Apparatus, system, and method for exhaust aftertreatment efficiency enhancement

A computer program product comprising a computer readable medium having computer usable program code programmed to enhance the efficiency of an exhaust aftertreatment system, the program product having operations comprising:

• interpreting a plurality of operating conditions comprising a fluid stream flow rate, a NOx fraction in the fluid stream, an NO2/NOx mole ratio in the fluid stream, and a temperature of a diesel oxidation catalyst (DOC) in a first flowpath;
• interpreting operating criteria for each of at least one target component;
• interpreting performance criteria for each of at least one conditioning component comprising the DOC, the performance criteria comprising an NO2/NOx mole ratio out of the DOC based on a flow rate through the DOC;
• determining a first fraction target based on the plurality of operating conditions, the operating criteria, and the performance criteria;
• and
• manipulating a bypass valve position based on the first fraction target, the bypass valve configured to direct a first fraction of the fluid stream to the first flowpath, wherein the first fraction comprises an amount between zero and one hundred percent inclusive of the fluid stream, the bypass valve further configured to direct a second fraction of the fluid stream to a second flowpath.

A system for enhancing the efficiency of an exhaust aftertreatment application, the system comprising:

• an internal combustion engine producing an exhaust stream;
• a bypass valve configured to direct a first fraction of the fluid stream to a conditioning component comprising a diesel oxidation catalyst (DOC), wherein the first fraction comprises an amount between zero and one hundred percent inclusive of the fluid stream;
• the bypass valve further configured to direct a second fraction of the fluid stream to a fluid conduit;
• a mixing component configured to combine the flow from the DOC and the fluid conduit;
• a reagent injector configured to add a reducing reagent to the flow from the mixing component;
• a target component comprising a selective catalytic reduction (SCR) component configured to reduce NOx to N2 within the flow from the mixing component;
• a controller comprising:
• a sensing module configured to interpreting a plurality of operating conditions comprising a fluid stream flow rate, a NOx fraction in the fluid stream, an NO2/NOx mole ratio in the fluid stream, and a temperature the DOC;
• a target selection module configured to interpret operating criteria comprising a NOx to N2 conversion based on an NO2/NOx mole ratio into the SCR component;
• a conditioning performance module configured to interpret performance criteria for the DOC, the performance criteria comprising an NO2/NOx mole ratio out of the DOC based on a flow rate through the DOC;
• a fraction determination module configured to determine a first fraction target based on the plurality of operating conditions, the operating criteria and the performance criteria;
• and
• a valve position module configured to manipulate the bypass valve position based on the first fraction target.

A method to modify an aftertreatment system comprising:

• installing a bypass valve and a second flowpath on an exhaust aftertreatment system, the bypass valve configured to allow a first fraction of an exhaust stream to flow through a diesel oxidation catalyst (DOC), and to allow a second fraction of the exhaust stream to flow through the second flowpath around the DOC, the first fraction comprising an amount between zero and one hundred percent inclusive of the exhaust stream;
• installing a controller configured to perform operations comprising:
• interpreting a plurality of operating conditions comprising a fluid stream flow rate, a NOx fraction in the fluid stream, an NO2/NOx mole ratio in the fluid stream, and a temperature the DOC;
• interpreting operating criteria for a target component;
• interpreting performance criteria for the DOC, the performance criteria comprising an NO2/NOx mole ratio out of the DOC based on a flow rate through the DOC;
• determining a first fraction target based on the plurality of operating conditions, the operating criteria and the performance criteria;
• and
• manipulating the bypass valve position based on the first fraction target.