太阳能自动跟踪发电系统的创新设计

针对现有太阳能光伏发电装置能量转换效率较低的缺陷,设计了一种新型太阳能光伏发电系统——双轴自动跟踪发电系统。研制了光电传感器,分析了光电传感器的工作原理;设计了系统的信号处理及控制电路。该系统能使太阳电池板在晴天始终保持与太阳光线垂直,在夜晚、阴天或太阳光辐照度低于工作照度时自动关机。为了得到该系统的发电功率随时间和天气变化的情况,进行了实验研究,最终得到光伏发电功率随时间和天气变化的规律。     

一种改进型的太阳能最大功率点跟踪控制与仿真

从实际应用角度出发,论述了采用改进间歇扫描跟踪的方法进行最大功率点跟踪控制的过程,并通过仿真实验验证其可行性和有效性,从而达到了较好利用太阳能的目的。     

太阳能最大功率跟踪装置的设计

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...     

太阳能光伏、光热及制冷一体机(上)

从对一般城镇居民用电结构的调查入手,通过对现有太阳能光伏系统能量转化和利用情况进行分析,确立了太阳能光伏、光热利用两条并行主线,提出了"以光变电、制热,用热制冷"的综合解决方案。通过设计新的反射聚光系统、由太阳电池板和集热器组成复合结构的光靶、集成吸收式制冷系统和仿生害羞虫避光式阳光跟踪传感器系统等,最终形成了太阳能光伏、光热和制冷功能一体化集成设计理念,以期通过整个系统的协调运行实现太阳能利用的高效率和经济性。     

碟式太阳能聚光器跟踪系统研究(上)

介绍了太阳能热发电系统中太阳能聚光器跟踪系统的跟踪控制方式、控制结构及其研究动态,探讨了碟式太阳能聚光器跟踪系统的研究关键,对研究开发碟式太阳能热发电系统具有积极意义。     

太阳能光伏、光热及制冷一体机(下)

<正>四一体机效能实验分析1实验条件、测试方法及效能实验分析(1)光伏发电运行实例1、运行实例2分别为两个完整白天光伏发电的运行测试数据,见表6和表7。实例1是用短路电流和开路电压得到峰值发电功率,进而估算出发电功率和发电量;实例2直接测量充电电流和     

新疆太阳能利用的情况和特点(下)

<正>2太阳能光伏利用的市场需求中国光伏发电的市场主要在通信和工业应用、农村和边远地区应用、光伏并网发电系统和太阳能商品及其他。所有这些应用领域中,约有53.8%属于商业化的市场(通信工业应用和太阳能光伏产品),而另外46.2%则属于需要政府和政策支持的市场,包括农村电气化和并网光伏发电。在今后的十几年     

太阳能光热与热电耦合发电技术综述(上)

正1太阳能光热发电技术概述太阳能光热发电即聚光太阳能热发电(Concentrating Solar Power),也称CSP,是太阳能发电中不同于光伏发电的另一种技术。光热发电技术是利用光聚焦原理,把太阳光线的分散能量进行高度聚集,通过吸热器中工质吸收阳光热能,直接或间接地加热水,产生一定参数的蒸汽,然后送往汽轮发电机组进行发电。实际应用的主要技术种类有槽式、塔式、碟式和线性菲涅尔式。1.1槽式光热发电技术分别采用槽式聚光镜和吸热管来聚焦和吸收太阳光热能,进而转化成电能。槽式聚光镜是一种高精密度的太阳反射镜,按主要制造材料可分为两种:玻璃反射镜和铝板反射镜,反射镜的横     

太阳能屋顶工程技术与应用(下)

<正>采用这种结构设计完成的屋顶电站使太阳能发电方阵作为建筑屋顶与建筑本体同寿命,实现真正意义上的光伏建筑一体化。值得注意的是在采用该方式申报获批的2012年太阳能光电建筑应用示范项目中,却不合理地把该技术定性为支架安装型。实践是检验真理的唯一标准,这种以建筑物为载体的用户侧并网太阳能发电模式具有显著的三零特性:零土地使用、零距离输电、用电黄金时段的零排放发电,完全符合资源节约、环境友好的科学发展观,是加快转变经济发展方式、实现低碳经济的有效技术手段,是城     

