Experimental Study Of Methane Combusting In Micro-scale Excess Enthalpy Combustor

The micro-power systems that use chemical fuels as energy source have various excellent characteristics such as the abroad fuel supply ,the convenience of the fuel complementarity, high energy density, low weight etc. The micro-power systems convert chemical energy into heat or convert chemical energy directly to electrical energy. The resulting need for Power MEMS has attracted great interests in the study of flame in small areas and channels. But they encountered great difficulty how to resolve the greater ratio of the area to the cubage and the short passage time.The excess-enthalpy combustor can increase the temperature of the combustible pre-mixed gas of the methane and air. It become an important pathway to resolve difficulty in micro-combustor. So that the ignition temperature could easily be met to create and maintain a flame. The reaction rate would also increase greatly and the recreation time can be reduced to meet the reduced resident time of the premixed gas in the combustor.In this thesis, experiment is conducted to investigate the characteristics of micro-scale flame and micro-scale combustion, and a new experimental system is designed to study the combustion of the pre-mixed methane/Air gas in micro scale combustor. There are 3 combustors been designed and examined. The combustors had all successfully been ignited and organized steady flame at the intended places in the combustors. The characteristic scale of the outlet channels of the I and III type is about 1mm while the scale of the 3 inlet gas channels and the outlet channels of the II type is about 0.6mm. The characteristics of the spiral countercurrent heat exchanger had been discussed. The characteristics of the maintenance of the flame are investigated experimentally in this system.The I type has lower temperature distribution while the II type has a more centralized temperature distribution. They can provide different heat sources to meet different needs perfectly. The III type is similar to the II type in structure while the temperature distribution is similar to the I type. The result point out the performance of the adiabatic material is not so satisfying. Newer combustor project and better adiabatic material should be found out. The III type has more potential to get higher temperature and larger difference in temperature between the center and the edge of the combustor.The component of the exhaust is investigated under different percentages of methane and different flow rate. The result showed that there is a dramatic effect on temperature when the proportion and the flow rate is changed. The component of the exhaust is mainly decided by the component of the gas supply. The effect of the flow rate is not so distinct. The influence of temperature is also neglectable, while the component of the exhaust is always very simple. Only the residual of the air and the production of the combustion such as H2, CO, CO2 are found. The unidentified component can not figure out.