Using Ion Current For In-Cylinder NOx Detection In Diesel Engines

摘要

Presented is a technique that utilizes ion current to determine the concentration of nitrogen oxides (NO_x) produced in the combustion chamber(s) of diesel engines, on a cycle by cycle basis during the combustion of conventional petroleum-based fuels, other alternate fuels, and renewable fuels. The technique uses an ion current measuring means, a calibration means and a signal processing means connected to the engine control unit (ECU). The ion current sensing means is positioned in the chamber(s) of the engine, to measure the ion current produced during the combustion process. The calibration means utilizes NO_x values measured in the exhaust port or manifold of the engine to calibrate the ion current signal. The calibrated ion current signal is fed into a processor that is connected to the ECU to adjust various operating parameters to improve the trade-off between NO_x and other emissions, fuel economy, and power output.