基于光纤温度传感器监测的聚光光伏发电系统

针对聚光型太阳能光伏电池能量转换效率和使用寿命受温度影响较大的问题,基于砷化镓半导体吸收式光纤温度传感器,提出一种对聚光光伏发电系统的温度进行实时监测和控制的方法。数值仿真实验结果表明,当冷却水的流速降低、聚光光伏电池工作温度升高时,半导体的吸收波长增加,光纤温度传感系统检测出来的温度较高,这时可以通过节流阀增加冷却水的流速,提高聚光光伏电池与冷却水之间的传热系数,从而降低聚光光伏电池的温度。该方法对于延长聚光光伏电池的使用寿命和提高太阳能的利用率具有一定的理论指导意义。     

从9个9到6个9,半导体业者的新大陆

Intel成立了生产太阳能电池新公司SpectraWatt并在美国俄勒冈州建了工厂,IBM在研发新电池技术"Li Air",台积电宣布进入太阳能电池市场,三星电子兴建了太阳能电池生产线……,半导体巨头们跨入太阳能光伏市场的步伐还在加快,而半导体人转向太阳能光伏领域更是比比皆是。     

车载光伏供电控温系统的设计

该文以ARM9为主控芯片,以光伏电池供电,以半导体制冷片为降温装置,以小功率加热器为加热装置,并以DS18B20为温度传感器设计了一个节能环保的小型车载全天候控温系统。通过测试验证了该系统设计和控制策略的可行性,在一定程度上解决了户外泊车时车内的温度控制问题。     

太阳能光伏驱动车载散热通风系统

文中设计一种太阳能光伏电池驱动的车载散热通风系统,采用光伏电池、SEPIC变换器、蓄电池和BUCK变换器的并联结构,由一片DSC芯片实现系统的功能控制与能量管理,实现光伏电池驱动车载风扇降温和为汽车蓄电池充电的双重功能。系统通过DSC芯片控制SEPIC变换器来改变光伏电池的负载特性曲线,使得环境因素变化时负载始终与电池外特性曲线相交于最大功率点,实现最大功率追踪;另外DSC芯片实时检测车内温度,控制散热风扇的转速,排出车内热空气,达到控制车内温度的效果;散热风扇运转功率来自光伏发电,且光伏发电多余电能为车载蓄电池充电。该设计提高了车辆的舒适性,具有一定节能减排的效果。通过Simulink仿真和实验验证了该设计的可行性和控制策略的有效性。     

太阳能光伏电池组件及材料应用

太阳能光伏是一种基于以太阳能为主要能量供应的半导体电池材料,而实现能量转换。经过转换之后的太阳能,以电能的形式作用于发电工程或系统中。在光伏发电系统中,光伏组件发挥着重要的能量传输与供应功能。其主要结构是由多种电池片组成,并按照列阵的形式加以整合和排列,最终以电池板的形态展现在太阳能发电相关工程系统结构中。通过光伏组件的有效应用,不仅实现了太阳能量的转换,更实现了绿色生态电能能源的存储。     

从9个9到6个9，半导体业者的新大陆

Intel成立了生产太阳能电池新公司SpectraWatt并在美国俄勒冈州建了工厂，IBM在研发新电池技术“Li Air”，台积电宣布进入太阳能电池市场，三星电子兴建了太阳能电池生产线……，半导体巨头们跨入太阳能光伏市场的步伐还在加快，而半导体人转向太阳能光伏领域更是比比皆是。我们知道，太阳能级硅（SG）Si含量一般在99．9999％，而电子级硅（EG）的Si含量一般要达到99．9999999％。太阳能光伏与半导体的关联性，正是人们所谓的6个9与9个9之别。     

基于单片机的智能冷热两用水杯的设计

文章基于单片机设计制作一种便携式智能化快速冷热两用水杯,该产品通过温度控制模块进行温度随意控制,利用半导体制冷片和热交换模块实现制冷和加热功能,并采用LCD屏实现温度的实时显示;该方案充分利用半导体制冷片的体积小、高效率、无污染的特点,设计方案效率高、易携带、用途多、温度可视化,为居家生活、外出旅游提供更好的便捷优质服务。     

电动船用光伏充电遮阳顶及其电路设计

本文为水上利用电力作为动力的船只提供一款光伏充电遮阳顶,利用遮阳顶部的太阳能电池组件发电为电动船提供及补充电能,延长电动船的使用时间.本文设计了一种新的保护电路,采用PWM控制,实现过充、防反充、防雷保护等功能,以提高电动船的可靠性.     

