Method and apparatus for an exhaust emissions control system

Abstract

A method for mutual adaptation of a delivery module and a metering module of an exhaust emissions control system that has an exhaust gas conduit and a control module, the delivery module having a reservoir that has a venting valve and contains a uric acid solution that is conveyed via a delivery pump to a pressure regulating valve; and in the metering module, an air stream being compressed with the aid of a pump, conveyed to a pressure accumulator, and conveyed via a regulating valve, together with the uric acid solution, out of the pressure regulating valve to a metering valve, and being conveyed from there to an atomizer unit disposed in the exhaust gas conduit, the value of a reference pressure based on the pressure forming in the exhaust gas conduit being stored in the control module. A method for mutual adaptation of a delivery module and a metering module of an exhaust emissions control system having a control module, a respective parameter or characteristic curve being created for the delivery module and for the metering module and being introduced into the respective module as a machine-readable code. An apparatus for mutual adaptation of a delivery module and metering module for an exhaust emissions control system having an exhaust gas conduit and a control module, the value of a reference pressure based on the pressure forming in the exhaust gas conduit in the context of a calibration cycle being stored in the control module. A mutual adaptation of any arbitrary metering and delivery modules can thereby be implemented in a simple and economical fashion.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method for mutual adaptation of a delivery module and a metering module of an exhaust emissions control system that has an exhaust gas conduit and a control module, the delivery module having a reservoir that has a venting valve and contains a uric acid solution that is conveyed via a delivery pump to a pressure regulating valve; and in the metering module, an air stream being compressed with the aid a pump, conveyed to a pressure accumulator, and conveyed via a regulating valve, together with the uric acid solution, out of the pressure regulating valve to a metering valve, and being conveyed from there to an atomizer unit disposed in the exhaust gas conduit. [0002] The present invention further relates to an apparatus for mutual adaptation of a delivery module and metering module for an exhaust emissions control system having an exhaust gas conduit and a control module. BACKGROUND INFORMATION [0003] Appropriate exhaus...

AI Technical Summary

Benefits of technology

[0012] As operation of the exhaust emissions control system proceeds, provision is made in a preferred embodiment for the adaptation of the delivery module and metering module to be accomplished as necessary and / or cyclically at specific time intervals. A recalibration as necessary may be required, for example, if an elevated nitrogen oxide content is detected with a sensor in the exhaust section. This allows a long-term and reliable reduction in nitrogen oxides from the exhaust gas during continuous operation. Any drift of the optimum working point as a result of aging of the components can thereby be compensated for.

[0014] An object relevant to the apparatus is achieved in that the value of a reference pressure based on the pressure forming in the exhaust gas conduit in the context of a calibration cycle is stored in the control module, with the result that a calculation of the optimum working point, and thus an optimum adaptation of the delivery and metering modules, can be effected.

Problems solved by technology

This complicates the process of compensating for production tolerances, which was previously still possible by applying a corresponding characteristic curve in the control unit.

For logistical reasons, this can be accomplished only with greater effort.

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