基于夏热冬冷气候冬季非空调工况的真空水流窗热性能测试

真空水流窗是一种新型透明围护结构技术,其应用能够降低建筑能耗。在成都市搭建试验测试平台,进行真空水流窗、中空水流窗和双层水流窗的对比试验,分析真空水流窗在冬季非空调工况下的热性能。结果表明,真空水流窗和中空水流窗对室内热环境均有良好的调节作用,双层水流窗调节能力略差。在强太阳辐射条件下,真空水流窗的太阳能集热能力显著高于中空与双层水流窗;在太阳辐射较弱时,水流层散热量受外界环境影响较大。相比双层水流窗和中空水流窗,真空水流窗的保温性能更好,因而具有更高的热利用率,节能效果更佳。当供水流量在600 mL/min以下时,实验窗内表面热通量随供水流量的增大明显增加。     

反光板对提高热管真空管热性能的研究

提出了对带反光板的吸热体接收太阳辐射量的分析方法，并对三种有渐开线反光板且吸热体形状不同的热管真空管和一种无反光板的热管真空管进行了对比实验。结果表明：渐开线反光板可大幅度提高热管真空管的热性能，而且其吸热体的形状对热性能提高的幅度有影响。     

真空管太阳能热水器冬季热性能研究

本文根据GB／T19141—2003,设计建立了一套太阳能热水器热性能的测试系统,并用此系统对天津市场上销售的16种太阳能热水器产品进行了冬季的热性能测试,并分析了其主要的热性能指标,日有用得热量和平均热损因数。     

含二氧化硅气凝胶和相变材料三层玻璃窗热性能分析

为了研究含二氧化硅气凝胶和相变材料三层玻璃窗对严寒地区建筑能耗的影响,建立了相变材料层与其他透明壁层结合发生的传热数值模型。分析了含二氧化硅气凝胶和相变材料三层玻璃窗在不同二氧化硅气凝胶厚度、导热系数和不同保温材料下的动态热调节性能,得到了含二氧化硅气凝胶和相变材料三层玻璃窗内表面热流密度和液相率随时间的变化规律。结果表明:随着二氧化硅气凝胶厚度增加,总传热量降低和液相率增加,当二氧化硅气凝胶厚度为20～30 mm时,可以实现有效的利用太阳能;随着二氧化硅气凝胶导热系数增加,总传热量升高和液相率降低;当二氧化硅气凝胶的导热系数从0.022降低到0.014 W/(m·K)时,最大液相率从0.83增加到1.00。二氧化硅作为保温层比相变材料作为保温层具有更好的保温隔热作用。     

真空玻璃与单层玻璃盖板PV/T集热器性能的对比研究

提出一种真空玻璃盖板平板式PV/T集热器,建立了真空玻璃和单层玻璃盖板PV/T集热器的传热模型,并分别搭建了两种PV/T热水系统的实验平台进行模型的实验验证。预测结果与实验测量结果的均方根偏差（RMSD）在0.71% ~ 11.17%之间。利用数学模型模拟了真空玻璃与单层玻璃盖板PV/T集热器在合肥冬季的热、电性能,并比较了两者性能的差异。模拟结果表明真空玻璃盖板PV/T集热器的顶部热损失平均为22 W,而单层玻璃盖板PV/T集热器热损失平均为107 W。使用真空玻璃盖板能显著减少PV/T集热器的顶部热损失。真空玻璃盖板PV/T集热器相对单层玻璃盖板PV/T集热器的全天热效率提高了5.68%,二者分别为41.76%和36.08%,全天电效率分别为11.76%和12.79%,相差1.03%。     

窄缝高真空平面玻璃作为太阳能集热器盖板的实验研究

窄缝高真空平面玻璃是一种带高真空夹层的平板玻璃,它是将两块普通平板玻璃之间的狭缝抽高真空而成,由于它具有良好的透光,隔热和隔音特性,因而有广阔的应用前景,通过对采用窄缝高真空平面玻璃作盖板的太阳能焦热器的集热性能进行实验测试,介绍了在空晒和有负载条件下焦热板的温升速率与太阳辐射强度的关系,对真空平面玻璃两面温差及其保温性能也作了测试,并与用普通双层玻璃作盖板的情况作了比较。     

