Abstract
Exhaust gas recirculation (EGR) cooler fouling occurs when particulate matter (PM) and hydrocarbons (HC) in diesel exhaust form a deposit on the walls of the EGR cooler through thermophoresis and condensation. To better understand the mechanisms controlling deposit formation and removal and how operating conditions can affect cooler performance, 20 identical tube-in-shell EGR coolers with sinusoidal fins were fouled using a 5-factor, 3-level experimental design. The deposit thickness was measured using two methods: (1) epoxy-mounting and polishing cooler cross-sections and comparing deposit thicknesses on the primary (outer tube) to the secondary (fins) heat transfer surfaces, and (2) milling tube sections such that the surface of a fin could be observed and measuring the deposit thickness across the fin using a 3D profilometer. Near the cooler inlet, high inlet gas temperatures reduced deposit thickness by promoting mud-cracking and spallation. Near the middle of the cooler, the flow rate had the largest impact on the deposit thickness through the effect on residence time of the PM. The HC concentration along with flow rate had the largest effects near the cooler outlet where the lower temperatures allows for more HC condensation. These insights into how engine operating conditions influence the development of fouling layers in EGR coolers learned through this study will aid in the development of more fouling resistant coolers in the future.
| Original language | English |
|---|---|
| Pages (from-to) | 509-520 |
| Number of pages | 12 |
| Journal | International Journal of Heat and Mass Transfer |
| Volume | 126 |
| DOIs | |
| State | Published - Nov 2018 |
Funding
Notice: This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). The authors would like to thank, T. Geer, S. Waters and R. Parten for assisting with the experimental work and M. DeBusk, M. Kass and E. Lara-Curzio for providing helpful comments on the manuscript. We also acknowledge B. Watkins at John Deere for providing fouled coolers for this study. This research was sponsored by the U.S. Department of Energy, Vehicle Technologies Office, Propulsion Materials Program and John Deere.
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | |
| John Deere | |
| Vehicle Technologies Office |
Keywords
- Deposit thickness
- Diesel engine
- Emission reduction
- Exhaust gas recirculation
- Heat exchanger fouling
- Sinusoidal channel geometry