Abstract: A method for controlling operation of an internal combustion engine determines an estimated NOx value as a function of at least one engine operating parameter. The method also determines an actual NOx value using a NOx sensor positioned in an exhaust gas stream of the internal combustion engine. The method detects at least one condition indicative of whether or not the actual NOx value is accurate. The actual NOx value is used for controlling engine operation when the at least one condition indicates that the actual NOx value is accurate, while the estimated NOx value is used for controlling engine operation when the at least one condition indicates that the actual NOx value is inaccurate.

Abstract: A method for determining the degree of saturation of a solid ammonia storage material in a storage unit includes activating a heater to release ammonia from the storage material until the pressure of the storage unit reaches a predetermined pressure. The method then deactivates the heater and determining a decay rate of the pressure of the storage unit while the heater is deactivated. The method estimates the degree of saturation of the ammonia storage medium in response to the decay rate. According to some embodiments, determining the decay rate may include measuring the time required for the pressure of the storage unit to drop from a first pressure threshold to a second pressure threshold.

Abstract: A system for storage and dosing of ammonia includes solid ammonia storage material capable of binding and releasing ammonia reversibly by adsorption/absorption. The system includes a start-up storage unit and a main storage unit, both of which hold ammonia storage material. A start-up heating device is arranged to heat the start-up storage unit to generate gaseous ammonia by thermal desorption from the solid storage material. A main heating device arranged to heat the main storage unit to generate gaseous ammonia by thermal desorption from the solid storage material. A controller modulates operation of the heating devices such that the main and start-up heating devices are not simultaneously activated.

Abstract: A system for mixing ammonia (reductant) with engine exhaust includes an exhaust flow created by a vehicle engine, an ammonia feed line passing into the exhaust flow, an injector connected to the feed line and positioned within the exhaust flow, the injector having at least one port for discharging ammonia into the exhaust flow, and a mixing plate positioned within the exhaust flow downstream of the ammonia injector and stabilizing at least one of either the feed line and the injector. An aspect of the invention is to stabilize the injector by attaching the mixing plate to the feed line to provide such stability. Alternatively or additionally, the mixing plate is attached to the injector to stabilize. The feed line may even pass through the mixing plate.

Abstract: A quantity of ammonia being consumed within an exhaust system of an internal combustion engine to reduce NOx in exhaust passing through the exhaust system by chemical reactions enabled by an SCR catalyst is calculated by processing, in accordance with an algorithm, certain data including data indicative of a quantity of NOx in exhaust upstream of where ammonia is being introduced into the exhaust system, data indicative of a quantity of NOx in exhaust downstream of the SCR catalyst, and data indicative of exhaust flow.

Abstract: A diesel engine (10) has an exhaust system (16) containing a diesel particulate filter (18) for trapping soot passing through the exhaust system as the engine operates. A trapped soot estimator (30) estimates soot trapped in the diesel particular filter by repeatedly executing an algorithm that calculates a data value for total soot trapped using Kalman filter processing (48) whose gain is controlled by at least one engine operating parameter.

Abstract: A method for controlling operation of an internal combustion engine determines an estimated NOx value as a function of at least one engine operating parameter. The method also determines an actual NOx value using a NOx sensor positioned in an exhaust gas stream of the internal combustion engine. The method detects at least one condition indicative of whether or not the actual NOx value is accurate. The actual NOx value is used for controlling engine operation when the at least one condition indicates that the actual NOx value is accurate, while the estimated NOx value is used for controlling engine operation when the at least one condition indicates that the actual NOx value is inaccurate.

Abstract: A method is provided for estimating the NOx content of exhaust gas produced by an internal combustion engine. The method includes determining a first NOx estimate corresponding to the NOx level output by the engine during a first engine operating condition. The method further includes determining a second NOx estimate corresponding to the NOx level output by the engine during a second engine operating condition. The method further includes determining a compensation factor based on intake manifold pressure and applying the compensation factor to the first and second NOx estimates to arrive at a final NOx estimate.

Abstract: A system and method for heating main unit containing host salt having ammonia that is used as reductant in an engine exhaust gas after-treatment system. Engine coolant is delivered from internal combustion engine to auxiliary heating device. When necessary, the auxiliary heating device heats the engine coolant to temperatures that will aid in releasing ammonia from the host salt. The auxiliary heating device may employ an electric heating element, a combustion element, or be an exhaust gas heat exchanger, among other heating methods. The heated engine coolant is delivered to a coolant heating manifold, where heat from the heated coolant is transferred to the main unit. The transferred heat may aid in elevating the temperature in/of the main unit to facilitate the release of stored ammonia from the host salt as a gaseous reductant. The gaseous ammonia may then flow from the main unit.

Abstract: A method of providing hydrocarbons to an engine exhaust for regenerating a diesel particulate filter within an exhaust system of a diesel engine. A mass flow rate of exhaust gas within an exhaust system is determined. A mass flow rate of oxygen within the exhaust gas entering the diesel oxidation catalyst is determined. A set point indicative of an allowable mass flow rate of oxygen within the exhaust gas exiting the diesel oxidation catalyst is received. A hydrocarbon threshold that may be injected into the exhaust system is calculated. Hydrocarbons are injected into the exhaust system upstream of the diesel oxidation catalyst, wherein the injected hydrocarbons do not exceed the calculated threshold amount of hydrocarbons.

