Методика определения теплового состояния среднеоборотного дизеля с учетом кипения охлаждающей жидкости

Abstract

Forcing medium-speed diesel engines by increasing the mean effective pressure leads to an increase in the thermal factor of the engine parts. High temperatures of the cylinder head fire deck and the cylinder liner working surface cause thermal fatigue cracks in these parts as well as piston scuffing. Therefore, the development of new methods of intensifying heat transfer in the cooling gallery and refined methods for determining the engine parts thermal state is currently relevant. In both areas of research, a significant role is played by the process of coolant boiling, which significantly intensifies heat transfer in the cooling system. A review of the literature showed that the existing methods of mathematical modeling of conjugate heat transfer in the cooling cavities taking into account the boiling process have a number of significant drawbacks. This paper presents the developed mathematical model and methods for determining the thermal state of medium-speed diesel engine parts taking into account boiling of the coolant, thus making it possible to combine the advantages of both the engineering approach and numerical simulation based on computational fluid dynamics. The thermal state of a new generation medium-speed diesel engine D500 was calculated and the thermal factor of the main engine parts was estimated.