气凝胶玻璃系统动态传热模型及能耗性能研究

研究纳米气凝胶玻璃对太阳辐射的透过、吸收特性,考虑室外太阳入射角变化和气凝胶材料吸收太阳辐射引起温度变化的影响,建立动态状态空间传热模型和太阳辐射传递模型,并实验验证模型的准确性。模拟分析该气凝胶玻璃在长沙地区的节能潜力,结果表明与中空玻璃对比,通过气凝胶玻璃的传热得热增加,太阳辐射得热减少,夏季气凝胶玻璃引起的总得热量比中空玻璃减少约20%,冬季通过中空玻璃的室内得热量比气凝胶玻璃低61%。     

百叶窗形蜂窝构件窗的热性能理论研究

针对百叶窗形蜂窝构件窗相比于矩形蜂窝构件窗的太阳辐射透过率高但热损系数增加的特点，为比较两者对普通双层窗热性能的改善程度，采用了3个不同纬度地区的气象数据，对这三种窗体结构进行了全年模拟计算。结果表明相比于普通双层窗，百叶窗形蜂窝构件窗和矩形蜂窝构件窗的热性能都得到了很大的提高，其中百叶窗形蜂窝构件窗又优于矩形蜂窝构件窗。但随着纬度的升高、太阳辐射的降低、环境温度的下降和当地风速的增加，两者之间的差别变得越来越小。     

Combined nongray radiative and conductive heat transfer in multiple glazing taking into account specular reflection and absorption

The problem of combined nongray radiative and conductive heat transfer in multiple glazing subjected to solar irradiation is analyzed. A spectral solar model proposed by Bird and Riordan is used to calculate direct and diffuse solar irradiance. The radiation element method by ray emission model, REM², is used to analyze the spectral dependence of radiative heat transfer. Specular reflection at boundary surfaces is taken into account. The spectral dependence of radiation properties of glass such as specular reflectivity, refraction angle, and absorption coefficient is taken into account. The steady‐state temperature and heat flux distributions in the glass layer are obtained and the insulating efficiency of multiple glazing is examined. The overall heat transfer coefficients predicted by the present method are compared with those based on the JIS method. The values obtained by the present method are slightly lower than those obtained by the JIS method. To investigate the spectral variation of radiative heat flux attenuated in the glass layer, the spectral heat flux at the room‐side surface and incident radiation are compared. © 2003 Wiley Periodicals, Inc. Heat Trans Asian Res, 32(8): 712–726, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10125     

超细纤维保温水箱与聚氨酯保温水箱热性能比较

超细生态纤维是一种对生物体和环境无害的无机非金属材料。本文通过对该种纤维保温的水箱与目前太阳热水器常用的聚氨酯发泡保温的水箱的热性能进行研究后认为，在同样水箱结构下，两种水箱热性能几乎相当。但生态纤维的耐高温、易降解及制做过程无毒的特性是聚氨酯所不可比拟的。     

配合集热器的盐梯度太阳池热性能实验与分析

构建表面积为1.50 m×1.50 m的小型实验用盐梯度太阳池,并与平板太阳能集热器配合使用,分别对普通太阳池和集热增强型太阳池进行了储热、放热实验。实验研究与理论分析表明:单独盐梯度太阳池的放热量为3.5×103k J,热效率为13.6%;集热增强型太阳池放热量可以达到4.8×103k J,且热效率增至28.1%。另外后者下对流层温度最高可提升10℃以上,从而证明太阳能集热器可以有效提高太阳池热效率,增加下对流层储热量。此外,考虑了放热过程换热器对太阳池下对流层的扰动,对比实验前后的溶液浓度,可以看出实验后太阳池盐度曲线合理,非对流层呈良好梯度分布,太阳池稳定性并未遭到破坏。     

