The Effect of Water Flow Velocity on Heat Collection Performance of Active Heat Storage and Release System for Solar Greenhouses

In order to explore the influence of water velocity on the heat collection performance of the active heat storage and release system for solar greenhouses,six different flow rates were selected for treatment in this experiment.The comprehensive heat transfer coefficient of the active heat storage and release system at the heat collection stage was calculated by measuring the indoor solar radiation intensity,indoor air temperature and measured water tank temperature.The prediction model of water temperature in the heat collection stage was established,and the initial value of water temperature and the comprehensive heat transfer coefficient were input through MATLAB software.The simulated value of water temperature was compared with the measured value and the results showed that the best heat transfer effect could be achieved when the water flow speed was 1.0 m3h-1.The average relative error between the simulated water tank temperature and the measured value is 2.70-6.91%.The results indicate that the model is established correctly,and the variation trend of water temperature can be predicted according to the model in the heat collection stage.

A Review of Applied Methods of Using Solar Energy in Iranian Buildings

Solar energy is the radiant light and heat from the Sun that has been harnessed by human since ancient times. Also secondary solar resources such as wind and wave power, hydroelectric power and biomass account for most of the available renewable energy on Earth, which can be used by human. Architects since alacient times have used various methods to hamesse and employ the solar energy for lighting, cooling and heating and etc. Meanwhile, Iran＇s ancient architecture, as an adaptive one, which consists of various climatic reigns, is filled with abounding examples of using sun energy in buildings. But, unfortunately despite these ancient methods, our modern architects mostly tend to provide energy of buildings with fossil fuels. This increases energy costs of the building＇s and also pollutes the environment. In this article it is intended to consider the ancient ways of using solar energy in Iran, and then suggest new methods for applying in modem buildings. The results of consideration show that among Solar technologies, passive and active methods, Iran＇s ancient architects have used passive methods, for example in mass and space, orientation and settlement of building. The idea of passive methods can be used in new shapes in current buildings, for instance by using solar space, central yard and etc. The suggestive method in this paper is combining the passive methods with the active ones.

风光储参与电网预防-紧急控制策略研究

基于风光储有功功率连续平滑调节能力,提出一种风光储协同切负荷优化的电网预防-紧急控制策略。首先,分析风光储参与电网预防-紧急控制原理,给出风光储参与电网预防-紧急控制策略。在故障发生前通过削减风光出力预留有功备用容量,通过调整发电机机组出力、储能充放电状态平抑风光出力改变引起的系统功率波动;在故障发生后,优先考虑风光预留有功备用量填补系统功率不平衡量,若风光预留有功备用量不足,则采取切负荷措施进行紧急控制。然后,综合考虑风光有功备用成本、预防、紧急控制措施成本,分别建立风光储参与电网预防、紧急控制模型,采用Matlab/CPLEX求解模型。最后在改进IEEE 39节点系统进行仿真验证本文所提控制策略的有效性。

考虑配电网波动的风光储互补系统有功功率控制系统

为了解决风光储互补系统稳定运行中功率补偿不足、耗能不够经济的问题,提出一种考虑配电网波动的风光储互补系统有功功率控制系统。系统构建时充分考虑风力发电系统与光伏发电系统之间的协同作用,同时对储能做出针对不同运行状态的优化控制。通过对风光储互补系统的实时在线优化,保证风光储互补系统在运行时更加经济高效,减少不必要的耗能以及避免产能过剩。结合某地风光储互补系统进行实际算例分析,改进系统能够更好促进风光储互补控制,减小有功功率偏差,及时调整方案。

Thick Active-Layer Organic Solar Cells

Organic solar cells(OSCs)present a promising renewable energy technology due to their cost-effectiveness,adaptability,and lightweight nature.The advent of non-fullerene acceptors has further boosted their significance,allowing for power conversion efficiencies surpassing 19%even with an active layer thickness of about 100 nm.However,in order to achieve large scale production,it is necessary to fabricate OSCs with thicker active layers exceeding 300 nm that are compatible with large-area printing techniques.Nevertheless,OSCs with thick active layers have inferior performance compared to those with thin active layers.To expedite the transition of OSCs from laboratory to industrial high-throughput manufacturing,considerable efforts have been made to comprehend the performance limitations of thick active-layer OSCs,develop novel photoactive materials that are high-performance and tolerant towards the thickness of the active layer,and optimize the morphology of the photoactive layer and device structure.This review aims to provide a comprehensive summary of the mechanisms that lead to efficiency loss in thick active-layer OSCs,the representative works on molecular design,and the optimization strategies for high-performance thick active-layer OSCs,and the remaining challenges that must be addressed.

