Monitor of ammonia in dosing system

Abstract

An ammonia dosing system has a canister whose interior contains ammonia luminophores and a delivery apparatus for delivering ammonia from the canister interior into an exhaust after-treatment system to entrain with engine exhaust flowing toward an SCR catalyst for catalytic conversion of NO x in engine exhaust.

What is claimed is: 
     
         1 . An internal combustion engine comprising:
 an exhaust after-treatment system comprising an SCR catalyst;   an ammonia dosing system comprising a canister having an interior containing ammonia luminophores and a delivery apparatus for delivering ammonia from the canister interior into the exhaust after-treatment system to entrain with engine exhaust flowing toward the SCR catalyst for catalytic conversion of NO x  in the engine exhaust.   
     
     
         2 . The internal combustion engine set forth in  claim 1  including a monitor of ammonia luminophores comprising at least one optical sensor for detecting luminescence of ammonia luminophores in the ammonia dosing system. 
     
     
         3 . The internal combustion engine set forth in  claim 2  in which the monitor comprises a device providing a signal distinguishing high luminescence of ammonia luminophores detected by the at least one optical sensor and low luminescence of ammonia luminophores detected by the at least one optical sensor. 
     
     
         4 . The internal combustion engine set forth in  claim 2  in which the at least one optical sensor provides a measure of luminescence of ammonia luminophores which the at least one optical sensor detects, and the monitor converts a measure of luminescence of ammonia luminophores which the at least one optical sensor detects into a quantitative measure of ammonia. 
     
     
         5 . The internal combustion engine set forth in  claim 4  in which the monitor provides a signal alert when a quantified measure of ammonia is less than a predetermined quantity. 
     
     
         6 . The internal combustion engine set forth in  claim 2  in which the canister comprises a port via which the canister separably connects to the delivery apparatus, and the at least one optical sensor is arranged to view luminescence of ammonia luminophores within the canister's interior. 
     
     
         7 . The internal combustion engine set forth in  claim 6  including a closure which, when the canister's port is connected to the delivery apparatus and the at least one optical sensor detects luminescence of ammonia luminophores greater than a predetermined luminescence, allows ammonia flow between the canister interior and the exhaust after-treatment system, and which, when the canister's port is connected to the delivery apparatus and the at least one optical sensor detects luminescence of ammonia luminophores less than the predetermined luminescence, disallows ammonia flow between the canister interior and the exhaust after-treatment  system. 
     
     
         8 . The internal combustion engine set forth in  claim 7  in which the closure and the at least one optical sensor are mounted on the delivery apparatus. 
     
     
         9 . A method for detection of ammonia in an ammonia dosing system which delivers ammonia into an engine exhaust after-treatment system to entrain with exhaust flowing toward an SCR catalyst for catalytic conversion of NO R , the method comprising:
 installing in the ammonia dosing system an ammonia storage canister which contains ammonia luminophores;   operating the ammonia dosing system to deliver ammonia from the ammonia storage canister into the exhaust after-treatment system; and   using at least one optical sensor to detect luminescence of ammonia luminophores in the ammonia dosing system.   
     
     
         10 . The method set forth in  claim 9  comprising providing a signal distinguishing high luminescence of ammonia luminophores detected by the at least one optical sensor and low luminescence of ammonia luminophores detected by the at least one optical sensor. 
     
     
         11 . The method set forth in  claim 9  comprising using a measure of luminescence of ammonia luminophores which the at least one optical sensor detects to quantify a measure of ammonia. 
     
     
         12 . The method set forth in  claim 11  including providing a signal alert when a quantified measure of ammonia is less than a predetermined quantity. 
     
     
         13 . The method set forth in  claim 9  comprising arranging the at least one optical sensor to view luminescence of ammonia luminophores in the canister's interior and when the at least one optical sensor detects luminescence of ammonia luminophores greater than a predetermined luminescence, allowing ammonia flow between the canister interior and the exhaust after-treatment system, and when the at least one optical sensor detects luminescence of ammonia luminophores less than the predetermined luminescence, disallowing ammonia flow between the canister interior and the exhaust after-treatment system.