Waste Heat Recovery From a Compression Ignition Engine using a Combined Diesel Particulate Filter Heat Exchanger

Abstract

Compression ignition (CI) engines have been a figurehead in the transportation industry for decades. However, as environmental regulations dictate increasingly strict emissions guidelines for engines, technologies must accordingly advance. To this end, this thesis describes the work of validating a combined diesel particulate filter heat exchanger (DPFHX) for CI engine exhaust waste heat recovery (WHR) in a Rankine Cycle (RC), a concept introduced in the first chapter of this thesis. The second chapter includes a comprehensive literature review, indicating the increasing prevalence of WHR in the literature. Additionally, with RC as the principal system for WHR and engine exhaust as the primary heat source, this research is exceptionally relevant. Furthermore, the primary aspects of an RC WHR system requiring individual optimization are the heat exchangers and expanders along with working fluid selection. As such, the third chapter discusses experiments to analyze and compare the DPFHX with various working fluids; thus, incorporating the literature trends of working fluid comparison and component specificity in the methodology. Consequently, in the DPFHX, water achieved a higher heat transfer rate by over 60% than the 50% by volume mixture of water and ethylene glycol, the two optimal working fluids in the apparatus without DPF cores. However, alterations made to the DPF cores’ outer diameters and lengths when installing them in the heat exchanger tubes prevented them from achieving the expected outcome (i.e., improving apparatus performance). Finally, the fourth chapter links the conclusions from this work to recommendations for future efforts to investigate DPFHXs.