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Heliostat field or solar tower collector is one of the most promising concentrated solar power technologies available in the market. Due to its high operating temperature, heliostat field collector can be implemented in a wide range of applications from solar power generation to industrial commodity production. There are several currently operating, under construction, and planned heliostat fields around the world. In this paper, a brief overview of the current state of the art, applications, assessment methods, future perspective, and methods of improvement are discussed. 相似文献
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经几何光学分析,导出了考虑接收塔阴影影响的太阳能塔式热发电站的定日镜有效利用率计算公式,并通过算例比较了考虑与不考虑接收塔阴影影响的定日镜有效利用率计算结果,验证了这些计算公式的正确性和考虑接收塔阴影影响的合理性。 相似文献
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Concentrated solar power technology is one of the most promising technologies in energy field. Arguably, the heliostat field layout is a crucial component in solar power tower system. Numerous studies have been developed for heliostat field optimization. However, most of the existing layouts which utilize radial staggered patterns are based on only two or four variables, leading to relatively rigid modes due to strong configuration constraints. In this article, we propose a new method called rose layout, which divides the regular radial staggered pattern into six sectors and they are optimized separately. Therefore, the radial increments between consecutive rows are not restricted to zones or rows, only relevant to which sector they belong to. This arrangement is more flexible and also efficient. Furthermore, a new differential evolution algorithm with a dynamic speciation-based mutation strategy (DSM-DE) is developed to solve this high-dimensional problem. In order to validate the proposed rose pattern and DSM-DE, three sets of comparative experiments were carried out. The first set of tests were operated with the conventional four optimization variables, the second series optimized total 43 radial increments between consecutive rows, whereas the third series employed the rose layout. All sets of cases were optimized by four competitive variants of differential evolution algorithm, ie, JADE, SHADE, EB-LSHADE, and DSM-DE. Experimental results verified that the rose layout can obtain higher overall optical efficiency and less land coverage than previous methods and DSM-DE is superior to other DE variants for this high-dimensional problem. The heliostat field studied in this article is simulated in Qinghai, China. By integrating rose layout with DSM-DE, the field unweighted efficiency progressed from 44.386% to 53.972%, and the annual weighted efficiency reached 59.091%, which was 0.318% higher than the 43-variable optimization. 相似文献
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Emilio Carrizosa Carmen‐Ana Domínguez‐Bravo Enrique Fernández‐Cara Manuel Quero 《国际能源研究杂志》2017,41(8):1096-1107
The design of a solar power tower plant involves the optimization of the heliostat field layout. Fields are usually designed to have all heliostats of identical size. Although the use of a single heliostat size has been questioned in the literature, there are no tools to design fields with heliostats of several sizes at the same time. In this paper, the problem of optimizing the heliostat field layout of a system with heliostats of different sizes is addressed. We present an optimization tool to design solar plants allowing two heliostat sizes. The methodology is illustrated with a particular example considering different heliostat costs. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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Owing to the energy scattered or absorbed by the constituents of earth's atmosphere and self‐absorption in the outer layers of the sun, the spectrum of solar flux at earth's surface is different from that of a blackbody. Consequently, the second law of thermodynamics for heat engine cycles operating between thermal reservoirs needs to be revised to determine the maximum conversion efficiency. A thermodynamic model similar to those for multi‐temperature plasmas and non‐isothermal particle‐exchange heat engines is proposed to estimate the maximum conversion efficiency of a mechanical or solid‐state heat engine subject to a radiation flux not having a blackbody spectrum. An example is given to illustrate the calculation of the maximum power that can be converted from a solar flux with considerable gas absorption. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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V. P. Sethi 《国际可持续能源杂志》2013,32(1-3):45-58
Five most commonly used single-span shapes of greenhouses such as even-span, uneven-span, vinery, modified arch and quonset type have been selected for comparison in a composite type of climate. The length, width and height (at the centre) are kept the same for all the shapes. The comparison is based on total solar radiation input (beam, diffused and ground reflected) to each shape through each wall, inclined surfaces and roofs. Total solar radiation is theoretically computed for each shape in east–west and north–south orientations and compared for each month of the year. The computed values for each shape are then introduced in a transient thermal model developed to compute the hourly inside greenhouse air temperature for the selected day of the year in each month. It is observed that the variation in greenhouse shape can cause up to 3.5–5.5 °C change in the inside air temperature during different hours of the day. Experimental validation of the model is carried out using the measured inside air temperature data (for a typical summer day) for an even-span greenhouse (in which capsicum is grown) at Ludhiana (31°N and 77°E), Punjab, India. The predicted and measured values are in close agreement. The results show that even-span or quonset shape in east–west orientation is the most suitable shape for year-round agricultural operations. 相似文献
