초록 ▼

A method and apparatus for the humidification of gas streams, such as reactant gas streams for fuel cells, wherein the specific water evaporation rate, gas delivery temperature, and degree of gas humidity may be adjusted and maintained at predetermined levels. An ultrasonic device providing a water

A method and apparatus for the humidification of gas streams, such as reactant gas streams for fuel cells, wherein the specific water evaporation rate, gas delivery temperature, and degree of gas humidity may be adjusted and maintained at predetermined levels. An ultrasonic device providing a water mist is used in the evaporation process. The amount of water vapor being introduced into the gas stream can be varied up to the saturation point of the reactant gas stream. As the water vapor leaves the evaporation chamber, it mixes with the gas stream in a gas humidification chamber or riser. The humidified reactant gas stream is then maintained at a set point temperature that is at least above the dew point temperature of the humidified reactant gas.

대표청구항 ▼

1. A method for humidifying a reactant gas stream for use in a fuel cell comprising:passing the reactant gas stream through a humidification chamber;providing liquid water into an evaporator chamber at a mass flow rate to produce water vapor at a mass flow rate in relation to the liquid water mass f

1. A method for humidifying a reactant gas stream for use in a fuel cell comprising:passing the reactant gas stream through a humidification chamber;providing liquid water into an evaporator chamber at a mass flow rate to produce water vapor at a mass flow rate in relation to the liquid water mass flow rate;communicating the water vapor from the evaporator chamber into the humidification chamber for humidifying the reactant gas stream;monitoring one or more parameters of the fuel cell operation; andchanging the flow rate of the liquid water to maintain a setpoint value for the one or more parameters, wherein the one or more parameters are selected from the group consisting of humidified reactant gas dew point temperature, humidified reactant gas pressure, applied load, fuel cell voltage, fuel cell stack voltage, the extent of membrane hydration and combinations thereof. 2. The method of claim 1, further comprising:monitoring the performance of the fuel cell while changing the flow rate of the water in proportion to the flow rate of the reactant gas stream. 3. The method of claim 1, further comprising:monitoring the temperature of the water vapor, and maintaining the temperature of the water vapor at a set point temperature. 4. The method of claim 1, further comprising:monitoring the performance of the fuel cell while changing the set point temperature of the humidified reactant gas stream. 5. The method of claim 1, further comprising:monitoring the evaporation rate of the water in the evaporation chamber; andadjusting the amount of water provided to the evaporation chamber based on the evaporation. 6. The method of claim 1, wherein the reactant gas stream is passed through the humidification chamber at a flow rate required to operate the fuel cell. 7. The method of claim 1, wherein the water vapor is communicated from the evaporator chamber into the humidification chamber through an orifice. 8. The method of claim 1, wherein the mass flow rate of the water vapor is in relation to the flow rate of the reactant gas stream. 9. The method of claim 1, further comprising monitoring the performance of the fuel cell while changing the flow rate of the water vapor. 10. The method of claim 1, further comprising transferring heat between the reactant gas stream and the water vapor. 11. The method of claim 1, further comprising superheating the water vapor. 12. The method of claim 1, further comprising condensing water vapor from the reactant gas stream in the humidification chamber. 13. The method of claim 1, further comprising: providing a gas transfer line from the humidification chamber to an outlet for communication with the fuel cell; and maintaining the gas transfer line temperature in relation to the outlet gas temperature. 14. The method of claim 1, further comprising: providing a gas transfer line from the humidification chamber to an outlet for communication with the fuel cell; and maintaining the gas transfer line temperature in relation to the outlet gas dewpoint temperature. 15. The method of claim 1, further comprising: providing a gas transfer line from the humidification chamber to an outlet for communication with the fuel cell; and heating the gas transfer line to prevent condensation of water vapor. 16. The method of claim 1, further comprising monitoring the temperature of the humidified gas stream; and maintaining the temperature of humidified gas stream at a set-point temperature.