共查询到20条相似文献,搜索用时 62 毫秒
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为分析太阳集热器接收面太阳辐射的接收情况, 根据太阳高度角、太阳方位角、晴天模型和集热器进口的几何设计, 采用蒙特卡洛法建立了太阳辐射能束的方向、大小、位置以及抛物反射面镜面反射的关键算法。以西安地区( 纬度) 为例, 分别对夏至、冬至与春分太阳时12 点, 8 点和16 点时进行了计算。结果显示了不同时刻接收面的太阳辐射接收分布情况; 并由面积分求解接收面上的平均辐射强度, 反演了常规设计方法确定的聚光比。研究表明, 该方法可模拟一年中任意时间接收面的太阳辐射情况, 为太阳能热发电系统用集热器辐射分布研究提供了方法。 相似文献
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O. S. Popel’ I. V. Prokopchenko A. V. Mordynskii S. E. Frid I. A. Ryzhikov A. S. Ilyin R. S. Lapin 《Thermal Engineering》2008,55(12):993-996
The results obtained from measurements of the spectral optical characteristics of monolithic sheet and honeycomb polycarbonate, and from calculations of the integral transmission coefficient for transparent coatings of solar collectors are presented. The effect of solar radiation incidence angle on the transmission capacity of these coatings is evaluated. Data from a comparison between the integral power performance characteristics of conventional and plastic solar collectors are presented together with the results of preliminary research activities on applying selective absorbing coatings on polymeric materials. 相似文献
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太阳能集热器是太阳能热驱动制冷系统中的关键部件,在系统能量转化和储存利用过程中起到决定性作用。采用动态模拟及多变量优化的方法对不同形式太阳能集热器的吸收式制冷系统进行研究。结果表明:在太阳能资源一般的地区,采用真空管式太阳能集热器的单效吸收式制冷系统和槽式太阳能集热器驱动的双效吸收式制冷系统运行平稳且能耗相对较少;基于优化参数,对不同系统的太阳能保证率、系统性能系数进行比较,真空管型太阳能集热器驱动的单效吸收式制冷系统的太阳能保证率最高,达到39.9%。该结论可以为太阳能集热器在热制冷领域中的应用提供指导。 相似文献
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Spectral splitting is an approach to the design of hybrid photovoltaic-thermal(PVT)collectors that promises significant performance benefits.However,the ultimate efficiency limits,optimal PV cell materials and optical filters of spectral-splitting PVT(SSPVT)collectors remain unclear,with a lack of consensus in the literature.We develop an idealized model of SSPVT collectors and use this to determine their electrical and thermal efficiency limits,and to uncover how these limits can be approached through the selection of optimal PV cell materials and spectral-splitting filters.Assuming that thermal losses can be minimized,the efficiency limit,optimal PV material and optimal filter all depend strongly on a coefficient w,which quantifies the value of the delivered thermal energy relative to that of the generated electricity.The total(electrical plus thermal)efficiency limit of SSPVT collectors increases at higher w and at higher optical concentrations.The optimal spectral-splitting filter is defined by sharp lower-and upper-bound energies;the former always coincides with the bandgap of the cell,whereas the latter decreases at higher w.The total effective efficiency limit of SSPVT collectors is over 20%higher than those of either standalone PV modules or standalone ST collectors when w is in the range from 0.35 to 0.50 and up to 30%higher at w~0.4.This study provides a method for identifying the efficiency limits of ideal SSPVT collectors and reports these limits,along with guidance for selecting optimal PV materials and spectral-splitting filters under different conditions and in different applications. 相似文献
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Ability of a DC electrical discharge to control low-velocity airflow along a flat plate is analyzed. Specifically, the electrodes are flush mounted on the insulating surface of the plate creating a tangential corona discharge at close vicinity of the wall. In this paper, visualizations of the low-velocity airflow (up to 1.4 m/s corresponding to Re=16 000) along the flat plate are presented. They show that the ionic wind induced by the corona discharge modifies the original airflow considerably, resulting in the airflow reattachment to the wall and reduction of the wake size. Velocity measurements by particle imaging velocimetry and by Pitot tube are conducted in a wind-tunnel loop for higher airflow velocities (up to 11 m/s corresponding to Re=117 800). Results show that the corona discharge at such high airflow velocities does affect significantly the velocity profile within the viscous boundary layer. 相似文献
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O. S. Popel’ S. E. Frid V. N. Shcheglov M. Zh. Suleimanov Yu. G. Kolomiets I. N. Prokopchenko 《Thermal Engineering》2006,53(3):175-180
We present a comparative analysis of the thermal-engineering parameters and design features of solar collectors made in Russia and abroad. Substantiated proposals are given for using in them new structural materials (plastics resistant to high temperatures and ultraviolet radiation). 相似文献
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综述了目前国内外研究最多的几类薄膜太阳电池,包括薄膜硅基、无机化合物类、有机类、染料敏化类、钙钛矿型薄膜太阳电池的材料、性能和转化效率等,并讨论了各自性能的优劣。结合国内外研究情况,对各类薄膜太阳电池国内研究现状和最新进展做了叙述,并探讨了薄膜太阳电池的发展趋势。 相似文献