Internal combustion engine with NOx adsorber

Abstract

An internal combustion engine includes first and second exhaust paths, and a first NO x adsorber located in the first exhaust path. A flow control valve controls the relative amounts of exhaust gas flowing through the first and second exhaust paths. A first injector injects a reductant into the exhaust gas stream. The injector is located so as to inject the reductant at a location adjacent to the flow control valve to cause mixing of the reductant and the exhaust gas and to allow regeneration of the first NO x adsorber.

1 . An internal combustion engine with a plurality of cylinders, the engine including an intake manifold and an exhaust manifold, the engine further comprising: 
 a first exhaust path for receiving and routing exhaust gases;    a first NO x  adsorber located in the first exhaust path;    a second exhaust path for receiving and routing exhaust gases;    a first flow control valve between the exhaust manifold and the first exhaust path and a second flow control valve between the exhaust manifold and the second exhaust path, the first and second flow control valves controlling the relative amounts of exhaust gas flowing through the first and second exhaust paths; and    a first injector for injecting a reductant into the exhaust gas stream, the first injector being located so as to inject the reductant at a location immediately adjacent to the first flow control valve;    wherein there is a pressure drop across the first flow control valve that results in turbulent flow in a region immediately adjacent to the flow control valve that includes the reductant injection location, thereby causing mixing of the reductant and the exhaust gas in a relatively short distance and to allow regeneration of the first NO x  adsorber.    
     
     
         2 . The internal combustion engine of  claim 1  further comprising: 
 a second NO x  adsorber located in the second exhaust path; and    a second injector for injecting a reductant into the exhaust gas stream, the second injector being located so as to inject the reductant at a location adjacent to the second flow control valve to cause mixing of the reductant and the exhaust gas and to allow regeneration of the second NO x  adsorber.    
     
     
         3 . The internal combustion engine of  claim 2  wherein the second injector is located so as to inject the reductant at a location immediately upstream of the second flow control valve along the second exhaust path.  
     
     
         4 . The internal combustion engine of  claim 1  wherein the first injector is located so as to inject the reductant at a location immediately upstream of the first flow control valve along the first exhaust path.