Internal combustion engine installation comprising a direct-injection otto engine and a catalyst system

Abstract

The invention relates to an internal combustion engine ( 10 ) comprising a direct-injection otto engine ( 12 ) which does not have a stratified charge capacity, or only to a small extent, and a catalyst system ( 16 ) which is arranged downstream from the otto engine ( 12 ) and is provided with at least one catalyst ( 18 ). According to the invention, the catalyst system ( 16 ) has a catalyst volume (KV) of below 0.8×engine capacity (VH) or below 1.3 per 100 kW rated engine power (PNENN), and the average specific precious metal load of the at least one catalyst ( 18 ) of the catalyst system ( 16 ) is below 3.59 g/dm3, the entire precious metal mass of the at least one catalyst ( 18 ) being below 2 g per litre of engine capacity (VH) or below 3.5 per 100 kW rated engine power (PNENN) of the otto engine ( 12 ).

1 - 36 . (canceled)  
   
   
       37 . An internal combustion engine installation ( 10 ), which has a directly injected gasoline engine ( 12 ), which is capable of operating in a stratified manner only slightly if at all, and a catalyst system ( 16 ), which is downstream from the gasoline engine ( 12 ) and has at least one catalyst ( 18 ), characterized in that the capitalist system ( 16 ) has a total catalyst volume (KV) of less than 0.8×the engine displacement (VH) or of less than 1.3 per 100 kW of rated horsepower (PNENN), and that the average specific noble metal loading of the at least one catalyst ( 18 ) of the catalyst system ( 16 ) is less than 3.59 g/dm 3 , the total mass of noble metal of the at least one catalyst ( 18 ) being less than 2 g per liter of engine displacement (VH) or less than 3.5 g per 100 kW of rated horsepower (PNENN) of the gasoline engine.  
   
   
       38 . The internal combustion engine installation of  claim 37 , characterized in that the catalyst system ( 16 ) has a total catalyst volume (KV) of less than 0.7×the engine displacement (VH) and especially a catalyst volume (KV) of less than 0.6×the engine displacement (VH).  
   
   
       39 . The internal combustion engine installation of  claim 37 , characterized in that the catalyst system ( 16 ) has a catalyst volume (KV) of less than 1.15 L per 100 kW of rated horsepower (PNENN) and especially of less than 1.00 L per 100 kW.  
   
   
       40 . The internal combustion engine installation of  claim 37 , characterized in that the catalyst system ( 16 ) consists of at least two catalysts ( 18 ), arranged in parallel, or of a main catalysts ( 22 ) with at least two pre-catalysts ( 20 ), arranged in parallel, or of at least two main catalysts ( 22 ), arranged in parallel, with in each case at least one pre-catalyst ( 20 ).  
   
   
       41 . The internal combustion engine installation of  claim 37 , characterized in that the average specific noble metal loading of the at least one catalyst ( 18 ) of the catalyst system ( 16 ) is not more than 2.87 g/dm 3  and especially not more than 2.15 g/dm 3 .  
   
   
       42 . The internal combustion engine installation of  claim 37 , characterized in that the pre-catalyst or pre-catalysts ( 20 ) have a specific noble metal loading, which is higher by up to 70%, especially by up to 50% and preferably by up to 30% than that of the main catalyst or catalysts ( 22 ).  
   
   
       43 . The internal combustion engine installation of  claim 37 , characterized in that the total mass of noble metal of the catalyst system ( 16 ) is less than 1.6 g per liter of engine displacement (VH) of the gasoline engine ( 12 ), especially less than 1.2 g per liter of engine displacement, preferably at less than 1.0 g per liter of engine displacement and, particularly preferably, less than 0.8 g per liter of engine displacement.  
   
   
       44 . The internal combustion engine installation of  claim 37 , characterized in that the total mass of noble metal of the catalyst system ( 16 ) is less than 3 g per 100 kW of rated horsepower of the gasoline engine ( 12 ), particularly less than 2.5 g per 100 kW of rated horsepower, preferably less than 2.1 g per 100 kW of rated horsepower and particularly preferably less than 1.7 g per 100 kW of rated horsepower.  
   
   
       45 . The internal combustion engine installation of  claim 37 , characterized that the at least one catalyst ( 18 ) or the at least one pre-catalyst ( 20 ) is at a distance of less than 800 millimeter exhaust gas pipeline length from the nearest outlet valve of the gasoline engine ( 12 ), particularly less than 500 mm of exhaust gas pipeline length and preferably less than 300 mm of exhaust gas pipeline length.  
   
   
       46 . The internal combustion engine installation of  claim 40 , characterized in that the at least one pre-catalyst ( 20 ) and the at least one downstream main catalyst ( 22 ) are at a distance of more than 100 mm from one another.  
   
   
       47 . The internal combustion engine installation of  claim 40 , characterized in that the at least one pre-catalyst ( 20 ) has a volume of not more than 70%, particularly a volume of not more than 50%, and preferably a volume of not more than 30% of the at least one downstream main catalyst ( 22 ).  
   
   
       48 . The internal combustion engine installation of  claim 37 , characterized in that the catalyst or catalysts of the catalyst system ( 16 ), especially of the at least one catalyst ( 18 ) or the at least one main catalyst ( 22 ), are based on a ceramic support.  
   
   
       49 . The internal combustion engine installation of  claim 38 , characterized in that the catalyst or catalysts ( 18 ) or main catalysts ( 22 ), based on a ceramic support, have a cell density of more than 500 cpsi and that the product of cell density (in cpsi=cells per square inch) and cell wall thickness (in mil=thousandths of an inch) is less than 2700, corresponding to 0.1063 when the cell density is expressed in cells per square millimeters and the cell wall thickness is expressed in millimeters.  
   
   
       50 . The internal combustion engine installation of  claim 40 , characterized in that the at least one pre-catalysts ( 20 ) has a support based on metal foil.  
   
   
       51 . The internal combustion engine installation of  claim 40 , characterized in that the at least one pre-catalyst ( 20 ) has a cell density of more than 500 cpsi and that the product of cell density (in cpsi=cells per square inch) and cell wall thickness (μ=thousandths of a millimeter) is less than 30,000 and preferably less than 20,000, corresponding to less than 46.5 and preferably less than 31, when the cell density is expressed in cells per square millimeter.  
   
   
       52 . The internal combustion engine installation of  claim 37 , characterized in that the gasoline engine ( 12 ) is capable of stratified operation in less than 7% of all operating points, especially in less than 5% of all operating points and preferably in less than 3% of all operating points  
   
   
       53 . The internal combustion engine installation of  claim 37 , characterized in that the gasoline engine ( 12 ) is naturally aspirated.