太阳能喷射式制冷系统的(火用)分析

针对太阳能喷射式制冷系统,利用分析的方法,得到系统各部件的损分布,分析其原因。分别改变发生温度及蒸发温度,探讨了参数变化对系统损的影响。     

A price‐regulated electric vehicle charge‐discharge strategy for G2V,V2H,and V2G

Electric vehicles (EVs) and smart grids are gradually revolutionising the transportation sector and electricity sector respectively. In contrast to unplanned charging/discharging, smart use of EV in home energy management system (HEMS) can ensure economic benefit to the EV owner. Therefore, this paper has proposed a new energy pricing controlled EV charging/discharging strategy in HEMS to acquire maximum financial benefit. EV is scheduled to be charged/discharged according to the price of electricity during peak and off‐peak hours. In addition, two different types of EV operation modes, ie, grid‐to‐vehicle (G2V) in off‐peak time and vehicle‐to‐home (V2H) in on‐peak time are considered to determine comparative economic benefit of planned EV charging/discharging. The real load profile of a house in Melbourne and associated electricity pricing is selected for the case study to determine the economic gain. The simulation results illustrate that EV participating in V2H contributes approximately 11.6% reduction in monthly electricity costs compared with G2V operation mode. Although the facility of selling EV energy to the grid is not available currently, the pricing controlled EV charging/discharging presented in the paper can be used if such facility becomes available in the future.     

Integration of a-Si:H solar cell with novel twist nematic liquid crystal cell for adjustable brightness and enhanced power characteristics

This study improves the output power and brightness characteristics of a translucent hydrogenated amorphous silicon (a-Si:H) solar cell by integrating the solar cell with a novel twist nematic (TN) liquid crystal (LC) cell incorporating a sub-wavelength metal grating polarization beam splitter (PBS). Although conventional TN-LC cells are widely used to adjust the brightness in many display applications, the sheet polarizers used in such cells decay when exposed to ultraviolet (UV) rays and have a low light efficiency. Accordingly, in this study, a sub-wavelength metal grating PBS is used to replace not only the sheet polarizers in the conventional TN-LC cell but also the upper and lower alignment layers and transparent electrodes. Therefore, a translucent a-Si:H solar cell integrating with the novel TN-LC cell with the sub-wavelength metal grating PBS could improve power efficiency and durability in UV ray environment. The experimental results show that the transmittance gap between the “on” and “off” states of the enhanced translucent a-Si:H solar cell/novel TN-LC cell is of the order of 26.6% (i.e. 4.3-30.9%) for incident light with a wavelength of 800 nm, 6.3% (i.e. 10.8-17.1%) for an incident wavelength of 400 nm and 2.7% (i.e. 0-2.7%) for an incident wavelength of 510 nm. Moreover, it is shown that the novel TN-LC cell increases the maximum electrical power developed by the translucent a-Si:H solar cell and improves its power conversion efficiency by 0.209% in the “off” state and 0.417% in the “on” state. As a result, the proposed device represents an ideal solution for building-integrated photovoltaic (BIPV) systems, automobile industry applications and many other adjustable brightness photovoltaic applications.     

不依赖空气动力装置（AIP）排出气体中CO2浓度在线检测装置研制

根据闭式循环柴油机不依赖空气动力装置（CCDAIP）排出气体中CO2浓度在线检测的实际需求，结合CCDAIP排出气体测试的具体条件，研究了CO2浓度在线检测装置的系统构成特点，计算了确定了气水分离器等重要部件的结构参数，设计了CO2浓度在线检测流程，在国内首次研制出AIP排出气体成份在线检测装置。经CCDAIP排出气体吸收试验，表明CO2在线检测装置设计合理，测量精度等性能指标工程要求，解决了AIP排出气体CO2浓度在线检测技术关键。     

An improved thermal and electrical model for a solar photovoltaic thermal (PV/T) air collector

