FLOW FIELD PLATE FOR IMPROVED COOLANT FLOW

摘要

Bipolar plate assemblies are disclosed in which the transition fuel channels are offset from the transition oxidant channels in the transition regions on the active sides of the plates. This configuration allows for a reduced pressure drop in the coolant flow in the transition regions on the inactive, coolant side of the plates and thereby improves coolant flow sharing. The assemblies are suitable for use in high power density solid polymer electrolyte fuel cell stacks.

主权项

1. A bipolar plate assembly having an internal coolant flow field for a fuel cell, the bipolar plate assembly comprising:
an anode plate comprising:
inlet and outlet ports for each of fuel, oxidant, and coolant fluids;a fuel flow field comprising a transition region and an active region on the anode side of the anode plate wherein the transition region comprises a plurality of transition fuel channels, the active region comprises a plurality of active fuel channels, and the transition fuel channels fluidly connect the active fuel channels to a fuel port; anda coolant flow field on the internal coolant side of the anode plate; a cathode plate comprising:
inlet and outlet ports for each of fuel, oxidant, and coolant fluids;an oxidant flow field comprising a transition region and an active region on the cathode side of the cathode plate wherein the transition region comprises transition oxidant channels, the active region comprises active oxidant channels and the transition oxidant channels fluidly connect the active oxidant channels to an oxidant port; anda coolant flow field on the internal coolant side of the cathode plate; wherein the internal coolant side of the anode plate is bonded to the internal coolant side of the cathode plate; andcharacterized in that the active fuel channels align with the active oxidant channels, and the transition fuel channels are offset from the transition oxidant channels.