共查询到18条相似文献,搜索用时 93 毫秒
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太阳能热电转换是光伏效应外另一种直接将太阳辐射转变为电能的途径, 近年来已经成为太阳能利用的热点之一. 本文以Bi2Te3材料为基础构建平板集热太阳热电器件模型, 采用有限元法分析AM1.5辐射条件下器件温度分布情况, 并结合基于温度的物性参数计算集热比、热臂截面积与长度变化等因素对器件的开路电压、 最大输出功率及转化效率的影响. 研究发现: 集热比与热臂长度的变化对器件性能有显著影响, 热臂截面积的变化对器件转化效率影响相对较弱; 在这一模型中, 平板集热太阳热电器件的转化效率达到1.56%. 相似文献
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热电材料可以实现热能和电能的相互转换,它是一种环境友好的功能性材料.当前,热电材料的热电转换效率低,这严重制约了热电器件的大规模应用,因此寻找更加优异热电性能的新材料或提高传统热电材料的热电性能成为热电研究的主题.与块状材料相比,薄膜具有二维的宏观性质和一维的纳米结构特性,方便研究材料的物理机制与性能的关系,还适用于制备可穿戴电子设备.本文总结了Cu2Se薄膜5种不同的制备方法,包括电化学沉积、热蒸发、旋涂、溅射以及脉冲激光沉积.另外,结合典型事例,总结了薄膜的表征手段,并从Cu2Se的电导率、塞贝克系数和热导率等参数出发,讨论了各个参数对热电性能的影响机制.最后介绍了Cu2Se薄膜热电的热门应用方向. 相似文献
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光伏-热电耦合系统器件选择原理 总被引:2,自引:0,他引:2
耦合器件的性能决定了光伏-热电耦合系统的可行性与优越性,但耦合系统器件的选择原理尚未被研究。本文建立了光伏热电耦合系统的理论模型,提出了使得光伏-热电耦合系统效率优于纯光伏系统的最小热电优值作为耦合系统器件选择与可行性评估的标准。提供了一套计算最小热电优值的方法,给出了采用具有不同效率及温度特性的光伏电池的耦合系统的最小热电优值,并讨论了热电器件结构和冷却系统对最小热电优值的影响。 相似文献
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《物理学报》2019,(24)
热电材料能够将废热能直接转换成电能,近年来受到了科技工作者们的广泛关注.本文采用非平衡格林函数方法系统地研究了晶界对石墨烯纳米带热电性能的调控作用.研究结果表明:晶界能有效地提高石墨烯纳米带的塞贝克系数,同时可以极大地抑制其热导(包含电子和声子部分).基于这两个积极的效应,多晶石墨烯纳米带的热电转换性能得到了显著的增强.在室温下,多晶石墨烯纳米带的热电品质因子约为0.3,较完美石墨烯纳米带(约为0.05)提升了6倍左右.并且发现晶界的数量和系统的长度还能进一步提升多晶石墨烯纳米带的热电性能,但系统的宽度对其影响有限.这些结果表明,多晶结构可以显著提升石墨烯纳米带的热电转换效率.这将为设计和制备基于石墨烯纳米带的热电器件提供新的途径. 相似文献
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一种基于虚拟技术的新型测量材料导热系数的方法 总被引:1,自引:0,他引:1
针对稳态平板法测量材料导热系数存在的缺点,介绍了一种新的测量方法——瞬时平面热带法,并用虚拟仪器采集数据、数据处理及数据显示。 相似文献
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本文提出一种新型的半导体温差发电模型,在温差发电过程的数值模拟中考虑了热电单元之间封闭腔体内空气传热的影响.同时进一步运用有限元的数值计算方法对不同电臂对数和不同型号温差发电模型的温度场、电压场进行了数值仿真计算,并对仿真结果进行分析.结果表明:采用127对热电单元模型计算的能量转换效率随冷热端温差增大而迅速提高,与采用1对热电单元模型计算的能量转换效率之差从冷热端温差为20℃的0.39%提高到冷热端温差为220℃时的5.16%,能量转换效率比1对热电单元平均高出3.02%.冷端温度恒定在30℃时,温差发电芯片的输出电压、功率以及能量转换效率均随着电偶臂的横截面积的增大而提高,且电偶臂冷热两端的温差越大提高幅度也越大,而温差发电芯片内阻则与电偶臂横截面积成反比关系,当温差为220℃时对应的输出功率最高达28.9 W. 相似文献
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Improvement of the heat transfer of the cold side is one of the approaches to enhance the performance of TEG systems.As a new type of heat transfer media, nanofluids can enhance the heat transfer performance of working liquid significantly.Based on a three-dimensional and steady-state numerical model,the heat transfer and thermoelectric conversion properties of TEG systems were studied. Graphene anoplatelet aqueous nanofluids were used as the coolants for the cold side of the TEG system to improve the heat transfer capacity of the cold side. The results showed that the heat absorbed by the hot side, voltage, output power, and conversion efficiency of the TEG system were increased greatly by the nanofluid coolants.The output power and the conversion efficiency using 0.1-wt% graphene nanoplatelet aqueous nanofluid as the coolant are enhanced by 26.39% and 14.74%, respectively. 相似文献
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本文建立了热电发电系统(TEG)多物理场数值模型,并充分考虑换热器流体影响,综合研究了具有不同热侧换热器翅片结构的TEG系统性能。在雷诺数为1000~10000范围内,分析了流体沿程温度分布特征、泵功及热电发电模块的能量转换特性.所研究的三种翅片结构包括:全流道等高度直翅片(Fin-1)、下游强化梯度翅片(Fin-2)以及上游强化梯度翅片(Fin-3).研究表明,通道长高比及热电材料覆盖率一定,热电发电功率及转换效率随流量呈二次曲线变化关系,存在最匹配流量使得系统发电性能最佳。等高度直翅片对流量的变化敏感,随流量增大,则压损增大,导致系统净输出功率及发电效率无收益.而梯度翅片可以在更大范围内产生正收益;下游强化梯度翅片具有最佳的流体沿程温度均匀性,但沿程局部热阻却最大.综合考虑沿程局部热阻分布及泵功消耗,上游强化梯度翅片TEG系统净转换效率最高,因此局部热阻分布及泵功综合因素应为TEG内的换热器合理设计的关键。 相似文献
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The effective properties of thermoelectric composites are well known to depend on boundary conditions, which causes the macro performance of thermoelectric composite to be difficult to assess. The overall macro-performance of multilayered thermoelectric medium is discussed in this paper. The analytical solutions are obtained, including the heat flux, temperature,electric potential, and the overall energy conversion efficiency. The results show that there are unique relationships between the temperature/electric potential and the electric current/energy flux in the material, and whether the material is independent of or embedded in thermoelectric composites. Besides, the Peltier effect at the interface can significantly improve the overall energy conversion efficiency of thermoelectric composites. These results provide a powerful tool to analyze the effective behaviors of thermoelectric composites. 相似文献