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为构建简便有效的基于建筑形体要素的太阳能采暖潜力评价方法,以额济纳旗、西安为例,开展西部太阳能采暖效率计算方法研究。将建筑高宽比、高长比、南向窗墙面积比作为太阳能采暖热利用关联紧密的形体要素,经过正交试验、动态能耗模拟、数理统计分析等方法得到基于建筑形体要素的建筑太阳能采暖潜力函数。将该函数图形化表达发现增大建筑高宽比、南向窗墙面积比均能优化建筑太阳能采暖效率。给出在额济纳旗和西安提升建筑太阳能采暖效率的有效措施。该研究并非旨在取代动态模拟工具,而是为建筑设计初期构建一种简便的太阳能采暖设计的热性能分析方法。 相似文献
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In this study, differential evolution was employed to perform optimization of a heliostat field. A complete mathematical code was developed for this purpose, which generates a heliostat field and calculates the optimum spacing between heliostats through differential evolution optimization technique. The optimization was executed for two sets of two cases and compared with an un‐optimized case. In the first case, only the optical performance was optimized, whereas in the second case, the normalized ratio of the optical performance to the land area covered by the heliostat field was maximized. In the first set of cases, the extra security distance between the heliostats was neglected, whereas in the second set of cases, the extra security distance was taken into account. To apply and examine the application of the optimization algorithm developed, 3 days of the year were selected: March 21, June 21, and December 21, considering Dhahran, Saudi Arabia as an illustrative example. For June 21, when the extra security distance between the heliostats is neglected, the optical efficiency of the un‐optimized case was 0.6026, while for the first optimized case, it was 0.6395, and for the second optimized case, it was 0.6033. However, when the extra security distance was considered, the optical efficiency of the un‐optimized case was 0.6167; while for the first optimized case, it was 0.6241, and for the second optimized case, it was 0.6167. Similar observations were realized for the other cases selected. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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一种高效平板太阳能集热器试验研究 总被引：11，自引：0，他引：11
性能良好的太阳能集热器是太阳能空调的关键设备之一,广东省江门市太阳能空调系统采用了一种高效的平板集热器,其主要技术特垂直 是增加了一块聚碳酸脂（PC）透明隔热板,本研究通过对比试验,确定了一种高交平板太阳能热器的技术方案,并测定了效率曲线,其热损系数仅为2.90W/(m^2.℃）。 相似文献
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A solar collector, part of a drying system using solar energy as a heat source, was developed and reported previously and used in product-drying applications. In this study, energy efficiency analyses of the drying system in terms of the collector efficiency were investigated. The results obtained show that the present collector used in this solar drying system is an efficient and effective unit for practical drying applications. 相似文献
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The performance of a masonry animal feed solar cooker was evaluated in terms of energy and exergy. It is a low-cost cooker made of cement, bricks, glass covers and a mild steel absorber plate. The energy and exergy efficiencies of the animal feed solar cooker were experimentally evaluated. The energy output of this cooker ranges from 1.89 to 49.4 kJ, whereas the exergy output ranges from 0.11 to 2.72 kJ during the same time interval. The energy efficiency of the cooker varies between 1.12% and 29.78%, while the exergy efficiency varies between 0.07% and 1.52 % during the same period. 相似文献
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太阳能增强型喷射式制冷系统的研究 总被引：8，自引：0，他引：8
对太阳能为热源的增强型喷射式制冷系统进行了热力学分析，并进行了初步实验。在９０℃热源、１２℃蒸发温度和２０００Ｗ制冷量的额定工况下，喷射系数可达０．６５１，整个系统的ＣＯＰ值达０．３３４，比传统的纯喷射制冷循环的ＣＯＰ值（≤０．２３）提高５０％。 相似文献
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叙述了对太阳能—电辅热联合供暖系统长期性能的研究,以费用年值为评价指标,建立数学模型,分析探讨了使费用年值最小的太阳能集热器面积的计算方法。并以太原为例进行了计算,结果表明,以2月份的太阳能保证率为100%作为集热器面积计算的依据,费用年值为最小。 相似文献
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In this paper, a small non‐imaging focusing heliostat is presented, and an analytical model for assessing its performance is described. The main novelty of the system lies in the tracking mechanism and the mirror mount, which are based on off‐the‐shelf components and allow a good trade‐off between accuracy and costs. The concentrator mirrors are moved by this two‐axis tracking machinery to reflect the sun's rays onto a fixed target, the dimensions of which can be varied to suit the user's needs. A prototype plant to be located in central Italy was designed and simulated with a ray‐tracing algorithm, and it comprises 90 heliostats for a total reflective area of 7.5 m2. The reflected solar rays are tracked taking the mechanical positioning errors of the tracking system into account. The total flux of radiation energy hitting the target was determined, and intensity distribution maps were drawn. Simulations showed that the system's optical efficiency can exceed 90% in summer, despite the tracking errors, mainly because of the smaller distance between the heliostats and the receiver. The solar concentration ratio over a receiver of 250 mm in diameter reached 80 suns with a very good uniformity. Over a 400‐mm receiver, the concentrated radiation was less uniform, and the solar concentration ratio reached 50 suns, with a higher optical efficiency and collected solar radiation. The present concentration ratio is still suitable for many applications ranging from the electric power production, industrial process heat, and solar cooling. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献