Method and system for diesel cylinder deactivation

Abstract

A system and method for cylinder deactivation in a multi-cylinder diesel engine comprises pumping air in to an intake manifold of the diesel engine using a turbocharger. Air is pumped in to the intake manifold using an intake air assisting device. And, fuel injection is selectively deactivated to at least one of the cylinders in the diesel engine. An intake valve and an exhaust valve is selectively deactivated for the at least one of the cylinders of the diesel engine.

1 - 106 . (canceled) 
     
     
         107 . A diesel engine system comprising:
 a plurality of combustion cylinders, each comprising an intake fuel injector, an intake valve, and an exhaust valve;   a catalyst for filtering pollution from an exhaust stream;   a sensor configured to monitor at least one parameter indicative of a condition of the exhaust stream;   a controller configured to iteratively:
 receive the at least one parameter from the sensor; and 
 when the at least one parameter meets a predetermined criterion for cylinder deactivation, deactivate the intake fuel injector, the intake valve, and the exhaust valve of at least one of the plurality of combustion cylinders, such that the plurality of combustion cylinders comprise one or more deactivated combustion cylinders and one or more active combustion cylinders, and adjust the air to fuel ratio in the active combustion cylinders to increase the temperature of the exhaust stream in the catalyst to a target temperature of about 200˜500° C. 
   
     
     
         108 . The diesel engine system of  claim 107 , wherein the target temperature is about 250˜300° C. 
     
     
         109 . The diesel engine system of  claim 107 , wherein the air to fuel ratio in the active combustion cylinders is from 22:1 to 24:1. 
     
     
         110 . The diesel engine system of  claim 107 , wherein the controller is configured to determine an engine output requirement based on an engine load and to adjust the number of combustion cylinders for deactivation to meet the engine output requirement. 
     
     
         111 . The diesel engine system of  claim 107 , wherein the sensor comprises a pollution sensor configured to measure a pollution level in the exhaust stream, and wherein the at least one parameter comprises the pollution level. 
     
     
         112 . The diesel engine system of  claim 111 , wherein the predetermined criterion comprises the pollution level in the exhaust stream exceeding a pollution threshold. 
     
     
         113 . The diesel engine system of  claim 112 , wherein the controller is configured to select the at least one of the plurality of combustion cylinders for deactivation when the pollution level in the exhaust stream exceeds the pollution threshold. 
     
     
         114 . The diesel engine system of  claim 111 , wherein the pollution sensor is configured to monitor a mono-nitrogen oxide level in the exhaust stream. 
     
     
         115 . The diesel engine system of  claim 111 , wherein the controller is configured to process the pollution level measured in the pollution sensor to iteratively adjust the air to fuel ratio until the pollution level is below the pollution threshold. 
     
     
         116 . The diesel engine system of  claim 107 , wherein the sensor comprises a temperature sensor configured to measure an exhaust temperature, and the at least one parameter comprises the exhaust temperature of the exhaust stream. 
     
     
         117 . The diesel engine system of  claim 116 , wherein the controller is configured to receive the measured exhaust temperature from the temperature sensor and, based on the exhaust temperature, iteratively adjust the quantity of fuel injected to the active combustion cylinders and adjust the number of combustion cylinders for deactivation. 
     
     
         118 . A diesel engine system comprising:
 a plurality of combustion cylinders, each comprising an intake fuel injector, an intake valve, and an exhaust valve;   a load sensor configured to monitor an engine load;   a controller configured to iteratively:
 receive the engine load from the load sensor; 
 determine whether the engine load meets criteria for cylinder deactivation; 
 when the engine load meets criteria for cylinder deactivation, select a number of combustion cylinders for deactivation and deactivate the selected number of combustion cylinders by deactivating the intake fuel injector, the intake valve, and the exhaust valve of the selected number of combustion cylinders; 
 monitor at least one parameter indicative of the engine condition; 
 determine if the at least one parameter meets a threshold for adjusting the number of cylinders for deactivation; and 
 continue monitoring the at least one parameter until the at least one parameter meets the threshold for adjusting the number of cylinders for deactivation. 
   
     
     
         119 . The diesel engine system of  claim 118 , wherein the at least one parameter comprises one or more of an exhaust temperature, a brake thermal efficiency, a pollution level, and an exhaust flow rate of the exhaust stream. 
     
     
         120 . The diesel engine system of  claim 118 , wherein the at least one parameter comprises an exhaust temperature, and the controller is configured to determine whether the exhaust temperature is within a threshold range or at a target temperature. 
     
     
         121 . The diesel engine system of  claim 118 , wherein the at least one parameter comprises a brake thermal efficiency, and the controller is configured to determine whether the brake thermal efficiency is above a brake thermal efficiency threshold. 
     
