Diagnostic methodology in four-stroke marine diesel engine by identifying operational parameters

For the purpose of assisting in the maintenance of diesel engines installed in ships and offshore platforms, a methodology was developed to detect, identify and quantify faults of its components. A thermodynamic zero-dimensional model of a 6-cylinder marine diesel engine was constructed taking into account the characteristics of the engine operation. The fuel burn rate was modeled using the double function of Wiebe, and because the performance was of interest, the emissions were ignored. The thermodynamic model was validated with data obtained experimentally. A methodology has been implemented that allows simulating four types of faults, based on the developed thermodynamic model. A sensitivity analysis was performed to identify which failures significantly affect the performance parameters. Finally, the diagnostic model was based on parameter estimation using the Levenberg-Marquardt method. Results showed a high degree of confidence in the identification of all the simulated faults.