• 공업화학
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• 제27권4호
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• pp.353-357
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• 2016

인구 증가와 문명 발전에 따른 에너지 고소비형 사회로 진행됨에 따라 기존에 사용하던 에너지원의 고효율화 방안이 강구되고 있다. 이 중 열에너지 고효율화 방안으로 열전발전 기술이 주목을 받고 있다. 현재 열전발전 분야는 나노기술 등이 발전함에 따라 폐열회수 분야 등에서 충분한 경쟁력을 가질 수 있는 ZT > 2를 도달하였고, 더 높은 효율을 갖는 소재 개발 연구가 진행되고 있다. 본 총설에서는 현재 진행되고 있는 온도영역별 열전발전 소재 개발 및 모듈기술에 대해 간략히 소개하고자 한다.

• 한국전기전자재료학회논문지
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• 제30권7호
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• pp.454-458
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• 2017

$Bi_2Te_3$-based alloys have been intensively investigated as active materials for thermoelectric power generation devices from low-temperature (< $250^{\circ}C$) waste heat. In the present study, we fabricated Pb-doped, p-type $Bi_{0.48}Sb_{1.52}Te_3$ polycrystalline bulks by using meltsolidification and spark plasma sintering techniques, and evaluated their thermoelectric transport properties in an effort to develop optimized composition for low-temperature power generation applications. The electronic and thermal transport properties of $Bi_{0.48}Sb_{1.52}Te_3$ could be manipulated by Pb doping. As a result, the temperature for a peak thermoelectric performance (zT) gradually shifted toward higher temperatures with Pb content, suggesting that thermoelectric power generation efficiency can be enhanced by controlled Pb doping.

• 한국전자통신학회논문지
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• 제19권3호
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• pp.589-602
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• 2024

열전 발전기(TEG)는 일반적으로 열 변환 효율이 높지 않다. 열전 발전기 모듈의 성능은 재료의 특성, 다리의 개수 외에도 다리의 형상에 따라 달라진다. 본 연구에서는 폐열을 효율적으로 수확할 수 있도록 열전소자의 다리 형상을 원통형, 큐브형 등 다양한 기하학적 구조로 모델링하여 전기적 특성을 수치상으로 비교하였다. 다리 형상에 따른 온도분포 및 발전량을 비교하였고 기존 Cube 모양이 가장 높게 나타났다. 냉각효과를 적용한 발전량을 비교한 결과 자연대류에서는 Cone, 강제대류에서는 Hourglass 모양이 가장 높았다. 본 연구 결과에 따르면 기하학적 구조가 열전 발전기의 효율에 영향을 미칠 수 있음을 확인하였다

• 한국전기전자재료학회논문지
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• 제28권12호
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• pp.852-856
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• 2015

In this study, we investigate the effect of high-energy ball milling on thermoelectric transport properties in double-filled $CoSb_3$ skutterudite ($In_{0.2}Yb_{0.1}Co_4Sb_{12}$). $In_{0.2}Yb_{0.1}Co_4Sb_{12}$ powders are milled using high-energy ball milling for different periods of time (0, 5, 10, and 20 min), and the milled powders are consolidated into bulk samples by spark plasma sintering. Microstructure analysis shows that the high-energy ball milled bulk samples are composed of nano- and micro-grains. Because the filling fractions are reduced in the bulk samples due to the kinetic energy of the high-energy ball milling, the carrier concentration of the bulk samples decreases with the ball milling time. Furthermore, the mobility of the bulk samples also decreases with the ball milling time due to enhanced grain boundary scattering of electrons. Reduction of electrical conductivity by ball milling has a decisive effect on thermoelectric transport in the bulk samples, power factor decreases with the ball milling time.

• 동력기계공학회지
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• 제16권2호
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• pp.17-23
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• 2012

The steady three-dimensional computational thermal flow analysis using standard k-${\varepsilon}$ turbulence model was carried out to investigate the heat transfer characteristics of a cabin cooler for a commercial vehicle. The heat exchanging method of this cabin cooler is to use the cooling effect of a thermoelectric module. In view of the results so far achieved, the air system resistance of a cabin cooler is about 12.4 Pa as a static pressure, and then the operating point of a cross-flow fan considering in this study is formed in the comparatively low flowrate region. The air temperature difference obtained from the cold part of an thermoelectric module is about $26^{\circ}C$, and the cooling water temperature difference obtained from the hot part of an thermoelectric module is about $3.5^{\circ}C$.

