Evaluating the Energy Efficiency Performance of a Micro Combustor with and without Heat Recuperation

D. Y. Jiang, W. M. Yang, N. Aqdas, K. J. Chua

Department of Mechanical Engineerings, National University of Singapore, Singapore.

DOI: 10.4236/ojee.2012.12003                

Abstract

Micro-combustion research works are motivated by development of portable, autonomous power generators such as the micro TPV with improvement in energy density over batteries. Heat recuperation is a technique which contributes to better energy efficiency performance by recovering heat from the exhaust gas. In this paper, a numerical simulation is carried out to study the impact of incorporating recuperation on the performance of micro modular combustor system. The simulation results have been validated by experiments; achieving close agreement between simulated and experi-mental data. It was observed that the mean wall temperature, radiation power and emitter efficiency markedly improved with the incorporation of a heat recuperator. In addition, 25.8% enhancement of total radiation power and 30.6% emitter efficiency could be realized when the hydrogen air equivalence ratio was 0.9.

Keywords

Modular Micro Combustor; Recuperation Temperature Distribution; Emitter Efficiency

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	L. C. Chia and B. Feng, “The Development of a Micro- power (Micro-Thermophotovoltaic) Device,” Journal of Power Sources, Vol. 165, No. 1, 2007, pp. 455-480. doi:10.1016/j.jpowsour.2006.12.006
[2]	S. K. Chou, W. M. Yang, K. J. Chua, J. Li and K. L. Zhang, “Development of Micro Power Generators—A Review,” Applied Energy, Vol. 88, No. 1, 2011, pp. 1-16. doi:10.1016/j.apenergy.2010.07.010
[3]	K. J. Chua, W. M. Yang and W. J. Ong, 2012, “Funda- mental Experiment and Numerical Analysis of a Modular Microcombustor with Silicon Carbide Porous Medium,” Industrial & Engineering Chemistry Research, Vol. 51, No. 18, pp. 6327-6339. doi:10.1021/ie203017g
[4]	A. H. Epstein and S. D. Senturia, “Macro Power from Micro Machinery,” Science, Vol. 276, No. 5316, 1997, p. 1211. doi:10.1126/science.276.5316.1211
[5]	C. Lee, “Design and Fabrication of a Micro Wankel Engine Using MEMS Technology,” Microelectronic Engineering, Vol. 73-74, 2004, pp. 529-534. doi:10.1016/S0167-9317(04)00206-0
[6]	I. A. Waitz, G. Gauba and Y.-S. Tzeng, “Combustors for Micro-Gas Turbine Engines,” Journal of Fluids Engineering, Vol. 120, No. 1, 1998, pp. 109-117. doi:10.1115/1.2819633
[7]	F. Lu, H. P. Lee and S. P. Lim, “Modeling and analysis of Micro Piezoelectric Power Generators for Micro-Elec- tromechanical-Systems Applications,” Smart Materials and Structures, Vol. 13, No. 1, 2004, pp. 57-63. doi:10.1088/0964-1726/13/1/007
[8]	G. J. Snyder, J. R. Lim, H. Chen-Kuo and J. P. Fleurial, “Thermoelectric Microdevice Fabricated by a MEMS- Like Electrochemical Process,” Nature Materials, Vol. 2, No. 8, 2003, pp. 528-531. doi:10.1038/nmat943
[9]	W. M. Yang, S. K. Chou, C. Shu, Z. W. Li and H. Xue, “Development of Microthermophotovoltaic System,” Ap- plied Physics Letters, Vol. 81, No. 27, 2002, pp. 5255- 5257. doi:10.1063/1.1533847
