DPF主动再生过程压差及温度场特性试验研究
丁晓辉1，2，徐文秀1，2，尹相恺1，2，董光雷1，2，郑雪1，2
1.内燃机与动力系统全国重点实验室，山东 潍坊 261061；2.潍柴动力股份有限公司，山东 潍坊 261061
摘要：为提高柴油机颗粒捕集器（diesel particulate filter，DPF）的可靠性并为其主动再生控制提供参考，通过发动机台架试验研究DPF积碳过程的压差特性以及主动再生时DPF内部温度的变化规律。结果表明：DPF在不同积碳阶段的压差特性存在较大差异，再生后再次积碳过程的DPF压差较再生前平均降低约2 hPa；正常主动再生过程中，DPF内部轴向温度从前向后依次升高，DPF后端面位置的温度最高，为715 ℃，径向温度分布存在差异， 表明DPF内部燃烧不均匀；再生过程降怠速（drop to idle,DTI）工况下DPF内部温度快速升高，可达到1 034 ℃；当碳载量大于4 g/L时，DPF内部温度随碳载量呈线性快速上升趋势；较高的氧化催化器起燃速率使得DPF内部温度短时间内快速升高，当起燃速率为6.5 ℃/s时，DPF内部温度达到1 076 ℃；主动再生DTI工况、较大的碳载量及较高的起燃速率，是增大DPF再生过程热风险的主要因素，在实际应用中应合理控制。
关键词：DPF；积碳；主动再生；DTI
Experimental study on pressure difference and temperature field characteristics during active regeneration of DPF
DING Xiaohui1,2, XU Wenxiu1,2, YIN Xiangkai1,2, DONG Guanglei1,2, ZHENG Xue1,2
1.State Key Laboratory of Engine and Powertrain System, Weifang 261061, China;
2.Weichai Power Co., Ltd., Weifang 261061, China
Abstract: In order to enhance the reliability of diesel particulate filters (DPF) and provide guidance for the active regeneration control, bench tests are conducted to investigate the pressure difference characteristics during the soot accumulation process of DPF and the internal temperature variation patterns during active regeneration. The results indicate significant differences in the pressure difference characteristics of DPF during different soot accumulation stages. The pressure difference of the DPF during the re-accumulation process after regeneration is on average about 2 hPa lower than before regeneration. During normal active regeneration, the axial temperature inside the DPF increases sequentially from the front to the rear, with the highest temperature point occurring at the rear end face of the DPF, reaching 715 ℃. The inconsistency of radial temperature indicate uneven combustion inside the DPF. During active regeneration process under drop to idle(DTI)operating conditions, the internal temperature of the DPF rises rapidly, reaching up to 1 034 ℃. When the soot loading exceeds 4 g/L, the internal temperature of the DPF increases linearly and rapidly with the soot loading. A higher DOC light-off rate causes the internal temperature of the DPF to rise rapidly in a short period of time. When the light-off rate is 6.5 ℃/s, the internal temperature of the DPF reaches 1 076 ℃. DTI operating conditions during active regeneration process, higher soot loading, and a higher DOC light-off rate are the main factors that increase the thermal risk during DPF regeneration, which must be reasonably controlled in practical applications.
Keywords: DPF; ash; active regeneration; DTI
