摘要:
A fuel cell power plant includes a fuel cell having a membrane electrode assembly (MEA), disposed between an anode support plate and a cathode support plate, the anode and/or cathode support plates include a hydrophilic substrate layer having a predetermined pore size. The pressure of the reactant gas streams is greater than the pressure of the coolant stream, such that a greater percentage of the pores within the hydrophilic substrate layer contain reactant gas rather than water. Any water that forms on the cathode side of the MEA will migrate through the cathode support plate and away from the MEA. Controlling the pressure also ensures that the coolant water will continually migrate from the coolant stream toward the anode side of the MEA, thereby preventing the membrane from becoming dry. Proper pore size and a pressure differential between coolant and reactants improves the electrical efficiency of the fuel cell.
摘要:
A fuel cell power plant (10) includes a fuel cell (12) having a membrane electrode assembly (MEA) (16), disposed between an anode support plate (14) and a cathode support plate (18), the anode and/or cathode support plates include a hydrophilic substrate layer (80, 82) having a predetermined pore size. The pressure of the reactant gas streams (22, 24) is greater than the pressure of the coolant stream (26), such that a greater percentage of the pores within the hydrophilic substrate layer contain reactant gas rather than water. Any water that forms on the cathode side of the MEA will migrate through the cathode support plate and away from the MEA. Controlling the pressure also ensures that the coolant water will continually migrate from the coolant stream toward the anode side of the MEA, thereby preventing the membrane from becoming dry. Proper pore size and a pressure differential between coolant and reactants improves the electrical efficiency of the fuel cell.
摘要:
A fuel cell power plant (10) includes a fuel cell (12) having a membrane electrode assembly (MEA) (16), disposed between an anode support plate (14) and a cathode support plate (18), the anode and/or cathode support plates include a hydrophilic substrate layer (80, 82) having a predetermined pore size. The pressure of the reactant gas streams (22, 24) is greater than the pressure of the coolant stream (26), such that a greater percentage of the pores within the hydrophilic substrate layer contain reactant gas rather than water. Any water that forms on the cathode side of the MEA will migrate through the cathode support plate and away from the MEA. Controlling the pressure also ensures that the coolant water will continually migrate from the coolant stream toward the anode side of the MEA, thereby preventing the membrane from becoming dry. Proper pore size and a pressure differential between coolant and reactants improves the electrical efficiency of the fuel cell.
摘要:
A fuel cell power plant includes a fuel cell having a membrane electrode assembly (MEA), which is disposed between anode and cathode support plates. Porous water transport plates or the support plates have interdigitated flow channels for the reactant gas streams to pass through and conventional flow channels for coolant streams to pass through. The pressure of the reactant gas streams is greater than the coolant stream which, within the porous water transport plates allows the coolant water to saturate the water transport plates thereby forcing the reactant gases into the anode and cathode support plates. This, in turn, increases the mass transfer of such gases into the support plates, thereby increasing the electrical performance of the fuel cell. Current densities of about 1.6 amps per square centimeter are achieved with air stochiometries of not over 2.50.
摘要:
A fuel cell having a polymer electrolyte membrane (16) between anode (14) and cathode (18) reactant flow fields includes a variable blower (32), the power control signal (61) of which is provided by a controller (75) in response to a current signal (63) indicative of the current of the load (71) sensed by a current detector (68). The controller responds to a schedule of blower power as a function of load current density to provide a stochiometry, S, which is fixed at a stochiometry of A, plus or minus a range of stochiometries, D, below a certain current density, C, and varies with higher current densities as: S=[A+B(i−C)]±D, where B is he slope of stochiometry as a function of current density, and i is the actual current density.