Thermal management for high-power downhole electronics using liquid cooling and PCM under high temperature environment

The logging tools detecting the hydrocarbon resources are obliged to operate for several hours under high temperature downhole environment. However, the internal electronics, especially the high-power electronics, cannot function for such long time limited by their temperature resistance. In previous thermal management, the heat conduction thermal resistance between the heat source and the PCM was high, resulting in a large temperature difference between them and the operating time of the electronics limited. To solve this problem, a thermal management for high-power downhole electronics combining liquid cooling with PCM under high temperature environment was proposed. Numerical simulation of the proposed thermal management method was calculated by finite element method. The results show that compared to conventional thermal management, the final temperature of the heat source is reduced by 29°C, the average equivalent thermal resistance is reduced by more than 0.5°C/W, and the PCM utilization is improved by 1.9%. Moreover, the heat flow from the heat source to PCM is enhanced compared to the convention thermal management.