Intelligent nitrogen and oxygen sensor and detection method implemented by same

Abstract

The invention relates to the technical field of nitrogen and oxygen sensors, in particular to an intelligent nitrogen and oxygen sensor and a detection method implemented by the same. The intelligentnitrogen and oxygen sensor comprises a matrix layer, a printed functional layer and a closed structure cavity. The matrix layer comprises an upper-layer zirconium oxide substrate, a middle-layer zirconium oxide substrate and a base-layer zirconium oxide substrate; the printed functional layer comprises a common external electrode, a main pump internal electrode, an auxiliary pump internal electrode, a mixed potential sensitive electrode, a measuring pump internal electrode, a reference air electrode, a first insulation wrapping layer, a second insulation wrapping layer, a heating circuit and 8electrode contacts, and the closed structure cavity comprises a first measuring cavity, a second measuring cavity and a reference air channel. The intelligent nitrogen and oxygen sensor and the detection method have the advantages that the total quantity of NOX in exhaust can be accurately measured by sensing chips of the intelligent nitrogen and oxygen sensor by the aid of current type working principles, the proportion of NO / NO2 in the exhaust further can be detected by the aid of mixed potential characteristics, and accordingly the concentration of NO and the concentration of NO2 in the exhaust can be accurately computed.

Description

technical field [0001] The invention relates to a sensor, in particular to an intelligent nitrogen and oxygen sensor and a detection method thereof. Background technique [0002] High-temperature combustion of diesel engines under oxygen-rich conditions will produce a large amount of nitrogen oxides. In the treatment of diesel engine exhaust, the Selective Catalytic Reaction (SCR) method is widely used because it can efficiently treat NOx. In this method, urea will be added as a Therefore, it is necessary to add nitrogen and oxygen sensors to the front and rear ends of the SCR treatment to accurately measure the concentration of NOx to meet the functions of precise control of the exhaust after-treatment system and on-board diagnostics. At present, the only nitrogen and oxygen sensor used in large quantities is based on the current-type working principle. It judges and detects the total NOX content based on the increase in oxygen content after NOX decomposition. When measurin...

AI Technical Summary

Problems solved by technology

At present, the only nitrogen and oxygen sensor used in large quantities is based on the current-type working principle. It judges and detects the total NOX content based on the increase in oxygen content after NOX decomposition. When measuring the exhaust gas atmosphere with NO as the main component, Its accuracy can ensure stability, but when measuring tail gas with NO2 as the main component or a considerable proportion, because the amount of oxygen in NO2 is twice as much as that of NO, the measured value is inaccurate

[0003] Since DOC is not installed in half of the national IV emission post-treatment, NO2 in the original exhaust at the front end of the SCR accounts for about 10% of the total NOX, and NO2 fully participates in the SCR in the fast reaction of NH3, and there is basically no NO2 at the back end of the SCR. Some nitrogen and oxygen sensors will not measure inaccurately due to NO2 in NOX

However, after the emissions are upgraded to National VI, it is almost mandatory to install DOC after the diesel engine treatment. NO2 in the exhaust gas at the front end of the SCR accounts for close to or even exceeds 50% of the total NOX. Under the condition that the National IV emission regulations require very low NOX limits, the existing current-type nitrogen and oxygen sensors can no longer meet the requirements of measurement accuracy, and there is an urgent need for a nitrogen and oxygen sensor with higher measurement accuracy for both NO and NO2

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