Transport Phenomena in Energy Conversion Systems

点击翻译按钮获取中文摘要

Heat and mass transport play critical roles in the design and performance of energy conversion systems. The proposed research has two components: (i) proton exchange membrane (PEM) fuel cells, considered part of future sustainable energy systems, and (ii) fuel atomization and sprays in diesel engines, a considerable part of today's energy systems. Hence, (ii) is targeted for maximum impact today and (i) for long-term gain. PEM fuel cells are increasingly designed to operate at high current (power) densities to address the critical technical challenges of cost and performance, requiring a thorough understanding of heat and mass transport phenomena in fuel cell components. While accurate transport properties are available for the gas diffusion layer, fewer are available for the microporous layer and even less for the catalyst layer. The proposed research will conduct a coordinated experimental and theoretical analysis to obtain accurate and reliable data for the transport properties in the microporous and catalyst layers. The results will be particularly useful for the Canadian fuel cell industry in their product development. High-pressure diesel injection is a strategy for clean diesel engines. With increased injection pressure, fuel vapor (cavitation) forms near the wall inside the injector and reaches the injector exit; thereafter fuel vapor tends to condense into the liquid phase. Fuel condensation on the liquid core interferes with the atomization of liquid. The proposed research will study the cavitation phenomena inside the injector and its interaction and impact on the subsequent liquid core atomization and spray characteristics. Both experimental and modeling approaches will be conducted to improve fuel injector performance, which will be useful for in-cylinder combustion and pollutant reduction.