Heat Loss Analysis of a Steel Piston and a YSZ Coated Piston in a Heavy-Duty Diesel Engine Using Phosphor Thermometry Measurements

Research output: Contribution to journalArticle

Abstract

Diesel engine manufacturers strive towards further efficiency improvements. Thus, reducing in-cylinder heat losses is becoming increasingly important. Understanding how location, thermal insulation, and engine operating conditions affect the heat transfer to the combustion chamber walls is fundamental for the future reduction of in-cylinder heat losses. This study investigates the effect of a 1mm-thick plasma-sprayed yttria-stabilized zirconia (YSZ) coating on a piston. Such a coated piston and a similar steel piston are compared to each other based on experimental data for the heat release, the heat transfer rate to the oil in the piston cooling gallery, the local instantaneous surface temperature, and the local instantaneous surface heat flux. The surface temperature was measured for different crank angle positions using phosphor thermometry. The fuel was chosen to be n-heptane to facilitate surface temperature measurements during non-skip-fire, thermally stabilized operating conditions. Assuming one-dimensional heat transfer inside each piston, the local instantaneous surface heat flux was calculated using the heat transfer rate to the oil in the piston cooling gallery and the surface temperature measurements. The results from this study show that the surface temperature variation is similar for both pistons. The instantaneous heat flux during combustion is however significantly greater for the steel piston than the coated piston. The heat release analysis also indicates that combustion is slower for the piston with the yttria-stabilized zirconia coating.

Details

Authors
Organisations
External organisations
  • Scania CV AB
  • KTH Royal Institute of Technology
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Energy Engineering
Original languageEnglish
JournalSAE International Journal of Engines
Volume10
Issue number4
Publication statusPublished - 2017 Mar 28
Publication categoryResearch
Peer-reviewedYes