太阳能供电系统光伏电池的合理配置

叙述了通信用太阳能供电系统光伏电池的合理配置,对系统的可靠性和经济性的影响,并对多级分组投入和稳压变换式两种供电系统光伏电池配置的特点进行了分析比较。通过两种稳定方式的太阳能供电系统光伏电池配置设计计算,阐述了稳压变换方式太阳能供电系统可以充分用光辐射,减少光伏电池配置,降低整体资金投入的优点。     

温差半导体空调制冷器制冷性能研究

设计了两种不同散热方式的半导体制冷器,实验表明制冷性能良好,为太阳能驱动半导体制冷装置的优化设计提供依据、奠定基础。半导体制冷模块热端采用汽车发动机散热系统标准部件、采取水冷却,能在有限的空间内将高热流密度热量散发出去,有利于提高制冷性能。半导体制冷模块在等功率状态下工作,制冷量为半导体器件最大制冷量的55%;若倾向于获得较大制冷系数,制冷量按最大制冷量的40%进行设计,制冷系数ε达1.65。     

Design of a Concentration Solar Thermoelectric Generator

Thermoelectric technology can be another direct way to convert solar radiation into electricity, using the Seebeck effect. Herein, a prototype concentration solar thermoelectric generator (CTG) and a discrete numerical model for the evaluation of the whole system are presented. The model takes into account the temperature dependence of the thermoelectric material properties by dividing the thermoelectric leg into finite elements and is proved to be more accurate for calculation of the conversion efficiency of the thermoelectric modules when large temperature gradients occur in the CTG system. Based on the best available properties of various bulk thermoelectric materials reported in the literature, the best possible performance of the CTG system is predicted, and the CTG system design, including the selection of the concentration ratio and the cooling method for different thermoelectric materials, are discussed in detail.     

Thermoelectric Self-Cooling System to Protect Solar Collectors from Overheating

Solar collectors for water heating have spread rapidly in recent years, as their use saves significant amounts of fuel and electricity. One of the main problems with these systems is overheating of the internal fluid, which takes place when an enormous amount of heat is collected but the demand for hot water is low, resulting in high-pressure, high-temperature conditions that damage some of the components. Nowadays, most such systems include either static or dynamic dissipators that remove excess heat. This paper presents a thermoelectric self-cooling system designed to dissipate excess heat from a solar-collector system and prevent overheating of the internal fluid. Thermoelectric self-cooling (TSC) is a novel thermoelectric application, proven to enhance the cooling of any heat-generating device without electricity consumption. This paper presents the design and computational study of a TSC system, pointing out that the most important parameters are the thermal resistances of the heat exchangers, and that their reduction significantly improves the performance of the thermoelectric system. The final design outperforms currently used static and dynamic dissipators, increasing the heat transfer coefficient by more than 50% and requiring no electricity, representing a promising alternative to prevent overheating of solar collectors.     

Electric Power Generation from Thermoelectric Cells Using a Solar Dish Concentrator

In this paper, design details, theoretical analysis, and outcomes of a preliminary experimental investigation on a concentrator thermoelectric generator (CTEG) utilizing solar thermal energy are presented. The designed CTEG system consisted of a parabolic dish collector with an aperture diameter of 1.8 m used to concentrate sunlight onto a copper receiver plate with 260 mm diameter. Four BiTe-based thermoelectric cells (TEC) installed on the receiver plate were used to convert the concentrated solar thermal energy directly into electric energy. A microchannel heat sink was used to remove waste heat from the TEC cold side, and a two-axis tracking system was used to track the sun continuously. Experimental tests were conducted on individual cells and on the overall CTEG system under different heating rates. Under maximum heat flux, a single TEC generator was able to produce 4.9 W for a temperature difference of 109°C, corresponding to 2.9% electrical efficiency. The overall CTEG system was able to produce electric power of up to 5.9 W for a 35°C temperature difference with a hot-side temperature of 68°C. The results of the investigation help to estimate the potential of the CTEG system and show concentrated thermoelectric generation to be one of the potential options for production of electric power from renewable energy sources.     

