Implementation of feedforward and feedback control in state mediator

Patent metadata

Field	Value
Publication number	US-10971748-B2
Application number	US-201715836716-A
Country	US
Kind code	B2
Filing date	Dec 8, 2017
Priority date	Dec 8, 2017
Publication date	Apr 6, 2021
Grant date	Apr 6, 2021

Abstract

A system for controlling airflow through a fuel cell circuit includes a fuel cell stack. The system also includes a valve having a valve position that affects a pressure of the gas and a valve area corresponding to a cross-sectional area of the valve through which the gas may flow. The system also includes a memory designed to store a map or function that correlates the valve area to the valve position. The system also includes an ECU to determine or receive a desired mass flow rate of the gas through the valve, and calculate a desired valve area to achieve the desired mass flow rate. The ECU is also designed to compare the desired valve area to the map or function to determine a desired valve position that provides the desired valve area, and to control the valve to have the desired valve position.

First claim

What is claimed is:

1. A system for controlling airflow through a fuel cell circuit, comprising:
a source of a gas;
a fuel cell stack having a plurality of fuel cells configured to receive the gas and generate electricity via a reaction using the gas;
a compressor located between the source of the gas and the fuel cell stack and configured to compress the gas;
an intercooler located between the source of the gas and the fuel cell stack and configured to adjust a temperature of the gas;
a valve having a valve position that affects a pressure of the gas in the fuel cell circuit and a valve area corresponding to a cross-sectional area of the valve through which the gas may flow;
a non-transitory memory programmed to store a map or function that correlates the valve area to the valve position; and
an electronic control unit (ECU) coupled to the valve and configured to:
determine or receive a desired pressure of the gas at the fuel cell stack,
determine a desired mass flow rate of the gas through the valve that will result in the pressure of the gas at the fuel cell stack reaching the desired pressure,
calculate a desired valve area to achieve the desired mass flow rate based on the desired mass flow rate,
compare the desired valve area to the map or function to determine a desired valve position that provides the desired valve area, and
control the valve to have the desired valve position.

2. The system of claim 1 wherein the ECU is further configured to:
determine a current Reynolds number for the gas flowing through the valve;
determine a numerical value that quantifies a current laminar, subsonic, or choked flow of the gas through the valve based on the current Reynolds number; and
further calculate the desired valve area based on the current laminar, subsonic, or choked flow.

3. The system of claim 2 wherein the valve includes a high pressure side and a low pressure side that is exposed to less pressure than the high pressure side, and wherein the ECU is further configured to calculate the desired valve area using the following equation:

m
.

=

Cd
⁢

⁢

A

R
s

*

T
u

⁢

P
u

⁢
Ψ
⁢
#

where {dot over (m)} is the desired mass flow rate, Cd is a discharge coefficient, A is the desired valve area, R s is a specific gas constant, T u is a temperature at the high pressure side of the valve, P u is a pressure at the high pressure side of the valve, and Ψ is the current laminar, subsonic, or choked flow.

4. The system of claim 1 further comprising a bypass branch configured to cause at least some of the gas to bypass the fuel cell stack, wherein the valve is a bypass valve positioned along the bypass branch, and the desired mass flow rate is a desired mass flow of the gas through the bypass branch.

5. The system of claim 1 wherein the valve is a restriction valve located downstream from the fuel cell stack, and the desired mass flow rate is a desired mass flow of the gas through the fuel cell stack.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Farnsworth Jared
• Folick Daniel
• Hasegawa Shigeki
• Tomi Naoki

Classifications

• H01M8/04753 Primary

  of fuel cell reactants · CPC title

• H01M8/24

  Grouping of fuel cells, e.g. stacking of fuel cells · CPC title

• Y02T90/40

  Application of hydrogen technology to transportation, e.g. using fuel cells · CPC title

• H01M8/04776

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

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title