Claims:1. A method (200) of dosing Diesel Exhaust Fluid (DEF) in a
Selective Catalytic Reduction (SCR) system (100), the SCR system
(100) comprising a tailpipe (105) mounted with a upstream NOx
sensor (104), a downstream NOx sensor (103) 5 and at least one
temperature sensor (106), said NOx and temperature sensor (106)s
in communication with an Electronic control unit (ECU (102)), the
ECU (102) stores a modelled value of storage quantity of DEF in
SCR catalyst, the method steps comprising:
receiving (201) a value of NOx levels from the NOx sensors;
receiving (202) a value of temperature in the tailpipe (105)
(105) from the temperature sensor (106);
detecting (203) a set a conditions based on the said received
values;
15 updating (204) the storage quantity in the ECU (102) model
based on the set of condition;
dosing (205) DEF into tailpipe (105) of the SCR system
(100) based on the updated storage quantity.
2. The method (200) of dosing Diesel Exhaust Fluid (DEF) in a
Selective Catalytic Reduction (SCR) system (100) as claimed in
claim 1, where the set of conditions comprise :
high temperature gradient detected by the temperature
sensors; and at least
the value of NOx detected by the upstream and downstream
NOx sensor (103)s are approximately equal.
3. An Electronic Control Unit (ECU (102)) adapted to dose Diesel
Exhaust Fluid (DEF) in a Selective Catalytic 5 Reduction (SCR)
system (100), the SCR system (100) comprising a tailpipe (105)
mounted with a upstream NOx sensor (104), a downstream NOx
sensor (103) and at least one temperature sensor (106), said NOx
and temperature sensor (106)s in communication with the
10 Electronic control unit (ECU (102)), the ECU (102) stores a
modelled value of storage quantity of DEF in SCR catalyst, the
ECU (102) configured to:
receive a value of NOx levels from the NOx sensors;
receive a value of temperature in the tailpipe (105) (105)
15 from the temperature sensor (106);
detect a set a conditions based on the said received values;
update the storage quantity in the ECU (102) model based on
the set of condition;
dose DEF into tailpipe (105) of the SCR system (100) based
20 on the updated storage quantity.
4. The Electronic Control Unit (ECU (102)) adapted to dose Diesel
Exhaust Fluid (DEF) in a Selective Catalytic Reduction (SCR)
system, where the set of conditions comprise :
high temperature gradient detected by the temperature
sensors; and at least
the value of NOx detected by the upstream and downstream
NOx sensor (103)s are approximately equal. , Description:The present disclosure proposes a method of dosing Diesel 5 Exhaust Fluid
(DEF) in a Selective Catalytic Reduction (SCR) system (100) and an
Electronic Control Unit (ECU (102)) thereof. The proposed method takes
into account the absorption of DEF by the SCR catalyst during certain
conditions. These conditions comprise high temperature gradient in
10 exhaust tailpipe (105) and approximately equal values of upstream and
downstream NOx. The stored quantity of DEF in SCR catalyst is updated
in a model of the ECU (102). The updated model of ECU (102) helps in
dosing of a metered quantity of DEF.