| Summary: | 碩士 === 中興大學 === 機械工程學系所 === 99 === Nowadays, the steady regeneration system is the best substitution for the boiler regeneration. Although vehicles have to stop the DPF (Diesel Particulate Filter) to regenerate, it takes less time. DPF usually be regenerated the by the boilers, and blow away the residual carbon particles after the regeneration, which takes too much time, and thus causing most of people have no interest to installing the DPF.
The Direct Oxidation Catalyst (DOC) is an important element in the regeneration, it has different operating temperature and diesel conversion efficiency, and the condition varies with the fuel injection rate. In this article, different burning fuel injection and the simulation value of burned fuel, were compared, results showed the fuel is not totally combusted. It is observed that regeneration process are complicated and related to the fuel injection rate、the oxygen density in exhaust and the inlet temperature of DOC.
The steady regeneration was operated under different steady engine speed and engine load operating condition. The main operating variables are exhaust temperature、fuel injection rate and regeneration time. The exhaust temperature and the fuel injection rate can effects the delay time of DOC, and the temperature ramp after the DOC. The regeneration time is based on the accumulated carbon particles in the DPF. When the exhaust temperature is controlled at 350℃,the fuel injection rate on 27%,the temperature ramp is 0.95, the regeneration time is 17.83 minutes, and the total fuel injection is 800c.c., 96% of the carbon particles can be burned out according to the weight record.
In the DPF regeneration period, the exhaust temperature is very high, we may there are some humid air and high temperature exhaust pass through the PM2.5 were found. The dilution system must construct to make sure that under high exhaust temperature condition exhaust can be sampled. A simulated test using pure CO2 as engine exhaust was carried out to validate the system performance. It was found that the dilute ratio varied in the range of 18~22, with the average value of 19.7 and standard deviation of 1.4%.
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