DOI QR코드

DOI QR Code

Design and Evaluation of Small-scale Supercritical Carbon Dioxide System with Solar Heat Source

태양열 적용을 위한 소형 초임계 이산화탄소 실험설비 설계 및 평가

  • Choi, Hundong (Department of Mechanical and Control Engineering, Handong Global University) ;
  • So, Wonho (Department of Mechanical and Control Engineering, Handong Global University) ;
  • Lee, Jeongmin (Department of Mechanical and Control Engineering, Handong Global University) ;
  • Cho, Kyungchan (Department of Mechanical and Control Engineering, Handong Global University) ;
  • Lee, Kwon-yeong (Department of Mechanical and Control Engineering, Handong Global University)
  • 최훈동 (한동대학교 기계제어공학과) ;
  • 소원호 (한동대학교 기계제어공학과) ;
  • 이정민 (한동대학교 기계제어공학과) ;
  • 조경찬 (한동대학교 기계제어공학과) ;
  • 이권영 (한동대학교 기계제어공학과)
  • Received : 2020.03.16
  • Accepted : 2020.06.05
  • Published : 2020.06.30

Abstract

This paper focuses on the design of a 12-kW small-scale supercritical CO2 test loop. A theoretical study, stabilization, and optimization of carbon dioxide were carried out with the application of a solar heat source based on solar thermal data in Pohang. The thermodynamic cycle of the test facility is a Rankine cycle (transcritical cycle), which contains liquid, gas, and supercritical CO2. The system is designed to achieve 6.98% efficiency at a maximum pressure of 12 MPa and a maximum temperature of 70℃. In addition, the optimum turbine inlet temperature and pressure were calculated to increase the cycle efficiency, and the application of an internal heat exchanger (IHX) was simulated. It was found that the maximum efficiency increases to 18.75%. The simulation confirmed that the efficiency of the cycle is 6.7% in May and 6.26% in June.

본 논문은 포항지역 태양광 데이터를 기반으로 태양열을 적용시켜 12kW의 소형 초임계 이산화탄소(s-CO2) 시험 루프의 설계와 실험 시설의 이론적 연구, 안정화 및 최적화를 통한 이산화탄소의 특성 연구에 초점을 맞추고 있다. 실험 시설의 열역학 사이클은 구성 요소의 한계로 인해 액체, 가스 및 초임계 CO2가 모두 존재하는 랭킨 사이클(임계점 순환 주기)이며, 펌프, 히터, 레귤레이터, 열교환기, 가스 부스터, 에어 컴프레서 등으로 구성된다. 현재 본 연구에서 제작된 12kW 소형 발전 시스템은 최고압력 12MPa 최고 온도 70℃의 조건에서 6.98%의 효율이 나타나도록 설계되었다. 본 실험 장치를 소형 Brayton cycle과 비교했을 때 약 2% 높은 효율을 가진다는 것을 이론적으로 확인하였고, 사이클 효율을 높이기 위해 최적의 터빈 입구 온도와 압력을 얻었으며, 이 조건에서 IHX(내부 열교환기)의 도입시 18.75%의 최대 효율을 기대할 수 있다는 결론을 도출하였다. 마지막으로, 실험 설비의 태양광 시뮬레이션 결과 5월에는 6.7%, 6월에는 6.26%의 효율로 태양열을 이용할 수 있음을 확인하였다.

Keywords

References

  1. J-I. Lee, Y-H. Ahn, J-E. Cha, "Introduction to supercritical CO2 power conversion system and its development status". Korean Society for Fluid Machinery collection of dissertations, vol. 17, no.6, pp. 95-103, December. 2014. DOI: https://doi.org/10.5293/kfma.2014.17.6.095
  2. Korea Atomic Energy Research Institute, "Component Technology Development for the Supercritical Gas Brayton Cycle," pp. 6-26, Ministry of Science, ICT and Future Planning, 2015.
  3. X.R. Zhang, H. Yamaguchi "An experimental study on evacuated tube solar collector using supercritical CO2", Applied Thermal Engineering, vol. 28, no.10, pp. 1225-1233, July. 2008. DOI: https://doi.org/10.1016/j.applthermaleng.2007.07.013
  4. D-N. Choi, J-Y. Yu, J-S. Kwon, U-B. Lee, K-J. Pi, C-H. Son, K-Y. Lee, J-Y. Lee, J-H. Sung, "Design on Small-scale Supercritical CO2 Cycle Test Facility". The Korean Society of Mechanical Engineers an academic conference, pp. 2540-2544, December. 2018.
  5. S-J. Kim, J-S. Lee, M-S. Kim, "Comparison and Characteristic Analysis of Supercritical CO Brayton Cycle and Steam Rankine Cycle for Waste Heat Recovery", The Society Of Air-Conditioning And Refrigerating Engineers Of Korea an academic conference, pp. 83-86, November. 2015
  6. Y-M. Kim, J-L. Sohn, E.S. Yoon, "Supercritical CO2 Rankine cycles for waste heat recovery from gas turbine". Energy, vol 118, 1. pp. 893-905, January, 2017. DOI: https://doi.org/10.1016/j.energy.2016.10.106
  7. H. Yamaguchi, X.R. Zhang, K. Fujima, M. Enomoto, N. Sawada, "Solar energy powered Rankine cycle using supercritical CO2", Applied Thermal Engineering, vol. 26, no.17-18, pp. 2345-2354, July. 2006. DOI: https://doi.org/10.1016/j.applthermaleng.2006.02.02.
  8. C. Guo, X. Du, Y. Zhou, L. Yang, Y. Yang, "Supercritical CO2 Rankine Cycle Using Low and Medium Temperature Heat Sources". ASME. Energy Sustainability, ASME 2013 7th International Conference on Energy Sustainability, pp. 9, December. 2013. DOI: https://doi.org/10.1115/ES2013-18398
  9. H. Yamaguchi, X.R. Zhang, D. Uneno, "Thermodynamic analysis of the CO2-based Rankine cycle powered by solar energy". International Journal of Energy Research. vol. 31, no.14, pp. 1414-1424. November, 2007. DOI: https://doi.org/10.1002/er.1304