The Study on the Influence of Ambient Condition on fhe Perfomance of Marine Diesel Engine

The marine diesel engines work covers a wide range of ambient temperatures between arctic condition and tropical (design) condition. This will result in the variation of marine diesel engine's performance parameters. In order to ensure the marine diesel engines work safely and reliably in the greatly variated ambient condition, it is necessary to study the influence of ambient temperature on the performance parameters of marine diesel engines. In this paper, the mathematic models of marine diesel engine, the turbocharger and the air cooler are established. Then, for the selected marine diesel engine, the marine diesel engine and its turbocharger operating parameters are calculated under the variation of ambient condition and the trend of these data are analyzed. When the inlet air temperature drops, the air density will increase to such an extent that the maximum permissible cylinder pressure is exceeded. The general methods of lowing maximum cylinder pressure are blowing off a certain mass of the scavenge air through a blow-off device or preheating scavenging air. The comparison calculations of these two methods are carried out.