Solar-heating boosted catalytic reduction of CO_(2） under full-solar spectrum

Catalytic converting CO2 into fuels with the help of solar energy is regarded as‘dream reaction’,as both energy crisis and environmental issue can be mitigated simultaneously.However,it is still suffering from low efficiency due to narrow solar-spectrum utilization and sluggish heterogeneous reaction kinetics.In this work,we demonstrate that catalytic reduction of CO2 can be achieved over Au nanoparticles(NPs)deposited rutile under full solar-spectrum irradiation,boosted by solar-heating effect.We found that UV and visible light can initiate the reaction,and the heat from IR light and local surface-plasmon resonance relaxation of Au NPs can boost the reaction kinetically.The apparent activation energy is determined experimentally and is used to explain the superior catalytic activity of Au/rutile to rutile in a kinetic way.We also find the photo-thermal synergy in the Au/rutile system.We envision that this work may facilitate understanding the kinetics of CO2 reduction and developing feasible catalytic systems with full solar spectrum utilization for practical artificial photosynthesis.

Electrostatic Discharge Effects on the High-voltage Solar Array

A certain number of charges are deposited on the surface of high-voltage solar array because of effects of space plasma,high-energy charged particles,and solar illumination,hence the surface is charged.Phenomena of electrostatic discharge(ESD) occur on the surface when the deposited charges exceed a threshold amount.In this paper,the mechanism of this ESD is discussed.The ground simulation experiment of the ESD using spacecraft material under surface charging is described,and a novel ESD protecting method for high-voltage solar array,i.e.an active protecting method based on the local strong electric field array is proposed.The results show that the reversal potential gradient field between the cover surface and the substrate materials of high-voltage solar array is a triggering factor for the ESD on the array.The threshold voltage for the ESD occurring on the surface is about 500 V.The charged particles could be deflected using the electric field active protecting method,and hence the ESD on the surface is avoided even when the voltage on the conductor array increases to a certain value.These results pave the way for further developing the protecting measures for high-voltage solar arrays.

A Possible Macroscopic-Photo-Catalysis Mechanism in Solar Furnace

Based on the experimental results of Chen et al. to use the solar furnace and medium frequency induction furnace to extract boron impurity from metallurgical silicon, we propose a strong radiation catalysis mechanism to explain the difference of reaction rates in these two furnaces. The postulate assuming the photons striking on the material not only increase the thermal energy of the molecules of reactants but also lower down the energy barrier of the reaction to speed up the chemical reaction. It is believed the photon catalysis mechanism is unlversall in most of high temperature chemical reactions and looking forward to more evidences for the postulate proposed in this article.

基于平板热管阵列的热激活主动保温墙体实验研究

针对太阳能等低温热源的被动传输与建筑利用问题,提出一种基于平板热管阵列的热激活主动保温墙体,测试热管倾角与热源温度对其能量传输性能影响,对比热激活主动保温墙体与普通节能墙体热工性能差异。结果表明:蒸发段施加低温模拟热源后,热管实测有效导热系数为4400~35400 W/(m·℃);主动保温情景下可降低热管倾角以提升有效导热系数,辅助功能情景下可提升倾角以达类似目的;低温热源注入可显著提升墙体热工性能,热源温度为25、35℃时,墙体实测U值由基准值0.50 W/(m^(2)·℃)分别降至0.19和-0.08 W/(m^(2)·℃)。

太阳纳米光子蒸馏膜的性能特性分析

为有效改善蒸馏膜(MD)的高能耗问题,提出一种低能耗的太阳纳米光子蒸馏膜(NESMD)组件,对其热力学性能开展研究,并分析关键操作参数对其热力学特性的影响规律。研究结果表明,温度极化是导致MD技术高能耗的主要内因,NESMD组件采用面加热方式进行料液加热,不存在温度极化现象,因此具有显著的节能优势。在相同进料温度和进料速度下,NESMD组件相较于MD组件,温度极化系数和热效率均有显著提升,NESMD组件热效率受潜热影响最大,可采取低进料速度和高进料温度来提高热效率;当将聚乙烯醇(PVA)涂层作为功率输入段时,NESMD和MD组件均存在最佳输入段长度使得热效率最大;NESMD组件相较于MD组件具有更好的拓展性和更长的活性长度。上述性能规律为进一步优化结构提供了科学依据。

