光子晶体光纤研究进展

与普通光纤相比，光子晶体光纤具有无休止的单模特性、奇异的色散特性、可控的非线形和易于实现的多芯传输等特点。表明它在光纤传感器、光子晶体天线、超宽色散补偿、光学集成电路等多方面具有广泛的应用前景。     

聚光型热光伏系统结构优化分析

利用净辐射方法建立了聚光型TPV系统的光谱辐射换热模型,讨论了聚光挡板对数的影响。结果表明,对该文讨论的系统结构,在电池面积小于一定值时,采用挡板的系统中可转换净辐射密度均明显大于无挡板的情况,且电池面积越小,净辐射密度越大;随可转换净辐射功率(与电池输出功率成正比)的减小,对应于最小电池面积和最大光谱效率的系统逐渐由开始的二对挡板转变成四对挡板的系统。     

用于太阳能光伏散热器的热虹吸管的设计

太阳能聚光光伏发电系统中电池温度过高会导致发电效率降低,对太阳能电池进行有效的冷却已经成为聚光光伏发电系统保证发电效率和安全运行的关键技术。介绍了采用两相闭式热虹吸管散热器(热管)的方式。根据已知参数设计一个热虹吸管,并做强度校核,保证在极限内热虹吸管可以正常的工作,并选取水作为工作介质。通过实验对热虹吸管的实际工作性能进行分析,得出提高热虹吸管工作效能的结论。     

采用热天平研究煤粉燃烧特性时的一维燃烧模型

采用热天平研究了试样量对煤粉燃烧特性试验结果的影响，将坩锅中具有一定厚度的试样的燃烧简化成一维燃烧，推导了试样层中氧浓度的分布计算，在此基础上提出了一维燃烧模型。模型的计算结果和试验结果吻合较好，为分析比较试样厚度变化时的煤粉燃烧特性试验结果提供了依据。图8表1参3     

采用辐射热阻网络法对热光伏系统热分析

采用辐射热阻网络方法建立了热光伏(TPV)系统的辐射换热模型,并指出不考虑石英玻璃管对辐射光子可能的波长转换作用会导致计算所得的石英玻璃管的光谱发射功率密度与普朗克定律相违背。采用添加单色波热源的方式对辐射换热模型进行了修正,得到了系统的辐射热流密度、光谱效率和石英玻璃管的等效辐射温度等一些重要参数,与参考文献中结果吻合较好。     

热光伏系统燃烧-辐射器的性能分析

分析了甲烷质量流率、回热器有效度、空燃比、几何尺寸等因素对热光伏系统中燃烧-辐射器性能的影响.计算结果表明:采用回热器可显著提高辐射表面的温度和化学能-辐射能转化效率;空气与甲烷的空燃比和甲烷质量流率分别以20.64:1.00和0.988kg/h为最佳.在此基础上讨论了几何尺寸对燃烧-辐射器的影响,发现在内、外管内径分别为27.2mm和38.5mm,内、外管壁厚分别为7.0mm和3.5mm的情况下燃烧-辐射器的性能最佳,辐射表面平均温度、表面辐射功率密度和化学能-辐射能转化效率分别为1523.8K、11.99W/cm2和73.7%.     

基于深度迁移学习的小样本光伏热斑识别方法

针对训练传统深度学习模型需大量数据而热斑效应样本数量相对少且不易采集的问题,提出基于深度迁移学习的小样本光伏热斑识别方法.在Inception-v3模型的基础上构建深度迁移学习模型,然后在负样本多分类的小样本热斑数据集上完成训练,得到可用于热斑识别的网络模型.实验结果表明,在样本数量不充足的情况下深度迁移学习方法训练出...     

应用于南极中山站的光伏支架的研究

针对南极中山站的极端环境条件,研究了低温环境和光伏方阵间距对光伏方阵受风荷载的影响,在此基础上确定了整个光伏发电系统光伏阵列的布局方案;然后结合光伏阵列的布局设计和风荷载分析结果,建立了光伏支架的力学分析模型,研究了多种光伏支架钢结构和底座的技术方案,优化了钢结构和底座的关键技术参数。     

太阳电池冷却及光伏/光热一体技术的新进展

由于太阳电池光电转换效率随自身温度的升高而下降,因而对太阳电池进行冷却成为当前太阳能光伏研究的一项重要内容;同时,在太阳电池冷却的研究课题当中引申出了光伏与光热相结合(PV/T)的概念,使太阳电池转换而成的热量得以应用,这是新能源产业的一项重要发展趋势.收集并整理了近5年国内外的太阳电池冷却方法和光伏光热一体化研究成果...     

基于一维/三维耦合仿真的工程机械冷却系统优化设计

本文针对一款设计中的工程机械冷却系统,建立了一维数值模型与三维CFD模型。通过一维/三维耦合计算,研究在散热器模块串联安置并留有间隙的情况下,部分空气绕过前排散热器流动对工程机械冷却系统换热性能造成的影响。将CFD计算结果的风速数据嵌入标准的一维数值模型,对一维仿真计算进行修正。修正后,前排低温油散热器尺寸需要增加约11.3%,经实验验证满足要求。一维/三维耦合仿真使冷却系统热管理仿真计算的精度得到提高,使一维仿真结果更加接近实际情况。     

BODY-FORCE ANALOGY FOR ONE-DIMENSIONAL COUPLED DYNAMIC PROBLEMS OF THERMOELASTICITY

ABSTRACT

The classical body-force analogy for static problems of thermoelasticity is extended toward dynamic coupled problems. We consider two dynamic problems, namely, a thermal problem without body forces, but with a given distribution of transient sources of heat, and a force problem without sources of heat but with body forces. Both problems are treated within the coupled theory of thermoelasticity such that temperature must also be taken into account in the force problem. We restrict our considerations to the one-dimensional case, and we show that, given suitable boundary and initial conditions, a distribution of body forces can be constructed such that the dynamic displacements in both problems become equal. This analogy is checked by means of illustrative analytical examples. We also discuss the relations between the stresses and the temperature in both problems, and we mention that a similar analogy can be established, requiring the temperatures in both problems to be equal.     

