Subfreezing phenomena

Subfreezing Phenomena in Polymer Electrolyte Fuel Cells... 

While there has been significant activity in this area in the patent literature, relatively little effort has been reported in peer-reviewed publications until quite recently. Several factors complicate an investigation into subfreezing phenomena. The first of these is that, other than mapping the nature and extent of phase changes as a function of temperature, freeze-related phenomena are inherently transient problems, as waste heat will raise the internal cell temperatures and stack exit temperatures well above ambient conditions. While there are many papers describing thermal and water balance in PEFC systems, many of these early papers describe... 

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