From fresh cylinder lubricant to drain oil - an evaluation of its performance profile

摘要

Drain oils in 2-stoke marine engines are receiving a lot of attention as they are expected to become a major contributor to optimise cylinder unit operation or define their predictive maintenance. Given the complexity of drain oil analysis and adequate interpretation, the objective of this study is to simulate and understand the transformation of Marine Cylinder Lubricant from "fresh oil" to "drain oil" during the engine running. It is also to establish a performance profile along the liner wall of the lubricant in use, in terms of thermal stability, neutralisation capacity and protection from abrasive and corrosive wear. Two different mechanistic approaches are proposed to describe the transformation process, combining neutralization with oxidation reactions. Validation of the test conditions is done through comparative testing of proven formulations of MCL, and simulation of drain oils sampled in the field. The study finally proposes a preferred mechanism. This will allow to further optimise formulations of Marine Cylinder Lubricants to the actual and future engine demands.