Study On The Cooling Performance Of The Water-cooling Bearing Body In Turbocharger Based On Boiling Heat Transfer Effect

Due to the outstanding performance in reducing exhaust emissions and improving dynamic of vehicles, the turbocharger are used in automobile industry more and more widely. As the requirements of user for the turbocharger performance improving, the work environment of the bearing body, as an important part of the turbocharger, is becoming more and more severe. Because of the uneven distribution of temperature of each part, there was a large temperature gradient and the bearing body was under the great thermal stress.This paper study on the thermal state of bearing body and the performance of the cooling system by combining the methods of numerical simulation and experimental verification, its main work and innovative points are as follows:(1)Based on the mechanism of water-cooled bearing in turbocharger, a liquid-solid coupling model under normal conditions was built. Under the conditions that considering the influence of the water boiling and not, the flow and heat transfer performance of cooling water-jacket of bearing in turbocharger were simulated separately. The simulation performances such as the flow field of the cooling water,wall temperature field of cooling water-jacket, temperature field of the bearing and the heat transfer coefficient distribution of the coupling wall were gotten. Two simulation results both show that the cooling performance of the bearing body can meet the requirements.(2)The simulation results between considering boiling and no boiling were compared and analyzed with experimental values. And the results revealed that the liquid-solid coupling model based on the influence of the water boiling is of more accuracy,which will provide the basis for the further research of optimizing the cooling performance of bearing.(3)The effect of the main factors that influence the cooling performance of the bearing body are studied through experiments. The impact degree of various factors on cooling performance was also analyzed by using grey correlation analysis method.The result could be referenced in improving the cooling performance.