Method and device pertaining to cooling of dosing units of SCR systems

摘要

A method for cooling a dosing unit (250) pertaining to an SCR system for exhaust cleaning, wherein after cessation of exhaust flow, cooling a reducing agent dosing unit (250) by a reducing agent supplied to it. Also running a feed device to supply the coolant reducing agent at reduced power, compared with ordinary operation. A computer program product containing program code (P) for a computer (200; 210) implements a method of the invention. Also an SCR system and a motor vehicle which is equipped with the SCR system are disclosed.

主权项

1. A method for cooling a reducing agent dosing valve pertaining to an SCR system for exhaust cleaning of a combustion engine exhaust of a combustion engine of a motor vehicle, said combustion engine producing exhaust flow during operation, wherein the dosing valve is located generally at the exhaust flow;
the method comprising performing the steps of: after the cessation of exhaust flow, by stopping of operation of said combustion engine, operating a pump to cool said reducing agent dosing valve by said pump supplying reducing agent to said dosing valve; after the cessation of said exhaust flow, reducing a power at which said pump is operated to supply said reducing agent, said reduced power of said pump being reduced by an electronic control unit, said reduced power of said ump being reduced compared with a level of power of said pump when said pump is operated while said combustion engine is operating, pumping coolant for said combustion engine through a line passing through a container of said reducing agent by said pump, and warming said reducing agent, wherein said pumping of said coolant and said warming of said reducing agent is performed when a temperature of said reducing agent in said container is less than or equal to a predetermined value.