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The cycle models of a single-stage and a two-stage semiconductor thermoelectric refrigeration system are established, based on non-equilibrium thermodynamics. They are used to derive the general expressions of three important performance parameters, such as the coefficient of performance (COP), the rate of refrigeration, and the power input. By using these expressions, the performance of the two-stage thermoelectric refrigeration system is discussed in detail. The maximum COP and rate of refrigeration are calculated, the internal structure parameter of the thermoelectric device is optimized, and the reasonable ranges of some parameters are determined. The results obtained here are compared with those of a single-stage thermoelectric refrigeration system, and consequently the advantages of two-stage thermoelectric refrigerators are expounded. 相似文献
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Xiaohang ChenLiwei Chen Juncheng GuoJincan Chen 《International Journal of Hydrogen Energy》2011,36(10):6099-6104
Based on the models of a proton exchange membrane (PEM) fuel cell working at steady state and a semiconductor thermoelectric generator, a hybrid system consisting of a PEM fuel cell, a semiconductor thermoelectric generator, and a regenerator is originally put forward. Expressions for the efficiencies and power outputs of the fuel cell, thermoelectric generator, and hybrid system are derived. The relation between the operating electric currents in the fuel cell and thermoelectric generator is obtained. The maximum power output of the hybrid system is numerically given. The optimally operating electric currents in the fuel cell and thermoelectric generator are calculated, and consequently, the optimal region of the hybrid system is determined. The results obtained here will provide some guidance for further understanding the performance and operation of practical PEM fuel cell-thermoelectric generator hybrid systems. 相似文献
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The performance of a thermoelectric refrigeration device, consisting of multi-couple thermoelectric elements and operating between two heat-reservoirs at constant temperatures, is investigated. The influence of the external and internal irreversibilities of the thermoelectric refrigeration device on the performance of the system is analyzed. The general expressions of the coefficient of performance and power input are derived by introducing some dimensionless parameters and variables. The coefficient of performance of the refrigeration device is maximized for a given cooling-load and total heat-transfer area of the system, and consequently, the structure parameters of the device and the area ratio of the heat exchangers of the system are determined optimally. The effects of the various parameters on the optimal performance of the device are discussed further. The results obtained here will be useful for a more detailed investigation and for the optimal design and manufacture of real thermoelectric refrigeration devices. 相似文献
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《International Journal of Hydrogen Energy》1988,13(6):333-339
The recent results of research and developments in photochemical and photoelectrochemical water decomposition technologies are reviewed. A new system using a semiconductor photoelectrode combined with thermoelectric generation is also introduced. Basic principles as well as the feasibilities of these hydrogen production systems are interpreted laying stress on the hybrid, homogeneous and heterogeneous methods. Unsolved problems in the reaction mechanisms, instabilities, and corrosion are discussed. The present aim of these systems is to attain a greater efficiency than that of the combined system of solar cells and water electrolysis. 相似文献
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温差发电技术及其在汽车发动机排气余热利用中的应用 总被引:7,自引:0,他引:7
介绍了采用半导体热电元件的温差发电技术的特征,包括对半导体材料的要求,适合作汽车排气余热发电的温差发电器的结构等,给出了美、日等国车用温差发电器的实例,还对相关技术的发展趋势作了分析。 相似文献
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《Energy Conversion and Management》1995,36(12):1197-1200
Heat transfer at a finite rate and electrical resistive losses are necessarily irreversible processes and unavoidable in a thermoelectric device. It is shown that the internal and exernal irreversibilities in a thermoelectric refrigerator may be characterized by a single parameter, named the device-design parameter. The presence of this parameter in the equations for the refrigeration effect and the maximum input power, shows that a real refrigerator has a smaller cooling capacity and needs more input power than an ideal refrigerator. 相似文献
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Thermoelectric devices are considered a promising technique for recycling waste heat. In the present work, a three-dimensional numerical model is developed to study the output performance of thermoelectric devices. A comprehensive analysis is performed based on a conventional π-type thermoelectric couple. The results indicate that the maximum power of thermoelectric devices generally increases with a decrease in height and an increase in cross-sectional area; the maximum efficiency exhibits the opposite trends. The best way to reduce heat losses is by using ceramic plates with higher thermal conductivity. Moreover, the parasitic internal resistance exists in the thermoelements, and its influencing factors are studied. To minimize electric losses, an asymmetric structure is proposed for thermoelectric devices. The results exhibit that the optimal cross-sectional area ratio of the p-type and n-type legs (Sp/Sn) is mainly contingent upon the thermoelectric material parameters; the greater the differences in the parameters of p-type and n-type thermoelectric materials, the greater the gains provided by the asymmetric structure. Furthermore, the experimental data present great consistency with the numerical results. The research results may help guide the design of thermoelectric devices with relatively lower power losses. 相似文献