Abstract: A reductant mixing system having injector and mixing plate positioned within mixing canister is disclosed. Injector discharges reductant directly into vehicle exhaust gases. Mixing plate effects turbulence to mix gases for NO reduction. Mixing plate includes plurality of arms each having surface area and extending from center of plate, barrier region defined by collective surface areas of arms and substantially centered for diverting fluid flow outward, and first and second cut-outs, which allow the gases diverted by barrier region to pass mixing plate into adjacent canister of exhaust treatment system. Each of the first cutouts is defined by outer edge between adjacent arms, and second tier of cut-outs defined by inner edge proximate end of each arm.

Abstract: A system for storage and dosing of ammonia includes solid ammonia storage material capable of binding and releasing ammonia reversibly by adsorption/absorption. The system includes a start-up storage unit and a main storage unit, both of which hold ammonia storage material. A start-up heating device is arranged to heat the start-up storage unit to generate gaseous ammonia by thermal desorption from the solid storage material. A main heating device arranged to heat the main storage unit to generate gaseous ammonia by thermal desorption from the solid storage material. A controller modulates operation of the heating devices such that the main and start-up heating devices are not simultaneously activated.

Abstract: A method for determining the degree of saturation of a solid ammonia storage material in a storage unit includes activating a heater to release ammonia from the storage material until the pressure of the storage unit reaches a predetermined pressure. The method then deactivates the heater and determining a decay rate of the pressure of the storage unit while the heater is deactivated. The method estimates the degree of saturation of the ammonia storage medium in response to the decay rate. According to some embodiments, determining the decay rate may include measuring the time required for the pressure of the storage unit to drop from a first pressure threshold to a second pressure threshold.

Abstract: An ammonia flow modulator having a housing, a fluid passage, a first valve, preferably having a precision orifice, positioned within the passage, and an orientation which prevents fluid from pooling in the passage is disclosed and claimed. As an added feature, the device may include a heat source positioned within the housing proximate at least one of a fluid inlet, a fluid outlet, and the fluid passage. The heat source may be provided by an electric heating element, an exhaust gas heat exchanger, or any other suitable source. As econd inlet and a second passage fluidly connecting the second inlet to the outlet by fluidly linking the second passage to the first passage and including a check valve to prevent backflow. A controller coupled to the first valve is used to control ammonia flow.

Abstract: A reductant storage and dosing system which uses at least one canister containing a supply of reductant to supply, via a delivery line, an exhaust gas after-treatment system having an injector is disclosed. A controller may be used to meter the flow of the reductant through the delivery line to the injector, while a status indicator indicates a status of the connection—i.e., connected or disconnected. In an embodiment, the status indicator provides a visual signal or indication, such as an LED or series of LEDs, an audible signal, such as a beep, click or buzz, or both. Iternatively, the status indicator may be an analog or digital gauge.

Abstract: Reductant delivery system having at least one canister containing reductant coupled, via delivery line, to after-treatment system having ammonia injector, is disclosed. Reductant includes ammonia adsorbing/desorbing material. Delivery line is connected at one end to ammonia injector and at another end detachably coupled by coupler to the canister. Controller may be used for metering flow of ammonia through delivery line to injector. Line-break detector detects disconnection within the delivery line to prevent loss of ammonia. Line-break indicator coupled to line-break detector is used, wherein the indicator activates upon the detector detecting a disconnection in the delivery line. Related methods for detecting and indicating a line break are disclosed.

Abstract: A reductant mixing system having injector and mixing plate positioned within mixing canister is disclosed. Injector discharges reductant directly into vehicle exhaust gases. Mixing plate effects turbulence to mix gases for NO reduction. Mixing plate includes plurality of arms each having surface area and extending from center of plate, barrier region defined by collective surface areas of arms and substantially centered for diverting fluid flow outward, and first and second cut-outs, which allow the gases diverted by barrier region to pass mixing plate into adjacent canister of exhaust treatment system. Each of the first cutouts is defined by outer edge between adjacent arms, and second tier of cut-outs defined by inner edge proximate end of each arm.

Abstract: A system for mixing ammonia (reductant) with engine exhaust includes an exhaust flow created by a vehicle engine, an ammonia feed line passing into the exhaust flow, an injector connected to the feed line and positioned within the exhaust flow, the injector having at least one port for discharging ammonia into the exhaust flow, and a mixing plate positioned within the exhaust flow downstream of the ammonia injector and stabilizing at least one of either the feed line and the injector. An aspect of the invention is to stabilize the injector by attaching the mixing plate to the feed line to provide such stability. Alternatively or additionally, the mixing plate is attached to the injector to stabilize. The feed line may even pass through the mixing plate.

Abstract: A system and method for calculating quantity of ammonia stored on an SCR catalyst at various times during an interval of time by processing certain data, including the aggregate quantity of ammonia introduced into an exhaust flow during the interval of time, calculating the efficiency of catalytic conversion of NOx to N2 and H2O by ammonia at each of the various times by processing certain data, including NOx measurements obtained from upstream and downstream NOx sensors, and establishing a correlation between efficiency of catalytic conversion of NOx to N2 and H2O by ammonia and quantity of ammonia stored on the SCR catalyst over the interval of time which comprises calculated efficiency of catalytic conversion of NOx and calculated quantity of ammonia stored on the SCR catalyst at each of the various times.

Abstract: An injector boss (114) for mounting an injector (110) that injects liquid reductant (U) into a flow of exhaust gas (EG) in an exhaust pipe (116) includes at least one sidewall (124) and a boss foundation (126). The boss foundation (126) is generally perpendicular to the at least one sidewall (124), and the at least one sidewall and the boss (114) define an internal area (120). A spray guard (132) extends from the boss foundation (126) into the internal area (120). The spray guard (132) h a first opening (138) for receiving liquid reductant (U) from the injector (110), and a second opening (140) for emitting liquid reductant into the internal area (120).