Study on the Relationship Between Combustion Characteristics and Properties of Marine Heavy Fuel Oil

Abstract

The combustion characteristics (ignition delay and combustion period in this paper) of marine heavy fuel oil are affected by many factors such as density, carbon residue, asphaltene, aromaticity and carbon/hydrogen (C/H) ratio. When investigating the causes of operational problems in diesel engines, what properties should we check to find whether the main causes of the problems are related to fuel oil or not? What is the threshold of ignition delay and combustion period of fuel oil? The authors studied these topics using a combustion test apparatus called FIA 100, and arrived at the following conclusions: 1. The aromaticity index (CCAI) and the C/H ratio have good correlation with the combustion characteristics of marine fuel oil. These factors cannot be ignored during troubleshooting. 2. The carbon residue and asphaltene in fuel oil have no correlation with ignition delay, but have some correlation with the combustion period. 3. There is practically no correlation between the average molecular weight of fuel oil, and both ignition delay and combustion period. 4. Tentative threshold values of ignition delay and combustion period can be set for fuel oils of poor quality (flame retardation).