Abstract
For safe engine operation and the most suitable combustion for environment, monitoring of combustion in a cylinder and combustion control technology are important while an electronic control of a marine diesel engine advances. Measurement of Indicated Mean Effective Pressure (IMEP) is needed to monitor combustion conditions. It is thought that the numbers for sampling data can be reduced, and the calculation can be performed faster for real-time combustion monitoring by IMEP. In this paper, the influence of the data sampling interval upon the calculation error of IMEP, and reasons, are analyzed. Concerning the IMEP calculation for the marine diesel engine, the authors use a new calculation method of IMEP, using the low frequency component of cylinder pressure. A conventional calculation method of IMEP uses cylinder pressure and volume change. When data sampling interval was long, the new calculation method which was recommended by the authors was found better than the conventional calculation method of the IMEP.
