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US 11,881,603 B2Granted
Fuel cell system, and method of estimating humidity in exhaust gas therefrom
AssigneeSubaru Corporation
InventorTakumi Nunokawa
Life of this patent
Estimating the term…
Abstract
A fuel cell system includes a mass flow rate measuring unit, an oxygen consumption mass flow rate acquiring unit, an exhaust-side air temperature acquiring unit, and an exhaust-side air humidity estimating unit. The mass flow rate measuring unit measures a first mass flow rate of intake-side air and a second mass flow rate of exhaust-side air. The oxygen consumption mass flow rate acquiring unit acquires a mass flow rate of oxygen consumption. The exhaust-side air humidity estimating unit estimate humidity in the exhaust-side air, on the basis of a difference between a flow rate of intake gas in the fuel cell system and a flow rate of exhaust gas from the fuel cell system, and the mass flow rate of the oxygen consumption.
Claims15
A fuel cell system for power generation for a fuel cell including a cathode electrode and a hydrogen electrode opposed to the cathode electrode with a solid polymer electrolyte membrane in between, the fuel cell system comprising:
- a first sensor arranged at an inlet of the fuel cell in an air supply path supplying air to the cathode electrode of the fuel cell, and configured to detect a first mass flow rate of air supplied into the inlet of the fuel cell in the air supply path;
- a second sensor arranged at an outlet of the fuel cell in the air supply path, and configured to detect a second mass flow rate of air exhausted, passing through the cathode electrode, from the outlet of the fuel cell in the air supply path;
- a third sensor arranged at the inlet of the fuel cell in the air supply path, and configured to detect a first humidity of air supplied into the inlet of the fuel cell in the air supply path at the first mass flow rate;
- and
- a controller coupled with the first sensor, the second sensor, and the third sensor, and configured to calculate a second humidity of air exhausted, passing through the cathode electrode, from the outlet of the fuel cell in the air supply path by:
- calculating a first difference that is mass other than moisture, included in air into the inlet of the fuel cell in the air supply path by using a difference between the first mass flow rate after deducting amount of moisture on a basis of the first humidity and oxygen consumption calculated by using current, detected by an ammeter coupled with the controller, generated by the fuel cell,
- calculating a second difference that is mass of water vapor included in air exhausted from the outlet of the fuel cell in the air supply path by using a difference between the second mass flow rate and the first difference, and
- calculating the second humidity that is a ratio of the second difference to an amount of saturated water vapor corresponding to temperature at the outlet of the fuel cell in the air supply path,
- wherein the controller is configured to humidify, by using a humidifier, air supplied into the inlet of the fuel cell in the air supply path in response to the second humidity.
6 more elements
A method of estimating humidity in air exhausted from a fuel cell in a fuel cell system, the fuel cell including a cathode electrode and a hydrogen electrode opposed to the cathode electrode with a solid polymer electrolyte membrane in between, the method comprising:
- acquiring, via a first sensor arranged at an inlet of the fuel cell in an air supply path supplying air to the cathode electrode of the fuel cell, a first mass flow rate of the air supplied to the cathode electrode on an intake side of the fuel cell;
- acquiring, via a second sensor arranged at an outlet of the fuel cell in the air supply path exhausting air from the fuel cell, a second mass flow rate of the air exhausted, passing through the cathode electrode, from the fuel cell;
- acquiring, via a third sensor arranged at the inlet of the fuel cell in the air supply path, a first humidity of air supplied into the inlet of the fuel cell in the air supply path at the first mass flow rate;
- and
- calculating a second humidity of air in the air supply path downstream of the solid polymer electrolyte membrane by:
- calculating a first difference that is mass other than moisture, included in air into the inlet of the fuel cell in the air supply by using a difference between the first mass flow rate after deducting amount of moisture on a basis of the first humidity and oxygen consumption calculated by using current, detected by an ammeter coupled with the controller, generated by the fuel cell,
- calculating a second difference that is mass of water vapor included in air exhausted from the outlet of the fuel in the air supply path by using a difference between the second mass flow rate and the first difference, and
- calculating the second humidity that is a ratio of the second difference to an amount of saturated water vapor corresponding to temperature at the outlet of the fuel cell in the air supply path,
- wherein the humidity of air in the inlet of the fuel cell in an air supply path is controlled in response to the calculated humidity of air in the air supply path downstream of the solid polymer electrolyte membrane,
- wherein the controller is configured to, in a case where the second humidity of air in the air supply path downstream of the solid polymer electrolyte membrane is low, perform humidification control to humidify air in the inlet of the fuel cell in an air supply path, and
- wherein the controller is configured to, in a case where the second humidity of air in the air supply path downstream of the solid polymer electrolyte membrane is high, perform drying control to dry air in the inlet of the fuel cell in an air supply path.
8 more elements
A fuel cell system configured to perform power generation by reaction of oxygen and hydrogen, the fuel cell system comprising:
- a fuel cell including a cathode electrode and a hydrogen electrode opposed to the cathode electrode with a solid polymer electrolyte membrane in between;
- i) a first sensor at an inlet of the fuel cell in an air supply path supplying air to the cathode electrode of the fuel cell and configured to measure a first mass flow rate of air supplied to the cathode electrode on an intake side of a fuel cell, ii) a second sensor arranged at an outlet of the fuel cell in the air supply path exhausting air from the fuel cell and configured to detect a second mass flow rate of air exhausted from the fuel cell;
- and iii) a third sensor arranged at the inlet of the fuel cell in the air supply path, and configured to detect a first humidity of air supplied into the inlet of the fuel cell in the air supply path at the first mass flow rate;
- and
- circuitry configured to:
- calculate a second humidity of air in the air supply path downstream of the solid polymer electrolyte membrane by:
- calculating a first difference that is mass other than moisture, included in air into the inlet of the fuel cell in the air supply by using a difference between the first mass flow rate after deducting amount of moisture on a basis of the first humidity and oxygen consumption calculated by using current, detected by an ammeter coupled with the controller, generated by the fuel cell,
- calculating a second difference that is mass of water vapor included in air exhausted from the outlet of the fuel in the air supply path by using a difference between the second mass flow rate and the first difference, and
- calculating the second humidity that is a ratio of the second difference to an amount of saturated water vapor corresponding to temperature at the outlet of the fuel cell in the air supply path,
- wherein the circuitry is configured to control humidity of air in the inlet of the fuel cell in an air supply path in response to the calculated humidity of air in the air supply path downstream of the solid polymer electrolyte membrane,
- wherein the circuitry is configured to, in a case where the second humidity of air in the air supply path downstream of the solid polymer electrolyte membrane is high, perform drying control to dry air in the inlet of the fuel cell in an air supply path, and
- wherein the circuitry is configured to, in a case where the second humidity of air in the air supply path downstream of the solid polymer electrolyte membrane is low, perform humidification control to humidify air in the inlet of the fuel cell in an air supply path.
9 more elements
Dependencies are inferred from the claim text.