多腔主动蓄放热系统优化设计与性能分析

主动蓄放热系统是温室太阳能高效热利用的一种设备,为了改良集热板结构,提升集热量和主动蓄放热系统的各项性能,以集热效率提升为目标,首先进行主动蓄放热系统集热板连接结构和流道设计优化,然后进行系统集成设计与加工制作,并在温室中对其进行性能测试。通过集热板内沿程阻力与对流换热系数关系的模拟计算,确定长16 mm和宽4 mm的圆角矩形作为集热板横截面腔室结构尺寸,管板插接激光焊作为集热板组装工艺。温室现场测试结果表明:在北京地区,冬至日以后的49 d内,多腔主动蓄放热系统的平均集热效率达到79.5%,以温室建筑面积计算,该系统日平均集热量为1.0 MJ·m^(-2),平均放热功率为23.9 W·m^(-2);该系统平均放热能效比为5.4,与电加热加温方式相比,平均节能率为81.2%。主动蓄放热系统的关键性改进优化可改善放热性能,系统运行稳定性、耐久性进一步提高,为主动蓄放热系统规模化应用提供技术支撑。

基于全寿命期优化的藏北高原低碳社区设计策略——以2021台达杯建筑设计竞赛获奖方案为例

在中国生态文明建设进入绿色转型、减污降碳的战略方向背景下,低碳社区的建设与发展对实现“双碳”目标意义重大。以2021年台达杯国际太阳能建筑设计竞赛获奖作品为例,考虑藏北高原的气候特点、自然环境及人文精神,挖掘与梳理藏族民居的环境适应性与建筑特色,以此作为方案生成的条件与土壤,从社区设计阶段、物化与拆除阶段、运行阶段三个阶段,建筑朝向、建筑布局、遮阳构件、材料选择、结构选型、被动式技术以及主动式技术七个角度对方案低碳设计进行全面剖析,对藏北高原地区牧民定居社区全寿命期低碳策略和方法进行总结,试图为当代牧民定居点的低碳社区营建提供一种全过程的设计思路及技术路线,同时为探索高海拔严寒地区低碳社区建设提供借鉴与参考。

日光温室主动加温技术与设备

日光温室是主要依靠太阳能并通过温室围护结构的高效保温来维持室内作物正常生长温度的一种高效节能温室。正常天气条件下,经过优化设计的日光温室依靠白天高效接受和储存太阳能、夜间严密保温和缓慢释放储热能,在北方大部分地区可以完全不用额外加温就能安全生产。但在一些高寒高纬度地区和遇到雾霾、沙尘、暴雪、严寒、连阴天等极端天气条件以及种植高品质作物要求可靠环境时,为保证作物正常生长,短期临时加温也很必要。本文按不同加热能源,包括太阳能、电能、生物质能等清洁能源和煤炭、柴油、天然气等传统化石能源,分类总结和阐述了目前国内日光温室主动加温的技术及其配套设备,可为日光温室设计和管理提供技术支持。

通过导纳谱表征铜铟镓硒电池中的缺陷

本文通过导纳谱技术表征铜铟镓硒(CIGSe)太阳电池吸收层中缺陷的能量分布,研究了CIGSe太阳电池退火后效率提高的机理.研究发现退火后CIGSe电池的暗电流减小了大约1个数量级,电池的理想因子也从退火前的2.16减小到退火后的1.85.在反向偏压下,退火前CIGSe太阳电池的电容高于退火后的.通过对电池的C-V特性进行1/C^(2)-V线性拟合获得退火前CIGSe电池吸收层中的自由载流子浓度高于退火后,此外还获得了CIGSe电池退火前后的内建电压分别为0.52 V和0.64 V.通过导纳谱的测试发现退火后吸收层中缺陷的激活能降低,但是缺陷浓度几乎不变.缺陷激活能的降低意味着铜铟镓硒太阳能电池中缺陷的SRH(Shockley-read-hall)复合概率降低,因此退火后太阳能电池的开路电压和并联电阻的增大提高了电池的性能.

风光储联合发电系统储能容量对有功功率的影响及评价指标

风力发电、太阳能光伏发电以及储能的技术特性、容量配置及控制策略对联合发电系统总有功功率特性有重要影响。分析了风光储联合发电系统的结构特点、数学模型和技术特点,提出了一种储能单元充放电优化模型,该模型以有功功率波动最小为目标函数,其约束条件考虑了每个步长的储能初始容量和储能充放电控制策略。根据该模型,提出了衡量风光储联合发电系统有功功率波动的3个指标,并结合评价风光储联合系统供电可靠性指标,综合评价总输出功率特性,通过Matlab编程进行了实例验算,分析了有功功率特性随储能容量配置方案的变化趋势及各指标的意义。