• Korean Chemical Engineering Research
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• 제49권2호
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• pp.263-270
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• 2011

본 논문의 목적은 리튬-암모니아 솔루션$(Li(NH_3)_n)$의 실험을 통하여 암모니아물질의 임계점인 $-40^{\circ}C$ 근처에서의 열전특성을 분석하고 이를 증명하는 것이다. 실험 결과 0.58 MPM~1.87 MPM을 갖는 리튬-암모니아 솔루션 $(Li(NH_3)_n)$ 은 온도차$({\Delta}T=0{\sim}15^{\circ}C)$에서 전류가 전압에 비례하는 열전전력을 발생시킨다는 사실을 확인하였다. 본 논문은 열전 물질 개발에 새로운 방향을 제시할 것이다.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.957-958
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• 2006

Fe doped skutterudite $CoSb_3$ with a nominal composition of $Fe_xCo_{1-x}Sb_{12}(0{\leq}x{\leq}2.5)$ have been synthesized by mechanical alloying (MA) of elemental powders, followed by vacuum hot pressing. Phase transformations during mechanical alloying and vacuum hot pressing were systematically investigated using XRD. Single phase skutterudite was successfully produced by vacuum hot pressing using as-milled powders without subsequent annealing. However, second phase of $FeSb_2$ was found to exist in case of $x\geq2$, suggesting the solubility limit of Fe with Co in this system. Thermoelectric properties as functions of temperature and Fe contents were evaluated for the hot pressed specimens. Fe doping up to x=1.5 with Co in $Fe_xCo_{4-x}Sb_{12}$ appeared to increase thermoelectric figure of merit (ZT) and the maximum ZT was found to be 0.78 at 525K in this study.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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• pp.138-139
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• 2006

Metal organic chemical vapor deposition has been investigated for growth of $Sb_{2-x}Bi_xTe_3$ films on (001) GaAs substrates using diisopropyltelluride, triethylantimony and trimethylbismuth as metal organic sources. The thermoelectric properties were measured at room temperature and include Seebeck coefficient, electrical conductivity and Hall effect. In-plane carrier concentration and electrical Hall mobility were highly dependent on precursor's composition ratio and deposition temperature. The thermoelectric Power factor($={\alpha}^2{\sigma}$) was calculated from theses properties. The best Power factor was $2.6\;{\times}\;10^{-3}W/mK^2$, given by grown $Sb_{1.6}Bi_{0.4}Te_3$ at $450^{\circ}C$. These materials could potentially be incorporated into advanced thermoelectric unicouples for a variety of power generation applications.

• Journal of Power Electronics
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• 제19권1호
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• pp.220-233
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• 2019

This work aims to study and analyze the various operating modes of universal power converter which is powered by solar and thermoelectric generators. The proposed converter is operated in a DC-DC (buck or boost mode) and DC-AC (single phase) inverter with high efficiency. DC power sources, such as solar photovoltaic (SPV) panels, thermoelectric generators (TEGs), and Li-ion battery, are selected as input to the proposed converter according to the nominal output voltage available/generated by these sources. The mode of selection and output power regulation are achieved via control of the metal-oxide semiconductor field-effect transistor (MOSFET) switches in the converter through the modified stepped perturb and observe (MSPO) algorithm. The MSPO duty cycle control algorithm effectively converts the unregulated DC power from the SPV/TEG into regulated DC for storing energy in a Li-ion battery or directly driving a DC load. In this work, the proposed power sources and converter are mathematically modelled using the Scilab-Xcos Simulink tool. The hardware prototype is designed for 200 W rating with a dsPIC30F4011 digital controller. The various output parameters, such as voltage ripple, current ripple, switching losses, and converter efficiency, are analyzed, and the proposed converter with a control circuit operates the converter closely at 97% efficiency.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.70-75
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• 2000

We report results of a comparative study of the normal-state and superconducting properties in the GdBa$_2$(Cu$_{2.9}$Al$_{0.1}$)O$_z$ system with substitutions by Pr for the Gd and Ba sites. It is observed that, fur both Pr-doped systems, the superconducting transition temperature(T$_c$) decreases almost linearly with the Pr-content, but Pr at Ba sites results in a faster T$_c$ drop than that of Pr at Gd sites. The thermoelectric power measurements indicate that there is a strong correlation between the T$_c$ and the room temperature value of thermoelectric power. The experimental results are discussed in connection with existing models.