共查询到18条相似文献,搜索用时 31 毫秒
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为了提高钢化真空玻璃的隔热能力,减少建筑能耗,研究支撑物各参数对钢化真空玻璃传热的影响。针对支撑物各参数对钢化真空玻璃传热能力的影响,研究支撑物各参数对钢化真空玻璃的传热机理,得到支撑物的布放间距和排列方式对玻璃的传热影响较大,通过有限元仿真软件建立钢化真空玻璃的传热模型,数值模拟分析钢化真空玻璃中心区域的最大热通量。结果表明:支撑物的布放间距越大,钢化真空玻璃的隔热能力越强;采用正方形排布时,玻璃的隔热效果较好。该分析方法在实际生产过程中,对于钢化真空玻璃支撑物参数的优选提供了理论依据,能够进一步提高钢化真空玻璃的保温隔热性能。 相似文献
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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%。 相似文献
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针对单层玻璃盖板平板型太阳能集热器、双层玻璃盖板平板型太阳集热器进行了热性能对比实验。结果显示:在28.7℃和41.4℃这2种工质进口温度下,单层玻璃盖板平板型太阳能集热器的瞬时效率比双层玻璃盖板平板型太阳能集热器的高,而在54.2℃和66.9℃这2种工质进口温度下,双层玻璃盖板平板型太阳能集热器的瞬时效率比单层玻璃盖板平板型太阳能集热器的高。单层玻璃盖板平板型太阳能集热器的瞬时效率截距比双层玻璃盖板平板型太阳能集热器的大;双层玻璃盖板平板型太阳能集热器的热损系数比单层玻璃盖板平板型太阳能集热器的小。 相似文献
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采用几何解析的方法,对带平面反射板的真空集热管的圆周方向能流分布进行分析.根据太阳辐射晴天模型计算理论太阳辐射值,运用MatLab编程计算得出上海地区的常规安装条件下,在不同入射角时真空集热管的能流分布.通过结果分析可知,接收太阳能的主要时间段是8:40-15:20.集热管的管间距对太阳能得热有较为明显的影响,一般1.5~2.0倍管外径较为合适.尽管平面反射板使真空集热管的得热量增大15%~36%,但是否会增强真空集热管的换热效果还有待通过模拟和实验进行证实. 相似文献
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This study includes design and experimental analysis of a solar domestic water heating system. Water heating systems with glazed and unglazed collectors were constructed and tested at Dhaka, Bangladesh, at a latitude of 23.7 °N. Collector thermal efficiency and capability of raising water temperature were considered as performance evaluation measures. A typical day analysis showed that collector efficiency varied with time and touched its peak at around 12:00 h. During testing, the efficiency of the glazed collector increased by about 70.3% when compared with the unglazed collector. Average collector efficiency over the whole test period was also estimated to be 57.3% and 33.7% for glazed and unglazed collectors, respectively. Maximum water temperatures measured at daytime user outlets were, respectively, 82.4 °C and 65.5 °C for domestic water heating systems with glazed and unglazed collectors and approximated to be 49 °C and 32 °C higher than the ambient temperature. The glazed collector eventually offered significantly higher performances over the unglazed collector in improving system performance. 相似文献
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The Solar Energy Research Group in the Universiti Kebangsaan Malaysia has been set-up more than two decades ago. One of the activities is in the field of solar thermal process, particularly in development of solar assisted drying systems. Solar drying systems technical development can proceed in two directions. Firstly simple, low power, short life, and comparatively low efficiency-drying system. Secondly, the development of high efficiency, high power, long life expensive solar drying system. The group has developed four solar assisted drying systems namely (a) the V-groove solar collector, (b) the double-pass solar collector with integrated storage system, (c) the solar assisted dehumidification system for medicinal herbs and (d) the photovoltaic thermal (PVT) collector system. The common problems associated with the intermittent nature of solar radiation and the low intensities of solar radiation in solar thermal systems can be remedied using these types of solar drying systems. These drying systems have the advantages of heat storage, auxiliary energy source, integrated structure control system and can be use for a wide range of agricultural produce. 相似文献
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太阳能全玻璃真空集热管用玻璃 总被引:1,自引:1,他引:1
根据全玻璃真空集热管对玻璃的要求,讨论了各种玻璃的物理、化学和工艺性能。符合ASTME-438、氧化铁一低于0.05%的硼硅玻璃3.3,是当前唯一可以大量生产并满足全玻璃真空集热管要求的适用玻璃。 相似文献
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综述了太阳集热管(器)寿命研究及选择性吸收材料老化性能检测方法的研究进展,分析认为单盖板平板型太阳集热器寿命研究同太阳选择性吸收材料的老化性能的检测方法一样要考虑温度(循环)、湿度及环境气氛的影响,而全玻璃真空太阳集热管(器)在长期运行过程中则会发生惰性气体及水分通过罩管玻璃向夹层渗透、吸气剂的变化而降低夹层真空度,气体导热损失增大,涂层(镀膜)和基底材料的相互作用、罩管积灰(尘)及内管结垢等改变涂层(镀膜)的光学性能,进而导致热性能的降低。最后,提出全玻璃真空太阳集热管(器)的寿命研究并形成检测方法的基本思路。 相似文献
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In this study, experiments were performed to find out how the thermal performance of a two-phase thermosyphon solar collector was affected by using different refrigerants. Three identical small-scale solar water heating systems, using refrigerants R-134a, R407C, and R410A, were constructed and tested side-by-side under various environmental and load conditions. The performance of the system under clear-sky conditions has been investigated with and without water load. Detailed temperature distributions and cumulative collection efficiencies were determined and presented. The experimental results were compared to the results found in the literature and they showed good agreement. 相似文献