Diagnostic system for an emissions control on an engine
AssigneeCaterpillar Inc.
InventorsCho Y. Liang, Steven R. McCoy
Life of this patent
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Abstract
A selective catalytic reduction emissions control includes a NOx-reducing reagent stored in a vessel. The system includes apparatus and a method for determining when the vessel is empty or when the vessel is filled with a substance other than an acceptable NOx-reducing reagent.
Claims13
An electronic control system for a compression ignition engine having an exhaust output, said control system comprising:
- a vessel for storing a solid ammonia producing reagent;
- a sublimation sensor associated with said vessel and producing a sublimation signal;
- a valve in fluid communication with said vessel and said exhaust output;
- a controller associated with said engine and controlling operation of the engine, said controller being connected with said valve and said sublimation sensor and modifying engine operation in response to said sublimation signal;
- and
- data representing at least one sublimation curve stored in said controller, said sublimation curve corresponding to a solid ammonia producing agent;
- wherein said sublimation sensor includes:
- a temperature sensor;
- and
- a pressure sensor;
- wherein said sublimation signal includes:
- a temperature signal produced by said temperature sensor;
- and
- a pressure signal produced by said pressure sensor b.
An emissions control system for reducing NOx emissions from exhaust of a compression ignition engine, said exhaust being passed through an SCR reactor effective for selective catalytic NOx reduction, comprising:
- an electronic controller associated with said engine for controlling fuel delivery to said engine;
- a vessel including a solid ammonia producing reagent;
- a heat source associated with said vessel to apply heat to said reagent;
- a valve in fluid communication with said vessel and an exhaust path of said engine, said valve controllably introducing ammonia produced by said reagent into said exhaust path;
- a temperature sensor associated with said vessel and producing a vessel temperature signal;
- a pressure sensor associated with said vessel and producing a vessel pressure signal;
- and
- data representing a sublimation curve stored in said electronic controller;
- and
- wherein said electronic controller receives said vessel temperature and pressure signals and modifies said fuel delivery as a function of said vessel temperature and pressure signals;
- and
- wherein said electronic controller compares said vessel temperature and pressure signals to at least a portion of said data and modifies said fuel delivery as a function of said comparison.
A method for inhibiting tampering with an emissions system on a compression ignition engine, said emissions system including a vessel having a solid ammonia producing reagent stored therein, said vessel being connected with an exhaust path of said engine, wherein said ammonia is introduced into the exhaust stream and the mixture of ammonia and exhaust runs through an SCR catalyst, said method comprising:
- determining a temperature of said vessel;
- determining a pressure of said vessel;
- comparing said temperature and pressure to a sublimation curve for the desired solid ammonia producing reagent;
- and
- modifying operation of the engine in response to said comparison.
Dependencies are inferred from the claim text.