Method and apparatus for adaptive feedback control of an excess air ratio in a compression ignition natural gas engine
First Claim
1. A computer-implemented method for correcting a deviation between a predicted gas excess air ratio and an actual gas excess air ratio in a compression ignited gaseous fueled engine, comprising:
- (A) using at least one programmed computer, predicting a gas excess air ratio fix the engine based on at least one detected current engine operating parameter;
(B) using the at least one programmed computer, calculating a predicted exhaust gas oxygen concentration value based at least in part on the predicted gas excess air ratio;
(C) using the at least one programmed computer, measuring an exhaust gas oxygen concentration using an oxygen sensor coupled to the compression ignited gaseous fueled engine;
(D) using at least one time-based factor, filtering, via the at least one programmed computer, a plurality of the measured exhaust oxygen concentration measurements and a plurality of the predicted exhaust oxygen concentrations to obtain a filtered measured exhaust gas concentration value and a filtered predicted exhaust oxygen concentration value;
(E) using the at least one programmed computer, comparing the filtered measured exhaust oxygen concentration value to the filtered predicted exhaust gas oxygen concentration value to determine an exhaust gas oxygen concentration deviation value; and
(F) using the at least one programmed computer, calculating a corrected gas excess air ratio if the deviation exceeds a designated threshold.
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Accused Products
Abstract
A computer-implemented method is used to correct deviations between a predicted gas excess air ratio and a calculated excess air ratio in a dual fuel engine or other gas fueled compression ignition engine. The method includes determining gas excess air ratio for the engine based at least in part on at least one detected current operating parameter and calculating a predicted exhaust gas oxygen concentration engine based on the predicted gas excess air ratio. A time based filtered predicted exhaust gas oxygen concentration value may then be calculated and compared to a time-based filtered measured exhaust gas oxygen concentration value. The resultant oxygen concentration deviation value may be used to generate a corrected predicted gas excess air ratio.
24 Citations
19 Claims
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1. A computer-implemented method for correcting a deviation between a predicted gas excess air ratio and an actual gas excess air ratio in a compression ignited gaseous fueled engine, comprising:
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(A) using at least one programmed computer, predicting a gas excess air ratio fix the engine based on at least one detected current engine operating parameter; (B) using the at least one programmed computer, calculating a predicted exhaust gas oxygen concentration value based at least in part on the predicted gas excess air ratio; (C) using the at least one programmed computer, measuring an exhaust gas oxygen concentration using an oxygen sensor coupled to the compression ignited gaseous fueled engine; (D) using at least one time-based factor, filtering, via the at least one programmed computer, a plurality of the measured exhaust oxygen concentration measurements and a plurality of the predicted exhaust oxygen concentrations to obtain a filtered measured exhaust gas concentration value and a filtered predicted exhaust oxygen concentration value; (E) using the at least one programmed computer, comparing the filtered measured exhaust oxygen concentration value to the filtered predicted exhaust gas oxygen concentration value to determine an exhaust gas oxygen concentration deviation value; and (F) using the at least one programmed computer, calculating a corrected gas excess air ratio if the deviation exceeds a designated threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A compression ignition internal combustion engine, comprising
a plurality of cylinders; -
a gaseous fuel supply system associated with the cylinders; a liquid fuel supply system associated with the cylinders; an intake manifold cooperating with each of the cylinders; an exhaust manifold also cooperating with each of the cylinders; an exhaust gas oxygen sensor that cooperates with the exhaust manifold and that measures exhaust gas oxygen concentration in the exhaust generated by the cylinders; and a control system that controls operation of the gaseous fuel supply based at least in part on gas excess air fuel ratio; predicts a gas excess air ratio for the engine based at least in part on at least one detected current operating parameter; calculates a predicted exhaust gas oxygen concentration for exhaust gas generated by the engine based on the predicted gas excess air ratio; using at least one time-based factor, filters a plurality of the measured exhaust oxygen concentration measurements and a plurality of the predicted exhaust oxygen concentrations to obtain a filtered measured exhaust gas concentration value and a filtered predicted exhaust oxygen concentration value, compares the filtered exhaust gas oxygen concentration to the filtered predicted exhaust gas oxygen concentration value to determine an exhaust gas oxygen concentration deviation value, and, if the deviation value exceeds a designated threshold, calculates a corrected gas excess air ratio. - View Dependent Claims (9, 10, 11, 12)
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13. A computer-implemented method, comprising:
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using at least one programmed computer, predicting an exhaust gas oxygen concentration for exhaust gas generated by a gaseous fueled compression ignition engine; using the at least one programmed computer, measuring an actual exhaust gas oxygen concentration for the engine; using the at least one programmed computer, using at least one time-based factor, filtering a plurality of the measured exhaust oxygen concentration measurements and a plurality of the predicted exhaust oxygen concentrations to obtain a filtered measured exhaust gas concentration value and a filtered predicted exhaust oxygen concentration value; and using the at least one programmed computer, calculating a corrected predicted gas excess air ratio and a corrected measured gas excess air ratio using the filtered predicted and measured exhaust gas oxygen concentration values. - View Dependent Claims (14, 15, 16, 17, 18, 19)
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Specification