Numerical Investigation On The Micro Combustor With Double-cavity/Micro-combustor With Multiple-channel

Micro Electro Mechanical System(MEMS) has made a continuous progress based on the micro-fabrication technology, but the energy supplement has become a bottleneck in the development of MEMS. Several micro power generation devices which use of hydrogen/hydrocarbon fuel have many advantages, and then have become a hot topic. Micro-thermal photovoltaic(MTPV) is a typical micro power device, which utilizes thermal energy released by chemical energy of fuel to generate electricity based on PV cell. A high and uniform temperature distribution is help to enhance the power output. This study mainly focuses on the micro combustor for MTPV system.The combustion performance of single-cavity combustor has been compared with that of combustor with a backward facing step based on the results of numerical simulation. The outer wall temperature of single-cavity combustor is higher than that of combustor with a backward facing step under different inlet rates. The outer wall temperature of single-cavity combustor is much more uniform than combustor with a backward at a larger inlet rate.A double-cavity micro combustor is proposed and simulation results indicate that the double-cavity combustor can obtain higher and more uniform temperature distribution, and also higher usable radiation energy and radiation efficiency. When the H2/air equivalence ratio is 0.3 and inlet velocity is 12 m/s, the single-cavity combustor can obtain the usable radiation energy with 2.13 W, and the double-cavity combustor can obtain 2.59 W.A multiple-channel micro combustor is studied and calculation results indicate that temperature distribution along the multiple-channel combustor is higher and more uniform. The profermance of radiation efficiency and radiation energy for multiple-channel combustor is better. When the H2/air equivalence ratio is 0.8 and flow rate is 100 cm3/s, the mean temperature of the single-channel combustor and multiple-channel combustor are 1256.0 K and 1294.9 K, and the wall temperature differences of the single-channel combustor and multiple-channel combustor are 107.6 K and 86.6 K. Assigning different equivalence ratios can further improve the temperature uniformity.