SIMULATION OF NOX REDUCTION BY CONSOLIDATED CONTROL OF MAIN ENGINE AND CPP

Abstract

The introduction of controllable pitch propellers (CPP) has increased ship manoeuvrability and the capability of using the shaft generator. The conventional control algorithms of these CPP systems are comparatively simple. However, the CPP system has essentially the capability to control two freedoms because there are two input parameters of a propeller pitch angle (P) and a regulator handle position (R) in the system. One freedom must be used for controlling the ship speed which is the most important controlled value for vehicles. Another freedom should be utilized positively to improve or optimize performance such as fuel consumption ratio (be) and NOx emission. This utilization is accomplished by controlling P and R simultaneously which is called consolidated control. In the study, "be" or "be" plus NOx was adopted as the performance index of the utilization. There are two types of consolidated control: on-line and off-line. This study focuses on the on-line consolidated control which was investigated by simulation.