Abstract:
A method of determining an optimized position for a burner in an exhaust aftertreatment system includes estimating temperature distributions across faces of exhaust treatment devices positioned within parallel paths based on an initial burner position upstream of the parallel paths. A temperature distribution across the faces of the exhaust treatment device is again estimated based on a changed burner position. A difference between the estimates is determined. The changing, estimating and determining steps are repeated to correlate the burner position with a temperature variance across the faces. An optimized burner position is determined based on minimizing the temperature variance across the faces of the exhaust treatment devices.
Abstract:
An exhaust aftertreatment system may include a reductant tank, a gaseous ammonia source, an injector, first conduit and a second conduit. The injector may receive the liquid reductant from the reductant tank and the gaseous ammonia from the gaseous ammonia source and inject the liquid reductant into a stream of exhaust gas in a first mode, inject the gaseous ammonia into the stream of exhaust gas in a second mode, and both the liquid reductant and the gaseous ammonia into the stream of exhaust gas in a third mode. The first conduit may communicate liquid reductant from the reductant tank to the injector. The second conduit may communicate gaseous ammonia from the gaseous ammonia source to the injector.
Abstract:
An after-treatment system including an exhaust treatment component provided in an exhaust passage, a tank carrying an aqueous reagent, and an electrochemical cell in communication with the tank and configured to receive the aqueous reagent therefrom. The electrochemical cell is configured to convert the aqueous reagent into a first exhaust treatment fluid and a second exhaust treatment fluid. A controller is in communication with the electrochemical cell. The controller is configured to vary amounts and/or composition of each of the first exhaust treatment fluid and the second exhaust treatment fluid produced by the electrochemical cell. An injector is in communication with the electrochemical cell and the exhaust passage, and is configured to receive one of the first exhaust treatment fluid or the second exhaust treatment fluid from the electrochemical cell, and dose the one exhaust treatment fluid into the exhaust passage at a location upstream from the exhaust treatment component.
Abstract:
An exhaust aftertreatment system may include a reductant supply and diluent supply conduits, an injector and a control module. The reductant supply conduit includes a first valve controlling a flow of reductant through the reductant supply conduit. The diluent supply conduit includes a second valve controlling a flow of diluent through the diluent supply conduit. The injector is in fluid communication with the reductant supply conduit and the diluent supply conduit and is configured to provide fluid to an exhaust stream. The control module may control the first valve to provide a targeted amount of reductant through the injector. The control module may control the second valve to maintain a fluid flow rate through the injector that is at or above a minimum flow rate threshold of the injector based on a difference between a flow rate through the reductant supply conduit and the minimum flow rate threshold.
Abstract:
Exhaust system for a dual-fuel engine that is provided with a first fuel and a second fuel. The exhaust system includes an exhaust passageway, with an exhaust treatment component provided in the exhaust passageway. A thermal enhancement device communicates with the exhaust passageway and is located upstream from the exhaust treatment component, wherein the thermal enhancement device is operable to raise a temperature of an exhaust located in the exhaust passageway during a switch between the first fuel and the second fuel that is provided to the dual-fuel engine. The exhaust treatment system can also include a by-pass pipe in communication with the exhaust passageway that by-passes the exhaust treatment component, wherein during combustion of the first fuel by the dual-fuel engine, the by-pass pipe is open. During combustion of the second fuel by the dual-fuel engine, the by-pass pipe is closed.
Abstract:
An exhaust after-treatment system includes an exhaust treatment component, a tank for holding an exhaust treatment fluid, and an exhaust treatment fluid dosing system. The dosing system includes a fluid distributor providing exhaust treatment fluid under pressure to a plurality of dosing modules that dose exhaust treatment fluid into the exhaust stream and a return for returning unused exhaust treatment fluid to the tank. A valve is positioned between the fluid distributor and the return and is configured to allow a flow of exhaust treatment fluid from the return to the fluid distributor before being returned to the tank during a purge operation. A controller is configured to open the valve and allow communication between the return and the fluid distributor during the purge operation such that unused exhaust treatment fluid drains during the purge operation.
Abstract:
An after-treatment system for treating exhaust gas discharged from a combustion engine, the after-treatment system comprising an exhaust after-treatment component including an exhaust after-treatment substrate, the exhaust after-treatment substrate including an inlet face including a first zone having a first catalyst located at a center of the inlet face, and a second zone having a second catalyst located radially outward from the center of the inlet face, wherein an amount of the exhaust gas that travels through the first zone is greater than an amount of the exhaust gas that passes through the second zone, and a catalyst loading of the first catalyst in the first zone is less than a catalyst loading of the second catalyst in the second zone.
Abstract:
An exhaust after-treatment system includes an exhaust treatment component, a tank for holding an exhaust treatment fluid, and an exhaust treatment fluid dosing system. The dosing system includes a fluid distributor providing exhaust treatment fluid under pressure to a plurality of dosing modules that dose exhaust treatment fluid into the exhaust stream and a return for returning unused exhaust treatment fluid to the tank. A valve is positioned between the fluid distributor and the return and is configured to allow a flow of exhaust treatment fluid from the return to the fluid distributor before being returned to the tank during a purge operation. A controller is configured to open the valve and allow communication between the return and the fluid distributor during the purge operation such that unused exhaust treatment fluid drains during the purge operation.
Abstract:
An aftertreatment system for treating exhaust gas discharged from a combustion engine, the aftertreatment system comprising a low temperature selective-catalytic-reduction catalyst, wherein the low-temperature selective-catalytic-reduction catalyst is a mixture of catalytic metals provided on a beta-zeolite support material, the mixture of catalytic metals being at least one mixture selected from Cu and Ce, Mn and Ce, Mn and Fe, Cu and W, Mn and W, and Ce and W.
Abstract:
An exhaust system for a dual-fuel engine includes an exhaust treatment component in an exhaust passageway. The exhaust treatment component is configured to treat exhaust from the combustion of a second fuel and not from combustion of a first fuel. A thermal enhancement device is in communication with the exhaust passageway and positioned upstream from the exhaust treatment component. A controller activates and deactivates the thermal enhancement device based on switching from the first fuel to the second fuel, wherein the first fuel has a higher sulfur content than the second fuel. The thermal enhancement device increases the temperature of an exhaust to combust a residual amount of the first fuel present in the exhaust passageway during the switch between the first fuel and the second fuel.