In this paper, an attempt is made to investigate the thermal and electrical performance of a solar photovoltaic thermal (PV/T) air collector. A detailed thermal and electrical model is developed to calculate the thermal and electrical parameters of a typical PV/T air collector. The thermal and electrical parameters of a PV/T air collector include solar cell temperature, back surface temperature, outlet air temperature, open-circuit voltage, short-circuit current, maximum power point voltage, maximum power point current, etc. Some corrections are done on heat loss coefficients in order to improve the thermal model of a PV/T air collector. A better electrical model is used to increase the calculations precision of PV/T air collector electrical parameters. Unlike the conventional electrical models used in the previous literature, the electrical model presented in this paper can estimate the electrical parameters of a PV/T air collector such as open-circuit voltage, short-circuit current, maximum power point voltage, and maximum power point current. Further, an analytical expression for the overall energy efficiency of a PV/T air collector is derived in terms of thermal, electrical, design and climatic parameters. A computer simulation program is developed in order to calculate the thermal and electrical parameters of a PV/T air collector. The results of numerical simulation are in good agreement with the experimental measurements noted in the previous literature. Finally, parametric studies have been carried out. Since some corrections have been down on thermal and electrical models, it is observed that the thermal and electrical simulation results obtained in this paper is more precise than the one given by the previous literature. It is also found that the thermal efficiency, electrical efficiency and overall energy efficiency of PV/T air collector is about 17.18%, 10.01% and 45%, respectively, for a sample climatic, operating and design parameters.     

Optimization of process parameters in a large-area hot-wire CVD reactor for the deposition of amorphous silicon (a-Si:H) for solar cell application with highly uniform material quality

Scale-up of a-Si:H-based thin film applications such as solar cells, entirely or partly prepared by hot-wire chemical vapor deposition (HWCVD), requires research on the deposition process in a large-area HWCVD system. The influence of gas supply and filament geometry on thickness uniformity has already been reported, but their influence on material quality is systematically studied for the first time. The optimization of deposition parameters for obtaining best material quality in our large-area HWCVD system resulted in an optimum filament temperature, T_fil≈1600°C, pressure, p=8 mTorr and silane flow, F(SiH₄)=100 sccm, keeping the substrate temperature at T_S=200°C. A special gas supply (gas shower with tiny holes of uniform size) and a filament grid, consisting of six filaments with an interfilament distance, d_fil=4 cm were used. The optimum filament-to-substrate distance was found to be d_fil–S=8.4 cm. While studying the influence of different d_fil and gas supply configurations on the material quality, the above-mentioned setup and parameters yield best results for both uniformity and material quality. With the setup mentioned, we could achieve device quality a-Si:H films with a thickness uniformity of ±2.5% on a circular area of 20 cm in diameter. The material, grown at a deposition rate of r_d≈4 Å/s, was characterized on nine positions of the 30 cm×30 cm substrate area, and revealed reasonable uniformity of the opto-electronic properties, e.g photosensitivity, σ_Ph/σ_D=(2.46±0.7)×10⁵, microstructure factor, R=0.17±0.05, defect densities, N_d(PDS)=(2.06±0.6)×10¹⁷ cm⁻³ and N_d(CPM)=(2.05±0.5)×10¹⁶ cm⁻³ (film properties are given as mean values and standard deviations). Finally, we fabricated pin solar cells, with the i-layer deposited on small-area p-substrates distributed over an area of 20 cm×20 cm in this large-area deposition system, and achieved high uniformity of the cell parameters with initial efficiencies of η=(6.1±0.2)% on the 20 cm×20 cm area.     

Optimizing the energy and exergy of building integrated photovoltaic thermal (BIPVT) systems under cold climatic conditions

Building integrated photovoltaic thermal (BIPVT) system has the potential to become a major source of renewable energy in the urban environment. In this paper, the system has been used as the roof top of a building to generate higher electrical energy per unit area and to produce necessary thermal energy required for space heating. One-dimensional transient model has been developed using basic heat transfer equations. On the basis of this model, an analysis has been carried in order to select an appropriate BIPVT system suitable for the cold climatic conditions of India. The PV performances, net energy gain and exergy of the building are determined. The results show that for a constant mass flow rate of air the system connected in series gives a better performance whereas for a constant velocity of air flow the system connected in parallel gives a better performance. The BIPVT system, fitted on the rooftop in an effective area of 65 m², is capable of annually producing the net electrical and thermal exergies of 16,209 kW h and 1531 kW h, respectively, at an overall thermal efficiency of 53.7%.     

