Exhaust after treatment device mode regulation

Abstract

Method and system for controlling the temperature dependent mode of an exhaust after treatment device, EATD, within an engine system comprising: identifying a target EATD mode. Regulating an EATD temperature to within a temperature range corresponding with the target mode by controlling a gas pressure difference of the engine system between a first location and a second location.

1 . A method of controlling a temperature dependent mode of an exhaust after treatment device, EATD, having a plurality of modes, within an engine system, the method comprising the steps of:
 identifying a target EATD mode out of the plurality of modes; and   regulating an EATD temperature to within a temperature range corresponding with the target EATD mode by controlling a gas pressure difference of the engine system between a first location and a second location.   
     
     
         2 . The method of  claim 1  further comprising the steps of:
 determining if the temperature of the EATD is within the temperature range corresponding with the target EATD mode; and 
 adjusting the gas pressure difference if the temperature of the EATD is outside of the temperature range corresponding with the target EATD mode. 
 
     
     
         3 . The method of  claim 2  further comprising the step of measuring the EATD or exhaust gas temperature. 
     
     
         4 . The method according to  claim 3  further comprising the step of measuring the gas pressure difference between the first location and the second location. 
     
     
         5 . The method according to  claim 4 , wherein the step of controlling a gas pressure difference further comprises the step of adjusting one or more pressure controlling valves at the first location and/or at the second location. 
     
     
         6 . The method according to  claim 5 , wherein the first location is selected from the group consisting of: air intake; intake manifold; turbo compressor-out; pre-charge cooler; pre-turbo compressor; post air filter; and ambient pressure outside of the engine system, and
 further wherein the second location is selected from the group consisting of: exhaust manifold; an inter-stage duct within a series turbo charger; between a turbo charger outlet and a back pressure valve; a back pressure valve and exhaust gas recirculation valve intake.   
     
     
         7 . The method according to  claim 6 , wherein the target EATD mode is selected from the group consisting of: diesel particulate filter, DPF, desulphation; diesel oxidation catalyst, DOC, desulphation; DPF soot oxidation; hydrocarbon evaporation; thermal management of selective catalytic reduction, SCR, aqueous urea injection; SCR urea deposit removal; thermal management of hydrocarbon dosing to remove urea deposits; and SCR desulphation. 
     
     
         8 . The method according to  claim 7 , wherein the step of regulating the EATD temperature further comprises determining a required change in temperature to bring the EATD temperature within the temperature range corresponding with the target EATD mode;
 determining a change in gas pressure difference necessary to bring the EATD temperature within the temperature range corresponding with the target EATD mode; and   adjusting the gas pressure difference by the determined change.   
     
     
         9 . The method of  claim 8 , wherein determining the change in gas pressure difference further comprises reading from a data set of EATD temperature or target EATD mode and corresponding gas pressure difference or pressure controlling valve configuration. 
     
     
         10 . The method according to  claim 9  further comprising the step of closing or opening a Back Pressure Valve, BPV, to regulate EATD temperature. 
     
     
         11 . The method according to  claim 10  further comprising the step of applying changes to fuelling and/or engine timing control to regulate the EATD temperature. 
     
     
         12 . The method according to  claim 11 , wherein the one or more EATD modes are regenerative EATD modes. 
     
     
         13 . An exhaust treatment system for an engine system comprising:
 an exhaust after treatment device, EATD, having a plurality of modes;   one or more valves configured to adjust a gas pressure difference of the engine system between a first location and a second location;   a controller in communication with the one or more valves and configured to identify a target EATD mode out of the plurality of modes, and control the temperature dependent EATD mode of the EATD by regulating the gas pressure difference using the one or more valves.   
     
     
         14 . The exhaust treatment system of  claim 13  further comprising a pressure difference sensor arranged to measure the gas pressure difference between the first location and the second location. 
     
     
         15 . The exhaust treatment system of  claim 14 , wherein the pressure difference sensor comprises a first pressure sensor located at the first location and a second pressure sensor located at the second location. 
     
     
         16 . The exhaust treatment system according to  claim 15 , wherein the EATD includes a diesel oxidation catalyst, DOC and/or a selective catalytic reduction system.