Fuel cell stack temperature control

Patent metadata

Field	Value
Publication number	US-2019148748-A1
Application number	US-201715811281-A
Country	US
Kind code	A1
Filing date	Nov 13, 2017
Priority date	Nov 13, 2017
Publication date	May 16, 2019
Grant date	—

Abstract

Various embodiments of the present disclosure provide a fuel cell system configured to modulate the flow of oxidant through the fuel cell system to maintain a desired temperature at the fuel cell stack. The fuel cell system is configured to control the flow of oxidant to maintain the desired temperature in the fuel cell stack based on temperature measurements of fluid outside of the fuel cell stack.

First claim

What is claimed is:

1 . A method of operating a fuel cell system comprising a fuel cell stack comprising multiple fuel cells each comprising an anode and a cathode, the method comprising:
providing, by an oxidant flow control device and at a substantially constant oxidant mass flow rate, an oxidant to the cathodes; sensing, by a temperature sensor, a temperature of the oxidant upstream of the fuel cell stack and sending, by the temperature sensor, a signal representing the sensed temperature to a controller; controlling, by the controller and based on the sensed temperature, an amount of heat an oxidant heater provides to the oxidant to heat the oxidant; and providing, by a fuel flow control device and at a fuel mass flow rate, a fuel to the anodes.

2 . The method of claim 1 , further comprising providing, by the fuel cell stack, an electrical current to an electrical load.

3 . The method of claim 2 , further comprising controlling, by the controller, the provision of the electrical current to the electrical load based on an electrical current set point.

4 . The method of claim 3 , further comprising controlling, by the controller, the fuel flow control device to provide the fuel to the anodes.

5 . The method of claim 4 , further comprising determining, by the controller, the fuel mass flow rate based on the electrical current set point and controlling, by the controller, the fuel flow control device to provide the fuel to the anodes at the determined fuel mass flow rate.

6 . The method of claim 5 , wherein a first electrical current set point corresponds to a first fuel mass flow rate and a second electrical current set point that is greater than the first electrical current set point corresponds to a second fuel mass flow rate that is greater than the first fuel mass flow rate.

7 . The method of claim 1 , further comprising controlling, by the controller, the oxidant flow control device to provide the oxidant to the cathodes and controlling, by the controller, the fuel flow control device to provide the fuel to the anodes.

8 . The method of claim 1 , further comprising controlling, by the controller and based on the sensed temperature, the amount of heat the oxidant heater provides to the oxidant to heat the oxidant by controlling, by the controller, a mass flow rate of an auxiliary fuel output by an auxiliary fuel flow control device to the oxidant heater.

9 . The method of claim 8 , further comprising determining, by the controller, a difference between the sensed temperature and a temperature set point and controlling, by the controller, the mass flow rate of the auxiliary fuel provided by the auxiliary fuel flow control device to the oxidant heater to reduce the difference between the sensed temperature and the temperature set point.

10 . The method of claim 9 , wherein determining the difference between the sensed temperature and the temperature set point comprises determining, by a proportional-integral-derivative (PID) module of the controller, the difference between the sensed temperature and the temperature set point.

11 . A fuel cell system comprising:
a fuel cell stack comprising multiple fuel cells each comprising an anode and a cathode; an oxidant flow control device in fluid communication with the cathodes and configured to provide an oxidant at an oxidant mass flow rate to the cathodes; a fuel flow control device in fluid communication with the anodes and configured to provide a fuel at a fuel mass flow rate to the anodes; a temperature sensor configured to sense a temperature of the oxidant upstream of the fuel cell stack; an oxidant heater configured to heat the oxidant upstream of the fuel cell stack; and a controller configured to:
control the oxidant flow control device to provide the oxidant to the cathodes such that the oxidant mass flow rate is substantially constant;
control, based on the sensed temperature, an amount of heat the oxidant heater provides to the oxidant to heat the oxidant; and
control the fuel flow control device to provide the fuel to the anodes.

12 . The fuel cell system of claim 11 , wherein the fuel cell stack is electrically connectable to an electrical load and configured to provide an electrical current to the electrical load.

13 . The fuel cell system of claim 12 , wherein the controller is further configured to control the provision of the electrical current to the electrical load based on an electrical current set point.

14 . The fuel cell system of claim 13 , wherein the controller is further configured to determine the fuel mass flow rate based on the electrical current set point and to control the fuel flow control device to provide the fuel to the anodes at the determined fuel mass flow rate.

15 . The fuel cell system of claim 14 , wherein a first electrical current set point corresponds to a first fuel mass flow rate and a second electrical current set point that is greater than the first electrical current set point corresponds to a second fuel mass flow rate that is greater than the first fuel mass flow rate.

16 . The fuel cell system of claim 11 , further comprising an auxiliary fuel flow control device in fluid communication with the oxidant heater and configured to provide an auxiliary fuel at an auxiliary fuel mass flow rate to the oxidant heater.

17 . The fuel cell system of claim 16 , wherein the controller is further configured to control the amount of heat the oxidant heater provides to the oxidant to heat the oxidant by controlling the auxiliary fuel mass flow rate.

18 . The fuel cell system of claim 17 , wherein the controller is further configured to determine a difference between the sensed temperature and a temperature set point and control the auxiliary fuel mass flow rate to reduce the difference between the sensed temperature and the temperature set point.

19 . The fuel cell system of claim 18 , wherein a proportional-integral-derivative (PID) module of the controller is configured to determine the difference between the sensed temperature and the temperature set point.

Assignees

• Lg Fuel Cell Systems Inc

Inventors

• Bozzolo Michele
• Caratozzolo Francesco
• Silveira Erel David
• Traverso Alberto

Classifications

• H01M8/0435

  of cathode exhausts · CPC title

• H01M8/04708

  of fuel cell reactants · CPC title

• H01M8/04365 Primary

  of other components of a fuel cell or fuel cell stacks · CPC title

• H01M8/04597

  of auxiliary devices, e.g. batteries, capacitors · CPC title

• H01M8/2425

  High-temperature cells with solid electrolytes · CPC title