Abstract: In one embodiment, an apparatus is disclosed for heating a reductant delivery line using coolant from an internal combustion engine where the reductant delivery line receives reductant from a reductant tank and a portion of a coolant line is positioned within the reductant tank. The apparatus includes a coolant temperature module that is configured to determine a reductant tank outlet coolant temperature target. Additionally, the apparatus includes a coolant flow rate module that is configured to generate a coolant valve flow rate command and transmit the command to a coolant valve. The coolant valve is controllable to regulate the flow rate of coolant through the coolant line. The coolant valve flow rate command is based on the reductant tank outlet coolant temperature target, a reductant tank inlet coolant temperature, and a reductant tank reductant temperature.

Abstract: An apparatus for introducing a reductant into an exhaust system is described. The apparatus includes a controller that generates a resulting dosing command used as an instruction to release an amount of reductant into the exhaust system. The controller includes a feedback control module that generates a weighing factor. The weighing factor is configured to be applied to a lower limit dosing command and configured to be applied to an upper limit dosing command, where the lower and upper limit dosing commands converted by the weighing factor are used by the controller to generate the resulting dosing command.

Abstract: In one embodiment, an apparatus is disclosed for heating a reductant delivery line using coolant from an internal combustion engine where the reductant delivery line receives reductant from a reductant tank and a portion of a coolant line is positioned within the reductant tank. The apparatus includes a coolant temperature module that is configured to determine a reductant tank outlet coolant temperature target. Additionally, the apparatus includes a coolant flow rate module that is configured to generate a coolant valve flow rate command and transmit the command to a coolant valve. The coolant valve is controllable to regulate the flow rate of coolant through the coolant line. The coolant valve flow rate command is based on the reductant tank outlet coolant temperature target, a reductant tank inlet coolant temperature, and a reductant tank reductant temperature.

Abstract: An apparatus for introducing a reductant into an exhaust system is described. The apparatus includes a controller that generates a resulting dosing command used as an instruction to release an amount of reductant into the exhaust system. The controller includes a feedback control module that generates a weighing factor. The weighing factor is configured to be applied to a lower limit dosing command and configured to be applied to an upper limit dosing command, where the lower and upper limit dosing commands converted by the weighing factor are used by the controller to generate the resulting dosing command.