Nitrogen oxygen sensor

A catalytic converter is part of a car's exhaust system. Catalytic conversion device is an exhaust purification device that converts CO, HC, and NOx in exhaust gas into gases that are harmless to human body by using the action of catalyst, also known as catalytic conversion device. The catalytic conversion device converts the three harmful gases CO, HC, and NOx in the exhaust gas into harmless gases carbon dioxide, nitrogen, Hydrogen and water. According to the purification form of catalytic converter, it can be divided into oxidation catalytic converter, reduction catalytic converter and three-way catalytic converter. The ceramic carrier is also a key component of the catalytic converter. One of its important materials is cordierite, which is resistant to high temperature, with a maximum continuous working temperature of 1200 °C, high strength and low coefficient of linear expansion. The carrier adopts an effective surface and a suitable pore structure. The opening rate of the domestic ceramic carrier can reach 400-460 mesh/inch2, and the minimum wall thickness can reach about 0.16mm. It can enhance the mechanical strength of the catalyst, as well as its ability to resist wear, impact, gravity, compression, high temperature, and phase change, improve the conductivity of the catalyst, and reduce the content of active components. Especially when using precious metal catalysts platinum, palladium and rhodium, the active components can be highly dispersed and the dosage can be reduced. In conclusion, the quality of the carrier is extremely important for the catalyst.

The urea pump is an important part of the urea solution injection metering system. Its main function is to extract the urea solution in the urea tank, maintain a certain pressure, and then deliver it to the injection unit to meet the requirements of the injection metering system for flow and pressure. As an important means of controlling diesel engine exhaust emissions, it has been widely used in developed countries such as Europe, and has played a significant role in improving the environmental pollution caused by exhaust emissions. After using SCR technology, the emission performance of the engine depends to a large extent on the calibration of the urea injection system and the related performance of the urea pump. Based on the basic principle of nitrogen and oxygen reduction, the SCR device uses a 32.5% urea aqueous solution as a reducing agent to reduce NOX in the exhaust gas to N2 and H2O under the catalytic action of the catalyst surface coating. The exhaust temperature of the diesel engine is generally 200-500 °C, which basically meets the activity requirements of the vanadium-based catalyst used in SCR. Therefore, the NOX in the exhaust gas discharged from the diesel engine quickly reacts with the urea aqueous solution to generate nitrogen and water. The urea dosing pump is the core component of the SCR system, and its performance is closely related to the emission function of the engine. In order to ensure that the working reliability of the urea dosing pump meets the working requirements of the SCR system, the urea dosing pump needs to be calibrated.

A nitrogen oxygen sensor or NOx sensor is typically a high-temperature device built to detect nitrogen oxides in combustion environments such as an automobile, truck tailpipe or smokestack. The drive to develop a NOx sensor arises from environmental factors. NOx gases can cause various problems such as smog and acid rain. Many governments around the world have passed laws to limit their emissions (along with other combustion gases such as SOx (oxides of sulfur), CO (carbon monoxide) and CO2 (carbon dioxide) and hydrocarbons). Companies have realized that one way of minimizing NOx emissions is to first detect them and then to employ some sort of feedback loop in the combustion process, thereby enabling the minimization of NOx production by, for example, combustion optimization or regeneration of NOx traps. Therefore, in many applications with exhaust-gas treatment systems, one NOx sensor is used upstream of the exhaust-gas treatment system (upstream) and a second sensor is used downstream of the exhaust-gas treatment system. The upstream sensor is used for the aforementioned feedback loop. Meanwhile, the downstream sensor is used mainly to confirm that the legislated emissions limits have not been exceeded.