Improving the Accuracy of Determining the In-cylinder Pressure of a Diesel Engine When Measured Through an Indicator Channel

摘要

The pressure in the cylinder of a piston engine reflects information about the engine's operating processes to the fullest, therefore, the in-cylinder pressure diagram is widely used in engine diagnostic systems. Under operating conditions the pressure in the engine cylinder is measured through the indicator channel, which introduces additional inaccuracies in the measurement results, distorting the signal waveform. These distortions do not allow to accurately determine such diagnostic parameters as the peak firing pressure, phase positions of representative points on the in-cylinder pressure diagram, and fuel burnup parameters. The paper proposes a method for obtaining a reliable indicator diagram based on the results of measuring the in-cylinder pressure through the indicator channel using the method of identifying the parameters of the heat release model. The report presents the results of an experimental testing of proposed methods, covering the results of comparing the reconstructed diagrams of internal cylinder pressure measured through the indicator channel with the results of direct pressure measurement in the engine cylinder.