Engine system with low and high NOx generation algorithms and method of operating same

Abstract

In certain engine systems, there may be a need, such as exhaust purification, to operate two power-producing portions of the engine system in different manners. The engine system of the present disclosure includes at least one engine that includes a first power-producing portion and a second power-producing portion. At least one electronic control module includes a high NOx generation algorithm in communication with the first power-producing portion and a low NOx generation algorithm in communication with the second power-producing portion. The high NOx generation algorithm is operable to signal at least one fuel injector within the first power-producing portion to inject fuel into at least one combustion chamber in a predetermined high NOx generation sequence that includes an injection during non-auto ignition conditions.

1 . An engine system comprising: 
 at least one engine including a first power-producing portion and a second power-producing portion, and at least the first power-producing portion including at least one fuel injector operable to inject fuel into at least one combustion chamber;    at least one electronic control module including a high NOx generation algorithm in communication with the first power-producing portion and a low NOx generation algorithm in communication with the second power-producing portion; and    the high NOx generation algorithm being operable to signal the at least one fuel injector within the first power-producing portion to inject fuel into the at least one combustion chamber in a predetermined high NOx generation sequence including an injection during non-auto ignition conditions.    
   
   
       2 . The engine system of  claim 1  wherein the first power-producing portion and the second power-producing portion being operable to run simultaneously.  
   
   
       3 . The engine system of  claim 1  wherein the predetermined high NOx generation sequence includes a first injection being the injection during non-auto ignition conditions and a second injection during auto ignition conditions.  
   
   
       4 . The engine system of  claim 3  wherein the high NOx generation algorithm being operable to create relatively lean combustion conditions.  
   
   
       5 . The engine system of  claim 3  wherein the at least one fuel injector includes a mixed-mode fuel injector being operable to inject fuel in a first spray pattern with a relative small average angle relative to a centerline of the combustion chamber, and a second spray pattern with a relative large average angle relative to the centerline of the combustion chamber; and 
 the predetermined high NOx generation sequence includes the first injection in the first spray pattern and the second injection in the second spray pattern.    
   
   
       6 . The engine system of  claim 1  wherein the first power-portion includes a low-displacement portion, and the second power-producing portion includes a high-displacement portion.  
   
   
       7 . The engine system of  claim 6  wherein the low NOx generation algorithm being based, at least in part, on a desired power output of the engine system.  
   
   
       8 . The engine system of  claim 1  wherein the first power-producing portion of the at least one engine includes a first engine, and the second power-producing portion of the at least one engine includes a second engine.  
   
   
       9 . The engine system of  claim 1  wherein the at least one engine includes a single engine with a plurality of fuel injectors associated with a plurality of combustion chambers, the first power-producing portion includes a first portion of the plurality of fuel injectors including the at least one fuel injector, and the second power-producing portion includes a second portion of the plurality of fuel injectors; and 
 the low NOx generation algorithm being operable to signal the second portion of fuel injectors to inject in a predetermined low NOx generation sequence.    
   
   
       10 . The engine system of  claim 1  including a first exhaust passage and a second exhaust passage fluidly connecting the first power-producing portion and the second power-producing portion of the at least one engine to a merged exhaust passage, respectively; and 
 a reductant-producing catalyst being positioned within the first exhaust passage, and a NOx selective catalyst being positioned within the merged exhaust passage.    
   
   
       11 . The engine system of  claim 10  wherein the high NOx generation algorithm includes a setting algorithm operable to set a high NOx production amount from the first power-producing portion to correspond to an ammonia production amount operable to reduce an expected NOx concentration from the second power-producing portion.  
   
   
       12 . The engine system of  claim 11  wherein the high NOx generation algorithm includes an alternative operation algorithm being operable to produce a low NOx production amount from the first power-producing portion when the expected NOx concentration is less than a predetermined threshold NOx concentration.  
   
   
       13 . The engine system of  claim 11  including a NOx sensor positioned within the low NOx section of the exhaust passage and being in communication with the electronic control module.  
   
   
       14 . The engine system of  claim 13  wherein the first power-producing portion and the second power-producing portion being operable to run simultaneously; 
 the at least one fuel injector of the first power-producing portion includes a mixed-mode fuel injector being operable to inject fuel in a first spray pattern with a relative small average angle relative to a centerline of the combustion chamber, and a second spray pattern with a relative large average angle relative to the centerline of the combustion chamber; and    the predetermined high NOx generation sequence includes the first injection being the injection during non-auto ignition conditions in the first spray pattern and a second injection in the second spray pattern during auto-ignition conditions.    
   
   
       15 . A method of operating an engine system: 
 controlling a first power-producing portion of at least one engine to produce exhaust with a high NOx concentration, at least in part, by signaling at least one fuel injector to inject fuel in a predetermined high NOx generation sequence including an injection during non-auto ignition conditions; and    controlling a second power-producing portion of the at least one engine to produce exhaust with a low NOx concentration.    
   
   
       16 . The method of  claim 15  including a step of operating the first power-producing portion and the second power-producing portion simultaneously.  
   
   
       17 . The method of  claim 15  wherein the step of controlling the first power-producing portion includes a step of signaling at least one fuel injector to inject a first injection being the injection during non-auto ignition conditions within at least one combustion chamber and a second injection during auto-ignition conditions within the at least one combustion chamber.  
   
   
       18 . The method of  claim 15  wherein the step of controlling the second power-producing portion includes a step of signaling at least one fuel injector to inject fuel in a predetermined low NOx generation sequence based, at least in part, on a desired power output of the engine system.  
   
   
       19 . The method of  claim 15  includes the steps of: 
 passing the exhaust from the first power-producing portion over a reductant-producing catalyst;    combining the exhaust from the first power-producing portion with the exhaust from the second power-producing portion; and    passing the combined exhaust over a NOx selective catalyst.    
   
   
       20 . The method of  claim 15  includes a step of controlling the first power-producing portion to produce a low NOx production amount when an expected concentration of NOx from the second power-producing portion is less than a predetermined threshold NOx concentration.