Systems and techniques for heating urea injection systems

摘要

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.

主权项

1. A system, comprising:
a reductant storage tank configured to store a reductant for treatment of an exhaust gas produced by an internal combustion engine; a doser configured to receive reductant from the storage tank and deliver a quantity of reductant for injection into the exhaust gas; a heat exchange circuit defining a flow path for a heat exchange fluid so that the heat exchange fluid flows from a pump to the doser, through the doser for thermal contact with reductant in the doser, from the doser to the storage tank, through the storage tank for thermal contact with reductant in the storage tank, from the storage tank to the doser, through the doser, and to the pump; and a control valve in the return loop of the heat exchange circuit operable to regulate a flow of the heat exchange fluid in the flow path.