1. (50 pts) BIPOLAR PLATE PRESSURE DROP ANALYSIS A Proton Exchange Membrane Fuel Cell uses a graphite bipolar plate whic

[answerhappygod]

1 50 Pts Bipolar Plate Pressure Drop Analysis A Proton Exchange Membrane Fuel Cell Uses A Graphite Bipolar Plate Whic 1 (52.95 KiB) Viewed 25 times

1. (50 pts) BIPOLAR PLATE PRESSURE DROP ANALYSIS A Proton Exchange Membrane Fuel Cell uses a graphite bipolar plate which has 350 [cm³] active cell area. The fuel cell operates with cathode inlet pressure of 1.75 [atm] at 60°C, and the air provided to cathode bipolar plate is 55% saturated. The saturated pressure of water at the operation temperature is 19947 [Pa]. The flow field consists of 40 parallel serpentine channels having 2 [mm] width, 2 [mm] depth and 2 [mm] space between channels. The fuel cell operates with current density of 0.75[A/cm²] at 0.45 [V] cell voltage. a) (40 pts) Calculate the pressure drop in the cathode side bipolar plate flow channels b) (10 pts) Why do we have pressure drop in bipolar plates? Please explain shortly with one-two sentences Stoichiometric ratio of oxygen, So₂ = 1 Mole fraction of the oxygen in air is, Xo₂ = 0.21 Dynamic viscosity of the air is; μ = 210-5 [Pa.s] at 60°C Local resistance at the elbows is, k = 3 Molecular weight of the air: MWair 29 [g/mole] Molecular weight of the water: MW water 18 [g/mole] Universal gas constant: R₁ = 8.314J/mol. K Faraday's constant: F = 96500 [C/mol.e"] Number of cells: Ncell = 1 PEMFC Cathode side: n = 4e are transferred per one mole of oxygen T [C] + 273.15= T[K] Be careful with the consistent units!