Method and apparatus for reducing locomotive diesel engine smoke using skip firing
First Claim
1. A method for selectively operating a locomotive powered by a diesel engine in a skip firing mode, wherein control of the diesel engine is provided by a discrete-position throttle, and wherein the engine includes a plurality of individually controllable cylinders, the method comprising:
- (a) during a predetermined time interval, determining the relationship between selected engine operating parameters and a predetermined reference value for each of the selected engine operating parameters;
(b) determining whether the throttle has been moved from a first to a second discrete position during the predetermined time interval; and
(c) in response to steps (a) and (b) implementing a skip firing pattern for the cylinders.
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Accused Products
Abstract
A diesel engine, having a plurality of individually controllable fuel injected cylinders, is operated in a skip firing mode to reduce smoke emissions during low power operation. The system senses certain identified engine operating parameters and when these parameters exceed predetermined thresholds for a predetermined time, then the skip firing is implemented. In another embodiment, it is possible to implement several different skip firing patterns dependent upon engine performance. Upon implementation of skip firing, the engine timing angle is reset by a fixed angle and a multiplication factor is included in the speed loop integrator to ensure that the appropriate fuel volume value is injected into each cylinder immediately upon initiation of skip firing. Skip firing is then disabled when another set of predetermined conditions is satisfied.
70 Citations
21 Claims
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1. A method for selectively operating a locomotive powered by a diesel engine in a skip firing mode, wherein control of the diesel engine is provided by a discrete-position throttle, and wherein the engine includes a plurality of individually controllable cylinders, the method comprising:
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(a) during a predetermined time interval, determining the relationship between selected engine operating parameters and a predetermined reference value for each of the selected engine operating parameters;
(b) determining whether the throttle has been moved from a first to a second discrete position during the predetermined time interval; and
(c) in response to steps (a) and (b) implementing a skip firing pattern for the cylinders. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A method for selectively operating a locomotive powered by a diesel engine in a skip firing mode, wherein control of the diesel engine is provided by a discrete-position throttle, and wherein the engine includes a plurality of individually controllable cylinders, the method comprising:
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(a) determining that the engine is operating in a steady state condition during a predetermined time interval;
(b) determining whether the throttle has been moved from a first to a second discrete position during the predetermined time interval;
(c) in response to steps (a) and (b);
(c1) implementing a skip firing pattern for the cylinders; and
(c2) including a multiplication factor in the engine speed control loop.
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18. A method for selectively operating a locomotive powered by a diesel engine in a skip firing mode, wherein the engine includes a plurality of individually fuelable cylinders, wherein the diesel engine is cooled by cooling water and drives a traction alternator for supplying motive power to the locomotive, the method comprising:
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implementing skip firing if a first engine operating condition is in a first predetermined state for a first predetermined time and if a second engine operating condition is in a second predetermined state for the first predetermined time, wherein the first engine operating condition comprises a cylinder firing test having an active state or an inactive state, a determination of a temperature of the cooling water and a determination of whether the engine traction alternator is supplying motive power, and wherein the first operating condition is in the first state when the cylinder firing test is in the inactive state, the temperature of the cooling water is greater than a predetermined value and the traction alternator is not supplying motive power;
terminating skip firing when either the first engine operating condition is not in the first predetermined state or when the second engine operating condition is not in the second predetermined state; and
terminating skip firing if a third engine operating condition is in a third state for a second predetermined time.
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19. An apparatus for selectively operating a locomotive powered by a diesel engine in a skip firing mode, wherein control of the diesel engine is provided by a discrete-position throttle, and wherein the engine includes a plurality of individually fuelable cylinders, the apparatus comprising:
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sensors for ascertaining selected engine operating conditions;
a comparator for determining that each selected operating condition has a predetermined relationship with a predetermined reference value for a predetermined time;
a module for determining whether the throttle has been moved from a first to a second position during the predetermined time; and
a controller for implementing a skip firing pattern by terminating fuel delivery to a number of the plurality of cylinders while the remaining cylinders continue operating, for changing the engine timing angle and for increasing the fuel delivered to the operating cylinders of the plurality of cylinders. - View Dependent Claims (20, 21)
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Specification