Diesel engine DPF trapping efficiency fault diagnosis method

Abstract

The invention belongs to the technical field of engine emission, and discloses a diesel engine DPF trapping efficiency fault diagnosis method. The diesel engine DPF trapping efficiency fault diagnosis method comprises the following steps: S1, DPF pressure difference measurement values under different working conditions are acquired, and corresponding engine exhaust gas volume flow, DPF carrier average temperature and DPF carbon load are obtained; S2, a DPF real-time pressure difference value calculation model is established, and a DPF real-time pressure difference value is calculated; S3, a fault diagnosis enabling area is calibrated according to the working condition information; and S4, a differential pressure deviation value between the DPF differential pressure measurement value and the DPF real-time differential pressure value is calculated, the differential pressure deviation value is compared with a differential pressure deviation threshold value, and when the differential pressure deviation value is not greater than the differential pressure deviation threshold value, it is judged that the trapping efficiency is normal, otherwise, it is judged that a fault exists. According to the diesel engine DPF trapping efficiency fault diagnosis method, the DPF trapping efficiency fault is diagnosed through the mathematical calculation model of the DPF real-time pressure difference value, the method is simple and accurate, a PM sensor is not used, and the cost is greatly reduced.

Description

technical field [0001] The invention relates to the technical field of engine emission, in particular to a method for diagnosing a fault in the collection efficiency of a DPF of a diesel engine. Background technique [0002] Due to its high thermal efficiency, power, economy and durability, diesel engines are widely used in transportation, construction machinery, agricultural machinery and other fields, but the exhaust emissions of diesel engines also have a greater impact on the atmospheric environment. The main emissions from diesel engines include nitrogen oxides (NOx), hydrocarbons (HC), carbon monoxide (CO) and particulate matter (PM). Diesel particulate filter (DPF) is an effective device to solve the emission of particulate matter from diesel engines, and it is an essential device to reduce the requirements for the quality and quantity of particulate matter in emissions in national standards and industry specifications. At present, PM sensors (particulate matter sens...

AI Technical Summary

Problems solved by technology

Due to the complex working principle of the PM sensor, the PM sensor itself has more than 30 fault monitoring items. In the market application process, the PM sensor itself has a high failure rate and low reliability. At the same time, the price of a single PM sensor is more than 400 yuan, which is relatively high.

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