A smart load-speed sensitive cooling map to have a high- performance thermal management system in an internal combustion engine

Abstract

Considering the fact that electrification is increasingly used in internal combustion engines, this paper aims at presenting a smart speed-load sensitive cooling map for better thermal management. For this purpose, first, thermal boundary conditions for the engine cooling passage were obtained by thermodynamic and combustion simulation. Next, the temperature distribution of the cooling passage walls was determined using conjugate heat transfer method. Then, the effect of engine load on wall temperature distribution was investigated, and it was observed that in the conventional mode where the cooling flow is only affected by the engine speed, the engine is faced with over-cooling and under-cooling. Therefore, the optimum flow for cooling the engine was achieved in such a way that the engine is hot enough and kept free from damage, while the engine has a more uniform temperature distribution. These calculations were performed by considering the boiling phenomenon. The results showed using the cooling map leads to a significant reduction in coolant flow, which in turn reduces the power consumption of the water pump and size of the radiator. Moreover, fuel consumption, hydrocarbon emission production, and the needed power of the coolant pump are enhanced by 2.1, 8.6, and 44.3%, respectively.