新型便携式太阳总辐射仪的研制

介绍了新型便携式太阳总辐射仪的设计与实现方法。它可实现瞬时太阳辐照度和一天至一周内太阳辐照度的测量与显示,同时还可实现现场环境温度的测量与显示。它由一个超低功耗智能型带１２位Ａ／Ｄ转换器和传感器宏编程语言解释程序的信号处理器和ＭＡＸＩＭ低功耗集成电路与硅太阳电池及半导体温度传感器组成。通过对实测结果的分析,该仪器令人满意。     

Realization of energy-saving glass using photonic crystals

This work successfully developed an energy-saving glass with wavelength selectivity. The glass is composed of a SiO₂ substrate and two layers of three-dimensional photonic crystals. Each crystal is composed of identical and transparent polystyrene spheres after their self-assembling. The glass then possesses dual photonic band gaps in the near-infrared region to suppress penetration of thermal radiation. Experimental results show that the energy-saving glass decreases temperature increment in a mini-house. Moreover, the temperature after thermal equilibrium is lower than that inside a counterpart using ordinary glass.     

新型太阳热反射隔热涂料的研制

以硫酸钛为钛源,采用非均相沉淀法制备二氧化钛包覆粉煤灰漂珠新型节能材料.主要研究了温度、pH值对二氧化钛包覆粉煤灰漂珠包覆效果的影响.通过SEM、EDS、XRO、白度、产率、热反射比的测试与分析,确定了包覆反应的最佳工艺参数.研究结果表明:当反应体系温度为70℃,pH值等于7时,所制备的二氧化钛包覆粉煤灰漂珠产率达98%,粉煤灰漂珠表面包覆层均匀,完整,XRD显示包覆层主晶相为锐钛矿型二氧化钛;利用该二氧化钛包覆粉煤灰漂珠制备太阳热反射隔热涂料的热反射比达97%.     

NEW FORMULAE FOR DYNAMICAL THERMAL STRESSES

A generalization of the function of influence of a unit heat source to the displacements is suggested for the boundary value problems in the dynamical uncoupled thermoelasticity. This generalization is a convolution over time and bulk of two influence functions. One of them is a Green's function for the heat conduction problem. The other is a function of influence of unit concentrated forces onto bulk dilatation. Broad possibilities are shown in constructing these influence functions. In particular, the theorem on dilatation constructing is proved. To calculate the convolutions successfully the following properties of the introduced function are found to be useful. (1) In coordinates of the point of observation, the function satisfies the equations used to find the Green's functions in the problem of heat conduction, with the unit heat source being replaced by the influence function of concentrated force onto dilatation; and (2) in coordinates of the point of heat source application, it satisfies the boundary value problem used to find Green's matrix, with the unit concentrated forces being replaced by derivatives of Green's function in the problem of heat conduction. Based on the introduced influence function, some new integral formulae for displacements and stresses are obtained, which are a generalization of Mysel's formula in the theory of dynamical thermal stresses. The proposed formulae have certain advantages allowing us to unite the two-staged process of finding the solutions for boundary value problems in thermoelasticity in a single stage. It is established that, based on the obtained results it becomes possible to compile a whole handbook on the influence functions and integral solutions for boundary value problems in dynamical thermoelasticity. As examples, the solutions for two boundary value problems in the theory of dynamical thermal stresses for the half-space and quarter-space are presented.     

A STRATEGY FOR THE DEVELOPMENT OF NEW ENERGY TECHNOLOGY IN THE GLOBAL ENVIRONMENT ERA (The Revised Sunshine Project)

The Japanese R & D Programme on solar energy under the Sunshine Project of MITI will be described. The programme is aiming at practical use of solar energy in the 21st century.     

新型HCFCs替代物筛选及性能实验

讨论了ＨＣＦｓ替代物的筛选方法，并对制冷空调系统中各种Ｒ２２替代物的组成及性能进行理论分析及实验验证。     

一种新修正的风电机组尾流分析模型

基于尾流区线性膨胀、径向风速损失呈高斯分布的假设,在BP模型基础上建立一种新修正的风电机组尾流分析模型。该模型针对BP模型无法对近尾流区进行分析的问题,基于质量守恒原理求解近尾流区速度损失分布;通过大涡模拟数据拟合,对BP模型中速度损失标准差方程进行修正,提升了模型在不同地表粗糙度下的计算精度。采用大涡模拟数据对多种工程尾流模型的计算结果进行比较。结果表明,相比于Jensen、Frandsen和BP模型,该模型能更好地预测全尾流范围的径向速度分布,并且具有更高的计算精度。     

一种独立光伏系统设计的新方法

在独立光伏系统设计中，目前国内普遍采用的计算蓄电池容量的公式不尽合理。本文根据能量平衡方程和放电深度要求，通过对光伏系统工作状态的分析，提出一种实用的设计方法。