System and method of controlling exhaust temperature

Abstract

An internal combustion engine system is provided. The system includes an engine defining a combustion chamber, a clean emission module and an air supply unit. The clean emission module is fluidly connected to an exhaust conduit from the combustion chamber. The air supply unit is configured to supply air into the combustion chamber and includes a compressor and a flow control device provided between the compressor and the combustion chamber. The compressor is configured to receive air from an air inlet via a first passage and supply the compressed air into the combustion chamber via a second passage. The flow control device is configured to selectively reduce the supply of compressed air into the combustion chamber such that an air fuel ratio in the combustion chamber is maintained between 15:1 to 18:1 at 20-90% engine load during a regeneration period for the clean emissions module.

What is claimed is: 
     
         1 . An internal combustion engine system comprising:
 an engine defining a combustion chamber;   a clean emission module fluidly connected to an exhaust conduit from the combustion chamber; and   an air supply unit configured to supply air into the combustion chamber, the air supply unit including:
 a compressor configured to receive air from an air inlet via a first passage, the compressor further configured to supply compressed air into the combustion chamber via a second passage; and 
 a flow control device provided between the compressor and the combustion chamber of the engine, the flow control device being configured to selectively reduce the supply of compressed air into the combustion chamber such that an air fuel ratio in the combustion chamber is maintained in a range from about 15:1 to 18:1 at 20-90% engine load during a regeneration period for the clean emission module. 
   
     
     
         2 . The system of  claim 1 , wherein the air supply unit further includes a controller operatively coupled to the flow control device and configured to control the flow control device based on a predetermined engine parameter. 
     
     
         3 . The system of  claim 2 , wherein the predetermined engine parameter is a desired temperature associated with an exhaust of the engine. 
     
     
         4 . The system of  claim 3  further includes one or more sensors associated with the exhaust of the engine, wherein the sensors are configured to provide output signals indicative of the exhaust temperature to the controller. 
     
     
         5 . The system of  claim 1 , wherein the flow control device is configured to selectively divert an amount of air from the second passage to the first passage. 
     
     
         6 . The system of  claim 1 , wherein the flow control device is configured to selectively divert an amount of compressed air from the second passage to an external atmosphere outside the engine system. 
     
     
         7 . The system of  claim 1 , wherein the flow control device is configured to selectively divert an amount of compressed air from the second passage to an exhaust passage exiting from the clean emission module. 
     
     
         8 . The system of  claim 1 , wherein the flow control device includes a variable position valve. 
     
     
         9 . A method of modulating air supply to a combustion chamber of an internal combustion engine to regenerate a clean emission module at an engine load of 20-90%, the method comprising:
 providing a flow of air from an air inlet to a compressor via a first passage;   providing a flow of compressed air from the compressor to the combustion chamber of the engine via a second passage; and   adjusting a flow control device provided between the compressor and the combustion chamber to selectively reduce an amount of compressed air provided to the combustion chamber such that the air to fuel ratio in the combustion chamber is between 15:1 and 18:1 during a regeneration period.   
     
     
         10 . The method of  claim 9 , wherein adjusting the flow control device further includes adjusting the flow control device based on a predetermined temperature associated with an exhaust of the engine. 
     
     
         11 . The method of  claim 9  further comprises selectively diverting an amount of compressed air from the second passage to the first passage. 
     
     
         12 . The method of  claim 9  further comprises selectively diverting an amount of compressed air from the second passage to an external atmosphere outside the engine system. 
     
     
         13 . The method of  claim 9  further comprises selectively diverting an amount of compressed air from the second passage to an exhaust passage exiting from the clean emission module. 
     
     
         14 . The method of  claim 9 , wherein the flow control device includes a variable position valve. 
     
     
         15 . An internal combustion engine system comprising:
 an engine defining a combustion chamber   a clean emission module fluidly connected to an exhaust conduit from combustion chamber; and   an air supply unit configured to supply air into the combustion chamber, the air supply unit including:
 a compressor configured to receive air from an air inlet via a first passage, the compressor further configured to supply compressed air into the combustion chamber via a second passage; 
 a flow control device provided between the compressor and the combustion chamber of the engine, the flow control device being configured to selectively reduce the supply of compressed air into the combustion chamber; and 
 a controller operatively coupled to the flow control device and configured to control the flow control device based on a predetermined engine parameter such that an air to fuel ratio in the combustion chamber is maintained between 15:1 to 18:1 at 20-90% engine load during a regeneration period for the clean emissions module. 
   
     
     
         16 . The system of  claim 15 , wherein the predetermined engine parameter is a desired temperature associated with an exhaust of the engine. 
     
     
         17 . The system of  claim 15 , wherein the flow control device includes a variable position valve. 
     
     
         18 . The system of  claim 15 , wherein the flow control device is configured to selectively divert an amount of air from the second passage to the first passage. 
     
     
         19 . The system of  claim 15 , wherein the flow control device is configured to selectively divert an amount of compressed air from the second passage to an external atmosphere outside the engine system. 
     
     
         20 . The system of  claim 15 , wherein the flow control device is configured to selectively divert an amount of compressed air from the second passage to an exhaust passage exiting from the clean emission module.