US 2016/0240875 A1 · ANODE BLEED CONTROL IN A FUEL CELL STACK

Abstract

An electrochemical fuel cell assembly comprises a fuel cell stack having a fuel delivery inlet and a fuel delivery outlet. The fuel cell stack further includes a number of fuel cells each having a membrane-electrode assembly and a fluid flow path coupled between the fuel delivery inlet and the fuel delivery outlet for delivery of fuel to the membrane-electrode assembly. A fuel delivery conduit is coupled to the fuel delivery inlet for delivery of fluid fuel to the stack. A bleed conduit is coupled to the fuel delivery outlet for venting fluid out of the stack. A variable orifice flow control device coupled to the bleed conduit configured to dynamically vary an amount of fluid from the fuel delivery outlet passing into the bleed conduit as a function of one or more of the control parameters: (i) measured fuel concentration; (ii) measured humidity; (iii) cell voltages of fuel cells in the stack; (iv) impedance of fuel cells in the stack; (v) resistance of fuel cells in the stack. The variable orifice flow control device may be coupled to a recirculation conduit and may be configured to dynamically vary a proportion of fluid from the fuel delivery outlet passing into the bleed conduit as a function of the control parameters.

Claims36

Dependent claims

An electrochemical fuel cell assembly comprising:

a fuel cell stack having a fuel delivery inlet and a fuel delivery outlet,
the fuel cell stack further comprising a number of fuel cells each having a membrane-electrode assembly and a fluid flow path coupled between the fuel delivery inlet and the fuel delivery outlet for delivery of fuel to the membrane-electrode assembly;
a fuel delivery conduit coupled to the fuel delivery inlet for delivery of fluid fuel to the stack;
a bleed conduit coupled to the fuel delivery outlet for venting fluid out of the stack;
a variable orifice flow control device coupled to the bleed conduit configured to dynamically vary an amount of fluid from the fuel delivery outlet passing into the bleed conduit as a function of one or more of the control parameters:
(i) measured fuel concentration;
(ii) measured humidity;
(iii) cell voltages of fuel cells in the stack;
(iv) impedance of fuel cells in the stack;
(v) resistance of fuel cells in the stack.

7 more elements

A computer program for use in an electrochemical fuel cell assembly having a fuel cell stack with a fuel delivery inlet and a fuel delivery outlet and a number of fuel cells each having a membrane-electrode assembly and a fluid flow path coupled between the fuel delivery inlet and the fuel delivery outlet for delivery of fuel to the membrane-electrode assembly, the fuel cell assembly further comprising a fuel delivery conduit coupled to the fuel delivery inlet for delivery of fluid fuel to the stack and a bleed conduit coupled to the fuel delivery outlet for venting fluid out of the stack and a variable orifice flow control device coupled to the bleed conduit;

the computer program configured, when loaded into a controller of the electrochemical fuel cell assembly, to cause the controller to provide output signals to control the variable orifice control device to dynamically vary an amount of fluid from the fuel delivery outlet passing into the bleed conduit as a function of one or more of the control parameters:
(i) measured fuel concentration;
(ii) measured humidity;
(iii) cell voltages of fuel cells in the stack;
(iv) impedance of fuel cells in the stack;
(v) resistance of fuel cells in the stack.

3 more elements

Dependencies are inferred from the claim text.

Anode bleed control in a fuel cell stack

Life of this patent

Anode bleed control in a fuel cell stack

Life of this patent

Abstract

Claims36