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利用TRNSYS软件仿真预测了采用不同跟踪方式的聚光光伏光热(CPV/T)系统在西安、兰州和拉萨这3个地区的全年热、电性能。仿真结果显示,以西安为例,3种跟踪方式中,采用双轴跟踪方式的CPV/T系统的全年热、电效率均最高,分别为40%和11.34%;采用单轴东西向跟踪方式的CPV/T系统的全年热、电效率次之,分别为35.67%和10.74%;采用单轴南北向跟踪方式的CPV/T系统的全年热、电效率均最低,分别为32.19%和10.16%。从动态投资回收期的角度对采用不同跟踪方式的CPV/T系统的经济性进行了评价,计算结果表明,采用单轴东西向跟踪方式的CPV/T系统的经济性最佳,在西安、兰州和拉萨这3个地区,其动态投资回收期分别为4.84、4.93和4.81年;采用双轴跟踪方式的CPV/T系统的经济性次之,在上述3个地区其动态投资回收期分别为5.65、5.69和5.48年;采用单轴南北向跟踪方式的CPV/T系统的经济性最差,在上述3个地区其动态投资回收期分别为6.09、6.26和6.00年。 相似文献
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介绍了一种新型的太阳能聚光跟踪技术。该技术将数十排或数百面庞大而笨重的聚光镜固定在地上常年保持不动,仅用一套跟踪控制装置即可对这数十排或数百面反射镜同时进行跟踪,不仅使系统的运行稳定性有了质的飞跃,还大幅度降低了制造成本,使太阳能聚光跟踪技术的经济合理性得以实现。 相似文献
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本文介绍了太阳跟踪系统的控制原理、控制算法和系统硬件组成,并重点介绍了控制电路的结构和原理,给出了软件的设计思路及主要的程序流程图.同时,在考虑当地的气象基础上设计一种跟踪精度高、结构简单、控制可靠的太阳能跟踪系统.实验结果表明,在太阳辐射强度、环境温度变化时,系统仍能准确地跟踪到太阳能电池的最大功率点,从而有效提高了... 相似文献
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槽式太阳能聚光集热系统在不同跟踪模式下的对比 总被引:2,自引:0,他引:2
根据合肥地区的实测气象数据,采用数值模拟和实验分析相结合的方法,对槽式太阳能聚光集热系统在春、夏、秋、冬4个典型工况下的3种不同跟踪模式(二维跟踪、东西向跟踪和南北向跟踪)的性能进行研究和分析。结果显示:采用东西向跟踪时,系统的集热性能主要受一年四季太阳位置的变化以及太阳辐照强度的影响,夏季时系统集热效率最大,达到0.351,冬季最小,降至0.196;而采用南北向跟踪和二维跟踪时,系统的集热性能主要受太阳辐照强度的影响,其中,南北跟踪时系统效率为0.300~0.312,二维跟踪时系统效率为0.347~0.363。 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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Evaluation method of the energy conversion efficiency of coal gasification and related applications 下载免费PDF全文
Traditional gasification parameters, such as cold gas efficiency, hot gas efficiency, or thermal efficiency, only evaluate the heat energy utilisation efficiency of gasifiers and do not take into account the gasification processes expending electricity and other types of energies. Therefore, the energy conversion efficiency cannot be assessed using these parameters. The calculation process on the energy conversion efficiency of underground coal gasification (UCG) is the basis for obtaining quantitative data of carbon emission reduction and establishing the carbon trading methodology of UCG. Moreover, the energy conversion efficiency both for surface coal gasification and UCG is a key research topic because it directly affects the economic and environmental benefits of gasification projects. This study proposed that two parameters, the integrated gasification efficiency (hcom) and the hot gas integrated gasification efficiency ( ), should be included into the coal gasification parameters and used to evaluate the energy conversion efficiency of coal gasification. In addition, the calculation methods of these two parameters for both surface gasification and UCG were established. Using the method, hcom and , of the UCG and Texaco gasification under the same scale was compared and that of various UCG processes was calculated. The results proved the necessity and reasonability of the two parameters and suggested that a certain amount of CO2 was favourable to improve hcom and of UCG. However, a certain amount of pure O2 can improve hcom of UCG without direct influences on . Under the condition of each process, to maximise hcom and , there must be an optimal steam (CO2) to O2 rate. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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太阳跟踪装置的双模式控制系统 总被引:1,自引:0,他引:1
介绍了用于太阳跟踪装置控制系统中的两种控制模式结构、组成和工作原理。对该模式进行适当设置,即可用于太阳能热水器、太阳能屋顶发电、太阳能干燥器、太阳能电池、太阳灶、太阳能空调、太阳能路灯等各种太阳跟踪装置中,实现双模式控制。双模式控制系统具有较强的通用性和适应性。 相似文献
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Ming Chen Zhiyu Zhang Cheng Wang Lei Zhang Jihong Li Sandra Chang Zongqiang Mao Shizhong Li 《International Journal of Hydrogen Energy》2013
In this study, we described an efficient electrical power generating system containing cyanobacterial photo-H2 production and custom-built proton exchange membrane fuel cell (PEMFC). The filamentous N2-fixing cyanobacterium Anabaena cylindrica was used as the photo-H2 producer. A photosynthesis inhibitor-diuron (DCMU) was used for the enhancement of photo-H2 production in the culture under argon gas. For the first time, a total of 1.0 μM DCMU was found to be the most effective treatment, as this produced 3.6 fold higher levels of H2 in microalgae. By measuring polarization curve, the gas mixture collected from the culture was proven to be an effective fuel for electrical generation through a custom-built PEMFC. When the PEMFC was directly combined with the culture tube, the cells generated as much as 843 mV during a 5-day incubation due to the efficient conversion of solar energy to H2 by A. cylindrica. Light energy conversion efficiency (LCE) for both solar energy to H2 and solar energy to electricity were also determined. The LCE for the cyanobacterial conversion of solar energy to H2 reached a peak at four days with a maximal value of 2.05% and an average value of 1.70% ± 0.17. The corresponding LCE for the conversion of solar energy to electricity in this system was 1.13% at peak and 0.94% ± 0.09 on average. 相似文献
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K.M. Gangotri Om Prakash Regar Chhagan Lal Prashant Kalla Kishna Ram Genwa Rajni Meena 《国际能源研究杂志》1996,20(7):581-585
Photogalvanic effects were studied in a photogalvanic cell containing toluidine blue, glucose and tergitol-7 as a photosensitizer, reductant and surfactant, respectively. The photocurrent and photopotential generated by this system were 70 μA and 315 mV, respectively. The effects of different parameters on the electrical output of the cell were observed. Current/voltage characteristics of the cell have also been studied, and a mechanism has been proposed for the generation of photocurrent in photogalvanic cell. 相似文献
