The piston reciprocates at high speed in actual work, and the top of the piston is in direct contact with the high temperature and high-pressure gas, which is easy to cause great thermal stress and thermal deformation of the piston. The hardness plug temperature measurement method was used to test and analyze the working temperature of two kinds of diesel engine aluminum alloy pistons with different specific power in the calibrated power condition. Based on the hardness plug temperature measurement data of 30 diesel engine models, a regression model of the temperature of the bowl rim, the center of the combustion chamber and the bottom of the combustion chamber with the change of diesel engine specific power was established in this condition. Research results show that, the thermal load of the piston increases with the rising specific power of the diesel engine. The temperature of piston head is high and the temperature gradient is large. The temperature of the bowl rim is the highest, and the bowl rim temperatures of piston I and II are 311 °C and 350 °C, respectively. The regression model was used to predict the piston temperature of I and II diesel engines, and the accuracy of the regression model was verified. The valuable working heat load conditions at the top of pistons of diesel engines with different specific powers are obtained, which provides strong support for the study of piston heat transfer and structural strength.
specific power; diesel engine; piston top; thermal distribution
第二届世界内燃机大会The 2nd World Congress on Internal Combustion Engines