Fuel cell gas management system
AssigneeEmprise Corporation
InventorRonald Arthur DuBose
Life of this patent
Estimating the term…
Abstract
A fuel cell gas management system including a cathode humidification system for transferring latent and sensible heat from an exhaust stream to the cathode inlet stream of the fuel cell; an anode humidity retention system for maintaining the total enthalpy of the anode stream exiting the fuel cell equal to the total enthalpy of the anode inlet stream; and a cooling water management system having segregated deionized water and cooling water loops interconnected by means of a brazed plate heat exchanger.
Claims25
A system for controlling the reactant and coolant streams to and from a fuel cell, the fuel cell of the variety having a first reactant inlet, a first reactant outlet, a second reactant inlet, a second reactant outlet, a coolant inlet, and a coolant outlet, said system comprising:
- (a) a first reactant 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, said first reactant humidification subsystem comprising an enthalpy wheel for collecting moisture from the first reactant exhaust stream and transferring a portion of the collected moisture to the first reactant inlet stream;
- (b) a second reactant humidity retention subsystem comprising a recirculation loop for collecting excess second reactant from the second reactant outlet of the fuel cell, a source of second reactant, mixing means for mixing second reactant from said source with second reactant collected from the second reactant outlet of the fuel cell, and motive means for circulating second reactant in said recirculation loop and for introducing second reactant into the second reactant inlet of the fuel cell;
- and
- (c) a coolant subsystem comprising a first coolant loop communicating with said coolant inlet and said coolant outlet, a second coolant loop, and a heat exchanger for transferring heat between said first and second coolant loops, said first coolant loop being segregated from said second coolant loop.
A method for controlling the reactant and coolant streams to and from a fuel cell, the fuel cell having a first reactant inlet, a first reactant outlet, a second reactant inlet, a second reactant outlet, a coolant inlet and a coolant outlet, said method comprising:
- (a) providing a first reactant supply stream for introduction to the first reactant inlet;
- (b) receiving a first reactant exhaust stream from the first reactant outlet;
- (c) collecting moisture from the first reactant exhaust stream;
- (d) transferring at least a portion of the collected moisture to the first reactant supply stream using an enthalpy wheel;
- (e) collecting an excess of second reactant from the second reactant outlet;
- (f) mixing the collected excess of second reactant with a supply of second reactant from an external source to form a mixture of second reactant;
- (g) circulating the mixture of second reactant under motive force for introduction into the second reactant inlet;
- (h) circulating coolant through a first coolant loop in communication with the coolant inlet and the coolant outlet;
- (i) transferring heat from the first coolant loop to a second segregated coolant loop;
- and
- (j) rejecting heat from the second coolant loop to the ambient.
A system for conditioning a stream of reactant supplied to a fuel cell, said system comprising:
- (a) exhaust collection means for collecting an exhaust stream of the reactant from the fuel cell;
- (b) supply means for supplying an inlet stream of the reactant to the fuel cell;
- and
- (c) an enthalpy wheel for collecting sensible and latent heat from the exhaust stream and transferring the sensible and latent heat to the inlet stream.
A method of conditioning air supplied as an oxidant to a fuel cell's cathode, the cathode comprising a cathode inlet and a cathode exhaust, said method comprising the steps:
- (a) collecting moisture from the cathode exhaust in an enthalpy wheel;
- and
- (b) transferring at least a portion of the collected moisture from the enthalpy wheel to the cathode inlet.
A system for conditioning a stream of reactant supplied to a fuel cell, the fuel cell having a reactant inlet stream and a reactant exhaust stream, said system comprising;
- (a) a recirculation loop for collecting excess reactant from the fuel cell;
- (b) mixing means for mixing the collected excess reactant with a supply of reactant from an external source to form a reactant mixture;
- (c) motive means for circulating reactant through said recirculation loop and introducing the reactant mixture into the fuel cell;
- and
- (d) control means for controlling the total enthalpy of reactant in the reactant exhaust stream to be approximately equal to the total enthalpy of the reactant introduced into the fuel cell.
A method of retaining moisture in a flow of hydrogen to an anode of a fuel cell, said method comprising:
- (a) collecting excess hydrogen discharged from the fuel cell;
- (b) mixing a first quantity of fresh hydrogen from an external source with a second quantity of the excess hydrogen collected from the fuel cell to form a mixture of hydrogen;
- (c) controlling the first and second quantities of hydrogen to control the total enthalpy of the mixture to be approximately equal to the total enthalpy of the hydrogen exhausted from the fuel cell;
- and
- (d) introducing the mixture into the fuel cell.
A coolant system for cooling a fuel cell, said coolant system comprising:
- (a) a first closed coolant loop communicating with said fuel cell employing a first coolant;
- (b) a second closed coolant loop employing a second coolant isolated from said first closed coolant loop;
- (c) a heat exchanger for transferring heat between said first coolant loop and said second coolant loop and said fuel cell;
- and
- (d) a radiator for rejecting heat from said second coolant loop.
A system for conditioning a stream of reactant supplied to a fuel cell, said system comprising:
- (a) exhaust collection means for collecting an exhaust stream of the reactant from the fuel cell;
- (b) supply means for supplying an inlet stream of the reactant to the fuel cell;
- (c) enthalpy transfer means for collecting sensible and latent heat from the exhaust stream, the latent heat being in the form of water vapor collected from the exhaust stream without condensing the water vapor, and transferring the sensible and latent heat to the inlet stream, the latent heat being transferred to the inlet stream by transferring the water collected form the exhaust stream to the inlet stream.
Dependencies are inferred from the claim text.