Innovative Thermal Management of Fuel Cell Power Electronics

Deep at the heart of any fuel cell system lays a crucial component, the power inverter. The design of this crucial component is a challenge for fuel cell systems due to packaging, thermal and electrical constraints. Unless the inverter is adequately and uniformly cooled it will suffer material degradation and premature failure. The search for a thermally viable inverter design is one of many challenges facing the fuel cell industry today. In this research effort several cooling techniques were considered such as pin-finned design, “cook-top” serpentine flow field, a “fish bone” fin design, high thermal conductivity graphite foam, heat pipes and aluminum extrusion with expanded metal turbulator. The pin-finned design techniques were evaluated using computational fluid dynamics. In order to enable design engineers to rapidly generate optimum designs two simplified techniques were introduced using the CFD results. 1) Formulas for computing the film coefficient based on spacing, side and configuration are provided for thermal finite element analysis that includes conduction and convection. This technique is an order of magnitude faster than the CFD analysis. 2) Behavioral modeling, an optimization technique imbedded within a feature based parametric CAD system is utilized to automatically size and build the solid model of the pin-finned design. The designer input is the heat that needs to be rejected and the available space. Behavioral modeling generates the design and plots the temperature distribution.Copyright © 2003 by ASME