Thermal optimization of high-temperature downhole electronic devices

The logging tools detecting the underground petroleum resources face a high-temperature downhole environment. Several passive thermal management systems have successfully protected the downhole electronic devices in previous studies but failed to exert a better temperature control performance. To solve this issue, the finite element method and the Nelder–Mead algorithm are combined to optimize the thermal design of the logging tool. The optimized logging tool is obtained after 61 optimization iterations and the maximum temperature of heat sources drops from 163.1 °C to 123 °C. Besides, phase change materials (PCMs) of the optimized logging tool store 13.7% more heat, avoiding the heat accumulation of the heat sources. An experiment was conducted to investigate the real thermal optimization effect. The maximum temperature of heat sources decreases by 30.1 °C in the optimized logging tool, and the simulated results well match the experimental results with an average error of 4.64 °C. The results verify the effectiveness of thermal optimization in logging tools, revealing the great potential of optimization algorithms in thermal design.