Fuel cell humidification system
AssigneeHydrogenics Corporation
InventorAkos Toth
Life of this patent
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Abstract
The present invention provides a fuel cell humidification system comprising features of a cathode humidification system, an anode humidity retention system and a countercurrent flow arrangement of the fuel and air streams in the fuel cell, which performs efficiently and is configured particularly for small fuel cells. The present invention further provides a simple method for controlling both cathode and anode humidification using the fuel cell humidification system of the present invention.
Claims17
A fuel cell system for humidifying a cathode and an anode of a fuel cell through respective streams of first and second reactants, the fuel cell having at least a first reactant inlet, a first reactant outlet, a second reactant inlet and a second reactant outlet, the system comprising:
- a cathode humidification subsystem for supplying a first reactant inlet stream to the first reactant inlet of the fuel cell and receiving a first reactant exhaust stream from the first reactant outlet of the fuel cell, the cathode humidification subsystem including a device for collecting moisture from at least a portion of the first reactant exhaust stream and transferring a portion of the collected moisture to the first reactant inlet stream;
- an anode humidity retention subsystem including a recirculation loop for collecting an excess amount of the second reactant from the second reactant outlet of the fuel cell, a source of the second reactant, a device for mixing the second reactant from the source with the second reactant collected from the second reactant outlet of the fuel cell to form a second reactant inlet stream in the recirculation loop, and a motive device for circulating the second reactant in the recirculation loop and for introducing the second reactant inlet stream into the second reactant inlet of the fuel cell;
- and
- a countercurrent flow arrangement of the fuel cell for conducting a countercurrent of the first and second reactant streams within the fuel cell, thereby enhancing water diffusion from the first reactant stream across a membrane electrode assembly of-the fuel cell.
A method for humidifying a cathode and an anode of a fuel cell through respective streams of first and second reactants, the fuel cell having at least a first reactant inlet, a first reactant outlet, a second reactant inlet and a second reactant outlet, the method comprising:
- (a) collecting moisture from a first reactant exhaust stream exiting from the first reactant outlet and transferring at least a portion of the collected moisture to a first reactant inlet stream for introduction to the first reactant inlet;
- (b) collecting an excess amount of the second reactant from the second reactant outlet and mixing same with a supply of the second reactant from an external source to form a mixture of the second reactant;
- (c) circulating the mixture of the second reactant as a second reactant inlet stream for introduction to the second reactant inlet;
- and
- (d) transferring water from the first reactant stream across a membrane electrode assembly by means of water diffusion.
Dependencies are inferred from the claim text.