本研究建立嵌入式熱電發電模組與廢氣煙道之三維物理模型，並透過數值模擬分析煙道內之流場以及熱電模組之溫度場與電場之分布。煙道內工作流體為400K~700K之氣體，因此煙道內之流場必須同時考慮對流熱傳與輻射熱傳。嵌入式熱電模組在煙道內藉由嵌入式鰭片增加熱傳面積達到熱傳增強效果，但相對伴隨著鰭片所產生之泵功。為驗證數值模擬之準確性，本研究利用自行架設之小型風洞實驗系統，量測圓形針狀鰭片與橢圓形針狀鰭片在不同鰭片排列型式及操作條件下，熱電模組之性能曲線：V-I(voltage-current)與P-I(power-current)曲線，將實驗結果與數值模擬進行比對後，發現其最大誤差約為11%。
本研究採用圓形針狀鰭片(circular pin fin)與橢圓形針狀鰭片(elliptical pin fin)作為熱電模組之熱擷取裝置，探討不同的鰭片排列型式(水平排列, in-lined arrangement、交錯排列, staggered arrangement)，以及鰭片幾何尺寸( 鰭片高度 0mm < Hfin < 150mm、鰭片橫向間距(Xt) )於不同操作條件下(進口風速Vin = 1、3、5 m/s；廢氣溫度Tgas = 450、550、650K)模組之發電性能。研究中分析熱電模組之理想發電密度(Pideal/A)與鰭片所造成的泵功密度(Ppump power/A)，再藉由兩者相減而得的淨發電密度(Pnet/A)作為比較嵌入式鰭片熱電模組性能優劣之依據。在鰭片熱傳面積相近的條件下，操作條件為廢氣溫度550K時，本研究發現交錯式橢圓形針狀鰭片熱電模組相較於交錯式圓形針狀鰭片與平板式鰭片熱電模組，其淨發電密度分別可提升約17.9% 與35.8%。

A 3D numerical model of thermoelectric generator (TEG) modules are attached to a large chimney plate is proposed and solved numerically using a control volume based finite difference formulation. The thermoelectric module consists of a thermoelectric generator, an elliptical pin fin heat sink, a cold plate based on water cooling. In the chimney the temperature of flue gases would be 450-650K. Therefore, both the effects of convection and radiation heat transfer should be considered. Although the TEG hot side temperature and thus the electric power output can be increased through inserting elliptical pin-fin heat sink into the chimney tunnel to increase the heat transfer area, the pin fin heat sink would cause extra pumping power at the same time. On the whole, the main purpose of this study is to analyze the effects of the geometrical parameters on both the electric power output and the chimney pressure drop characteristics. In addition, the effects of different operating conditions, including different inlet velocities (Vin = 1、3、5 m/s) and different inlet temperatures (Tgas = 450、550、650K) are also discussed in detail. The predicted numerical data for the power vs. current (P-I) curve are in good agreement (within 11%) with the experimental data.

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