Combustion-based Small-scale High-power-density Power Generation System

J. Peng, M. Lee, and Y. Suzuki

Overview

In the present study, we aim at development of micro thermophotovoltaic (TPV) system using micro ceramic combustor. Advantages of such system are three folds; firstly, TPV systems will provide power generation per unit area that is one order of magnitude larger than DMFC. Secondly, no active device for peripheral such as pumps or valves is required.

A micro-scale catalytic combustor using high-precision ceramic tape-casting technology has been developed. Pd/Nano porous alumina fabricated through anodic oxidation was employed for the catalyst layer having good adhesion to the substrate. In order to minimize thermal stress at high operation temperature, catalyst arrangement that gives much smaller temperature gradient has been proposed based on a series of CFD analysis of heat and fluid flow and surface reaction in micro channels. The present finding with CFD has been confirmed by combustion experiments; the wall temperature as high as 850 °C and extremely high heat generation density of 2-3x10^8 W/m^3 have been achieved with the present combustor prototype. It is also found that the wall temperature gradient is significantly reduced with the present catalyst arrangement.

Metal-coated silicon microcavities have also been developed as selective emitter. Vacuum arc evaporation is employedfor the metal film deposition on the microcavities. For 1.8 um microcavities with 50 nm-thick Ti film, an emittance peak appears at the wavelength of 3.2 um, which corresponds well to the first electromagnetic resonance mode. By using a Ge PV cell, energy conversion efficiency with the present microcavity at 915 °C is found to be 3.2 %, which is in good agreement with the estimates with an equivalent circuit model. Assuming the radiation view factor of 0.93, the energy conversion efficiency based on the present model is increased to 7.6 % for the emitter temperature of 1200 °C.

Micro catalytic combustor using high-precision ceramic tape casting technology (Kamijo et al., 2009)

Metal-coated micro caviteis for radiation spectral control (Kirikae et al., 2010)

Recent Reports

Micro-scale Catalytic Combustor

  • Sakata, K., Tagomori, K., Sugiyama, N., Takenouchi, M., Shinya, Y., and Suzuki, Y.,
    “Development of Nano-Porous Alumina Catalyst Support by Anodic Oxidation of Thermally and Kinetically Sprayed Aluminum Coatings,”
    Int. Thermal Spray 2012 Conf. and Expo. (ITSC2012), Houston, (2012), pp. 287-291.
  • Kamijo, T., Suzuki, Y., Kasagi, N., and Okamasa, T.,
    "High-temperature Micro Catalytic Combustor with Pd/Nano-porous Alumina,"
    Proc. Comb. Inst., Vol. 32, Issue 2, pp. 3019-3026 (2009).
    (doi: 10.1016/j.proci.2008.06.118)
  • Okamasa, T., Lee, G.-G., Suzuki, Y., Kasagi, N., and Matsuda, S.,
    "Micro Catalytic Combustor Using High-Precision Ceramic Tape Casting,"
    J. Micromech. Microeng., Vol. 16, No. 9, S198-S205 (2006).
    (doi:10.1088/0960-1317/16/9/S05 )
  • Suzuki, Y., Saito, J., and Kasagi, N.,
    "Development of Micro Catalytic Combustor with Pt/Al2O3 Thin Films,"
    JSME Int. J., Vol. 47, No. 3, Ser. B, pp. 522-527 (2004).
    (doi:10.1299/jsmeb.47.522)

Radiation Spectral Control with Submicron Periodic Structure

  • Kirikae, D., Suzuki, Y., and Kasagi, N., “Silicon Microcavity Selective Emitter with Smooth Surface for Thermophotovoltaic,” J. Micromech. Microeng., Vol. 20, Issue. 10, No. 104006, 7pp, (2010).
    (doi:10.1088/0960-1317/20/10/104006)
  • Kirikae, D., Suzuki, Y., and Kasagi, N., "Selective-emitter-enhanced Micro Thermophotovoltaic Power Generation System," 23rd IEEE Int. Conf. Micro Electro Mechanical Systems (MEMS2010), Hong Kong, pp.1195-1198 (2010).
  • Takagi, D., Suzuki, Y., and Kasagi, N., "Pyrolyzed Parylene Structure as Selective Emitter for High-Efficiency Thermophotovoltaic," 20th IEEE Int. Conf. Micro Electro Mechanical Systems (MEMS 2007), Kobe, pp. 883-886 (2007).

Micro Ejector

  • Takada, M., Morimoto, K., Suzuki, Y., and Ikoma, K.,
    “Effect of Fuel Supply on Pressure Increase of Anode Gas Recirculation Supersonic Ejector for SOFC,”
    8th KSME-JSME Thermal and Fluids Engineering Conf., Incheon, FR07-003, 4pp, (2012).
  • Fan, Y., Suzuki, Y., and Kasagi, N.,
    "Development of Large-Entrainment-Ratio Supersonic Ejector for Micro Butane Combustor,"
    J. Micromech. Microeng., Vol. 16, No. 9, S211-S219 (2006).
    (doi:10.1088/0960-1317/16/9/S07 )

Last update: 2019-03-31