Method and apparatus for thermal control in a fuel cell

Patent metadata

Field	Value
Publication number	US-2018019487-A1
Application number	US-201615544486-A
Country	US
Kind code	A1
Filing date	Jan 26, 2016
Priority date	Jan 29, 2015
Publication date	Jan 18, 2018
Grant date	—

Abstract

There is disclosed a method and apparatus for controlling an internal temperature of a fuel cell system. The method and system includes measuring a burner temperature of the high temperature fuel cell system comprising a fuel cell stack and a burner, the fuel cell stack comprising at least one fuel cell. The method further includes comparing the measured burner temperature with a predetermined burner temperature set point to identify a burner temperature difference between the measured burner temperature and the predetermined burner temperature set point and controlling an amount of oxidant supplied to the burner to decrease or increase the amount of oxidant supplied to the burner to thereby reduce the burner temperature difference and control a fuel cell stack inlet temperature.

First claim

1 . A method for controlling an internal temperature of a high temperature fuel cell system, comprising:
measuring a burner temperature of the high temperature fuel cell system comprising a fuel cell stack and a burner, the fuel cell stack comprising at least one fuel cell; comparing the measured burner temperature with a predetermined burner temperature set point to identify a burner temperature difference between the measured burner temperature and the predetermined burner temperature set point; and controlling an amount of oxidant supplied to the burner to decrease or increase the amount of oxidant supplied to the burner to thereby reduce the burner temperature difference and control a fuel cell stack inlet temperature.

2 . The method as claimed in claim 1 , further including the steps of:
determining a predetermined fuel cell stack current set point; and determining a corrective function to vary the predetermined burner temperature set point based on the predetermined fuel cell stack current set point to reduce the burner temperature difference and control the fuel cell stack inlet temperature.

3 . The method as claimed in claim 1 , further including the steps of:
determining the fuel cell stack temperature by measuring the temperature of the at least one fuel cell in the solid oxide fuel cell system; comparing the measured stack temperature with a predetermined stack inlet temperature to identify a stack temperature difference; and determining a corrective function to vary the predetermined burner temperature set point to reduce the stack temperature difference.

4 . The method as claimed in claim 1 , wherein the amount of oxidant supplied to the burner is controlled by controlling a valve.

5 . The method as claimed in claim 1 , wherein the amount of oxidant supplied to the burner is controlled by controlling a rotational speed of a turbo generator.

6 . The method as claimed in claim 1 , further including determining an average burner temperature difference by calculating a mean, mode or median burner temperature difference, calculated from measurements received from a temperature sensor positioned at the burner.

7 . The method as claimed in claim 6 , wherein the average burner temperature difference is determined via a proportional integral derivative controller.

8 . The method as claimed in claim 6 , further including controlling the amount of oxidant supplied to the burner based on the average burner temperature difference.

9 . The method as claimed in claim 5 , wherein the method includes setting a predetermined generator set point at which the turbo generator is operated.

10 . The method as claimed in claim 5 , wherein the generator set point ranges from approximately 60,000 revolutions per minute to approximately 100,000 revolutions per minute.

11 . A high temperature fuel cell system comprising:
a fuel cell stack, a compressor and a valve, the fuel cell stack comprising at least one fuel cell, each fuel cell comprising an electrolyte, an anode and a cathode, the compressor being arranged to supply at least a portion of the oxidant to the cathode of the at least one fuel cell, a fuel supply being arranged to supply to the anode of the at least one fuel cell, the fuel cell being arranged to supply a portion of the unused fuel from the anode of the at least one fuel cell to a burner, an oxidant supply arranged to supply the burner, the burner being arranged to supply the burner exhaust gases to a first inlet of a heat exchanger to the valve, the at least a portion of the oxidant from the compressor and the unused oxidant from the cathode of the at least one fuel cell being arranged to be supplied to a second inlet of the heat exchanger to preheat the oxidant supplied to the cathode of the at least one fuel cell, the heat exchanger comprising a temperature sensor configured to measure the temperature at the second inlet of the heat exchanger, the heat exchanger being arranged to supply the at least a portion of the oxidant from the compressor and the unused oxidant from the cathode of the at least one fuel cell from a second outlet of the heat exchanger to the cathode of the at least one fuel cell; and a controller, configured to determine a burner temperature of the high temperature fuel cell comprising a fuel cell stack and a burner, the fuel cell stack comprising at least one fuel cell, the controller configured to compare the burner temperature with a predetermined burner temperature set point to identify a burner temperature difference between the measured burner temperature and the predetermined burner temperature set point, and to control an amount of oxidant supplied to the burner by controlling an oxidant valve to decrease or increase the amount of oxidant supplied to the burner thereby to reduce the burner temperature difference and control a fuel cell stack inlet temperature.

12 . The high temperature fuel cell system as claimed in claim 11 , wherein the controller is configured to determining a predetermined fuel cell stack current set point; and to determine a corrective function to vary the predetermined burner temperature set point based on the predetermined fuel cell stack current set point to reduce the burner temperature difference and control the fuel cell stack inlet temperature.

13 . The high temperature fuel cell system as claimed in claim 11 , wherein the controller is configured to determine the fuel cell stack temperature by measuring the temperature of the at least one fuel cell in the fuel cell system and to compare the measured stack temperature with a predetermined stack inlet temperature to identify a stack temperature difference and to determine a corrective function to vary the predetermined burner temperature set point to reduce the stack temperature difference.

14 . The high temperature fuel cell system as claimed in claim 11 , wherein the valve is a rotational speed of a turbo generator.

15 . The high temperature fuel cell system as claimed in claim 11 , wherein the fuel cell stack comprises a number of burners and a temperature sensor located at each outlet to each burner.

16 . The high temperature fuel cell system as claimed in claim 14 , wherein the fuel cell stack comprises a number of integrated blocks and each fuel cell module is provided with a temperature sensor.

17 . The high temperature fuel cell system as claimed in claim 16 , wherein the temperature sensor is a thermocouple.

18 . The high temperature fuel cell system as claimed in claim 15 , wherein the controller is configured to determine a second temperature difference using a measured stack temperature measured by the number of temperature sensors.

19 . The high temperature fuel cell system as claimed in claim 15 , wherein the controller is configured to calculate a mean, mode or median burner temperature and/or measured stack temperature from the temperature sensors.

20 . The high temperature fuel cell system as claimed in claim 11 , wherein the controller is configured to determine an average burner temperature difference via a proportional integral derivative controller.

21 . The high temperature fuel cell system as claimed in claim 20 , wherein the controller is configured to control the amount of oxidant supplied to the burner to reduce the average burner temperature difference.

22 . The high temperature fuel cell system as claimed in claim 11 , wherein a generator module is configured to operate at a predetermined generator set point.

Assignees

• Lg Fuel Cell Systems Inc

Inventors

• Bozzolo Michele
• Traverso Alberto
• Pierce Adam

Classifications

• H01M8/04373 Primary

  of auxiliary devices, e.g. reformers, compressors, burners · CPC title

• H01M8/04022 Primary

  Heating by combustion · CPC title

• H01M8/04589

  of fuel cell stacks · CPC title

• H01M8/04201

  Reactant storage and supply, e.g. means for feeding, pipes · CPC title

• H01M8/04776

  at auxiliary devices, e.g. reformer, compressor, burner · CPC title