USAGE OF NUMERICAL PROFILES OF THE WORK PROCESS TO ANALYZE THE EFFICIENCY OF THE LOW-SPEED MARINE ENGINE

Abstract

Introduction. The current state of development of marine internal combustion engines demands compliance with strict requirements for a number of economic and environmental characteristics, compliance with which is possible only if the engines are in good condition. The main task that vessels engineers solve during routine operation is examination and support of the engine condition in good order. Effective determination is based on a comparison of the current parameters of the processes in the engine’s working space with reference values or curves which are characterizing the course of the processes. Purpose. Taking into account the significant changes in the logistics systems of modern shipping and the growth of environmental requirements, the main thing is the necessity for defined reference parameters of the work process at partial engine load modes, for carrying out diagnostic procedures during the vessel’s operation at the specified operating mode. This research is devoted to the solution of these questions. Results. Using the methodology of creating a digital profile of the working process of a low-speed marine engine, based on the approximation of the basic diagrams obtained during its bench tests, a set of numerical arrays corresponding to the indicator diagrams of the engine is determined on the whole range of operating modes with a step of 1% depending on the load. The calculation complex developed by the authors allows you to export to it data’s arrays for non-specification modes both: in the form of reference diagrams and in the form of data obtained as a result of engine indication during its operation. Based on the results of array processing, the calculation complex forms a set of diagrams of the work process in рφ- and рV-coordinates, as well as diagrams characterizing the dynamics of the work process and the process of heat generation. The processing of these diagrams allows you to define a set of parameters that characterize the course of the work process, which is expanded in comparison with other similar complexes. Conclusions. The developed methodology makes it possible to provide the process of engine diagnostics according to the parameters of the work process, by a basis for comparing actual indicators with calculated reference ones in all areas of engine operating modes.