提高太阳能集热器热性能的实验研究

在能量平衡方程的基础上,以《家用太阳热水器热性能试验方法》（GB／T12915—1991）为依据,对两种有渐开线反光板且吸热体形状不同的热管真空管和一种无反光板的热管真空管进行了对比实验。结果表明,渐开线反光板可大幅度提高热管真空管热水器的日平均效率,加反光板且吸热体为圆柱形的集热器能够达到更好的效果。     

磁纳米流体热管太阳能集热装置换热性能试验

设计了一套换热系统试验台,分别把磁纳米流体和水作为热管的工质,对玻璃真空管内插热管式太阳能集热器进行对比试验,分析两种集热器处于不同倾角、不同天气条件、不同总辐射量下的光热转换瞬时效率及日平均效率。此外,比较了玻璃真空集热器和热管内插式集热器的平均热损失系数。研究表明:内插热管式集热器的平均热损失系数约为全玻璃真空管集热器的2.32%,远小于全玻璃真空集热管,且工质为纳米流体的热管式玻璃真空管太阳能集热器的热损失系数比水工质热管真空集热管更低,其瞬时效率及日平均效率更高,运行更加高效、安全、稳定。     

美国、加拿大窗户能耗等级评价体系综述

窗户带来的建筑能耗是巨大的。同时显著影响室内环境的热舒适程度。合理地进行住宅窗户材料选择和结构设计，可有效降低采暖或制冷能耗、节省费用。该文对加拿大、美国建立的窗户能耗等级评价体系的原理及应用进行概述，并对两者的评价结果进行比较；分析了太阳得热系数对降低能耗、提高热舒适性的重要性，为在中国建立相应的窗户能耗等级评价体系、设计开发节能新产品提供积极的参考。     

Performance analysis of a hybrid solar thermoelectric generator

In this paper, a theoretical model is developed to investigate the performance of the hybrid solar thermoelectric generator (HSTEG) system, which is designed without (B-HSTEG) and with an evacuated glass tube (V-HSTEG). The heat loss, power output, thermal efficiency, and electrical efficiency of the B-HSTEG/V-HSTEG system are evaluated by analyzing the design parameters such as geometric solar concentration ratio, thermoelectric figure of merit, and cold-side inlet fluid temperature. The performance of the B-HSTEG is compared with the V-HSTEG system using two heat transfer fluids: water and Therminol VP-1. The maximum electrical efficiency of the B-HSTEG and V-HSTEG is estimated to be 12.2 and 15.6% (ZT = 3) with a corresponding thermal efficiency of about 61.9 and 60.3%, respectively. Overall, this paper provides a systematic performance analysis of HSTEG systems.     

Predicted thermal performance of triple vacuum glazing

The simulated triple vacuum glazing (TVG) consists of three 4 mm thick glass panes with two vacuum gaps, with each internal glass surface coated with a low-emittance coating with an emittance of 0.03. The two vacuum gaps are sealed by an indium based sealant and separated by a stainless steel pillar array with a height of 0.12 mm and a pillar diameter of 0.3 mm spaced at 25 mm. The thermal transmission at the centre-of-glazing area of the TVG was predicted to be 0.26 W m⁻² K⁻¹. The simulation results show that although the thermal conductivity of solder glass (1 W m⁻¹ K⁻¹) and indium (83.7 W m⁻¹ K⁻¹) are very different, the difference in thermal transmission of TVGs resulting from the use of an indium and a solder glass edge seal was 0.01 W m⁻² K⁻¹. This is because the edge seal is so thin (0.12 mm), consequently there is a negligible temperature drop across it irrespective of the material that the seal is made from relative to the total temperature difference across the glazing. The results also show that there is a relatively large increase in the overall thermal conductance of glazings without a frame when the width of the indium edge seal is increased. Increasing the rebate depth in a solid wood frame decreased the heat transmission of the TVG. The overall heat transmission of the simulated 0.5 m by 0.5 m TVG was 32.6% greater than that of the 1 m by 1 m TVG, since heat conduction through the edge seal of the small glazing has a larger contribution to the total glazing heat transfer than that of the larger glazing system.