Patent ID: 11881603
Assignee: SUBARU CORPORATION
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H  Y | IPC H

Claim 14:
15. 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.