Emissions control
AssigneeWesterbeke Corporation
InventorsJohn H. Westerbeke, Jr., Erik S. Larson
Life of this patent
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Abstract
A method of controlling emissions from a fixed-speed internal combustion engine includes injecting a controlled flow of air into the exhaust between a first catalyst bed adapted to reduce HC and NOx emissions, and a second catalyst bed adapted to reduce CO emissions. The flow of air is controlled to optimize the level of CO emissions, preferably as a function of engine load or temperature. In a marine engine-generator set, the flow of air is controlled as a function of generator load or temperature of the exhaust mixture entering the second catalyst bed, and seawater is injected into the exhaust stream downstream of the catalysts.
Claims58
A method of controlling emissions from a fixed-speed internal combustion engine, the method comprising
- governing engine speed with respect to a selected constant speed;
- flowing exhaust from the engine through a water-jacketing housing of an exhaust system, the exhaust flowing through, in order, a first catalyst, an inter-catalyst space, and a second catalyst, the first and second catalysts substantially being disposed within the housing of the exhaust system;
- injecting oxygen-laden gas into the exhaust in the inter-catalyst space, such that the exhaust and the oxygen-laden gas both flow through the second catalyst;
- and
- controlling a rate of oxygen-laden gas injection as a function of a variable that changes with engine load.
A method of controlling emissions from a fixed-speed internal combustion engine, the method comprising
- governing engine speed with respect to a selected constant speed;
- flowing exhaust from the engine through a water-jacketing housing of an exhaust system, the exhaust flowing through, in order, a first catalyst, an inter-catalyst space, and a second catalyst, the first and second catalysts being substantially disposed within the housing of the exhaust system;
- injecting oxygen-laden gas into the exhaust in the inter-catalyst space, such that the exhaust and the oxygen-laden gas both flow through the second catalyst;
- and
- controlling a rate of oxygen-laden gas injection as a function of temperature within the inter-catalyst space.
An engine-generator set comprising
- a fixed-speed internal combustion engine, the engine including an exhaust system comprising a water-jacketing housing substantially containing first and second catalyst beds and defining an inter-catalyst space between the beds;
- an electrical generator coupled to an output shaft of the engine;
- and
- an air pump connected to the exhaust system to introduce a flow of air into the inter-catalyst space as a function of a variable that changes with engine load.
An engine-generator set comprising
- a fixed-speed internal combustion engine, the engine including an exhaust system containing first and second catalyst beds and defining an inter-catalyst space between the beds;
- an electrical generator coupled to an output shaft of the engine;
- and
- an air pump connected to the exhaust system to introduce a flow of air into the inter-catalyst space as a function of temperature within the inter-catalyst space,
- wherein the first and second catalysts are both disposed within a water-jacketed housing.
A method of controlling emissions from a fixed-speed internal combustion engine, the method comprising
- governing engine speed with respect to a selected constant speed;
- flowing exhaust from the engine through an exhaust system, the exhaust flowing through, in order, a first catalyst, an inter-catalyst space, and a second catalyst;
- injecting oxygen-laden gas into the exhaust in the inter-catalyst space, such that the exhaust and the oxygen-laden gas both flow through the second catalyst;
- and
- sensing carbon monoxide at a point downstream of the second catalyst;
- and controlling a rate of injection of the oxygen-laden gas as a function of sensed carbon monoxide.
Dependencies are inferred from the claim text.