An Optimization Design Of Micro Combustor In Micro-Thermophotovoltaic System

Micro-TPV (thermophotovoltaic) system is a system to transfer the radiation power from fuel combustion to electricity by photovoltaic cells. This system offers challenges to both the micro combustion process and photoelectric conversion process including the stabilizing of combustion inside the micro combustor, obtaining higher and more uniform temperature distribution at the outer surface of micro combustor and achieving higher photoelectric conversion process.The flame temperature is a factor to judge the combustion process. In the experiment, it is difficult to measure the flame temperature. However, the wall temperature of the micro combustor can be measured by infrared thermometer. As a result, the relationship between wall temperature and flame temperature is essential to predict the flame temperature. In this thesis, a two dimensional laminar pre-mixed flame model was employed to establish the relationship between flame temperature and wall temperature by scale analysis method. The influence of different boundary conditions such as constant wall temperature and constant heat flux were compared.By employing both numerical and experimental method, this study did the research on cylindrical micro combustor. Impact factors such as the material of micro combustor, thickness of the combustor and the flow rate of fuel were analyzed to achieve the highest temperature distribution. A quartz cover was designed and put on top of the cylindrical micro combustor to recover the heat from the exhaust gas. From the experiment, the combustion efficiency was improved by25%.Micro modular combustors have been more and more attractive for its higher surface to volume ratio. Furthermore, the micro modular combustors can be easily assembled. In this thesis, an optimized structure was designed about micro modular combustor. The optimization on inlet pipes, flow rate of the fuel and fuel air equivalence ratio were analyzed. GaSb photovoltaic cells were installed on the micro-TPV system to test the electrical power output.