Comparative analysis of thermoelectric elements optimum geometry between photovoltaic-thermoelectric and solar thermoelectric
Comparative analysis of thermoelectric elements optimum geometry between photovoltaic-thermoelectric and solar thermoelectric
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DOI：
10.1016/j.energy.2019.01.057
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发表时间：
2019-01
期刊：
影响因子：
9
通讯作者：
Guiqiang Li;Samson Shittu;Xiaoli Ma;Xudong Zhao
中科院分区：
文献类型：
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作者：
Guiqiang Li;Samson Shittu;Xiaoli Ma;Xudong Zhao
优化热电器件的几何结构是提高热电器件效率和输出功率的重要途径之一。然而，由于光伏与热电器件之间的复杂关系，需要对光电-热电混合器件中热电器件的最佳几何形状进行研究。因此，本研究探讨了光伏热电（PV-TE）器件和太阳能热电发电机（STEG）的最佳性能的最佳热电几何形状。采用三维有限元法对不同热电腿几何形状的PV-TE和STEG进行了建模。研究了两种不同PV电池和不同TE支腿几何形状的PV-TE的性能，并与STEG的性能进行了比较，确定了每种设备的最佳支腿几何形状。此外，还分析了太阳辐射和浓度比对优化后器件几何性能的影响。结果表明，混合PV- te器件的最佳热电几何形状取决于PV电池类型，这与相同条件下的STEG器件不同。当使用对称（矩形）热电腿时，具有1号电池的PV- te设备具有提高的整体效率，然而，当PV电池类型改变时，情况就不同了。事实上，当使用梯形热电腿而不是矩形腿时，具有电池2的PV-TE设备具有提高的整体效率，这与在STEG的情况下观察到的趋势相同。因此，独立太阳能热电发电机的最佳几何形状不能直接作为PV- te器件的参考，因为PV电池的特性会影响PV- te的最佳几何形状。本研究结果将揭示STEG和PV-TE的不同最佳几何形状，并为混合PV-TE器件的优化工作提供坚实的基础。
The optimization of the thermoelectric (TE) device geometry is one of the significant ways to improve its efficiency and power output. However, the complex relationship between the Photovoltaic and the thermoelectric device necessitates the need for the study of the optimum geometry of the thermoelectric device in a hybrid Photovoltaic-thermoelectric device. Therefore, this study investigates the optimum thermoelectric geometry for optimum performance of a Photovoltaic-thermoelectric (PV-TE) device and a solar thermoelectric generator (STEG). A three-dimensional finite element method is used to model the PV-TE and the STEG with different thermoelectric leg geometries. The performance of the PV-TE with two different PV cells and different TE leg geometries is investigated and compared with that of the STEG, and the optimum leg geometry for each device is identified. In addition, the effects of solar radiation and concentration ratio on the optimized device geometry performance are presented. Results obtained showed that the optimum thermoelectric geometry in a hybrid PV-TE device is dependent on the PV cell type and this is different from that of the STEG under the same conditions. The PV-TE device with cell 1 has an improved overall efficiency when a symmetrical (rectangular) thermoelectric leg is used however, this is different when the PV cell type is changed. In fact, the PV-TE device with cell 2 has an improved overall efficiency when a trapezoidal thermoelectric leg is used instead of a rectangular leg and this is the same as is the same trend observed in the case of the STEG. Therefore, the optimum geometry for a stand-alone solar thermoelectric generator cannot be directly used as a reference for the PV-TE device as the characteristics of the PV cell affects the PV-TE optimum geometry. Results from this study will indicate the different optimum geometries of STEG and PV-TE, and also provide a solid basis for optimization efforts in hybrid PV-TE devices.