Sensor for measuring concentration of nitrogen oxide and detecting ammonia slip

Abstract

The present invention relates to a gas sensor and, more specifically, to a gas sensor capable of measuring the concentration of nitrogen oxide and detecting ammonia slip. The present invention provides a sensor for measuring the concentration of nitrogen oxide and detecting ammonia slip, comprising: an oxygen ion-conductive solid electrolyte; a first electrode coming into contact with the solid electrolyte, and being reactive with nitrogen oxide; a second electrode coming into contact with the solid electrolyte, separated from the first electrode, and being reactive with nitrogen oxide; a third electrode coming into contact with the solid electrolyte, separated from the second electrode, connected in parallel with the first electrode, and being reactive with ammonia; a power supply deviceformed so as to apply power between the second electrode and the first electrode and third electrode, which are connected in parallel with each other; and a measurement device formed so as to measurethe potential difference or the current between the first electrode and the third electrode, which are connected in parallel with each other, and the second electrode. According to the present invention, the sensor for measuring the concentration of nitrogen oxide and detecting ammonia slip can simultaneously measure nitrogen monoxide and nitrogen dioxide. In addition, whether ammonia is discharged can be simultaneously measured. According to the present invention, manufacturing costs of the sensor for measuring the concentration of nitrogen oxide and detecting ammonia slip are reduced since anitrogen oxide sensor and an ammonia sensor share a part of the electrodes, the solid electrolyte, a heating part and the like. In addition, installation costs are also reduced since the nitrogen oxide sensor and the ammonia sensor do not need to be separately installed.

Description

technical field [0001] The invention relates to a gas sensor. Specifically, it relates to a gas sensor capable of not only measuring the concentration of nitrogen oxides but also detecting ammonia leakage. Background technique [0002] Nitrogen oxides are substances produced by combining nitrogen and oxygen contained in air and fuel, including: nitrogen monoxide (NO), nitrogen dioxide (NO 2 ), nitrogen trioxide (N 2 o 3 ) and nitrous oxide (N 2 O), with NO x express. Among them, nitrogen monoxide and nitrogen dioxide account for the majority of nitrogen oxide gases, and they are both sources of air pollution. Therefore, it is necessary to measure its concentration and properly control the emission. [0003] Internal combustion engines of automobiles, ships, power plants, heavy equipment, agricultural machinery, etc. are the main sources of nitrogen oxide emissions. In order to remove nitrogen oxides produced by internal combustion engines, generally figure 1 The sel...

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Problems solved by technology

If the injected urea solution is insufficient, the conversion efficiency of NOx will decrease, and if the injected excessive amount, ammonia will be emitted into the air

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