Systems and methods for sensing an ammonia concentration in exhaust gases
View Patent ↗Systems and methods for determining an NH 3 concentration in exhaust gases from an engine are provided. In one exemplary embodiment, a method includes generating a first signal from an NH 3 sensor fluidly communicating with the exhaust gases. The method further includes generating a second signal from an air humidity sensor disposed proximate to an air intake manifold of the engine indicating a humidity level. The method further includes determining an air/fuel ratio associated with the engine. The method further includes determining an NH 3 deviation value in a calibration table based on the second signal and the air/fuel ratio, utilizing a controller. The method further includes determining an NH 3 concentration value based on the first signal and the NH 3 deviation value, utilizing the controller. The NH 3 concentration value is indicative of the NH 3 concentration in the exhaust gases. The method further includes storing the NH 3 concentration value in a memory device, utilizing the controller.
1. A method for determining an NH 3 concentration in exhaust gases from an engine, comprising:
generating a first signal from an NH 3 sensor fluidly communicating with the exhaust gases;
generating a second signal from an air humidity sensor disposed proximate to an air intake manifold of the engine indicating a humidity level;
determining an air/fuel ratio associated with the engine;
determining an NH 3 deviation value in a calibration table based on the second signal and the air/fuel ratio, utilizing a controller;
determining an NH 3 concentration value based on the first signal and the NH 3 deviation value, utilizing the controller, the NH 3 concentration value indicative of the NH 3 concentration in the exhaust gases; and
storing the NH 3 concentration value in a memory device, utilizing the controller.
2. The method of claim 1 , wherein determining an air/fuel ratio associated with the engine comprises:
generating a third signal from an air-fuel ratio sensor fluidly communicating with the exhaust gases; and
determining the air/fuel ratio based on the third signal, utilizing the controller.
3. The method of claim 1 , wherein the NH 3 sensor is an electrochemical cell NH 3 sensor.
4. A system for determining an NH 3 concentration in exhaust gases from an engine, comprising:
an NH 3 sensor fluidly communicating with the exhaust gases, the NH 3 sensor configured to generate a first signal;
an air humidity sensor disposed proximate to an air intake manifold of the engine, the humidity sensor configured to generate a second signal indicative of a humidity level;
a controller operably communicating with the NH 3 sensor and the humidity sensor, the controller configured to determine an air/fuel ratio associated with the engine;
the controller further configured to determine an NH 3 deviation value in a calibration table based on the second signal and the air/fuel ratio;
the controller further configured to determine an NH 3 concentration value based on the first signal and the NH 3 deviation value, the NH 3 concentration value indicative of the NH 3 concentration in the exhaust gases; and
the controller further configured to store the NH 3 concentration value in a memory device.
5. The system of claim 4 , further comprising:
an air-fuel ratio sensor fluidly communicating with the exhaust gases, the air-fuel ratio sensor configured to generate a third signal; and
the controller configured to determine the air/fuel ratio associated with the engine based on the third signal.
6. The system of claim 4 , wherein the NH3 sensor is an electrochemical cell NH 3 sensor.