Fuel cell stack with integrated process endplates

Abstract

This disclosure related to polymer electrolyte member fuel cells and components thereof, including fuel cell endplates.

1 . A fuel cell system, comprising:
 a plurality of fuel cells, each comprising an anode and a cathode, wherein the plurality of fuel cells are placed adjacent to each other to form a fuel cell stack, and the fuel cell stack comprises conduits for anode feed gas, anode exhaust, and cathode feed gas, cathode exhaust; and   an endplate at one end of the stack;   wherein the endplate comprises a first fluid channel connected to the conduit for anode feed gas and a second fluid channel connected to the conduit for anode exhaust.   
     
     
         2 . The fuel cell system of  claim 1 , further comprising a fluid handling component affixed to the end plate, said component is chosen from a valve, a pump, a gas blower, and a gas ejector. 
     
     
         3 . The fuel cell system of  claim 2 , wherein the gas ejector comprises a Venturi tube or an orifice plate, a motive gas inlet, a suction gas inlet, and a gas mixture outlet for venting a mixture of the first motive gas and the suction gas. 
     
     
         4 . The fuel cell system of  claim 3 , wherein the motive gas inlet is fluidly connected to a source of a fuel gas, the suction gas inlet is fluidly connected to the conduit for anode exhaust gas, and the gas mixture outlet is fluidly connected to the conduit for anode feed gas. 
     
     
         5 . The fuel cell system of  claim 4 , further comprising a water separator, wherein the water separator is installed between and fluidly connected to the suction gas inlet in the gas ejector and the conduit for anode exhaust in the fuel cell. 
     
     
         6 . The fuel cell system of  claim 5 , wherein water is removed from the anode exhaust gas in the water separator. 
     
     
         7 . The fuel cell system of  claim 3 , wherein the gas ejector further comprises a piston and a spring,
 wherein the piston comprises a piston disk connected to a valve stem, and   the spring exerts a first force on one side of the piston and the mixture of the motive gas and the suction gas exerts a second force on the other side of the piston disk.   
     
     
         8 . The fuel cell of  claim 7 , wherein when the second force is lower than the first force, the piston opens the motive gas inlet to introduce the motive gas into the ejector. 
     
     
         9 . The fuel cell system of  claim 1 , wherein the endplate further comprises a third fluid channel connected to the conduit for the cathode feed gas and a fourth fluid channel connected to the conduit for cathode gas exhaust. 
     
     
         10 . The fuel cell system of  claim 9 , further comprising a gas eductor comprising a motive gas inlet fluidly connected to a source of an oxidant gas, a suction gas inlet fluidly connected to the conduit for cathode exhaust, and a gas mixture outlet fluidly connected to conduit for cathode feed gas. 
     
     
         11 . The fuel cell system of  claim 1 , wherein the fuel cell stack further comprises a conduit for an incoming coolant and a conduit for an exiting coolant, wherein the endplate further comprises a fifth fluid channel connected to the conduit for the incoming coolant and a sixth fluid channel connected to the conduit for the exiting coolant. 
     
     
         12 . The fuel cell system of  claim 11 , wherein the fifth fluid channel is a straight channel in the endplate. 
     
     
         13 . The fuel cell system of  claim 11 , wherein the fifth fluid channel traverses an extended length inside the endplate. 
     
     
         14 . The fuel cell system of  claim 13 , wherein the fifth fluid channel is a serpentine channel. 
     
     
         15 . The fuel cell system of  claim 11 , wherein the sixth fluid channel is a straight channel in the endplate. 
     
     
         16 . The fuel cell system of  claim 11 , wherein the sixth fluid channel that traverses an extended length inside the endplate. 
     
     
         17 . The fuel cell system of  claim 16 , wherein the sixth fluid channel is a serpentine channel. 
     
     
         18 . A method for circulating an anode exhaust into a fuel cell stack, comprising:
 arranging a gas ejector having a motive gas inlet, a suction gas inlet, and an gas mixture outlet;   fluidly connecting the motive gas inlet to a source of fuel gas;   fluidly connecting the gas mixture outlet to a conduit for anode feed gas in a fuel cell;   fluidly connecting the suction gas inlet to a conduit for anode exhaust in a fuel cell; and   drawing an electric current from the fuel cell stack.   
     
     
         19 . The method of  claim 18 , wherein the gas ejector further comprises a piston and a spring,
 wherein the piston has a piston disk, the spring exerts a first force on one side of the piston and the mixture of the motive gas, and the suction gas exerts a second force on the other side of the piston disk.   
     
     
         20 . The method of  claim 19 , wherein when the second force is lower than the first force, the piston opens the motive gas inlet to introduce the motive gas into the ejector.