Heating of an exhaust gas aftertreatment system by dragging of an internal combustion engine with the aid of an electric motor

Abstract

A method is introduced for heating an exhaust-gas aftertreatment system ( 15 ). The method has the following steps: detection of a necessity to heat (S 1 ) the exhaust-gas aftertreatment system ( 15 ), and actuation (S 5 ) of an electric motor ( 5 ) in such a way that the electric motor ( 5 ) drags the internal combustion engine ( 3 ) which produces exhaust gas. Here, the internal combustion engine ( 3 ) is held at a predefinable rotational speed by the electric motor ( 5 ).

1 . A method for heating an exhaust gas aftertreatment system, the method comprising the following steps:
 detecting a need to heat the exhaust gas aftertreatment system;   controlling an electric motor such that the electric motor drags an internal combustion engine that produces exhaust gas;   wherein the internal combustion engine is thereby maintained at a specifiable revolution rate.   
     
     
         2 . The method as claimed in  claim 1 , also comprising
 dragging the internal combustion engine such that exhaust gases of the internal combustion engine have a higher temperature than during operation of the internal combustion engine without an electric motor.   
     
     
         3 . The method as claimed in  claim 1 , also comprising
 selecting injection parameters and/or ignition parameters of the internal combustion engine such that an independent operation of the internal combustion engine is not possible.   
     
     
         4 . The method as claimed in  claim 3 ,
 wherein the revolution rate, as well as the injection parameters and/or the   ignition parameters are adjusted such that a temperature of the exhaust gases is increased at the cost of a torque-generating proportion of the combustion of the   internal combustion engine compared to the operation of the   internal combustion engine without an electric motor.   
     
     
         5 . The method as claimed in  claim 1 , further comprising determining a current temperature in the exhaust gas aftertreatment system. 
     
     
         6 . The method as claimed in  claim 5 , also comprising
 comparing of the current temperature with a specifiable target temperature value;   terminating the dragging process by the electric motor once the current temperature corresponds to or exceeds the specifiable target temperature value.   
     
     
         7 . The method as claimed in  claim 1 , also comprising
 terminating the dragging process by the electric motor once a specifiable time interval since detecting a need to heat the exhaust gas aftertreatment system is exceeded.   
     
     
         8 . A control device, which is designed to implement the method as claimed in  1 . 
     
     
         9 . A computer program element,
 wherein the computer program element is designed to implement the method as claimed in  claim 1  if it is executed on a processor.   
     
     
         10 . Computer-readable medium,
 wherein the program element as claimed in  claim 9  is stored on the medium.