Journal of the Korean Society of Marine Environment & Safety (해양환경안전학회지)

The Korean Society of Marine Environment and safety (해양환경안전학회)
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Numerical Study on the Effect of Area Changes in Air Inlets and Vent Ports on the Ventilation of Leaking Hydrogen

급·배기구 면적 변화가 누출 수소 환기에 미치는 영향에 관한 수치해석적 연구

  • Lee, Chang-Yong (Division of Marine Engineering, Incheon National Maritime High School) ;
  • Cho, Dae-Hwan (Division of Marine Engineering, Mokpo National Maritime University)
  • 이창용 (국립인천해사고등학교) ;
  • 조대환 (목포해양대학교 기관시스템공학과)
  • Received : 2022.02.21
  • Accepted : 2022.04.27
  • Published : 2022.04.30
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Abstract

Hydrogen has reduced greenhouse gas (GHG) emissions, the main cause of global warming, and is emerging as an eco-friendly energy source for ships. Hydrogen is a substance with a lower flammability limit (LFL) of 4 to 75% and a high risk of explosion. To be used for ships, it must be sufficiently safe against leaks. In this study, we analyzed the effect of changes in the area of the air inlet / vent port on the ventilation performance when hydrogen leaks occur in the hydrogen tank storage room. The area of the air inlet / vent port is 1A = 740 mm × 740 mm, and the size and position can be easily changed on the surface of the storage chamber. Using ANSYS CFX ver 18.1, which is a CFD commercial software, the area of the air inlet / vent port was changed to 1A, 2A, 3A, and 5A, and the hydrogen mole fraction in the storage chamber when the area changed was analyzed. Consequently, the increase in the area of the air inlet port further reduced the concentration of the leaked hydrogen as compared with that of the vent port, and improved the ventilation performance of at least 2A or more from the single air inlet port. As the area of the air inlet port increased, hydrogen was uniformly stratified at the upper part of the storage chamber, but was out of the LFL range. However, simply increasing the area of the vent port inadequately affected the ventilation performance.

수소는 지구 온난화의 주범인 온실가스(GHG) 배출을 감소시키고 선박용 친환경 연료로서 대두되고 있다. 수소는 가연 하한계(Lower Flammability Limit, LFL)가 4 ~ 75 %이고 폭발 위험성이 큰 물질이다. 그래서 선박용으로 사용되려면 누출에 대비한 안전성이 충분히 확보되어야 한다. 본 연구에서는 수소탱크 저장실에서 수소 누출이 발생한 경우, 급·배기구의 면적 변화가 환기 성능에 미치는 영향을 분석하였다. 급·배기구의 면적은 1A = 740 mm × 740 mm이며 저장실 표면에 크기 및 위치 변경이 쉽도록 설정하였다. CFD 상용 소프트웨어인 ANSYS CFX ver 18.1을 이용하여 급·배기구의 면적을 1A, 2A, 3A, 5A로 변경하였고, 면적 변화에 따른 저장실 내의 수소 몰분율을 분석하였다. 그 결과 급기구 면적이 배기구 면적 증가에 비해 누출 수소의 농도를 더 감소시켰으며 단일 급기구보다 최소 2A 이상에서 환기 성능이 향상되었다. 급기구의 면적이 증가할수록 수소 층화가 저장실 상부부터 균일하게 형성되었지만 LFL 범위는 벗어나 있었다. 그러나 배기구는 면적을 단순히 증가하는 것만으로는 환기 성능에 미치는 영향은 미비하였다.