A General Model for the Electric Power and Energy Efficiency of a Solar Thermoelectric Generator

A general model for the electric power and energy efficiency of a solar thermoelectric generator is discussed, considering the influences of the input energy, the thermal conductivity, the absorptivity and emissivity of the heat collector, and the cooling water. The influences of these factors on the performance of the thermoelectric device are discussed, considering the thermoelectric generator as a whole, including the heat collector, the thermoelectric device, and the cooling. Results show that high input energy, and high absorptivity and low emissivity of the heat collector, are helpful for obtaining a high-performance thermoelectric generator. A high thermal transfer coefficient of the cooling water can increase the temperature difference across the thermoelectric device but results in greater accessory power requirements if increased further.     

Design and Numerical Simulation of a Symbiotic Thermoelectric Power Generation System Fed by a Low-Grade Heat Source

All liquid heating systems, including solar thermal collectors and fossil-fueled heaters, are designed to convert low-temperature liquid to high-temperature liquid. In the presence of low- and high-temperature fluids, temperature differences can be created across thermoelectric devices to produce electricity so that the heat dissipated from the hot side of a thermoelectric device will be absorbed by the cold liquid and this preheated liquid enters the heating cycle and increases the efficiency of the heater. Consequently, because of the avoidance of waste heat on the thermoelectric hot side, the efficiency of heat-to-electricity conversion with this configuration is better than that of conventional thermoelectric power generation systems. This research aims to design and analyze a thermoelectric power generation system based on the concept described above and using a low-grade heat source. This system may be used to generate electricity either in direct conjunction with any renewable energy source which produces hot water (solar thermal collectors) or using waste hot water from industry. The concept of this system is designated “ELEGANT,” an acronym from “Efficient Liquid-based Electricity Generation Apparatus iNside Thermoelectrics.” The first design of ELEGANT comprised three rectangular aluminum channels, used to conduct warm and cold fluids over the surfaces of several commercially available thermoelectric generator (TEG) modules sandwiched between the channels. In this study, an ELEGANT with 24 TEG modules, referred to as ELEGANT-24, has been designed. Twenty-four modules was the best match to the specific geometry of the proposed ELEGANT. The thermoelectric modules in ELEGANT-24 were electrically connected in series, and the maximum output power was modeled. A numerical model has been developed, which provides steady-state forecasts of the electrical output of ELEGANT-24 for different inlet fluid temperatures.     

Feasibility Study on the Use of a Solar Thermoelectric Cogenerator Comprising a Thermoelectric Module and Evacuated Tubular Collector with Parabolic Trough Concentrator

We have designed a new solar thermoelectric cogeneration system consisting of an evacuated tubular solar collector (ETSC) with a parabolic trough concentrator (PTC) and thermoelectric modules (TEMs) to supply both thermal energy and electricity. The main design concepts are (1) the hot side of the TEM is bonded to the solar selective absorber installed in an evacuated glass tube, (2) the cold side of the TEM is also bonded to the heat sink, and (3) the outer circulated water is heated by residual solar energy after TEM generation. We present an example solar thermal simulation based on energy balance and heat transfer as used in solar engineering to predict the electrical conversion efficiency and solar thermal conversion efficiency for different values of parameters such as the solar insolation, concentration ratio, and TEM ZT values.     

