Method and device pertaining to cooling of dosing units of hc dosing systems for exhaust cleaning

Abstract

A method pertaining to an HC dosing system for exhaust cleaning for an engine which comprise a dosing unit ( 250 ) for fuel. After cessation of an exhaust flow, deciding about a need to cool the fuel dosing unit by use of fuel. Predicting a temperature pattern of the dosing unit ( 250 ) as a basis for deciding. Predicting whether a predetermined temperature of the dosing unit ( 250 ) will be reached after exhaust flow cessation. Also a computer programme product containing programme code (P) for implementing the method. Also an HC dosing system and a motor vehicle which is equipped with the HC dosing system are disclosed.

1 . A method pertaining to an HC dosing system for exhaust cleaning of an engine which generates exhaust during operation, wherein the system comprises a dosing unit for fuel, the dosing unit being located generally at the engine exhaust;
 the method comprising the steps of:   operating the engine which generates exhaust flow, then ceasing operation of the engine and the exhaust flow;   before cessation of the exhaust flow from the engine, deciding about a need to cool said fuel dosing unit by supplying fuel to said dosing unit;   predicting a temperature pattern of said dosing unit as a basis for deciding about said need to cool; and   also predicting whether a predetermined temperature of said dosing unit will be reached after said cessation of exhaust flow and using the predictions to decide about said need to cool.   
     
     
         2 . The method according to  claim 1 , wherein said predetermined temperature is a functionally critical temperature for said dosing unit. 
     
     
         3 . A method according to  claim 1 , further comprising predicting a temperature pattern of at least one further portion of said HC dosing system comprised of at least one of a particle filter, a silencer and the fuel. 
     
     
         4 . A method according to  claim 3 , further comprising using said prediction of said temperature pattern of said at least one portion of said HC dosing system for indirectly determining a future temperature of said dosing unit. 
     
     
         5 . A method according to  claim 1 , wherein said prediction of said temperature pattern comprises catering for rewarming effects of at least one portion of said HC dosing system. 
     
     
         6 . A method according to  claim 1 , wherein said step of predicting said temperature pattern of at least one portion of said HC dosing system comprises a calculation model comprising a predetermined parameter configuration. 
     
     
         7 . A method according to  claim 6 , wherein said step of deciding about said need takes place either before said cessation of exhaust flow or after said cessation of exhaust flow. 
     
     
         8 . A method according to  claim 1 , wherein said fuel is diesel fuel or another hydrocarbon-based fuel. 
     
     
         9 . An HC dosing system comprising a device for exhaust cleaning of an engine which generates exhaust during operation, the engine comprises a dosing unit for fuel, the dosing unit being located generally at the engine exhaust;
 the system comprising:   a need to cool deciding device for deciding, after cessation of an exhaust flow from the engine, to cool said fuel dosing unit using fuel intended to be supplied to said dosing unit;   a prediction apparatus for predicting a temperature pattern of said dosing unit to serve as a basis for deciding about said need to cool and for predicting whether a predetermined temperature of said dosing unit will be reached after said cessation of exhaust flow.   
     
     
         10 . An HC dosing system according to  claim 9 , wherein said predetermined temperature is a functionally critical temperature for said dosing unit. 
     
     
         11 . An HC dosing system according to  claim 9 , wherein said prediction apparatus for predicting a temperature pattern of said dosing unit is configured to predicting a temperature pattern of at least one further portion of said HC dosing system wherein said further portion comprises at least one of a particle filter, a silencer and the fuel. 
     
     
         12 . An HC dosing system according to  claim 9 , wherein said prediction apparatus is configured such that said prediction of said temperature pattern of said at least one portion of said HC dosing system enables determining indirectly a future temperature of said dosing unit. 
     
     
         13 . An HC dosing system according to  claim 9 , wherein said prediction of said temperature pattern includes considering rewarming effects of at least one portion of said HC dosing system. 
     
     
         14 . An HC dosing system according to  claim 9 , further comprising said predicting apparatus being configured for predicting said temperature pattern of at least one portion of said HC dosing system by a calculation model comprising a predetermined parameter configuration. 
     
     
         15 . An HC dosing system according to  claim 14 , wherein said need deciding device is configured for deciding before said cessation of exhaust flow or after said cessation of exhaust flow. 
     
     
         16 . A device according to  claim 9 , wherein said fuel is diesel fuel or some other hydrocarbon-based fuel. 
     
     
         17 . A motor vehicle comprising an HC dosing system according to  claim 9 . 
     
     
         18 . A motor vehicle according to  claim 17 , comprising a truck, bus or passenger car. 
     
     
         19 . A computer programme product pertaining to an HC dosing system for exhaust cleaning of an engine, wherein said programme product comprises non-transitory programme code with non-transitory programme instructions for causing a computer system to perform steps on an electronic control unit or causing another computer connected to the electronic control unit to perform steps according to  claim 1  when instructions in said code are run on said computer system. 
     
     
         20 . A computer programme product according to  claim 19 , wherein said product contains a programme code stored on a non-transitory computer-readable medium which can be read by said computer system for performing method steps, wherein said computer programme is run on an electronic control unit or another computer connected to said electronic control unit.