Fuel Cell Based Power Generation Systems and Methods of Operating the Same

Abstract

A power generation system has a fuel cell stack and at least one condensation point in the system at which water present after shutdown of the power generation system can condense or collect. Drying after shutdown is improved by maintaining a temperature gradient between the condensation point and at least one other component in the power generation system after shutdown. In one embodiment, the temperature gradient is maintained by housing the fuel cell stack in a thermally insulated container and arranging the condensation point outside of the insulating container. In another embodiment, drying after shutdown is accomplished with an adsorption unit having a water-adsorbing material arranged in a desired location within the power generation system.

1 . A fuel cell based power generation system comprising:
 a water-collecting device; and   a water adsorbing material coupled to the water-collecting device;   wherein the water adsorbing material is located within the power generation system to attract water present within the system after an operational shutdown of the system.   
     
     
         2 . The power generation system of  claim 1 , further comprising:
 a fuel cell stack having at least one fuel cell; and   a compressor to supply an oxidant stream to the fuel cell stack;   wherein the water-collecting device is disposed between the fuel cell stack and the compressor.   
     
     
         3 . The power generation system of  claim 1 , wherein the water adsorbing material is one of a silica gel, a zeolite and an ion exchange resin. 
     
     
         4 . The power generation system of  claim 1 , further comprising: a heating element operable to regenerate the adsorbing material. 
     
     
         5 . The power generation system of  claim 1 , further comprising:
 a first component operable to condense water present in the power generation system, the first component having a first temperature after an operational shutdown of the power generation system,   at least one other component having a second temperature that is higher than the first temperature of the first component after the operational shutdown of the power generation system; and   a subsystem to maintain a temperature gradient between the first component and the at least one other component for a substantial amount of time after the operational shutdown of the power generation system.