Diesel engine system for use with emission control device
AssigneeFord Global Technologies, LLC
InventorsMichiel J. van Nieuwstadt, Devesh Upadhyay, William Charles Ruona
Life of this patent
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Abstract
An exhaust valve downstream of a diesel engine splits exhaust gasses between two catalysts. In one position, most of the exhaust gasses go to a first catalyst, and the remaining exhaust gasses, along with injected reductant go to a second catalyst. In a second position, most of the exhaust gasses go to the second catalyst, and the remaining exhaust gasses, along with injected reductant go to the first catalyst. In this way, a reduced cost system is achieved.
Claims29
A vehicle system, comprising:
- a diesel fueled engine having an exhaust manifold through which exhaust gasses flow;
- an exhaust valve having at least first, second, third, and fourth unions, said valve directing exhaust gas from said first union to both said second and fourth unions and a second medium from said third union to said fourth union when in a first position, and directing said exhaust gas from said first union to both said second and fourth unions and said second medium from said third union to said second union when in a second position;
- an injector coupled to said third union that injects said second medium;
- a first emission control device coupled to said second union;
- and
- a second emission control device coupled to said fourth union.
A method for controlling an engine, the engine having an exhaust through which exhaust gasses flow, said exhaust having at least a first an second catalyst and at least a first reductant injector, the method comprising:
- providing a first portion of the exhaust gas flow to said first catalyst and a second portion of the exhaust gas flow to said second catalyst;
- operating in a first mode where said first portion is greater than said second portion;
- during at least a first interval while in said first mode, injecting reductant from said first reductant injector into said second portion of exhaust gas flow;
- operating in a second mode where the second portion is greater than said first portion;
- and
- during at least a second interval while in said second mode, injecting reductant from said first reductant injector into said first portion of exhaust gasses.
A method for controlling an engine, the engine having an exhaust through which exhaust gasses flow, said exhaust having at least a first an second NOx storage catalyst and at least a first fuel injector, the method comprising:
- providing a first portion of the exhaust gas flow to said first catalyst and a second portion of the exhaust gas flow to said second catalyst;
- operating in a first mode where said first portion is greater than said second portion;
- during at least a first interval while in said first mode, injecting reductant from said first fuel injector into said second portion of exhaust gas flow without injecting fuel from said first fuel injector into said first portion of exhaust gas flow, said fuel in said second portion creating a stoichiometric or rich air-fuel ratio to react NOx stored in the second catalyst, with NOx in said first portion being stored in the first catalyst;
- operating in a second mode where the second portion is greater than said first portion;
- and
- during at least a second interval while in said second mode, injecting fuel from said first fuel injector into said first portion of exhaust gasses without injecting fuel from said first fuel injector into said second portion of exhaust gasses, said fuel in said first portion creating a stoichiometric or rich air-fuel ratio to react NOx stored in the first catalyst, with NOx in said second portion being stored in the second catalyst.
A vehicle system comprising:
- a diesel fueled engine having an exhaust manifold through which exhaust gasses flow;
- an exhaust conduit coupled to said exhaust manifold having a first and second outlet;
- an injector coupled to exhaust conduit that injects said second medium;
- a first emission control device coupled to first outlet;
- a second emission control device coupled to second outlet, said second emission control device having a smaller capacity for retaining at least one exhaust emission constituent;
- and
- a controller for operating the exhaust gas flow to have an overall lean air-fuel ratio for a first duration when a majority of said exhaust gas flows to said first catalyst, and operating the exhaust gas flow to have an overall lean air-fuel ratio for a second duration, when said majority of exhaust gas flows to said second catalyst, said first duration being longer than said second duration.
A system comprising:
- an engine having an exhaust system through which exhaust gasses flow;
- a first and second emission control device in said exhaust system of said engine;
- an injector in said exhaust system that injects a reductant;
- an exhaust valve in said exhaust system upstream of said first and second emission control device, said valve having at least a first and second position, said first position creating a first path for said reductant from said injector to reach said first emission control device, and a second position creating a second path for said reductant from said injector to reach said second emission control device.
A method for controlling an emission system, the system having an engine and an exhaust through which exhaust gasses flow, said exhaust having at least a first and second catalyst and at least one reductant injector, the method comprising:
- operating in a first mode where exhaust gasses flow to said first catalyst, and during at least a first interval while in said first mode, injecting reductant from the reductant injector into the exhaust system that reaches said second catalyst;
- and
- operating in a second mode where exhaust gasses flow to said second catalyst, and during at least a second interval while in said second mode, injecting reductant from the reductant injector into the exhaust system that reaches said first catalyst.
Dependencies are inferred from the claim text.