     
         122 . The diesel engine system of  claim 118 , wherein the at least one parameter comprises a pollution level, and the controller is configured to determine whether the pollution level is within a threshold range or at a target level. 
     
     
         123 . The diesel engine system of  claim 118 , wherein the controller is configured to adjust air to fuel ratio to the active combustion cylinders. 
     
     
         124 . The diesel engine system of  claim 118 , wherein the controller is configured to adjust one or more of the timing or quantity of fuel injection, intake flow, exhaust gas recirculation, valve opening or valve closing profile for the active combustion cylinders. 
     
     
         125 . A method of operating a diesel engine system, comprising:
 monitoring at least one parameter indicative of a condition of an exhaust stream of an engine having a plurality of combustion cylinders;   determining whether the at least one parameter meets a predetermined criterion for cylinder deactivation;   when the at least one parameter meets the predetermined criterion, selecting at least one of the plurality of combustion cylinders for deactivation and deactivating an intake fuel injector, an intake valve, and an exhaust valve of the selected at least one combustion cylinder, such that the plurality of combustion cylinders comprise one or more deactivated combustion cylinders and one or more active combustion cylinders; and   adjusting the air to fuel ratio in the active combustion cylinders to increase the temperature of the exhaust stream to a target temperature of about 200˜500° C.   
     
     
         126 . The method of  claim 125 , wherein the target temperature is about 250˜300° C. 
     
     
         127 . The method of  claim 125 , wherein the air to fuel ratio in the active combustion cylinders is from 22:1 to 24:1. 
     
     
         128 . The method of  claim 125 , further comprising determining an engine output requirement based on a load of the engine and adjusting the number of combustion cylinders for deactivation to meet the engine output requirement. 
     
     
         129 . The method of  claim 125 , further comprising monitoring a pollution level in the exhaust stream, wherein the at least one parameter comprises the pollution level. 
     
     
         130 . The method of  claim 129 , wherein the predetermined criterion comprises the pollution level in the exhaust stream exceeding a pollution threshold. 
     
     
         131 . The method of  claim 130 , further comprising selecting the at least one of the plurality of combustion cylinders for deactivation when the pollution level in the exhaust stream exceeds the pollution threshold. 
     
     
         132 . The method of  claim 129 , wherein measuring the pollution level comprises monitoring a mono-nitrogen oxide level in the exhaust stream. 
     
     
         133 . The method of  claim 129 , further comprising processing the pollution level to iteratively adjust the air to fuel ratio until the pollution level is below the pollution threshold. 
     
     
         134 . The method of  claim 125 , further comprising monitoring an exhaust temperature in the exhaust stream, wherein the at least one parameter comprises the exhaust temperature of the exhaust stream. 
     
     
         135 . The method of  claim 134 , further comprising, based on the exhaust temperature, iteratively adjusting the quantity of fuel injected to the active combustion cylinders and adjusting the number of combustion cylinders for deactivation. 
     
     
         136 . A method of operating a diesel engine system, comprising:
 monitoring a load of an engine having a plurality of combustion cylinders;   determining wither the load meets criteria for cylinder deactivation;   when the load meets the criteria for cylinder deactivation, selecting a number of combustion cylinders for deactivation and deactivating the selected number of combustion cylinders by deactivating an intake fuel injector, an intake valve, and an exhaust valve of the selected number of combustion cylinders;   monitoring at least one parameter indicative of the engine condition;   determining if the at least one parameter meets a threshold for adjusting the number of cylinders for deactivation; and   continuing monitoring the at least one parameter until the at least one parameter meets the threshold for adjusting the number of cylinders for deactivation.   
     
     
         137 . The method of  claim 136 , wherein the at least one parameter comprises one or more of an exhaust temperature, a brake thermal efficiency, a pollution level, and an exhaust flow rate of the exhaust stream. 
     
     
         138 . The method of  claim 136 , wherein the at least one parameter comprises an exhaust temperature, and the method further comprises determining whether the exhaust temperature is within a threshold range or at a target temperature. 
     
     
         139 . The method of  claim 136 , wherein the at least one parameter comprises a brake thermal efficiency, and the method further comprises determining whether the brake thermal efficiency is above a brake thermal efficiency threshold. 
     
     
         140 . The method of  claim 136 , wherein the at least one parameter comprises a pollution level, and the method further comprises determining whether the pollution level is within a threshold range or at a target level. 
     
     
         141 . The method of  claim 136 , further comprising adjusting an air to fuel ratio to the active combustion cylinders. 
     
     
         142 . The method of  claim 136 , further comprising adjusting one or more of the timing or quantity of fuel injection, intake flow, exhaust gas recirculation, valve opening or valve closing profile for the active combustion cylinders.