Indirect monitoring and control of visible exhaust emissions from a diesel engine
First Claim
1. A method for limiting visible exhaust emissions from an operating diesel engine, the engine being coupled to an engine fuel control responsive to an engine load rate command for controlling fuel supplied to the engine, the method comprising the steps of:
- establishing a table of desired values of air-fuel ratio (AFR) as a function of engine speed;
monitoring engine speed and periodically obtaining from the table a desired value of air-fuel ratio at the monitored speed;
computing an actual value of air-fuel ratio from monitored engine operating conditions;
comparing the desired value of air-fuel ratio to the computed value and determining any difference therebetween; and
adjusting the engine horsepower application rate so as to minimize the difference obtained in said comparing step.
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Accused Products
Abstract
A system and method are provided for limiting visible exhaust emissions from a diesel-electric traction vehicle system including a multi-cylinder diesel engine connected for driving a synchronous generator to produce AC electric power, a rectifier connected for converting the AC electric power to DC electric power on a DC link, at least one inverter coupled to the DC link for providing controlled frequency AC power to at least one electric traction motor coupled in driving relationship to at least one wheel of the vehicle. The air-fuel ratio at the engine is regulated to minimize any difference between actual air-fuel ratio and a predetermined preferential air-fuel ratio as a function of engine speed. The air-fuel ratio of an operating engine is measured while monitoring actual visible exhaust emissions in order to create a table of preferential air-fuel ratios as a function of engine speed so that the table values can be used to control visible exhaust without direct monitoring.
56 Citations
17 Claims
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1. A method for limiting visible exhaust emissions from an operating diesel engine, the engine being coupled to an engine fuel control responsive to an engine load rate command for controlling fuel supplied to the engine, the method comprising the steps of:
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establishing a table of desired values of air-fuel ratio (AFR) as a function of engine speed; monitoring engine speed and periodically obtaining from the table a desired value of air-fuel ratio at the monitored speed; computing an actual value of air-fuel ratio from monitored engine operating conditions; comparing the desired value of air-fuel ratio to the computed value and determining any difference therebetween; and adjusting the engine horsepower application rate so as to minimize the difference obtained in said comparing step. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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- 12. A method for limiting visible exhaust emissions from a diesel-electric traction vehicle system including a multi-cylinder diesel engine connected for driving a synchronous generator to produce AC electric power, a rectifier connected for converting the AC electric power to DC electric power on a DC link, at least one inverter coupled to the DC link for providing controlled frequency AC power to at least one electric traction motor coupled in driving relationship to at least one wheel of the vehicle, wherein the method comprises regulating of the air-fuel ratio at the engine to minimize any difference between actual air-fuel ratio and a predetermined preferential air-fuel ratio as a function of engine speed.
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17. A system for limiting visible exhaust emissions from an operating diesel engine, the engine being coupled to an engine fuel control responsive to an engine load rate command for controlling fuel supplied to the engine, comprising:
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a table of desired values of air-fuel ratio (AFR) as a function of engine speed; means for monitoring engine speed and periodically obtaining from the table a desired value of air-fuel ratio at the monitored speed; means for computing an actual value of air-fuel ratio from monitored engine operating conditions; a comparator for comparing the desired value of air-fuel ratio to the computed value and determining any difference therebetween; and means for adjusting the engine horsepower application rate so as to minimize the difference obtained in said comparing step.
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Specification