Energy and Exergy Analysis of a Single‐Pass Sequenced Array Baffled Solar Air Heater with Packed Bed Latent Storage Unit for Nocturnal Use

The current study presents an experimental investigation on evaluation of thermal performance of a single‐pass double‐glazed solar air heater with the use of packed bed paraffin wax as a phase change material (PCM). Moreover, the absorber plate is equipped with baffles attached over its top. Galvanized sheets with a thickness of 0.4 mm and total surface areas of 30 cm² are chosen as baffles that are placed in a sequential manner over the absorber plate. The solar energy was stored in the packed bed PCM during the diurnal period (charging process) and was released at night for nocturnal use (discharging process). The tests were performed at three different mass flow rates of 0.009 0.014 and 0.017 resulting in the creation of different Reynolds numbers along the channel. The measured parameters were inlet, outlet, and the PCM temperatures under the meteorological condition of Mashhad, Iran. Energy and exergy efficiencies of the system have been calculated according to the first and second laws of thermodynamics. The experimental results illustrate that the daily energy efficiency varied between 20.7% and 26.8%, whereas the daily exergy efficiency varied between 10.7% and 19.5%.     

Energy modeling and data structure framework for Sustainable Human-Building Ecosystems (SHBE) — a review

This paper contributes an inclusive review of scientific studies in the field of sustainable human building ecosystems (SHBEs). Reducing energy consumption by making buildings more energy efficient has been touted as an easily attainable approach to promoting carbon-neutral energy societies. Yet, despite significant progress in research and technology development, for new buildings, as energy codes are getting more stringent, more and more technologies, e.g., LED lighting, VRF systems, smart plugs, occupancy-based controls, are used. Nevertheless, the adoption of energy efficient measures in buildings is still limited in the larger context of the developing countries and middle income/low-income population. The objective of Sustainable Human Building Ecosystem Research Coordination Network (SHBE-RCN) is to expand synergistic investigative podium in order to subdue barriers in engineering, architectural design, social and economic perspectives that hinder wider application, adoption and subsequent performance of sustainable building solutions by recognizing the essential role of human behaviors within building-scale ecosystems. Expected long-term outcomes of SHBE-RCN are collaborative ideas for transformative technologies, designs and methods of adoption for future design, construction and operation of sustainable buildings.     

Application of real-time spectroscopic ellipsometry for characterizing the structure and optical properties of microcrystalline component layers of amorphous semiconductor solar cells

Over the past few years, we have applied real-time spectroscopic ellipsometry (RTSE) to probe hydrogenated amorphous silicon (a-Si:H)-based solar cell fabrication on the research scale. From RTSE measurements, the microstructural development of the component layers of the cell can be characterized with sub-monolayer sensitivity, including the time evolution of (i) the bulk layer thickness which provide the deposition rates, and (ii) the surface roughness layer thickness which provide insights into precursor surface diffusion. In the same analysis, RTSE also yields the optical properties of the growing films, including the dielectric functions and optical gaps. Results reported earlier have been confined to p-i-n and n-i-p cells consisting solely of amorphous layers, because such layers are found to grow homogeneously, making data analysis relatively straightforward. In this study, we report the first results of an analysis of RTSE data collected during the deposition of an n-type microcrystalline silicon (μc-Si:H) component layer in an a-Si:H p-i-n solar cell. Such an analysis is more difficult owing to (i) the modification of the underlying i-layer by the H₂-rich plasma used in doped μc-Si:H growth and (ii) the more complex morphological development of μc-Si:H, including surface roughening during growth.     

Solar material protection factor (SMPF) and solar skin protection factor (SSPF) for window panes and other glass structures in buildings

The two quantities solar material protection factor (SMPF) and solar skin protection factor (SSPF) are introduced in order to measure and calculate the capability of glass to protect indoor materials and human skin from degradation caused by the solar radiation. Comparison of the SMPF and SSPF values for different glass fabrications enables one to select the most appropriate glass material for the specific buildings. Numerical examples are shown with measurements and calculations carried out on various glass materials, including two electrochromic window (ECW) devices, and several two- and three-layer window pane combinations. Visibility levels at various protection degrees are also given.