# 밀폐된 공간 내 공랭식 PEMFC의 자연대류 열전달에 대한 실험적 연구

LEE, JUNSIK;KIM, SEUNGGON;SOHN, YOUNGJUN
이준식;김승곤;손영준

• Accepted : 2016.02.28
• Published : 2016.02.29
• 21 56

#### Abstract

This study presents an experiment investigation on natural convection heat transfer of air-cooling Proton exchange membrane fuel cells (PEMFCs) in a enclosure system for unmanned aerial vehicles (UAVs). Considered are replacing fuel cell stack with Aluminum block for heat generating inside a enclosure chamber. The volume ratio of fuel cell stack and chamber for simulation to the actual size of aerial vehicle is 1 to 15. The parameters considered for experimental study are the environmental temperature range from $25^{\circ}C$ to $-60^{\circ}C$ and the block heat input of 10 W, 20 W and 30 W. Effect of the thermal conductivity of the block and power level on heat transfer in the chamber are investigated. Experimental results illustrate the temperature rise at various locations inside the chamber as dependent upon heat input of fuel cell stack and environmental temperature. From the results, dimensionless correlation in natural convection was proposed with Nusselt number and Rayleigh number for designing air-cooling PEMFC powered high altitude long endurance (HALE) UAV.

#### Keywords

Air-cooling;PEMFC;Natural convection;Nusselt number;Rayleigh number;UAV

#### References

1. O. Gonzalez-Espasandin, J. T. Leo, and E. Navarro-Arevalo, "Fuel Cells: A Real Option for Unmanned Aerial Vehicles Propulsion", The Scientific World Journal, 2014, pp. 1-12.
2. T. Kim, and S. Kwon, "Design and Development of a Fuel Cell-Powered Small Unmanned Aircraft", International Journal of Hydrogen Energy, Vol. 37, 2012, pp. 615-622. https://doi.org/10.1016/j.ijhydene.2011.09.051
3. M. Cha, M. Kim, Y. Sohn, and T. Yang, "Design, Control and Evaluation Methods of PEM Fuel Cell Unmanned Aerial Vehicle: A review", Trans. of the Korean Hydrogen and New Energy Society, Vol. 45, No. 4, 2014, pp. 405-418.
4. S. Cho, M. Kim, Y. Sohn, and T. Yang, "Research trend and analysis of altitude and endurance for fuel cell unmanned aerial vehicles", Trans. of Korean Hydrogen and New Energy Society, Vol. 25, No. 4, 2014, pp. 397-404.
5. D. Park, S. Kim, D. Kim, and T. Kim, "Performance Evaluation of Hydrogen Generator for Fuel Cell Unmanned Aircraft", Journal of The Korean Society for Aeronautical & Space Sciences, Vol. 39, No. 7, 2011, 2011, pp. 627-633. https://doi.org/10.5139/JKSAS.2011.39.7.627
6. S. Kang, B. Kim, and H. Kim, "Experimental Study on the Characteristics of Heat Exchanger of 1 kW PEMFC System for UAV", Trans. of the Korean Hydrogen and New Energy Society, Vol. 22, No. 60, 2011, pp. 819-826.
7. Y. Jee, Y. Sohn, G. Park, C. Kim, Y. Choi, and S. Cho, "Power System Development of Unmanned Aerial Vehicle using Proton Exchange Membrane Fuel Cell" Trans. of the Korean Hydrogen and New Energy Society, Vol. 23, No. 3, 2012, pp. 250-255. https://doi.org/10.7316/KHNES.2012.23.3.250
8. G. Romeo, F. Borello, G. Correa, and E. Cestino, "ENFICA-FC: Design of Transport Aircraft Powered by Fuel Cell & Flight Test of Zero Emission 2-seater Aircraft Powered by Fuel Cells Fueled by Hydrogen", International Journal of Hydrogen Energy, Vol. 38, 2013, pp. 469-479. https://doi.org/10.1016/j.ijhydene.2012.09.064
9. K. Bae, C. Yi, H. Jeong, and H. Chung, "A Study on Natural Convection in a Rectangular Enclosure with a Heating Source", Proceeding of The KSME Spring Conference B, 2000, pp. 296-303.
10. Y. Ahn, H. Cho, and H. Yong, "A Finite Element Analysis of Conjugate Heat Transfer Inside a Cavity with a Heat Generating Conducting Body", Trans. of The Korean Society of Mechanical Engineers B, Vol. 33, No. 3, 2009, pp. 170-177. https://doi.org/10.3795/KSME-B.2009.33.3.170
11. J. Lee, and M. Ha, "Numerical Simulation of Natural Convection in a Horizontal Enclosure with a Heat-generating Conducting Body", International Journal of Heat and Mass Transfer, Vol. 49, 2006, pp. 2684-2702. https://doi.org/10.1016/j.ijheatmasstransfer.2006.01.010

#### Acknowledgement

Supported by : 산업통상자원부