常壓下熱電材料特性量測方法之模擬與分析

Simulation and Analysis of Thermoelectric Measurement Methods Under Atmospheric Pressure

王傳鈞(Chuan-Jyun Wang)

指導教授 ： 洪銘聰

國立中央大學/工學院/能源工程研究所/碩士(2011年)

摘要

本論文主要是介紹常壓下熱電量測的模擬分析及設計過程。由於常壓下的模擬和量測，必須考慮到環境因素的條件，因此，自行設計了一封閉系統，使系統內的環境溫度呈一穩定的狀態，來減少量測過程中的誤差。所以在此必須先瞭解熱電材料的統御方式，再透過有限元素的分析，使其對熱電材料模擬，並且藉由模擬的過程中，可以看出熱電材料所呈現的變化。
除了熱電材料的模擬外，還特別考慮到封閉系統內的流場變化，也就是針對自然熱對流的效應去探討，並且選用Navier-Stokes和熱傳方程式去模擬分析，利用熱流耦合的方式去分析整個流場的熱對流效應，使瞭解熱電塊材在封閉系統內，是否會受到流場變化的影響。
然而現今熱電材料已被廣泛的研究和使用，但好像都沒有一定的量測方式，因此，利用模擬的方式去探討熱電變化的過程，經過模擬的驗證後，再藉由此方式去架設熱電量測的設備，讓此設備可以同時進行Seebeck係數和熱傳導係數的量測。
最後再針對兩種不同結構的材料去量測，分別去探討矽及多孔矽結構的材料，去比較其量測值之間的差異，並藉由量測的結果去瞭解相同的材料而不同的結構，就會產生不同的熱電效應，也就是因為熱傳導係數的改變，而影響到熱電優值(ZT)的變化。
本模擬是利用Comsol有限元素分析軟體建立熱電模型，探討其溫度分佈及熱流耦合效應的影響。

關鍵字

熱電模擬 ； 熱電材料 ； 熱電量測 ； 多孔矽 ； 自然對流

並列摘要

This paper is to introduce the thermoelectric simulation analysis and design measured at atmospheric pressure.When the simulation and measurement at atmospheric pressure, the environmental factor needs to be considered.Therefore, designing a closed system in order to let the temperature become stable and reduce the error during the process of measurement.At first, we need to understand the way of controlling thermoelectric materials, and simulate the thermoelectric materials by finite element. From the process of simulation, we would observe the change of thermoelectric materials.
This experience is based on : 1.thermoelectric simulation 2. closure of the flow patterns within the system. we use Navier-Stokes and Thermal diffusion equation to simulate and analyze. We discuss the effect of natural convection especially.
However, the current thermoelectric materials have been extensively studied and used, but did not seem to be the measurement standard, therefore, with the simulations to investigate the thermal changes in the process of verification through simulation, then by the way Set up thermal power measurement equipment, so the device can be Seebeck coefficient and thermal conductivity measurements.
Finally, the structure for two different materials to measure, respectively, to explore the structure of silicon and porous silicon materials, to compare the differences between the measured values, and by measuring the results to understand the same material, but different Structure, will have different thermoelectric effect, which is due to changes in thermal conductivity, which affects the figure of merit (ZT) changes.
This simulation is the use of Comsol finite element analysis software thermal model to investigate the temperature distribution and thermal coupling effect.

並列關鍵字

thermoelectric materials ； thermoelectric simulation ； thermoelectric measurements ； porous silicon ； natural convection

參考文獻

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