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

Abstract

A method for cooling a dosing unit pertaining to an HC dosing system for exhaust cleaning. The unit includes a dosing unit ( 250 ) for fuel and a feed device ( 230 ) for fuel for cooling the fuel dosing unit ( 250 ) using fuel supplied to it, and running the feed device ( 230 ) to supply coolant fuel at reduced power. Also a computer program product containing program code (P) for implementing the method. Also an HC dosing system and a motor vehicle equipped with the system.

1 . A method for cooling a dosing unit pertaining to an HC dosing system for exhaust cleaning of an engine which produces exhaust during operation, the engine comprising a dosing unit for fuel and a feed device for feeding coolant fuel to said dosing unit;
 the method comprising the steps of:   cooling said fuel dosing unit by supplying engine operating fuel as a coolant to said dosing unit; and   running said feed device to supply said coolant fuel at reduced power of said feed device compared with ordinary operation of said feed device at ordinary power.   
     
     
         2 . A method according to  claim 1 , further comprising the step of:
 running said feed device at least a possible power and with substantially unchanged cooling power of said dosing unit, for as long as cooling continues.   
     
     
         3 . A method according to  claim 2 , running said feed device at a power corresponding to 10-30% of said power at which said feed device is run during ordinary operation. 
     
     
         4 . A method according to  claim 1 , further comprising the step of:
 said running of said feed device is for a predetermined period of time.   
     
     
         5 . A method according to  claim 1 , further comprising the step of:
 measuring temperature of at least one portion of said HC dosing system, and running said feed device on the basis of said measured temperature.   
     
     
         6 . A method according to  claim 1 , wherein said running of said feed device entails catering for rewarming effects. 
     
     
         7 . A method according to  claim 1 , further comprising the step of:
 continuously running said feed device at reduced power compared with said power at which said feed device is run at ordinary operation of said feed device.   
     
     
         8 . A method according to  claim 1 , wherein said feed device is configured to supplying fuel to an injection system of the engine or said feed device is a separate feed device. 
     
     
         9 . A method according to  claim 1 , further comprising the step of powering said dosing unit by a compressed air source. 
     
     
         10 . A method according to  claim 1 , further comprising:
 operating the engine which produces exhaust flow, then ceasing operation of the engine and ceasing exhaust flow; and   cooling said fuel dosing unit by fuel after cessation of exhaust flow from said engine.   
     
     
         11 . An HC dosing system for exhaust cleaning of a combustion engine which produces exhaust during operation, the engine comprises a coolable dosing unit for fuel and a feed device for said fuel,
 said dosing system comprising:   a device for cooling said fuel dosing unit by supplying fuel to said dosing unit; and   a control device for running said feed device to supply said coolant fuel at reduced power of said feed device as compared with supply of coolant fuel at ordinary operation of said feed device.   
     
     
         12 . An HC dosing system according to  claim 11 , further comprising:
 said control device being configured and operable for running said feed device at a least possible power, with substantially unchanged cooling power of said dosing unit, for as long as cooling continues.   
     
     
         13 . An HC dosing system according to  claim 11  , further comprising said control device being configured for running said feed device at a power corresponding to 10-30% of said power at which said feed device is run during ordinary operation. 
     
     
         14 . An HC dosing system according to  claim 11 , further comprising:
 said control device being configured for running said feed device for a predetermined period of time after cessation of said exhaust flow.   
     
     
         15 . An HC dosing system according to  claim 11 , further comprising:
 said control device being configured for running said feed device on the basis of a measured temperature of at least one portion of said HC dosing system.   
     
     
         16 . An HC dosing system according to  claim 11 , in which said feed device is configured to cater for rewarming effects. 
     
     
         17 . An HC dosing system according to  claim 11 , further comprising:
 said control device being configured for continuously running said feed device at a reduced power as compared with said power at which said feed device is run during ordinary operation.   
     
     
         18 . An HC dosing system according to  claim 11 , wherein said feed device is configured and connected to supply fuel to an injection system of the engine or is a separate feed device. 
     
     
         19 . An HC dosing system according to  claim 11 , further comprising a compressed air supply connected to power said dosing unit. 
     
     
         20 . An HC dosing system according to  claim 11 , further comprising:
 a control for cooling said fuel dosing unit with fuel after cessation of exhaust flow.   
     
     
         21 . A motor vehicle comprising an HC dosing system according to  claim 11 . 
     
     
         22 . A motor vehicle according to  claim 21 , which is a truck, bus or passenger car. 
     
     
         23 . A computer programme pertaining to an HC dosing system for exhaust cleaning of an engine which generates exhaust during operation, wherein said dosing system comprises a dosing unit for fuel and a feed device for the fuel, and wherein said programme contains non-transitory programme code with a non-transitory programme 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. 
     
     
         24 . A computer programme product according to  claim 23 , wherein the 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, when said computer programme is run on an electronic control unit or another computer connected to said electronic control unit.