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

Abstract

A method for cooling a dosing unit ( 250 ) pertaining to HC dosing system for exhaust cleaning. The dosing unit ( 250 ) for fuel and a feed device ( 230 ) to supply fuel for cooling. The steps include cooling a fuel dosing unit ( 250 ) by fuel supplied to intermittently, in mutually successive respective periods of zero operating power of the feed device, or running at certain operating powers by running a fuel feed device ( 230 ) at reduced power compared with ordinary operation. A computer programme product containing programme code (P) for a computer ( 200; 210; 500 ) for implementing the method. An HC dosing system. 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 generates exhaust when the engine operates, and the engine comprises said dosing unit for fuel and a feed device to supply coolant fuel for cooling;
 the method comprising the steps of:   cooling said fuel dosing unit by supplying fuel to said dosing unit;   selectively running said feed device at a first operating power or at a zero operating power, which comprises   intermittently running said feed device, in mutually successive respective periods of zero operating power and then running at certain operating powers, comprising running said fuel feed device at a reduced power compared with ordinary operation of said feed device.   
     
     
         2 . A method according to  claim 1 , wherein said feed device is configured and operable to run intermittently with a predetermined interval configuration. 
     
     
         3 . A method according to  claim 2 , wherein said predetermined interval configuration of said feed device entails catering for rewarming effects of said dosing unit. 
     
     
         4 . A method according to  claim 1 , further comprising measuring a temperature of at least one portion of said HC dosing system and operating said feed device based on the measured temperature. 
     
     
         5 . A method according to  claim 1 , further comprising operating said feed device for cooling said dosing unit to a temperature below a predetermined limit value. 
     
     
         6 . A method according to  claim 1 , wherein said fuel is diesel fuel or another hydrocarbon-based fuel. 
     
     
         7 . A method according to  claim 1 , wherein said feed device is configured and operable to supply fuel to an injection system of an engine, or is a separate feed device. 
     
     
         8 . A method according to  claim 1 , further comprising powering said dosing unit with a compressed air source. 
     
     
         9 . A method according to  claim 1 , further, comprising cooling said fuel dosing unit by supplying fuel after cessation of an exhaust flow from the engine. 
     
     
         10 . An HC dosing system for exhaust cleaning of a an engine which generates an exhaust flow when the engine operates, and the dosing system comprises a coolable dosing unit for fuel and a feed device to supply 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 intermittently running said feed device, in mutually successive respective periods, of zero operating power and then running at certain operating powers comprising running said feed device to supply said coolant fuel at reduced power as compared with supply of coolant fuel at ordinary operation of said feed device.   
     
     
         11 . An HC dosing system according to  claim 10 , in which said feed device is configured and operable to being run intermittently with a predetermined interval configuration for powered operation and zero power operation. 
     
     
         12 . An HC dosing system according to  claim 11 , wherein said predetermined interval configuration for said feed device entails catering for rewarming effects of said dosing unit. 
     
     
         13 . An HC dosing system according to  claim 10 , further comprising a temperature measurement device located and configured for measuring temperature of at least one portion of said HC dosing system, and said feed device is configured for operation of said feed device based on the measured temperature. 
     
     
         14 . An HC dosing system according to  claim 10 , wherein said feed device is configured for cooling said dosing unit to a temperature which is below a predetermined limit value during its operation. 
     
     
         15 . An HC dosing system according to  claim 10 , wherein said fuel is diesel fuel or another hydrocarbon-based fuel. 
     
     
         16 . An HC dosing system according to  claim 10 , wherein said engine includes an injection system for fuel, and said feed device supplies fuel to said injection system of an engine or said feed device is a separate feed device. 
     
     
         17 . An HC dosing system according to  claim 10 , further comprising compressed air supply to power said dosing unit. 
     
     
         18 . An HC dosing system according to  claim 10 , comprising:
 a further cooling device configured for cooling said fuel dosing unit by feeding fuel after cessation of an exhaust flow.   
     
     
         19 . An HC dosing system according to  claim 10 , which system comprises a DPF system. 
     
     
         20 . A motor vehicle comprising an HC dosing system according to  claim 10 . 
     
     
         21 . A motor vehicle according to  claim 20 , comprising a truck, bus or passenger car. 
     
     
         22 . A computer programme product pertaining to an HC dosing system for exhaust cleaning of an engine which generates exhaust when operating, wherein said dosing system comprises a dosing unit for fuel and a feed device for the fuel, and wherein said programme product comprises non-transitory programme code with non-transitory program instructions for causing a computer system to perform steps according to  claim 1  on an electronic control unit or causing another computer connected to the electronic control unit to perform such steps when instructions in said code are run on said computer system. 
     
     
         23 . A computer programme product according to  claim 22 , 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.