Abstract: A reductant delivery system is provided for delivery of reductant to an engine exhaust aftertreatment system that is heated during cold temperature conditions. A heat exchange fluid flows through a heat exchange circuit that provides a flow path from the heat source to the doser, from the doser to the reductant storage tank, and from the reductant storage tank to the heat source. A control valve controls the flow of the heat exchange fluid in the heat exchange circuit so that at least one heat exchange cycle includes a circulation period that increases the temperature of the reductant in the doser and storage tank and a termination period where circulation is stopped until reductant temperature in the doser reaches a lower limit.

Abstract: A reductant delivery system is provided for delivery of reductant to an engine exhaust aftertreatment system that is heated during cold temperature conditions. A heat exchange fluid flows through a heat exchange circuit that provides a flow path from the heat source to the doser, from the doser to the reductant storage tank, and from the reductant storage tank to the heat source. A control valve controls the flow of the heat exchange fluid in the heat exchange circuit so that at least one heat exchange cycle includes a circulation period that increases the temperature of the reductant in the doser and storage tank and a termination period where circulation is stopped until reductant temperature in the doser reaches a lower limit.

Abstract: A reductant delivery system is provided for delivery of reductant to an engine exhaust aftertreatment system that is heated during cold temperature conditions. A heat exchange fluid flows through a heat exchange circuit that provides a flow path from the heat source to the doser, from the doser to the reductant storage tank, and from the reductant storage tank to the heat source. A control valve controls the flow of the heat exchange fluid in the heat exchange circuit so that at least one heat exchange cycle includes a circulation period that increases the temperature of the reductant in the doser and storage tank and a termination period where circulation is stopped until reductant temperature in the doser reaches a lower limit.

Abstract: Urea injection system wash cycle methods and systems are disclosed. An exemplary wash cycle method includes operating a urea injection system to provide urea solution to a first inlet of a blending chamber, provide pressurized gas to a second inlet of the blending chamber, and output a combined flow of pressurized gas and urea solution from the blending chamber. A pressure of the combined flow at a location downstream from the first inlet and the second inlet is monitored. A wash cycle is performed based upon the monitored pressure wherein the flow of pressurized gas is turned off and urea solution is provided to the blending chamber. An exemplary system includes a controller configured to control a urea injection system to perform a wash cycle in accordance with the exemplary method.

Abstract: According to one embodiment, an apparatus for reintroducing air includes a bypass valve that reduces pressure in an accumulator that stores reductant to less than an air supply pressure of an air supply. The apparatus also includes a metering valve that fills the accumulator with air from the air supply at the air supply pressure, and a pump that pumps reductant into the accumulator.

Abstract: Urea injection system wash cycle methods and systems are disclosed. An exemplary wash cycle method includes operating a urea injection system to provide urea solution to a first inlet of a blending chamber, provide pressurized gas to a second inlet of the blending chamber, and output a combined flow of pressurized gas and urea solution from the blending chamber. A pressure of the combined flow at a location downstream from the first inlet and the second inlet is monitored. A wash cycle is performed based upon the monitored pressure wherein the flow of pressurized gas is turned off and urea solution is provided to the blending chamber. An exemplary system includes a controller configured to control a urea injection system to perform a wash cycle in accordance with the exemplary method.

Abstract: Reductant dosing systems and methods for engine exhaust aftertreatment are disclosed. The opening and closing of a metering valve in the reductant dosing system is controlled in a manner that mitigates pressure oscillations in the dosing system. The metering valve is opened in response to the dosing command exceeding a minimum threshold value and the differential pressure across the metering valve exceeding a differential pressure threshold. The metering valve is closed in response to either the differential pressure across the metering valve dropping below a differential pressure threshold or the actual dosed quantity exceeding the dosing command.

Abstract: A system includes a cylindrical blend chamber having two inlets and one outlet. The outlet is fluidly coupled to a transfer line, and a nozzle is positioned downstream of the transfer line. The nozzle is fluidly coupled to an exhaust stream of an internal combustion engine. The system further includes a first inlet fluidly coupled to a diesel exhaust fluid (DEF) stream, and a second inlet fluidly coupled to an air stream. The DEF stream and the air stream intersect at a divergent angle.

Abstract: A reductant delivery system is provided for delivery of reductant to an engine exhaust aftertreatment system that is heated during cold temperature conditions. A heat exchange fluid flows through a heat exchange circuit that provides a flow path from the heat source to the doser, from the doser to the reductant storage tank, and from the reductant storage tank to the heat source. A control valve controls the flow of the heat exchange fluid in the heat exchange circuit so that at least one heat exchange cycle includes a circulation period that increases the temperature of the reductant in the doser and storage tank and a termination period where circulation is stopped until reductant temperature in the doser reaches a lower limit.

Abstract: A system includes a cylindrical blend chamber having two inlets and one outlet. The outlet is fluidly coupled to a transfer line, and a nozzle is positioned downstream of the transfer line. The nozzle is fluidly coupled to an exhaust stream of an internal combustion engine. The system further includes a first inlet fluidly coupled to a diesel exhaust fluid (DEF) stream, and a second inlet fluidly coupled to an air stream. The DEF stream and the air stream intersect at a divergent angle.

Abstract: Mass air flow sensing for internal combustion engines. In one aspect, a sensor adaptor for use in an internal combustion engine includes an inlet housing including an approximately 90-degree elbow and directing air within the inlet housing to the internal combustion engine in an airflow direction. A mass air flow sensor is coupled to the housing at a location after the 90-degree elbow with respect to the airflow direction and senses the air flowing within the inlet housing.