A Numerical Investigation on the Influence of Engine Coolant Temperature under Low Temperature Combustion in a Diesel Engine. Issue 11 (2nd November 2017)

• Record Type: Journal Article
• Authors: Li, Tingting; Caton, Jerald A.; Jacobs, Timothy J.
• Is Part Of: Combustion science and technology. Volume 189:Issue 11(2017)
• Page Start: 1992
• Page End: 2011
• Publication Date: 2017-11-02
• Subjects: Engine coolant temperature -- Engine simulation -- Low heat rejection -- Low temperature combustion; Combustion -- Periodicals; Combustion engineering -- Periodicals; 541.36105
• DOI: 10.1080/00102202.2017.1353501
• Languages: English
• ISSNs: 0010-2202

Abstract

ABSTRACT: This study evaluates a technology of integrated low heat rejection (LHR) and low temperature combustion (LTC) aiming to achieve improved energy conversion efficiency of internal combustion engines. Different from the use of thermal-barrier coatings in traditional LHR diesel engines, altering engine coolant temperature (ECT) is used to realize LHR in this study. In a separate study, the engine was overcooled to low ECTs and then increased to 100°C in an effort to get trend-wise behavior without exceeding safe ECTs. This study uses an engine simulation of the same multi-cylinder, four-stroke, 1.9-L diesel engine operating at 1500 rpm and ~35% EGR to examine the engine performance and combustion phasing at different ECTs under the LTC mode. As compared to conventional LHR operation mode, also studied in a second separate study, increasing ECT yields more significant improvements in fuel conversion efficiency under LTC-LHR mode, 28.8% of indicated efficiency and a doubling of brake efficiency gains, pointing to a higher sensitivity to ECT variations under LTC conditions compared to conventional conditions.