舶用Ｃ重油の燃焼特性と重油中の炭素成分との関連性についての実験的研究

Abstract

The combustion characteristics (ignition delay, combustion period, and rate of maximum heat release position) of marine heavy fuel oil are affected by many factors, including density, carbon residue, asphaltene content, aromaticity, carbon/hydrogen (C/H) ratio, paraffinic carbon, and others.In investigating the causes on operational problems of marine diesel engines, it is very important to consider what properties we should examine to determine whether the main causes of the problems are related to the fuel oil in use. There might be a threshold of poor fuel oil quality that is related to ignition delay, combustion period, and position of maximum heat release rate. We studied these topics using a constant-volume combustion test apparatus (called FIA 100), and reached the following conclusions:1. Percentage of paraffinic carbon (%CP) and C/H mass ratio are closely correlated with the combustion characteristics of marine fuel oil.2. Density has some correlation with combustion characteristics.3. Carbon residue and asphaltene content in fuel oil show no correlation with ignition delay, but have some correlation with combustion period.4. There is practically no correlation between sulfur content and combustion characteristics.5. There is no correlation between oil viscosity and combustion characteristics.6. Tentative threshold values of C/H mass ratio=8.3 minimum and paraffinic carbon=51 % m/m maximum in marine heavy fuel oil combustion characteristics can be set for fuel oils of poor quality.