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The overall efficiency of solar thermal power plants is investigated for estimating the upper limit of their practical performances. This study consists of the theoretical optimization of the heat engine and the optimization of the overall system efficiency, which is the product of the efficiency of the solar collector and the efficiency of the heat engine. In order to obtain a more realistic performance of the solar thermal power plant, the solar collector concentration ratio, the diffused solar radiation and the convective and radiative heat losses of the solar collector are taken into account. Instead of the classical Carnot efficiency, the efficiency at maximum power is used as the optimal conversion efficiency of a heat engine. By means of simple calculations, the optimal overall system efficiency and the corresponding operating conditions of the solar collector are obtained. The results of the present work provide an accurate guide to the performance estimation and the design of solar thermal power plants. 相似文献
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Simulation and experimental research on energy conversion efficiency of scroll expander for micro‐Compressed Air Energy Storage system 下载免费PDF全文
A scroll expander was applied to the Micro‐Compressed Air Energy Storage system, and its energy conversion efficiency was investigated. In order to study the variation mechanism of the volume, mass, pressure and temperature of the air in different chambers, the mathematical model of the expansion process was developed on the base of the geometric model, mass conservation equation, ideal gas equation and energy conservation equation. Then, the mathematical model was implemented in Matlab, and the simulated energy conversion efficiency defined as the ratio between the output shaft power of the scroll expander and the input compressed air power was obtained. Furthermore, a test system was built in order to validate the mathematical model and study the improvement of the energy conversion efficiency. The prototypes of the scroll expander with different cross‐sectional areas of the intake port or the discharge port were fabricated and tested in the experiments. Results show that the simulated torque and energy conversion efficiency agree well with the experimental results. Also, there is a small deviation between the expansion process and the ideal isentropic process due to the gas leakage, intake and discharge loss. In addition, the air supply pressure and the cross‐sectional area ratio of the discharge port to the intake port are two important parameters for the improvement of the energy conversion efficiency. The experiments show that the energy conversion efficiency varies from 23% to 36% at the air supply pressure of 0.35 to 0.65 MPa, indicating that it is proportional to the air supply pressure. It can also be concluded from the experiments that when the air pressure is higher than 0.45 MPa, the ideal ratio range can be determined as 0.6‐0.8. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Huibo Su Jun Cheng Junhu Zhou Wenlu Song Kefa Cen 《International Journal of Hydrogen Energy》2009,34(21):8846-8853
In this study, we investigated a two-phase process of combining the dark- and photo-fermentation methods to reutilize the residual solution derived from dark fermentation and increase the hydrogen yield (HY) from glucose. In dark fermentation, an orthogonal experimental design was used to optimize the culture medium for Clostridium butyricum (C. butyricum). The optimal culture medium composition was determined as glucose 20 g/l, NaCl 3 g/l, MgCl2 0.1 g/l, FeCl2 0.1 g/l, K2HPO4 2.5 g/l, l-cysteine 0.5 g/l, vitamin solution 10 ml/l, and trace element solution 10 ml/l. In this method, the maximum HY increased from 1.59 to 1.72 mol H2/mol glucose and hydrogen production rate (HPR) from 86.8 to 100 ml H2/l/h. The metabolite byproducts from dark fermentation, mostly containing acetate and butyrate, were inoculated with Rhodopseudomonas palustris (R. palustris) and reutilized to produce hydrogen in photo-fermentation. In photo-fermentation, the maximum HY was 4.16 mol H2/mol glucose, and the maximum removal ratios of acetate and butyrate were 92.3% and 99.8%, respectively. Combining dark fermentation and photo-fermentation caused a dramatic increase of HY from 1.59 to 5.48 mol H2/mol glucose. The conversion efficiency of heat value in dark fermentation surged from 13.3% to 46.0% in the two-phase system. 相似文献
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Electrokinetic power generation efficiency using a two-dimensional axisymmetrical model is numerically investigated. A finite-length nanoscale surface-charged cylindrical capillary with reservoirs connected at the capillary ends is considered as the physical domain. The Navier–Stokes, Laplace, Poisson, and Nernst–Planck equations are solved simultaneously to obtain the fluid flow, electrical potential, ion concentration and electrical current in the flow field. The energy conversion efficiency predicted using a one-dimensional model assuming an infinitely long channel, Boltzmann ion distribution and equal ionic electrical mobility is also carried out and compared with the two-dimensional result. 相似文献