔窑的结构，列举了各种电极的特点，提出了布置电极、分配电能的一般原则，简述了选择耐火材料的目的和确定电极间玻璃液电阻的方法。     

Effects of Thermal Stresses on the Frequency-Temperature Behavior of Piezoelectric Resonators

The frequency-temperature behavior of a piezoelectric crystal resonator can be predicted quite accurately if the resonator is under a stress-free and steady-state uniform temperature condition. The condition is however seldom achieved practically. Most practical resonators are subjected to thermal stresses. Conventional finite element analytical tools such as ANSYS cannot provide a sufficiently accurate model for the frequency-temperature behavior of piezoelectric quartz resonators. A new dynamic frequency-temperature model which accurately predicted the frequency-temperature behavior of quartz resonators affected by transient and steady state temperature changes was presented. Lagrangean equations for small vibrational (incremental) displacements superposed on initial thermal stresses and strains were employed. The initial thermal stresses and strains were obtained from the uncoupled heat and thermoelastic equations. The constitutive equations for the incremental displacements incorporated the temperature derivatives of the material constants. Numerical results were compared with the experimental results for a 50 MHz AT-cut quartz resonator mounted on a glass package. Good comparisons between the experimental results and numerical results from our new model were found. The differences between the thermal expansion coefficients of glass and quartz gave rise to the thermal stresses that had adverse effects on the frequency stability of resonators. Different optimal crystal cut angles of quartz, and resonator geometry were found to achieve stable frequency-temperature behavior of the resonator in a glass package. The dynamic frequency-temperature model was used in the theoretical analyses and designs of high Q, 3.3 GHz, quartz thin film resonators.     

A low cost collector-cum-storage type solar water heater

A low cost collector-cum-storage type solar water heater has been developed. The cost of the heater is reduced by replacing window glass cover with 0.2 mm thick PVC film to avoid glass breakage in transportation and maintenance. In this paper the performances of solar water heaters having double glazing of PVC and glass have been compared. It was found that their performances are similar. Moreover, by providing an insulating cover in the night, the water remains warm till next morning for taking a bath etc. in the early hours when there is no sunshine.     

Solar-control films

The magnitude of the transmittance of solar radiation through glass is dependent upon its angle of incidence, the emissivity of the glass surface and the length that the light beam travels through the glass. To alter the emissivity of a glass surface a solar-control film can be attached to it. However, none of the present generation of ‘solar’ films that are applied to transparent glass surfaces is able to inhibit insolation gain during the summer while providing satisfactory thermal-radiation insulation with respect to energy leaving the building during the winter. This is because different wavelengths of radiation need to be inhibited for these two processes to be successful, namely short-wave radiation in the case of insolation and long-wave radiation for thermal insulation. Neither of these films inhibits glare satisfactorily. As expected, the energy transmittance and rate of heat gain by the affected room decrease as the angle of incidence (of the energy source, i.e. the sun, with respect to the glass) increases. Also the magnitude of this rate of heat gain depends upon the type (reflective, insulating or absorptive) of solar-control film applied to the glass.     

An evacuated glass tube solar collector and its application to a solar cooling, heating and hot water supply system for the hospital in Kinki University

A solar cooling, heating and hot water supply system for the Hospital with evacuated glass tube type solar collectors was described. Analysis has been made of the evacuated glass tube collector and some results of the calculation were shown. The results of the performance of the solar collectors in the large scale system were shown for one year operation to confirm the results as expected at the time of designing.