Method of detecting air/fuel ratio in combustor by detecting oxygen in combustion gas

Patent · Tue Sep 23 00:00:00 EDT 1980

OSTI ID:6800452

Aoki, H; Ikezawa, K; Ishitani, S; Kimura, S; Takao, H

A method is described for detecting numerical values for air/fuel ratio of either a lean air-fuel mixture or a rich mixture supplied to, for example, a combustion engine by means of an oxygen sensor disposed in the exhaust gas. The sensor comprises a porous measurement electrode layer on one side of a porous solid electrolyte layer, e.g., of zirconia and a porous reference electrode layer on the other side with a shield layer thereon, so that the reference electrode layer communicates with the exhaust gas through pores in the sensor. Measurement is accomplished by keeping a dc current flowing between the two electrode layers to establish a reference oxygen partial pressure on the reference electrode side. The intensity of the current is made below a critical value above which an emf generated by the sensor becomes substantially constant unless the air/fuel ratio changes across the stoichiometric ratio, and the direction of the current flow is chosen depending on whether the air-fuel mixture is a lean one or a rich one.

• Assignee: Nissan Motor Co Ltd (Japan)
• Patent Number(s): US 4224113
• OSTI ID: 6800452
• Resource Relation: Patent Priority Date: Priority date 2 Nov 1978, Japan
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
FUEL-AIR RATIO
MEASURING INSTRUMENTS
INTERNAL COMBUSTION ENGINES
OXYGEN METERS
DESIGN
COMBUSTORS
ELECTRIC CURRENTS
ELECTROCHEMICAL CELLS
ELECTROMOTIVE FORCE
EXHAUST GASES
OXYGEN
CURRENTS
ELEMENTS
ENGINES
FLUIDS
GASEOUS WASTES
GASES
HEAT ENGINES
METERS
NONMETALS
WASTES
330101* - Internal Combustion Engines- Spark-Ignition