Study on characteristics of particulate emission of diesel aftertreatment with reciprocating flow

Yangbo Deng,Hongwei Wu,Yang Guo,Xiaolong Wang,Jingming Dong,Zhitao Han,Rongrui Li,Wenbin Cui

doi:10.1002/ese3.882

Yangbo Deng, Hongwei Wu + Show 6 more

Open Access

https://doi.org/10.1002/ese3.882

Copy DOI

Abstract

AbstractIn this article, in order to optimize diesel aftertreatment system with periodically reciprocating flow (PRF), an experimental study is conducted to investigate its characteristics such as pollution emissions, regeneration of diesel particulate filter (DPF), concentration, and size distribution of particulate matter (PM) escaped as well as temperature distribution under unidirectional flow and PRF operating conditions. The effects of reciprocating flow cycle and exhaust gas flow on the performance of aftertreatment system are investigated in detail. The energy efficiency analysis of the aftertreatment system is also carried out. Experimental results show that (a) as the temperature is lower than the light‐off threshold of combustible gas, the aftertreatment system cannot restrain the formation of second particles under the low‐temperature condition of unidirectional flow; and (b) the aftertreatment system demonstrates excellent performance of trapping particles and filter regeneration as the symmetrical temperature distribution is formed. The PM filter efficiency is 92%, and the specific energy consumption β is 124% for symmetrical temperature distribution; (c) the increase in reciprocating flow cycle could lead to the shifting of the temperature profiles, and this would affect the particle size distribution; (d) a certain increase in exhaust gas flow from engine would have insignificant change for the temperature distribution; and (e) the critical energy efficiency of the system could reach 96.61%.

Highlights

Reverse flow reactor (RFR) can regenerate the heat through periodically reciprocating flow (PRF), and it can be recognized as one of most effective ways to increase the thermal efficiency of chemical reactor
The exhaust gas flows from exhaust port to P1 through an exhaust pipe, the temperature of the exhaust gas at P1 drops to 120°C, and most of nuclei mode particles have been accumulated into mode particles through coalescence and agglomeration at P1
These further illustrate that the particulate matter (PM) detected are formed from the agglomeration of ultrafine particles and is belong to second particles. It can be seen, as the temperature is lower than the light-o ff threshold of combustible gas in the exhaust gas, the aftertreatment system can only remove the PM existed in the exhaust gas and cannot restrain

Summary

Introduction

Reverse flow reactor (RFR) can regenerate the heat through periodically reciprocating flow (PRF), and it can be recognized as one of most effective ways to increase the thermal efficiency of chemical reactor. . It is recognized that early scientists at Matros Technologies Inc, and Alternative Fuel Systems, Inc, applied the concept of RFR to remove pollutants from natural gas diesel engine and dual-fuel engine (DFE).[8,9] Their research work demonstrated that PRF could compensate for insufficient catalyst activity with the higher temperature achieved through regenerative heat exchange inside the catalyst monolith. The RFR technique was used to facilitate the regeneration of diesel particulate filter (DPF) by Konstandopoulos and Kostoglou.[12] Their simulation results showed that PRF mechanism that could capture a high-temperature region in the DPF substrate could be capable of reducing the supplemental energy during regeneration process and to improve the overall thermal efficiency of the engine.[13]

Methods

Results

Conclusion