Intelligent Air Management for Ultimate Flexibility of Ship Propulsion Plant Operation - 1st Report: Experiment and Simulation

Abstract

Constantly tightening regulations and rules related to emissions and energy-efficiency lead to a more complex design of the ship systems where several new technologies are applied simultaneously. Since the scavenging process is the most important factor affecting the performance, efficiency and emission characteristics of a two-stroke engine, most of the technologies, somehow or other, relate to engine air supply system. Thus in order to ensure the optimal systems integration and operation, an intelligent air management of the engine is required. In this paper, the results of scavenging characteristics measurements and simulations are reported. The tests were performed on a two-stroke marine diesel engine varying scavenging air pressure, engine speed and exhaust valve close (EVC) timing, next the simulation software was used to get an insight of the scavenging process. The obtained results set prerequisites for the development a simple estimation model of the air excess ratio available for the combustion which can be used for the intelligent scavenging system control, furthermore, a simple correlation of the specific fuel consumption and the air excess ratio has also been found.