石秀勇, 蒋得刚. 柴油机颗粒捕集器再生温度预测模型[J]. 农业工程学报, 2019, 35(20): 17-24. DOI: 10.11975/j.issn.1002-6819.2019.20.003
    引用本文: 石秀勇, 蒋得刚. 柴油机颗粒捕集器再生温度预测模型[J]. 农业工程学报, 2019, 35(20): 17-24. DOI: 10.11975/j.issn.1002-6819.2019.20.003
    Shi Xiuyong, Jiang Degang. Model for predicting the regeneration temperature of diesel particulate filter[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(20): 17-24. DOI: 10.11975/j.issn.1002-6819.2019.20.003
    Citation: Shi Xiuyong, Jiang Degang. Model for predicting the regeneration temperature of diesel particulate filter[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2019, 35(20): 17-24. DOI: 10.11975/j.issn.1002-6819.2019.20.003

    柴油机颗粒捕集器再生温度预测模型

    Model for predicting the regeneration temperature of diesel particulate filter

    • 摘要: 柴油机颗粒捕集器在再生阶段的温度预测问题直接与后处理系统甚至整车的经济性、安全性相关。该文采用仿真分析计算与发动机试验验证相结合的方式,对柴油机颗粒捕集器在再生阶段的温度特性及其影响因素进行分析。首先运用GT-Power软件对后处理系统进行建模,并分析了不同再生目标温度对再生效率的影响以及不同碳载量对稳态再生温度的影响。仿真结果表明:较高的再生目标温度有助于降低单位质量颗粒物的再生油耗,当再生目标温度为500 ℃时,单位质量颗粒物的再生油耗为372.7 g,当目标温度提高到700 ℃时该值降低至3.8g,但当目标温度达到600 ℃以上,再生目标温度对单位质量颗粒物再生油耗的改善效果不明显;当碳载量超过46 g(12.7 g/L)再生时,颗粒捕集器内部温度超过800 ℃,颗粒捕集器出现烧蚀失效的风险较高,因此应当限制触发再生的碳载量限值。在仿真计算结果的基础上,运用发动机台架试验对再生温度特性进行测试验证,试验结果与仿真结果较吻合,结果表明,该温度预测模型可对颗粒捕集器再生阶段的温度分布、再生油耗及最高温度等进行预测,对提高再生阶段燃油经济性,降低颗粒捕集器的烧蚀失效风险,具有重要的指导意义。

       

      Abstract: The question of how to estimate diesel particulate filter (DPF) inner temperature distribution and peak temperature performance during DPF regeneration phase in diesel vehicle real-world application is a great challenge to many companies. The temperature prediction during DPF regeneration phase is directly related to the safety and economy performance of diesel engine after-treatment system and the vehicle. The temperature performance inside DPF during regeneration phase highly depends on the chemical reactions carried out inside diesel oxidation catalyst (DOC). According to the reaction mechanisms , reaction speed is related to the activation temperature of chemical reactions, carrier local wall temperature, and mole fraction of components involved in chemical reactions. In this paper, the temperature characteristics and their influencing factors were evaluated by means of one-dimensional simulation in combination with engine test bench validation. Firstly, main influencing factors to DPF regeneration temperature performance were analyzed. Theoretical analysis showed that when catalyst performance was already determined, DPF regeneration temperature performance were mainly affected by carrier local wall temperature and mole fraction of components involved in chemical reactions. Secondly, a one-dimensional after-treatment system model was built using GT-Power for DPF regeneration temperature prediction purpose, the influence of different regeneration target temperature on regeneration efficiency and the influence of different soot loading quantity on temperature distribution inside DPF during regeneration phase were analyzed. Simulation results showed that higher regeneration target temperature could benefit regeneration efficiency, and help to reduce fuel consumption of regenerating each gram of soot accumulated in DPF channels. When regeneration target temperature was 500 ℃, fuel consumption to regenerate each gram of soot would be 372.7 g. When regeneration target temperature was 550 ℃, fuel consumption would be 55.9 g. When regeneration target temperature was 600 ℃, fuel consumption would be 10.3 g. When regeneration target temperature was 650 ℃, fuel consumption would be 5.7 g. When regeneration target temperature was 700 ℃, fuel consumption to regenerate each gram of soot would be reduced to 3.8 g. However, higher target temperature had no obvious effect on the improvement of regeneration fuel consumption for each gram of soot when regeneration target temperature was higher than 600 ℃. According to the simulation result, when DPF soot loading quantity was higher than 46 g (12.7 g/L), the DPF inner temperature during regeneration phase would be higher than 800 ℃, leading to very high risk of DPF carrier burning crack, so soot loading quantity threshold for regeneration trigger should be well limited. Thirdly, regeneration temperature characteristics were tested on engine test bench. Test results showed that engine test bench results agreed well with simulation results when soot loading quantity were 15.5 and 21.9 g. Relative deviation with 15.5 g soot loading quantity was -1.0% to 0.4%, and relative deviation with 21.9 soot loading quantity was -1.4% to 0.8%. When soot loading quantity was 36.5 g, engine test bench result showed a different temperature ramping character for DPF tail position, the time to reach to maximum DPF inner temperature differed from simulation result, but still, the relative error of maximum temperature could be used for further investigation.

       

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