Thermal and electrical analysis of SiGe thermoelectric unicouple filled with thermal insulation materials
Thermal and electrical analysis of SiGe thermoelectric unicouple filled with thermal insulation materials
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填充隔热材料的SiGe热电偶的热电分析
DOI：
10.1016/j.applthermaleng.2018.01.100
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发表时间：
2018-04-01
影响因子：
6.4
通讯作者：
Xiang, Yongchun
中科院分区：
文献类型：
--
作者：
Li, Jing;Xiang, Qingpei;Xiang, Yongchun
采用有限元法模拟了四种绝热材料填充SiGe单偶的热电性能。关键设计参数包括热电腿长度L、间距t（i）、热侧温度T-h（1073-1223 K）和冷侧温度T-c（573-773 K）对单偶性能的影响进行了评估。分析了Cassini飞船RTG用SiGe（Cassini SiGe）和国产球磨SiGe（BM SiGe）的单耦合模型。发现单位面积功率输出P-A、单位面积吸热量Q（hA）和单位面积放热量Q（cA）与腿长和腿间空间面积成反比。SiGe热电腿的转换效率η在T_h = 1223 K（1173 K）和T_c = 573 K时接近7.5%，如果腿间没有填充物，单偶的η将降低到1%以下。单偶填充绝热材料后，辐射热被屏蔽，填料的热流使η降低0.07- 0.5%，单偶η分别为7.09%和6.89%。建立了温差发电系统质量和功率密度的计算模型，并利用该模型对温差发电系统进行了优化。
Thermoelectric performance of SiGe unicouple filled with four kinds of thermal insulation materials is simulated using finite element method. Crucial design parameters including thermoelectric leg length L, space t(i), hot side temperature T-h within 1073-1223 K and cold side temperature T-c within 573-773 K were evaluated for their impact on the unicouple performance. Unicouple models consisted of SiGe served in RTG on board Cassini spacecraft (Cassini SiGe) and home-made ball milled SiGe (BM SiGe) are analyzed, respectively. It is found that the power output per unit area P-A, heat absorption per unit area Q(hA) and heat released per unit area Q(cA) are inversely proportional to leg length and space area between legs. The conversion efficiency eta of SiGe thermoelectric legs is similar to 7.5% at T-h = 1223 K (1173 K) and T-c = 573 K.eta of unicouple will decrease to below 1% if there is no fillers in the space between legs. For unicouple filled with thermal insulation materials, radiation heat is shielded, and heat flow from filler will lead to a eta decrease of 0.07-0.5%, where eta(unicouple) of 7.09% and 6.89% can be obtained, respectively. A model calculating system mass and power density for thermoelectric generator is built, and is used to optimize the system.