Fuel cell system

Patent metadata

Field	Value
Publication number	US-2016141659-A1
Application number	US-201514938189-A
Country	US
Kind code	A1
Filing date	Nov 11, 2015
Priority date	Nov 14, 2014
Publication date	May 19, 2016
Grant date	—

Abstract

A fuel cell system includes a control unit that estimates a discharge amount of the fuel gas partially discharged from the fuel cell partially discharged during an opening period of the discharge valve based on a lost amount of the fuel gas during the opening period and a consumed amount of the fuel gas by electric generation of the fuel cell during the opening period, wherein a pressure increase period during which the pressure increases and a pressure decrease period during which the pressure decreases exist due to intermittent injection of the fuel gas, and the control unit estimates the lost amount of the fuel gas based on a decrease rate of the pressure during the pressure decrease period within the opening period, and based on an assumed decrease rate of the pressure during the pressure increase period within the opening period.

First claim

What is claimed is:

1 . A fuel cell system comprising:
a fuel cell; a fuel injection portion that injects a fuel gas to the fuel cell; a supply passage through which the fuel gas injected from the fuel injection portion flows to the fuel cell; a circulation passage through which the fuel gas partially discharged from the fuel cell flows to the supply passage; a gas-liquid separator that is arranged in the circulation passage and that stores and separates water from the fuel gas partially discharged from the fuel cell; a discharge passage that is connected to the gas-liquid separator, discharges stored water in the gas-liquid separator to an outside, and partially discharges the fuel gas partially discharged from the fuel cell to the outside; a discharge valve that is arranged in the discharge passage; a pressure detecting portion that detects pressure in the supply passage; and a control unit that estimates a discharge amount of the fuel gas partially discharged from the fuel cell partially discharged during an opening period of the discharge valve on a basis of a lost amount of the fuel gas during the opening period and a consumed amount of the fuel gas by electric generation of the fuel cell during the opening period, wherein a pressure increase period during which the pressure increases and a pressure decrease period during which the pressure decreases exist due to intermittent injection of the fuel gas from the fuel injection portion, and the control unit estimates the lost amount of the fuel gas based on a decrease rate of the pressure during the pressure decrease period within the opening period, and based on an assumed decrease rate of the pressure during the pressure increase period within the opening period, the pressure during the pressure increase period being assumed to decrease at the assumed decrease rate same as the decrease rate of the pressure during the pressure decrease period.

2 . The fuel cell system according to claim 1 , wherein
the control unit uses the decrease rate of the pressure during the pressure decrease period just before the pressure increase period as the assumed decrease rate of the pressure during the pressure increase period.

3 . The fuel cell system according to claim 1 , wherein
the control unit uses an average value of decrease rates of the pressure obtained during the pressure decrease period as the assumed decrease rate of the pressure.

4 . The fuel cell system according to claim 1 , wherein
the control unit closes the discharge valve when an estimated discharge amount of the fuel gas is not less than a target discharge amount.

5 . A fuel cell system comprising:
a fuel cell; a fuel injection portion that injects a fuel gas to the fuel cell; a supply passage through which the fuel gas injected from the fuel injection portion flows to the fuel cell; a circulation passage through which the fuel gas partially discharged from the fuel cell flows to the supply passage; a gas-liquid separator that is arranged in the circulation passage and that stores and separates water from the fuel gas partially discharged from the fuel cell; a discharge passage that is connected to the gas-liquid separator, discharges stored water in the gas-liquid separator to an outside, and partially discharges the fuel gas partially discharged from the fuel cell to the outside; a discharge valve that is arranged in the discharge passage; a pressure detecting portion that detects one of pressure in the circulation passage and pressure in the gas-liquid separator; and a control unit that estimates a discharge amount of the fuel gas partially discharged from the fuel cell partially discharged during an opening period of the discharge valve on a basis of a lost amount of the fuel gas during the opening period and a consumed amount of the fuel gas by electric generation of the fuel cell during the opening period, wherein a pressure increase period during which the pressure increases and a pressure decrease period during which the pressure decrease exist due to intermittent injection of the fuel gas from the fuel injection portion, and the control unit calculates the lost amount of the fuel gas during the opening period based on a decrease rate of the pressure during the pressure decrease period within the opening period, and based on an assumed decrease rate of the pressure during the pressure increase period within the opening period, the pressure during the pressure increase period being assumed to decrease at the assumed decrease rate same as the decrease rate of the pressure during the pressure decrease period.

6 . A fuel cell system comprising:
a fuel cell; a fuel injection portion that injects a fuel gas to the fuel cell; a supply passage through which the fuel gas injected from the fuel injection portion flows to the fuel cell; a gas-liquid separator that stores and separates water from the fuel gas discharged from the fuel cell; a first discharge passage that supplies the fuel gas partially discharged from the fuel cell to the gas-liquid separator; a second discharge passage that is connected to the gas-liquid separator, discharges stored water in the gas-liquid separator to an outside, and partially discharges the fuel gas partially discharged from the fuel cell to the outside; a discharge valve that is arranged in the second discharge passage; a pressure detecting portion that detects one of pressure in the supply passage, pressure in the first discharge passage, and pressure in the gas-liquid separator; and a control unit that estimates a discharge amount of the fuel gas partially discharged from the fuel cell partially discharged during an opening period of the discharge valve on a basis of a lost amount of the fuel gas during the opening period and a consumed amount of the fuel gas by electric generation of the fuel cell during the opening period, wherein the fuel cell system is an anode non-circulation type fuel cell system that does not return the fuel gas partially discharged from the fuel cell to the supply passage, a pressure increase period during which the pressure increases and a pressure decrease period during which the pressure decreases exist due to intermittent injection of the fuel gas from the fuel injection portion, and the control unit calculates the lost amount of the fuel gas during the opening period based on a decrease rate of the pressure during the pressure decrease period within the opening period and based on an assumed decrease rate of the pressure during the pressure increase period within the opening period, the pressure during the pressure increase period being assumed to decrease at the assumed decrease rate same as the decrease rate of the pressure during the pressure decrease period.

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamamoto Kazuo
• Imanishi Hiroyuki

Classifications

• H01M8/04097

  with recycling of the reactants (H01M8/04119, H01M8/04104 take precedence) · CPC title

• H01M8/0444

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

• H01M8/04164 Primary

  by condensers, gas-liquid separators or filters · CPC title

• H01M8/04201

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

• H01M8/04179

  by purging or increasing flow or pressure of reactants · CPC title