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A hybrid solar system with high temperature stage is described. The system contains a radiation concentrator, a photovoltaic solar cell and a heat engine or thermoelectric generator. Two options are discussed, one with a special PV cell construction, which uses the heat energy from the part of solar spectrum not absorbed in the semiconductor material of the cell; the other with concentration of the whole solar radiation on the PV cell working at high temperature and coupled to the high temperature stage. The possibilities of using semiconductor materials with different band gap values are analyzed, as well as of the different thermoelectric materials. The calculations made show that the proposed hybrid system could be practical and efficient. 相似文献
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The paper studied the performances of parallel thermoelectric generator (TEG) by theoretical analysis and experimental test. An analytical model of parallel TEG was developed by theoretical analysis and calculation, based on thermodynamics theory, semiconductor thermoelectric theory and law of conservation of energy. Approximate expressions of output power and current of parallel TEG were deduced by the analytical model. An experimental system was built to verify the model. The results indicate that only when all of the thermoelectric modules (TE modules) in the parallel TEG have the same inherent parameters and working conditions, the parallel properties of the TEG are the same as that of common DC power. The existence of contact resistance is just like the increase of the TE module’s internal resistance, which leads to the deceases of output power. The thermal contact resistance reduces the output power by reducing the temperature difference between the two sides of the thermocouples. The results derived from the model are basically consistent with the experimental results, the model is suitable for the performance researching and designing of parallel TEG. 相似文献
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《International Journal of Hydrogen Energy》2022,47(34):15547-15555
Today, the earnest need for earth-abundant and environmentally friendly thermoelectric materials has revealed the importance of semiconductor metal oxides in order to eliminate the barrier towards their wide-ranging use in industrial applications. In the present work, we demonstrate the synthesis of p-type tin oxide thin films on quartz glass and Si substrates by using electron beam evaporation technique followed by rapid thermal annealing process at 200 °C for 20 min in Ar-atmosphere. Annealing-induced structural, electrical, optical and thermoelectric properties of pristine and annealed SnO thin films are primarily studied. The compositional and structural analysis of SnO films are performed by using X-Ray Diffraction, Scanning Electron Microscope as well as Atomic Force Microscope. Moreover, the mechanism of thermoelectric transportation at different measurement temperatures is deeply inspected via thermoelectric measurements. The Seebeck coefficient, carrier concentration and hole mobility in conjunction with the development of thin film nanostructures are discussed, predominantly. The optimal annealing may tune structural, electro-optic and thermoelectric properties of SnO films for the commercial-level maturity of thermoelectric devices for energy applications. 相似文献
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B. M. Abdurakhmanov M. M. Adilov M. Kh. Ashurov Kh. B. Ashurov S. E. Maksimov B. L. Oksengendler 《Applied Solar Energy》2012,48(2):79-83
The work presents a model of equivalent medium that allows one to estimate the thermoelectric characteristics of nonuniform semiconductor materials. The model describes experimental results obtained on microgranular silicon and defines ways of achieving high values of thermoelectric Q factor in transformers of thermal energy based on granulated semiconductors in a temperature range that can be easily achieved using solar concentrators. 相似文献
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A surge in interest in developing alternative renewable energy technologies has been observed in recent years. In particular, thermoelectrics has drawn attention because thermoelectric effects enable direct conversion between thermal and electrical energy, and provide power generation and refrigeration alternatives. During the past decade, the performance of thermoelectric materials has been considerably improved; however, many challenges continue to exist. Developing thermoelectric materials with superior performance means tailoring interconnected thermoelectric physical parameters-electrical conductivities, Seebeck coefficients, and thermal conductivities for a crystalline system. The objectives of this paper are to introduce the recent developments in semiconductor thermoelectric materials, and briefly summarize the applications of such materials. 相似文献
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In this paper, a mathematical model of two-stage thermoelectric refrigeration system is established considering the influence of external heat transfer and its performance is analysed based on finite-time thermodynamics and Newton's heat transfer law. Taking the cooling capacity and coefficient of performance of the two-stage thermoelectric refrigeration system as separate objective functions, the general relationship between cooling capacity, coefficient of performance, and working design parameters of the system is determined. The influence of the fluctuation of the input design parameters on the output performance parameters is studied using a global sensitivity analysis based on the variance response. The main and total Global sensitivity indices of input parameters that affect the output performance are calculated, and the related sensitivity ranking are obtained. The results can be used to guide the performance analysis and parameter optimization of two-stage thermoelectric refrigeration system in application. 相似文献
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针对空间核电转换系统静态热电转换发电效率低的问题,设计开发了一种新型的热离子-碱金属混合发电系统。将热离子热电转换系统作为高温热源,配合碱金属热电转换系统耦合发电,通过建立耦合发电系统数理模型,研究了系统接收极功函数和系统电流密度对混合发电系统功率效率的影响。计算结果表明:热离子-碱金属混合发电系统较热离子热电转换系统发电效率提高约6.00%,较碱金属热电转换系统发电效率提高约10.00%,为静态热电转换系统的效率优化提供了理论依据。 相似文献