[10]	K. Kim, D. Le and S. Kwon, “Effects of Thermal and Chemical Surface—Flame Interaction on Flame Quench- ing,” Combustion and Flame, Vol. 146, No. 1-2, 2006, pp. 19-28. doi:10.1016/j.combustflame.2006.04.012
[11]	A. Veeraragavan and C. P. Cadou, “Flame Speed Predic- tions in Planar Micro/Mesoscale Combustors with Con- jugate Heat Transfer,” Combustion and Flame, Vol. 158, No. 11, 2011, pp. 2178-2187. doi:10.1016/j.combustflame.2011.04.006
[12]	J. Li, S. K. Chou, Z. W. Li and W. M. Yang, “Experi- mental Investigation of Porous Media Combustion in a Planar Micro-Combustor,” Fuel, Vol. 89, No. 3, 2010, pp. 708-715. doi:10.1016/j.fuel.2009.06.026
[13]	S. K. Chou, W. M. Yang, J. Li and Z. W. Li, “Porous Media Combustion for Micro Thermophotovoltaic Sys- tem Applications,” Applied Energy, Vol. 87, No. 9, 2010, pp. 2862-2867. doi:10.1016/j.apenergy.2009.06.039
[14]	J. H. Park, J. S. So, H. J. Moon and O. C. Kwon, “Meas- ured and Predicted Performance of a Micro-Thermo- photovoltaic Device with a Heat-Recirculating Micro- Emitter,” International Journal of Heat and Mass Trans- fer, Vol. 54, No. 5-6, 2011, pp. 1046-1054. doi:10.1016/j.ijheatmasstransfer.2010.11.028
[15]	J. A. Federici and D. G. Vlachos, “A Computational Fluid Dynamics Study of Propane/Air Microflame Stability in a Heat Recirculation Reactor,” Combustion and Flame, Vol. 153, No. 1-2, 2008, pp. 258-269. doi:10.1016/j.combustflame.2007.09.009
[16]	W. Yang, S. Chou, K. Chua, H. An, K. Karthikeyan and X. Zhao, “An Advanced Micro Modular Combus- tor-Radiator with Heat Recuperation for Micro-TPV Sys- tem Application,” Applied Energy, Vol. 97, 2012, pp. 749-753. doi:10.1016/j.apenergy.2011.12.024
[17]	B.-J. Tsai and Y. L. Wang, “A Novel Swiss-Roll Recu- perator for the Microturbine Engine,” Applied Thermal Engineering, Vol. 29, No. 2-3, 2009, pp. 216-223. doi:10.1016/j.applthermaleng.2008.02.028
[18]	J. C. G. Andrae and P. H. Bjornbom, “Wall Effects of Laminar Hydrogen Flames over Platinum and Inserted Surfaces,” American Institute of Chemical Engineers Journal, Vol. 46, No. 7, 2000, pp. 1454-1460. doi:10.1002/aic.690460718
[19]	D. F. W, and L. M. K. Boelter, “Heat Transfer in Automobile Radiators of the Tubular Type,” University of California Publications in Engineering, Vol. 2, No. 13, 1930, pp. 443-461.
[20]	F. A. Williams, “Combustion Theory: Fundamental The- ory of Chemical Reacting Flow Systems,” 2nd Edition, Benjamin/Cummings, Menlo Park, 1985, pp. 265-293.
[21]	D. G. Norton and D. G. Vlachos, “A CFD Study of Pro- pane/Air Microflame Stability,” Combustion and Flame, Vol. 138, No. 1-2, 2004, pp. 97-107. doi:10.1016/j.combustflame.2004.04.004
[22]	“Fluent 14.0 User's Guide,” ANSYS, Inc., Canonsburg, PA, 2011.
[23]	W. M. Yang, D. Y. Jiang, S. K. Chou, K. J. Chua, K. Karthikeyan and H. An, “Experimental Study on Micro modular Combustor for Micro-Thermophotovoltaic System Application,” International Journal of Hydrogen Energy, Vol. 37, No. 12, 2012, pp. 9576-9583. doi:10.1016/j.ijhydene.2012.03.129
[24]	J. Pan, J. Huang, D. Li, W. Yang, W. Tang and H. Xue, “Effects of Major Parameters on Micro-Combustion for Thermophotovoltaic Energy Conversion,” Applied Thermal Engineering, Vol. 27, No. 5-6, 2007, pp. 1089-1095. doi:10.1016/j.applthermaleng.2006.07.038