Evaluation and Selection of the Primary Zeldovich Reaction Rate Constant for NO Formation in Marine Diesel Engines

Accurate prediction of nitrogen oxide emissions from marine medium-speed four-stroke diesel engines is crucial for meeting increasingly stringent environmental standards. This paper focuses on the evaluation and selection of the optimal rate constant for the first and most significant reaction of the extended Zeldovich mechanism within a specific simulation framework. A numerical engine model was developed and validated against experimental measurements of combustion pressure, power, and emissions at 81% of the Maximum Continuous Rating (MCR). The research analyzes the influence of thirteen distinct chemical reaction rate constants on the accuracy of nitric oxide concentration predictions under the assumptions and inherent structural limitations of the developed zero-dimensional multi-zone model. The results demonstrate that by carefully selecting these kinetic parameters, the numerical model’s deviation can be reduced to just −0.93%. Crucially, these findings reflect the performance of alternative kinetic formulations within this specific diagnostic modeling framework rather than a fundamental investigation into the universal chemical kinetics of nitrogen oxide formation. By systematically examining the primary Zeldovich reaction through its pre-exponential factor, temperature exponent, and activation energy, this approach provides a reliable calibration framework that significantly improves the fidelity of this specific emission formation simulation without increasing computational complexity.