Thermodynamic and NO_x emission analysis of diesel engine with intake manifold steam injection

The steam injection method is an effective solution for thermal efficiency enhancement. While there exist different steam injection methods, only one of them is discussed in this paper presenting a thermodynamic analysis of steam injection in the intake manifold of a diesel engine to identify possible steam effects on the performance and combustion characteristics. The impact of steam injection mass on the thermodynamics of the diesel engine was evaluated by the engine model, which was created in the ExtenSim7 software, including the relevant mathematical relationships. The engine KDI 1903M was chosen for analysis, and its technical characteristics were used to obtain the modelling data. As a result of the model operation, it is assumed that steam was injected into the intake manifold at the time of the induction stroke at different steam injection mass: 10, 20, 30, 40 and 50 mg. The model confirmed growth of the pressure increase ratio and effective power with the increase of the steam injection mass, as also variations in the temperatures at the end of compression and combustion. Some other important parameters, like NOx emissions, are also discussed and compared using steam injection and without it. The results showed that at 50 mg of steam injection, the combustion temperature and NOx emissions decreased by 36 K and 62 ppm, respectively. At the same time, a slight increase in power in the amount of 4.3% is observed due to a growth of the pressure increase ratio. The results provide guidance for the future experimental studies in laboratory conditions.