Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China; Mechanical Engineering Institute, Chongqing University, Chongqing 400044, China.
Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China.
Ecotoxicol Environ Saf. 2022 Jun 15;238:113576. doi: 10.1016/j.ecoenv.2022.113576. Epub 2022 May 2.
Non-road emission regulations are becoming increasingly rigorous, which makes it necessary for non-road engines to adopt aftertreatment systems. The commonly used aftertreatments mainly include diesel oxidation catalytic (DOC), diesel particulate filter (DPF), particle oxidation catalyst (POC), selective catalytic reduction (SCR) and ammonia purification catalyst (ASC). The purpose of this study is to investigate the effects of using an integrated system (DOC + DPF/POC + SCR + ASC) on non-road diesel engine emissions under steady-state and transient operating conditions, respectively. The major works are the comparison between POC and DPF from the viewpoint of emission reduction. The results show that both POC and DPF can effectively reduce particulate matter (PM) and nitrogen oxide (NO) emissions under steady-state conditions, and DPF has better purification effect than POC, especially for PM. The PM conversion rate of DPF is up to 87%, while that of POC is only 60% under the non-road steady-state test cycle (NRSC). Both NO and hydrocarbon (HC) conversion rates are high, exceeding 95%. The conversions of PM, NO, HC, and carbon monoxide (CO) of DPF in the non-road transient test cycle (NRTC) are 92.83%, 96.99%, 96.86% and 81.45%, respectively, while those of POC are 60.12%, 95.45%, 92.82% and 79.51%, respectively. Both the POC and DPF systems can meet the emission regulation limits. As a result, POC has the potential to substitute DPF in non-road engines due to its lower product and maintenance costs. We hope that the comparison study will provide useful guidance for improving the emissions performance of non-road diesel engines.
非道路排放标准日趋严格，这使得非道路发动机需要采用后处理系统。常用的后处理技术主要包括柴油机氧化催化转化器（DOC）、柴油机颗粒捕集器（DPF）、颗粒氧化催化器（POC）、选择性催化还原（SCR）和氨净化催化剂（ASC）。本研究的目的是分别考察在稳态和瞬态工况下，采用集成系统（DOC+DPF/POC+SCR+ASC）对非道路柴油机排放的影响。主要工作是从减排的角度对 POC 和 DPF 进行比较。结果表明，POC 和 DPF 均可在稳态条件下有效降低颗粒物（PM）和氮氧化物（NOx）排放，且 DPF 的净化效果优于 POC，特别是对 PM。在非道路稳态测试循环（NRSC）下，DPF 的 PM 转化率高达 87%，而 POC 仅为 60%。NO 和碳氢化合物（HC）的转化率均较高，超过 95%。在非道路瞬态测试循环（NRTC）中，DPF 对 PM、NO、HC 和一氧化碳（CO）的转化率分别为 92.83%、96.99%、96.86%和 81.45%，而 POC 分别为 60.12%、95.45%、92.82%和 79.51%。POC 和 DPF 系统均能满足排放法规限值。因此，由于 POC 的产品和维护成本较低，它有可能替代非道路发动机中的 DPF。希望本比较研究能为提高非道路柴油机的排放性能提供有益的指导。