光伏储能双向DC-DC变换器的自抗扰控制方法研究

为了提高光伏储能系统的快速性和抗干扰能力,同时考虑到双向变换器的非线性特性,在建立双向DC-DC变换器数学模型的基础上,提出一种基于自抗扰控制器（active disturbance rejection control,ADRC）的双向DC-DC变换器控制方法,设计适用于光伏储能双向DC-DC变换器的自抗扰控制器,并对系统进行实验验证。实验结果表明基于ADRC的控制策略能有效抑制直流母线电压波动和冲击,提高光伏储能系统的动态性能和抗干扰能力。

高产杂交籼稻Ⅱ优129光合碳同化特性的研究

从光能利用率差异的角度探讨了高产杂交籼稻Ⅱ优 12 9和对照汕优 6 3的光合碳同化特性。结果表明 :a)Ⅱ优 12 9的光能利用率和产量显著高于汕优 6 3,但其叶面积指数、消光系数及生育期无显著差异 ,说明光合效率及光合功能期是导致两组合光能利用率差异的主要原因 ;b)Ⅱ优 12 9剑叶的CO2 日同化量、叶源量及单茎CO2同化量均极显著高于汕优 6 3 ,说明前者的碳同化能力较后者强 ;c)提高一个耐光抑制等级即可减少约 3 %的CO2日同化量的损失 ,提高品种的耐光抑制等级可进一步提高光能利用率 ;d)用光合速率高值指数作为衡量叶片一生中光合机构高效运行状态的一个生理指标 ,有助于揭示光合功能衰退对产量影响的生理机制 。

太阳能固体吸附式制冰机不同吸附工质对的实验研究

在构建的太阳能制冰机的基础上,选用活性炭 甲醇、活性炭 乙醇作为吸附制冷工质对,在外界环境条件及辐射能量条件相同的条件下,分别对两种不同的吸附制冷工质对进行解吸量、吸附量和制冰量的实验。通过对大量实验数据的分析与整理,所得出的结论是:对固体吸附式制冰机装置而言,活性炭 甲醇工质对仍是最佳的吸附制冷工质对,活性炭 乙醇工质对不适合于太阳能固体吸附式制冰机中。

高浓度O_3及太阳辐射减弱对冬小麦PSⅡ光合活性及光能耗散的影响

为给地表太阳辐射减弱和O3浓度增加等大气环境变化条件下我国粮食生产和安全提供安全评估依据,利用开顶式气室(OTC)和黑色遮光网开展了1种熏气水平和2种辐射减弱程度的大田试验(野外CK,T1:遮光20%,T2:遮光40%,T3:O3浓度100 nL/L,T4:O3浓度100 nL/L与遮光20%复合,T5:O3浓度100 nL/L与遮光40%复合)。结果表明:T1、T2和T4组的Fv/Fm、L(PFD)与CK均相似且变化不明显,Yield、qP、Y(NO)、(1-qP)/NPQ分别较CK不同程度下降,而NPQ和Y(NPQ)较CK分别较大程度升高;T3—T5组的Fv/Fm,L(PFD)、Yield、qP、Y(NO)和(1-qP)/NPQ较CK不同程度降低,而NPQ和Y(NPQ)较CK分别显著升高且T5增幅显著大于T1—T4组。综上表明,复合胁迫下,冬小麦光能更多地向调节性热耗散途径分配,辐射减弱效应能使臭氧胁迫下冬小麦较好地自我调节以更好地适应逆境环境。尽管冬小麦对复合胁迫具有一定的适应能力,地表臭氧浓度升高和辐射减弱仍然是我国粮食生产中面临的一个重要问题。

日光温室主动采光机理与透光率优化试验

中国的日光温室实现了高效的太阳能利用,温室采光面的采光设计是其结构设计中的一个极其重要的方面。但是,在实践的设计中,对于自然光入射角小于40°的光照透过率未进行深入的理论研究,使得温室采光的设计长期停滞于经验设计为主的状态。该文采用光学理论计算和试验研究的方法,详细分析了温室采光面在小幅调整条件下自然光的透过率,以及温室采光面角度调整与室内光照强度透过率的增加之间的定量关系。从经典光学理论出发,推导了温室采光设计的计算系统计算方法,并结合理论要求并进行试验研究。通过理论推导和试验得到,对于可以主动改变采光角度的主动采光温室条件下,在太阳光入射角达到20°,30°和40°时,太阳光的强度透过率,分别达到了85.68%,76.47%,64.72%。特别是当入射角大于40°时,直射光强度透射率下降更加明显,在入射角为50°和60°时,直射光强度透射率分别为53.38%和39.67%。理论分析和试验研究表明,将温室采光面的倾角从25°提高到35°,理论计算与试验结果均表明通过小幅改变温室采光面的角度即可达到大幅提高温室强度透过率,当温室采用了可以改变采光角度的主动采光屋面后,温室内的光照强度透过率可以提高20.7%~22.8%。