Performance Analysis of a Thermoelectric Solar Collector Integrated with a Heat Pump

A novel heat pump system is proposed. A thermoelectric solar collector was coupled to a solar-assisted heat pump (TESC-HP) to work as an evaporator. The cooling effect of the system’s refrigerant allowed the cold side of the system’s thermoelectric modules to work at lower temperature, improving the conversion efficiency. The TESC-HP system mainly consisted of transparent glass, an air gap, an absorber plate that acted as a direct expansion-type collector/evaporator, an R-134a piston-type hermetic compressor, a water-cooled plate-type condenser, thermoelectric modules, and a water storage tank. Test results indicated that the TESC-HP has better coefficient of performance (COP) and conversion efficiency than the separate units. For the meteorological conditions in Mahasarakham, the COP of the TESC-HP system can reach 5.48 when the average temperature of 100 L of water is increased from 28°C to 40°C in 60 min with average ambient temperature of 32.5°C and average solar intensity of 815 W/m², whereas the conversion efficiency of the TE power generator was around 2.03%.     

A Four-Quadrant Operation Diagram for Thermoelectric Modules in Heating–Cooling Mode and Generating Mode

The operation of a thermoelectric module in heating–cooling mode, generating mode, and regenerating mode can be discussed in terms of power, cooling load, and current. A direct current machine in motoring mode and generating mode and an induction motor in motoring mode and regenerating mode are analogous to thermoelectric modules. Therefore, the first objective of this work is to present the four-quadrant (4-Q) operation diagram and the 4-Q equivalent circuits of thermoelectric modules in heating–cooling mode and generating mode. The second objective is to present the cooling and regenerating curves of a thermoelectric module in cooling mode and regenerating mode. The curves are composed from the cooling powers and the generating powers, the input and output current, the thermal resistance of the heat exchanger, and the different temperatures that exist between the hot and cold sides of the thermoelectric module. The methodology used to present the data involved drawing analogies between the mechanical system, the electrical system, and the thermal system; an experimental setup was also used. The experimental setup was built to test a thermoelectric module (TE₂) in cooling mode and regenerating mode under conditions in which it was necessary to control the different temperatures on the hot and cold sides of TE₂. Two thermoelectric modules were used to control the temperature. The cold side was controlled by a thermoelectric module labeled TE₁, whereas the hot side was controlled by a second thermoelectric module labeled TE₃. The results include the power, the cooling load, and the current of the thermoelectric module, which are analogous to the torque, the power, the speed, and the slip speed of a direct current machine and an induction motor. This 4-Q operation diagram, the 4-Q equivalent circuits, and the cooling and regenerating curves of the thermoelectric module can be used to analyze the bidirectional current and to select appropriate operating conditions in the cooling and regenerating modes.     

复杂环境下半导体致冷器的动态模型及温度控制

半导体致冷器在环境温度变化大,热传导不稳定,温度调节时间要求快等恶劣条件下工作时具有复杂的热电．特性,基于小信号线性化方法得出了半导体致冷器在复杂环境下的线性动态模型,推导结果表明该模型有两个极点和一个零点,并且模型随工作条件的变化而变化．基于平均意义上的动态模型,采用模糊自适应PID控制算法和脉宽调制技术设计了半导体致冷器冷端的温度控制系统．阶跃反应表明该温度控制系统具有良好的动态性能和稳态品质,并具有良好的抗干扰特性,制冷10％的时间约为70s,稳态误差非常小,达到0．1℃．在简单环境下工作．其温度控制效果优于0．1℃．实验亦表明该温度控制系统在常温环境下,最大制冷温度与环境温度之差达到23℃,且随着控制温度的降低,阶跃反应的时间也越来越长,主要是和半导体致冷器的制冷效率、热沉的散热功率和半导体致冷器的供电电流饱和有关．     

大功率半导体激光器的精密模糊PID温控系统

介绍了一种大功率半导体激光器的精密模糊PID温控系统.利用半导体致冷器作为控温执行器件,构成了全固态致冷系统,并且针对TEC的驱动特性,设计了一种高精度数字PWM功率驱动器.本系统采用AT89C52单片机,利用软件实现了在线参数自整定模糊PID控制算法以及热敏电阻的非线性补偿.试验证明,温度控制精度可达±0.06℃.