Stress analysis of copper tubes during the post-rolling cooling process

Abstract

With the ever-increasing demand for heat exchange, copper heat exchanger tubes are developing toward thinner walls and lighter weights, which raises higher requirements for the copper tube production process. After the copper tubes undergo rolling and cooling processes, stress concentrations often occur, which can affect the subsequent processing of the copper tubes and reduce their production quality. To explore the stress field and temperature field distribution during the cooling process after rolling, this paper establishes a thermal-fluid-solid three-dimensional coupled simulation model of the copper tube cooling process, revealing the influence of the cooling water jacket structure on the stress distribution of the copper tubes. According to the simulation results, it was found that there are multiple “static areas” with a flow velocity of 0 m/s within the cooling water jacket of the traditional structure. It was also found that after the cooling process is complete, the stress distribution in the copper tube is concentrated, with the maximum circumferential residual stress and the minimum axial residual stress. By changing the position of the inlet and outlet of the cooling water jacket, it was discovered that adjusting the inlet position from the outer circumference to the end face of the copper tube can better reduce the residual stress after cooling. Finally, the residual stress of the copper tube is detected using a laser ultrasound stress measurement device, verifying the feasibility of changing the inlet position of the cooling water jacket to reduce the residual stress of the copper tube.