Apparatus for humidifying the air stream of a fuel cell power plant

A water recovery fuel cell system, comprising:

• a fuel cell defining a cathode flow field including a cathode input port and a cathode output port, and an anode flow field including an anode input port and an anode output port;
• combustor means having an input port communicating with the anode output port and to be coupled an oxidant supply, and having an output communicating with the cathode output port at a junction for providing a combustor exhaust combined at the junction with cathode exhaust leaving the cathode output port to form a process exhaust gas;
• a contact condenser defining a water input port, a water output port, a gas input port and a gas output port, the gas input port of the contact condenser communicating with the junction, and the gas output port of the contact condenser communicating with a power plant exhaust conduit to thereby form an exhaust path from the cathode output port to the power plant exhaust conduit via the contact condenser;
• a contact saturator defining a water input port, a water output port, a gas input port and gas output port, the gas input port of the contact saturator for receiving an oxidant gas flow, the gas output port of the contact saturator being coupled to the cathode input port of the fuel cell and to the input port of the combustor means, the water output port of the contact condenser being coupled to the water input port of the contact saturator, and the water output port of the contact saturator being coupled to the water input port of the contact condenser to thereby form a closed-loop for circulating water through the contact condenser and the contact saturator;
• means for circulating water through the contact condenser and the contact saturator;
• and
• a water recovery condenser disposed along the power plant exhaust path between the junction and the power plant exhaust conduit.

A water recovery fuel cell system, comprising:

• a fuel cell defining a cathode flow field including a cathode input port and a cathode output port, and an anode flow field including an anode input port and an anode output port;
• combustor means having an input port communicating with the anode output port and to be coupled to an oxidant supply, and having an output communicating with the cathode output port at a junction for providing a combustor exhaust combined at the junction with cathode exhaust leaving the cathode output port to form a process exhaust gas;
• a water recovery condenser including a gas input port and a gas output port, the gas output port coupled to a power plant exhaust conduit;
• a contact condenser defining a water input port, a water output port, a gas input port and a gas output port, the gas input port of the contact condenser being coupled to the junction, and the gas output port of the contact condenser being coupled to the gas input port of the water recovery condenser;
• a contact saturator defining a water input port, a water output port, a gas input port and gas output port, the gas input port of the contact saturator for receiving an oxidant gas flow, the gas output port of the contact saturator being coupled to the cathode input port of the fuel cell and to the input port of the combustor means, the water output port of the contact condenser being coupled to the water input port of the contact saturator, and the water output port of the contact saturator being coupled to the water input port of the contact condenser to thereby form a closed-loop for circulating water through the contact condenser and the contact saturator;
• and
• means for circulating water through the contact condenser and the contact saturator.

A water recovery fuel cell system, comprising:

• a fuel cell defining a cathode flow field including a cathode input port and a cathode output port, and an anode flow field including an anode input port and an anode output port;
• combustor means having an input port communicating with the anode output port and to be coupled to an oxidant supply, and having an output communicating with the cathode output port at a junction for providing a combustor exhaust combined at the junction with cathode exhaust leaving the cathode output port to form a process exhaust gas;
• a water recovery condenser including a gas input port and a gas output port, the gas input port being coupled to the junction;
• a contact condenser defining a water input port, a water output port, a gas input port and a gas output port, the gas input port of the contact condenser coupled to the gas output port of the water recovery condenser, and the gas output port of the contact condenser communicating with a power plant exhaust conduit;
• a contact saturator defining a water input port, a water output port, a gas input port and gas output port, the gas input port of the contact saturator for receiving an oxidant gas flow, the gas output port of the contact saturator being coupled to the cathode input port of the fuel cell and to the input port of the combustor means, the water output port of the contact condenser being coupled to the water input port of the contact saturator, and the water output port of the contact saturator being coupled to the water input port of the contact condenser to thereby form a closed-loop for circulating water through the contact condenser and the contact saturator;
• and
• means for circulating water through the contact condenser and the contact saturator.