DOI QR코드

DOI QR Code

알칼리금속 열전기변환장치의 접합과 출력성능

Joining and Performance of Alkali Metal Thermal-to-electric Converter (AMTEC)

  • 투고 : 2016.03.22
  • 심사 : 2017.01.03
  • 발행 : 2017.07.01

초록

알칼리금속을 이용한 열전기변환장치(Alkali-Metal Thermal-to-electric Converter)는 열을 전기로 직접 변환하는 기술이다. AMTEC 기술은 기존 에너지기술 대비 고효율성과 고밀도성을 지니는 정적 에너지 변환 장치로서 이론 발전효율이 40%로 높고 단위발전량이 500 W/kg, $2.01W/cm^2$로 우수하다. AMTEC의 작동원리는 작동유체인 소듐이 분압차이에 의해서 고체전해질인 베타알루미나(BASE)의 내부에서 외부로 이온화를 거쳐며 통과하는데, 이때 전자를 주고 받으며 전기를 생성한다. BASE내외부의 분압차 형성을 위해서는 고온내구성과 기밀성이 높은 접합기술이 요구된다. 개발된 접합기술을 이용하여BASE/절연부/금속부 시스템의 안정적인 전기적/구조적 시스템을 구성하고 멀티-셀 모듈들을 제작하여 개방회로 전압과 전류-전압특성을 측정하는 방법으로 AMTEC 모듈전지들의 출력성능과 수명을 평가하였다.

The alkali-Metal Thermal-to-electric Converter (AMTEC) is one of the promising static energy conversion technologies for the direct conversion of thermal energy to electrical energy. The advantages over a conventional energy converter are its high theoretical conversion efficiency of 40% and power density of 500 W/kg. The working principle of an AMTEC battery is the electrochemical reaction of the sodium through an ion conducting electrolyte. Sodium ion pass through the hot side of the beta"-alumina solid electrolyte (BASE) primarily as a result of the pressure difference. This pressure difference across the BASE has a significant effect on the overall performance of the AMTEC system. In order to build the high pressure difference across the BASE, hermeticity is required for each joined components for high temperature range of $900^{\circ}C$. The AMTEC battery was manufactured by utilizing robust joining technology of BASE/insulator/metal flange interfaces of the system for both structural and electrical stability. The electrical potential difference between the anode and cathode sides, where the electrons emitted from sodium ionization and recombined into sodium, was characterized as the open-circuit voltage. The efforts of technological improvement were concentrated on a high-power output and conversion efficiency. This paper discusses about the joining and performance of the AMTEC systems.

키워드

참고문헌

  1. Kummer, J.T. and Weber Neill, 1968, "A Sodium- Sulfur Secondary Battery," Trans. S.A.E., Vol. 76, pp. 1003-1007.
  2. Weber, N., 1974 "A Thermoelectric Device based on Beta-alumina Solid Electrolyte," Energy Conversion, Vol. 14, No. 1, pp. 1-8. https://doi.org/10.1016/0013-7480(74)90011-4
  3. Cole, T., 1983, "Thermoelectric Energy Conversion with Solid Electrolytes," Science, Vol. 221, No. 4614, pp. 915-920. https://doi.org/10.1126/science.221.4614.915
  4. El-Genk, M.S. and Tournier, J.-M., 1998, "Recent Advances in Vapor-anode, Multi-tube, Alkali Metal Thermal-to-electric Conversion Cells for Space power," Eur. Space Agency Spec. Publ. SP, 416, pp. 257-264.
  5. Wu, S.-Y., Xiao, L. and Cao, Y.-D., 2009, "A Review on Advances in Alkali Metal Thermal to Electric Converters (AMTECs)," Int. J. Energy Res., Vol. 33, No. 10, pp. 868-892. https://doi.org/10.1002/er.1584
  6. Tournier, J.-M. and El-Genk, M.S., 1999, "Performance Analysis of Pluto/Express, Multitube AMTEC Cells," Energy Convers. Manage., Vol. 40, No. 2, pp. 139-173. https://doi.org/10.1016/S0196-8904(98)00048-X
  7. Tournier, J.-M. and El-Genk, M.S., 1999, "Analysis of Test Results of a Ground Demonstration of a Pluto/Express Power Generator," Energy Convers. Manage., Vol. 40, No. 11, pp. 1113-1128. https://doi.org/10.1016/S0196-8904(99)00027-8
  8. Williams, RM, et al., 1990, "Kinetics and Transport at AMTEC Electrodes -I. The Interfacial Impedance Model," J. Electrochem. Soc., Vol. 137, No. 6, pp. 1709-1716. https://doi.org/10.1149/1.2086775
  9. Jerebtsov, D.A. and Mikhailov G.G., 2001, "Phase Diagram of CaO - $Al_2O_3$System," Ceram. Int., Vol. 27, pp. 25-28. https://doi.org/10.1016/S0272-8842(00)00037-7
  10. Suh, M.S., et al, 2014, "Dissimilar Joining of Metal- Ceramics and Joining Strength," Proc. Korean Soc. Mech. Eng., 2014 Spring, pp. 71-72.
  11. Suh, M.S., et al, 2015, "Joining and Their Performance of Alkali Metal Thermoelectric Converter (AMTEC)," Proc. Korean Soc. Mech. Eng., 2015 Spring, p. 80.