Planar High Temperature Heat Pipes for SOFC/SOEC Stack Applications

Targeting transient operation of high temperature solid oxide cell (SOC) systems this paper proposes an enhanced heat management mechanism using planar high temperature heat pipes that can be integrated into the SOC-stack structure. Flat heat pipes with thicknesses down to 4mm filled with liquid alkali metals for almost isothermal 2D heat spreading, even for intense heat transfer rates, are demonstrated. A new pathway towards a temperature gradient shrinking in SOC-stacks without using large amounts of additional air-cooling is shown. The paper will present latest development results on design concepts, size reduced fabrication and filling procedure. An experimental study demonstrates the heat spreading capabilities and power limitations of planar heat spreaders for high temperature applications as in SOEC/SOFC stacks.