A method for estimating dpf carbon load

Abstract

The present invention proposes a method for estimating the carbon load of a DPF. By introducing a reliability factor F to evaluate the degree of influence of the carbon load inside the DPF by passive regeneration, it is calibrated under the rapid accumulation of carbon and different carbon loads at both ends of the DPF. Map1 of the correspondence between pressure difference and exhaust gas flow; calibration Map2 of the correspondence between pressure difference at both ends of DPF and exhaust gas flow under different carbon loads after rapid passive regeneration; between pressure difference at both ends of DPF and exhaust gas flow The corresponding relation PV is: PV=Map1×F+Map2×(1‑F). According to the exhaust gas flow and the pressure difference across the DPF, the carbon load of the DPF is estimated through the corresponding relationship PV between the pressure difference at both ends of the DPF and the exhaust gas flow. Compared with the prior art, the estimation method provided by the present invention can continuously adjust the actual calibration characteristic curve according to the influence of passive regeneration and carbon accumulation, so that more accurate estimation of the carbon load can be realized.

Description

technical field [0001] The invention relates to the technical field of post-treatment of exhaust gas of an internal combustion engine, in particular to a method for estimating the carbon load of a DPF. Background technique [0002] At present, in electronically controlled diesel engines using DPF (Diesel Particulate Filter, diesel particulate filter) technology, it is a very common method to evaluate the carbon load of the DPF by using the pressure difference across the DPF. This method is usually to collect the pressure difference exhaust gas flow characteristics under different carbon loads, and then estimate the carbon load of the engine based on this characteristic. However, in the actual application process, it is found that the passive regeneration inside the DPF has a great influence on the flow characteristics of the differential pressure exhaust gas, such as figure 1 shown. It can be seen that the same carbon load of 5g / l, the form of rapid carbon accumulation and...

AI Technical Summary

Problems solved by technology

Even at a small flow rate, it is difficult to distinguish between the pressure difference of 5g / l after rapid passive regeneration and the rapid carbon accumulation to 2g / l and the exhaust gas flow characteristics, which can easily lead to a decrease in the accuracy of the carbon load inside the DPF and a large The volatility of the engine leads to false alarms and frequent regeneration of the engine.

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