US 6,948,475 B1 · Optimized combustion control of an internal combustion engine equipped with exhaust gas recirculation

Abstract

An EGR equipped internal combustion engine is controlled to maximize the beneficial effects and minimize the detrimental effects of EGR on engine operation. Specifically, at least one parameter indicative of the O2 concentration in the intake mixture and/or at least one parameter indicative of the H2O concentration in the intake mixture is monitored, and the monitored parameter is relied on to control one or more aspects of engine operation by open loop adjustment of other control strategies and/or by a separate closed loop control strategy. These controls are applicable to virtually any engine, and are particularly beneficial to lean burn engines such as diesel (compression ignition) engines, spark ignited natural gas engines, and dual fuel or other compression ignited natural gas engines. The engine may be equipped with either actively controllable EGR or passive and uncontrolled EGR.

Claims39

Dependent claims

A method comprising:

(A) exhausting gases from an exhaust of an internal combustion engine that comprises one of a compression ignition engine and a spark ignited natural gas engine;
(B) mixing a portion of said exhaust gases (EGR) with air to form an intake mixture;
(C) directing said intake mixture into an intake of said engine;
(D) measuring a parameter indicative of the oxygen concentration of said intake mixture;
and
(E) adjusting, based on the measuring step, at least one of a fuel supply timing, a fuel supply quantity, ignition timing, manifold absolute pressure (MAP), and air charge temperature (ACT).

3 more elements

An engine comprising:

(A) at least one cylinder in which combustion takes place by one of compression ignition and spark ignition of natural gas;
(B) a fuel supply device communicating with said cylinder;
(C) an exhaust passage conveying exhaust gasses from said cylinder;
(D) an intake system including
(1) an air intake passage in communication with said cylinder, and
(2) an EGR line having an inlet connected to said exhaust passage and an outlet connected to said air intake passage;
(E) a sensor arrangement including at least one of an oxygen sensor that is configured to measure a parameter indicative of the oxygen concentration of a mixture of air and EGR in said air intake system and a moisture sensor that is configured to measure a parameter indicative of the moisture concentration of the mixture;
and
(F) a controller that is connected to said sensor arrangement and that is operable to:
(1) calculate, based on signals received from said sensor arrangement, at least one of a parameter indicative of the partial pressure of oxygen in the mixture and a parameter indicative of the partial pressure of water vapor in the mixture;
and
(2) adjust at least one engine operating characteristic based on the calculation, the engine operating characteristic including at least one of a fuel supply timing, a fuel supply quantity, ignition timing, manifold absolute pressure (MAP), and air charge temperature (ACT).

9 more elements

Dependencies are inferred from the claim text.

Optimized combustion control of an internal combustion engine equipped with exhaust gas recirculation

Life of this patent

Optimized combustion control of an internal combustion engine equipped with exhaust gas recirculation

Life of this patent

Abstract

Claims39