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Mario Wolf Alexey Rybakov Richard Hinterding Armin Feldhoff 《Entropy (Basel, Switzerland)》2020,22(11)
Besides the material research in the field of thermoelectrics, the way from a material to a functional thermoelectric (TE) module comes alongside additional challenges. Thus, comprehension and optimization of the properties and the design of a TE module are important tasks. In this work, different geometry optimization strategies to reach maximum power output or maximum conversion efficiency are applied and the resulting performances of various modules and respective materials are analyzed. A Bi2Te3-based module, a half-Heusler-based module, and an oxide-based module are characterized via FEM simulations. By this, a deviation of optimum power output and optimum conversion efficiency in dependence of the diversity of thermoelectric materials is found. Additionally, for all modules, the respective fluxes of entropy and charge as well as the corresponding fluxes of thermal and electrical energy within the thermolegs are shown. The full understanding and enhancement of the performance of a TE module may be further improved. 相似文献
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《Comptes Rendus Physique》2016,17(10):1047-1059
Decades of research on thermoelectrics stimulated by the fact that nano- and meso-scale thermoelectric transport could yield higher energy conversion efficiency and output power has recently uncovered a new direction on inelastic thermoelectric effects. We introduce the history, motivation, and perspectives on mesoscopic inelastic thermoelectric effects. 相似文献
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Jin-cheng ZHENG 《Frontiers of Physics in China》2008,3(3):269-279
By converting waste heat into electricity through the thermoelectric power of solids without producing greenhouse gas emissions,
thermoelectric generators could be an important part of the solution to today’s energy challenge. There has been a resurgence
in the search for new materials for advanced thermoelectric energy conversion applications. In this paper, we will review
recent efforts on improving thermoelectric efficiency. Particularly, several novel proof-of-principle approaches such as phonon
disorder in phonon-glass-electron crystals, low dimensionality in nanostructured materials and charge-spin-orbital degeneracy
in strongly correlated systems on thermoelectric performance will be discussed.
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Thermoelectric materials provide a renewable and eco-friendly solution to mitigate energy shortages and to reduce environmental pollution via direct heat-to-electricity conversion. Discovery of the novel thermoelectric materials and optimization of the state-of-the-art material systems lie at the core of the thermoelectric society, the basic concept behind these being comprehension and manipulation of the physical principles and transport properties regarding thermoelectric materials. In this mini-review, certain examples for designing high-performance bulk thermoelectric materials are presented from the perspectives of both real objects and local fields. The highlights of this topic involve the Rashba effect, Peierls distortion, local magnetic field, and local stress field, which cover several aspects in the field of thermoelectric research. We conclude with an overview of future developments in thermoelectricity. 相似文献