Studies of a Heat-Pipe Cooled Piston Crown

Abstract

Designing pistons with effective cooling is crucial to preventing piston failure and improving engine service life. A piston design that incorporates the heat-pipe cooling technology may provide a new approach that could improve the thermal-tribological performance of heavy-duty diesel engine pistons. A simplified piston crown with an annular reciprocating heat pipe is constructed to demonstrate this concept. The piston crown is experimentally tested on a specially designed reciprocating apparatus. Experimental data indicate that the annular heat-pipe cooling can greatly assist in reducing the temperature gradient and peak temperature along the ring bank. In order to predict the performance in a more realistic piston working condition, a three-dimensional finite element modeling is used to analyze the thermal performance of this annular heat-pipe cooled crown (AHPCC). The heat-transfer coefficient under the reciprocal environment of the experimental apparatus and the effective thermal conductance of the heat pipe are determined by correlating the numerical calculations with the experimental measurements. The results indicate that the heat-pipe-cooling concept presented in this paper can provide an effective means for piston temperature control under real piston operating conditions. [S0742-4795(00)01501-5]