Cu2O半导体陶瓷釉的研究

叙述了半导体陶瓷在电点火系统半导体电嘴中的作用，以及半导体陶瓷釉的优点。通过对Ｃｕ２Ｏ半导体陶瓷釉的研究，探讨了它的配方组成，工艺方法及影响因素。经过性能测试和发动机台架试验、飞机试飞，认为是一种适合于半导体电嘴用的性能良好的半导体陶瓷釉。     

低温差下半导体温差发电器(火用)分析

半导体温差发电器的性能通常用输出功率和工作效率来进行评价，但在低温差对低品位能的利用上，只用工作效率来评价是不全面的。从[火用]的角度对低温差下半导体温差发电器的工作性能进行了分析，提出了[火用]效率，用炯效率来作为低温差下半导体温差发电器的评价参数。实验结果表明，随着温差的减小，半导体温差发电器的工作效率明显下降，但[火用]效率则基本稳定。     

势垒和P-N结

半导体在光照之下产生光伏效应的核心是半导体内存在一个电场区。如果使两个导电型相反的半导体紧密接触,就能产生这个电场区。半导体和绝缘体的区别就在于对电子的束缚力不同,通常用能量来表示,     

两级热电热泵的有限时间热力学分析

建立了考虑外部传热影响的两级半导体热电热泵模型，用有限时间热力学对牛顿传热规律下两级半导体热电热泵的性能进行分析，导出了供热率、供热系数与工作电流的一般关系式，得到了热电单元数的最优分配，并分析了多种因素对其性能的影响。     

半导体多级制冷器设计的(火用)效率分析

对半导体多级制冷器不同的设计方法作了介绍,提出了最大（火用）效率分析的设计方案,导出了各种设计方案的设计公式。建立了半导体单级到四级制冷器的数学模型,并进行数值计算。通过对各种设计方法的理论分析,指出了采用最大（火用）效率设计的独特之处及得出了半导体多级制冷器设计的一些重要结论。     

优化半导体制冷工况的理论分析

对半导体制冷的原理进行简单介绍,同时对三种不同工况下半导体制冷进行理论分析,导出使制冷量和制冷系数达到最大值时的电流值,并由此得出设计用的主要参数,给半导体制冷器的设计提供了依据。     

半导体制冷材料及工况优化分析

对半导体制冷原理进行简单介绍,从半导体制冷的材料和三大工况进行简要分析并由此得出设计用的主要参数,为半导体制冷器提供设计依据。     

两级热电热机的有限时间热力学分析

建立了考虑外部传热影响的两级半导体热电热机模型，用有限时间热力学对牛顿传热规律下两级半导体热电热机的性能进行分析，导出了功率、效率与工作电流的一般关系式，得到了两侧换热器的最优面积分配和热电单元数的最优分配，并分析了多种因素对其性能的影响。     

电化学太阳电池

电化学太阳电池也叫液体结太阳电池,简称为ESC。这是在概念上有别于常规太阳电池,在开发利用太阳能上更具灵活性、多用性的一类光电化学器件。图1是用n型半导体做光阳极的ESC能级图。在液体结太阳电池中,半导体电极和电解质溶液形成“结”,当n型半导体电极吸收了能量大干它的禁带宽度的光子后,被激发产生电子-空穴对。这些电子-     

湿式光电池原理及其发展

目前世界上湿式光电池的研究日趋活跃起来,有关论文也日渐增多,一致认为湿式光电池制造简单,具有把光能直接转变为电能和产生化学反应的两个主要功能,在太阳能利用方面有广阔的发展前景。一、湿式光电池的构成湿式光电池是由半导体电极、氧化还原溶液和金属电极组成(如图1)。半导体除光照面以外均用绝缘膜覆盖,使其不与溶液接触。当光照射半导体电极时,激发半导体价带的电子移到传导带,通过导线移向金属电极。在半导体电极表面,R被半导体价带的空穴夺走,生成OX,OX扩散在溶液中,移向金属电极,接受电子又恢复到R状态,这样溶液的组成没有变化,但有向外部供给电力的光电池的作用,因此为了与固体     

金属基相变材料的研究进展及应用

金属基相变材料由于具有储能密度高、热稳定性好、热导率高等优点,在潜热热能储存系统中具有极大的优势。本文回顾了金属基相变材料的发展历程,归纳了金属基相变材料的性能参数,总结了各种热物性的测量方法,探讨了金属基相变材料与容器材料的相容性问题,分析了金属基相变材料在太阳能热发电、工业余热回收和电力削峰填谷中的应用前景。金属基相变材料的高温腐蚀性是目前限制其在热控制中应用的主要因素。为了实现金属基相变材料的广泛应用,需要重点解决金属基相变材料的封装问题。     

Impurity thermovoltaic effect of semiconductor structures: Specific features and outlook

The concept and approach aimed at the development of high-performance inexpensive converters of thermal energy, including solar energy, into electric energy have been proposed. This approach is based on the use of technical (metallurigical grade) semiconductor materials. A number of proposals have been formulated relating to the conditions of the impurity thermovoltaic effect and development of silicon thermoelectric cells.     

