Fuel cell system and method for controlling same

Patent metadata

Field	Value
Publication number	US-2020381754-A1
Application number	US-201716629649-A
Country	US
Kind code	A1
Filing date	Jul 28, 2017
Priority date	Jul 28, 2017
Publication date	Dec 3, 2020
Grant date	—

Abstract

A fuel cell system that supplies fuel gas and oxidant gas to a fuel cell stack and causes the fuel cell stack to generate power includes a tank that stores aqueous solution containing oxygen-containing fuel, and a reformer that reforms mixed gas obtained as the aqueous solution is vaporized, and generates the fuel gas. The fuel cell system also includes an actuator that supplies the mixed gas to the reformer, a heating device that heats the reformer, a detecting unit that estimates or detects a concentration of the oxygen-containing fuel in the mixed gas that is supplied to the reformer, and a controller programmed to control operations of the actuator and the heating device so that the fuel cell generates power. The controller is programmed to increase a thermal dose to the reformer from the heating device or reduces a supply amount of the mixed gas to the reformer by the actuator when the concentration of the oxygen-containing fuel is high, compared to when the concentration is low.

First claim

1 . A fuel cell system in which fuel gas and oxidant gas are supplied to a fuel cell so that the fuel cell generates power, the fuel cell system comprising:
a tank that stores aqueous solution containing oxygen-containing fuel; a reformer that reforms mixed gas obtained as the aqueous solution is vaporized, the reformer thus generating the fuel gas; an actuator that supplies the mixed gas to the reformer; a heating device that heats the reformer; a detecting unit that estimates or detects a concentration of the oxygen-containing fuel in the mixed gas that is supplied to the reformer; and a controller programmed to control operations of the actuator and the heating device so that the fuel cell generates power, wherein the controller is programmed to increase a thermal dose to the reformer from the heating device or reduces a supply amount of the mixed gas to the reformer by the actuator when the concentration of the oxygen-containing fuel is high, compared to when the concentration is low.

2 . The fuel cell system according to claim 1 ,
wherein the controller prioritizes heating control over reduction control, the heating control being executed for increasing the thermal dose from the heating device, and the reduction control being executed for reducing the supply amount of the mixed gas by the actuator.

3 . The fuel cell system according to claim 1 ,
wherein the detecting unit detects, as the concentration of the oxygen-containing fuel, temperature of the mixed gas supplied to the reformer and temperature of the fuel gas discharged from the reformer; and when a temperature difference between temperature of the mixed gas and temperature of the fuel gas is small, compared to when the temperature difference is large, the controller increases the thermal dose to the reformer or reduces the supply amount of the mixed gas to the reformer.

4 . The fuel cell system according to claim 1 ,
wherein the detecting unit detects an output of the fuel cell as the concentration of the oxygen-containing fuel, and the controller increases the thermal dose to the reformer or reduces the supply amount of the mixed gas to the reformer so that the output of the fuel cell becomes a predetermined value.

5 . The fuel cell system according to claim 1 ,
wherein the detecting unit is provided in the tank, and detects a concentration of the oxygen-containing fuel in the aqueous solution.

6 . The fuel cell system according to claim 1 ,
wherein the detecting unit estimates the concentration of the oxygen-containing fuel based on a temperature difference between temperature of the mixed gas and temperature of the fuel gas.

7 . The fuel cell system according to claim 1 ,
wherein the detecting unit estimates the concentration of the oxygen-containing fuel based on an output of the fuel cell.

8 . A control method for a fuel cell system that includes a reformer that reforms mixed gas of oxygen-contained fuel gas and steam, an actuator that supplies the mixed gas to the reformer, and a heating device that heats the reformer, the control method comprising:
a power generation controlling step in which power generation of a fuel cell is controlled by supplying fuel gas to the fuel cell, the fuel gas being reformed by the reformer; and a reform controlling step in which an operation amount of the heating device is increased or an operation amount of the actuator is reduced when a concentration of oxygen-containing fuel in the mixed gas supplied to the reformer is high, compared to when the concentration is low.

Assignees

• Nissan Motor

Inventors

• Kagami Fumio

Classifications

• H01M8/04007

  related to heat exchange · CPC title

• H01M8/0444

  Concentration; Density (H01M8/04492 takes precedence) · CPC title

• H01M8/04776 Primary

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

• H01M8/04037

  Electrical heating · CPC title

• Y02E60/50

  Fuel cells · CPC title