Keywords

References

  1. Afghan Haji Abbas, M., S. Kheradmand, and H. Sadoughipour (2020), Numerical study of the effect of hydrogen leakage position and direction on hydrogen distribution in a closed enclosure, International Journal of Hydrogen Energy, Vol. 45, No. 43, pp. 23872-23881. https://doi.org/10.1016/j.ijhydene.2020.06.202
  2. ANSYS Inc(2018a), ANSYS CFX-Pre User's Guide.
  3. ANSYS Inc(2018b), ANSYS Meshing User's Guide and CFX Documentation.
  4. Borman, G. L. and K. W. Ragland(1998), Combustion engineering, McGraw-Hill Science, NewYork.
  5. Cerchiara, G. M., N. Mattei, M. Schiavetti, and M. N. Carcassi(2011), Natural and forced ventilation study in an enclosure hosting a fuel cell, International Journal of Hydrogen Energy, Vol. 36, pp. 2478-2488. https://doi.org/10.1016/j.ijhydene.2010.03.124
  6. Dadashzadeh, M., A. Ahmad, and F. Khan(2016), Dispersion modelling and analysis of hydrogen fuel gas released in an enclosed area: a CFD-based approach, Fuel, Vol. 184, pp. 192-201. https://doi.org/10.1016/j.fuel.2016.07.008
  7. Hajji, Y., B. Jouini, M. Bouteraa, A. El Cafsi, A. Belghith, and P. Bournot(2015), Numerical study of hydrogen release accidents in a residential garage, International Journal of Hydrogen Energy, Vol. 40, pp. 9747-9759. https://doi.org/10.1016/j.ijhydene.2015.06.050
  8. Hajji, Y., M. Bouteraa, A. El Cafsi, A. Belghith, P. Bournot, and F. Kallel(2014), Dispersion and behavior of hydrogen during a leak in a prismatic cavity, International Journal of Hydrogen Energy, Vol. 39, pp. 6111-6119. https://doi.org/10.1016/j.ijhydene.2014.01.159
  9. Hwang, D. J., B. L. Kil, S. K. Park, and M. H. Kim(2017), Numerical study on the location of exhaust outlet for effective ventilation in the event of hydrogen gas leakage in a hydrogen tank storeroom, Journal of the Korean Society of Marine Engineering, Vol. 41, No. 7, pp. 619-625.
  10. Hwang, D. J., B. L. Kil, S. K. Park, and M. H. Kim(2018), Numerical study on the location of exhaust outlet for effective ventilation in the event of hydrogen gas leakage in a hydrogen tank storeroom, Journal of the Korean Society of Marine Engineering, Vol. 42, No. 3, pp. 142-147.
  11. Launder, B. E. and D. B. Spalding(1974), The numerical computation of turbulent flows, Computer Methods in Applied Mechanics and Engineering, Vol. 3, No. 2, pp. 269-289. https://doi.org/10.1016/0045-7825(74)90029-2
  12. Lee, C. Y.(2022), A Numerical Analysis Study on the Optimal Ventilation of Hydrogen Tank Storage Room for a Ship, Graduate School Mokpo National Maritime University, doctorial thesis, pp. 1-156.
  13. Li, F., Y. Yuan, X. Yan, R. Malekian, and Z. Li(2018), A study on a numerical simulation of the leakage and diffusion of hydrogen in a fuel cell ship, Renewable and Sustainable Energy Reviews, Vol. 97, pp. 177-185. https://doi.org/10.1016/j.rser.2018.08.034
  14. Matsuura, K.(2009), Effects of the geometrical configuration of a ventilation system on leaking hydrogen dispersion and accumulation, International Journal of Hydrogen Energy, Vol. 34, pp. 9869-9878. https://doi.org/10.1016/j.ijhydene.2009.09.044
  15. Miola, A., B. Ciuffo, E. Giovine, and M. Marra(2010), Regulating air emissions from ships: the state of the art on methodologies technologies and policy options, Joint Research Centre Reference Report, Luxembourg.
  16. Papanikolou, E. A., A. G. Venetsanos, M. Heitsch, D. Baraldi, A. Huser, J. Pujol, J. Garcia, and N. C. Markatos(2010), HySafe SBEP-V20: Numerical studies of release experiments inside a naturally ventilated residential garage, International Journal of Hydrogen Energy, Vol. 35, pp. 4747-4757. https://doi.org/10.1016/j.ijhydene.2010.02.020
  17. Park, S. K. and Y. M. Youn(2014), Analysis of international standardization trend for the application of fuel cell systems on ships, Journal of the Korea Society of Marine Environment & Safety, Vol 20, No. 5, pp. 579-585. https://doi.org/10.7837/kosomes.2014.20.5.579
  18. Stefano, M. De., X. Rocourt, I. Sochet, and N. Daudey(2019), Hydrogen dispersion in a closed environment, International Journal of Hydrogen Energy, Vol. 44, pp. 9031-9040. https://doi.org/10.1016/j.ijhydene.2018.06.099