HEAT TRANSFER CONTROL IN QUIESCENT AIR WITH THERMAL GRADIENT BY MAGNETIZING FORCE UNDER BOTH GRAVITATIONAL AND NONGRAVITATIONAL FIELDS

ABSTRACT

Two-dimensional numerical computations were carried out to clarify the influence of magnetizing force on quiescent air with thermal gradient in a vertical cylindrical container under both gravitational and nongravitational fields. Several sizes and axial positions of a circular electric coil were tested so that the magnetizing force depended on the magnetic gradient. Under both gravitational and nongravitational fields, the convection was induced in quiescent air with thermal gradient by the magnetizing force; however, flow pattern and Nusselt number depended strongly on the size and the axial position of the circular electric coil in addition to the magnetic strength.     

Free convection in a liquid-encapsulated molten semiconductor in a vertical magnetic field

This paper treats the free convection in a layer of boron oxide, called a liquid encapsulant, which lies above a layer of a molten compound semiconductor (melt) between cold and hot vertical walls in a rectangular container with a steady vertical magnetic field. The magnetic field provides an electromagnetic (EM) damping of the molten semiconductor which is an excellent electrical conductor but has no direct effect on the motion of the liquid encapsulant. The competition between the two free convections determines the direction of the velocity of the interface.     

Analysis of cool storage for air conditioning

The paper investigates the thermal performance of ice-water cool storage systems theoretically and experimentally. Cool storage systems are used to shift electric demand from periods of high demand to those of low demand. A general lump model to determine the thermal storage characteristics is developed. The solution of the system equations is found through a Laplace transformation method. Experimental data of temperature profiles obtained for both single container and packet containers under the conditions of various flow rates and different inlet coolant temperatures confirm the validity of the theory. A closed form solution of the required time for latent-heat storage has also been established on the basis of the quasi-steady-state assumption of the coolant.     

Solar cells and batteries with unusual selective coatings for combined supply of heat and electricity by solar power stations

Optical coatings are used to increase the efficiency, extend the life, and to improve the electrophysical characteristics and stability of solar energy converters based on various physical principles, including semiconductor solar cells. When solar cells are placed on the exterior of collectors in photothermal systems, and generate both electric and thermal power, the optical coating applied to their surfaces gives them highly unusual selective properties, namely, reduced reflection of solar radiation (and high transparency in this part of the spectrum), which leads to higher integrated solar absorption coefficient, and enhanced infrared reflection which ensures that the thermal emission coefficient is as low as possible. Solar cells then not only generate electric power but, at the same time, covered by these coatings, act as selective optical surfaces for solar collectors.     

Numerical simulation of nanostructured thermoelectric generator considering surface to surrounding convection

Thermoelectric systems (TE) can directly convert heat to electricity and vice-versa by using semiconductor materials. Therefore, coupling between heat transfer and electric field potential is important to predict the performance of thermoelectric generator (TEG) systems. This paper develops a general two-dimensional numerical model of a TEG system using nanostructured thermoelectric semiconductor materials. A TEG with p-type nanostructured material of Bismuth Antimony Telluride (BiSbTe) and n-type Bismuth Telluride (Bi₂Te₃) with 0.1 vol.% Silicon Carbide (SiC) nanoparticles is considered for performance evaluations. Coupled TE equations with temperature dependant transport properties are used after incorporating Fourier heat conduction, Joule heating, Seebeck effect, Peltier effect, and Thomson effect. The effects of temperature difference between the hot and cold junctions and surface to surrounding convective on different output parameters (e.g., thermal and electric fields, power generation, thermal efficiency, and current) are studied. Selected results obtained from current numerical analysis are compared with the results obtained from analytical model available in the literature. There is a good agreement between the numerical and analytical results. The numerical results show that as temperature difference increases output power and amount of current generated increase. Moreover, it is quite apparent that convective boundary condition deteriorates the performance of TEG.     

Effect of thermo physical properties of heat exchanger material on the performance of latent heat storage system using an enthalpy method

In this paper, a simple two‐dimensional theoretical model based on enthalpy formulation of a latent heat storage system has been developed to study the effects of thermo physical properties of heat exchanger container materials on the thermal performance of the storage system. Numerical results show that thermal conductivity, specific heat and density of the heat exchanger container materials increases, the melting time of the PCM decreases. Numerical results also show that high value of thermal conductivity of the heat exchanger container materials did not make significant contribution on the melt fraction. It is also found that initial temperature of the PCM does not have very important effects on the melting time, while the boundary wall temperature play an important role during melting. Copyright © 2005 John Wiley & Sons, Ltd.     

温差发电器件导热系数

建立了半导体温差发电器件的基本模型，推导出器件等效导热系数的数学表达式，发现其与N型、P型半导体材料及两端陶瓷片的导热系数紧密相关，对半导体材料和陶瓷片的导热系数随温度的变化关系进行了实验研究并进行了数值拟合，绘制了器件等效导热系数与温度的曲线，得到的计算值与实验结果基本吻合。