Diesel engine exhaust gas purifier diagnosing method based on sound wave signal HHT marginal spectrum

Abstract

The invention relates to a diesel engine exhaust gas purifier diagnosing method based on a sound wave signal HHT marginal spectrum and belongs to a diagnosing technique of a diesel engine exhaust gas aftertreatment system. In a diesel engine operation process, a sound wave signal collector (4) can send sound wave signals x(t) collected by the outlet end of a purifier to a sound wave signal processing unit (9), HHT marginal spectrum analysis is carried out on the signals, the signals are processed to obtain sound wave HHT marginal spectrum feature signals, and the sound wave HHT marginal spectrum feature signals comprise tested feature frequency and tested feature energy. An electrical control unit (5) can inquire the sound wave HHT marginal spectrum feature signals MAP to find out the sound wave HHT marginal spectrum feature signals under the corresponding work condition according to the rotation speed signals and the torque signals of a current diesel engine, and the sound wave HHT marginal spectrum feature signals comprise calibrated feature frequency and calibrated feature energy. The electrical control unit (5) can compare four parameters to determine whether the exhaust gas purifier works normally. The method can accurately identify plug conditions and give out regeneration time and can accurately identify breakage, especially micro breakage, of the exhaust gas purifier.

Description

technical field [0001] The invention belongs to the diagnosis technology of a diesel engine exhaust post-treatment system, and in particular relates to a diagnosis method for a diesel engine exhaust purifier. Background technique [0002] According to the statistics of relevant departments, about 22% of ultrafine particles (PM2.5) in the atmosphere come from the exhaust emitted by diesel vehicles. However, current studies have shown that ultrafine particles can enter the human respiratory system smoothly and stay for a long time, which is a major hazard to human health. Therefore, the emission control target of diesel vehicles began to change from controlling the quality of exhaust particles to controlling the quantity of ultrafine particles in the exhaust gas that are harmful to human health. At present, the European Union has limited the number of ultrafine particles in diesel vehicles to 6×10 11 units / km is included in the Euro V standard and has been implemented since ...

AI Technical Summary

Problems solved by technology

However, when the tiny cracks in the exhaust purifier are not enough to cause the exhaust back pressure to drop, it is difficult to detect and deal with the micro cracks in the exhaust purifier in a timely manner by the diagnostic method based on the exhaust back pressure.

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