Numerical and experimental study of an integrated thermoelectric active cooling system for ultra-high temperature downhole electronics

Abstract

The external polar plate circuit is a critical component of the scanning imaging logging tool which must work in ultra-high temperature environment, and thus effective thermal management is imperative. However, the limited internal space and the requirement for stretching functionality present great challenges. In this study, a novel integrated thermoelectric cooling system (TCS) is proposed to cool the external circuit in an environment reaching 230 °C, a condition far more extreme than those addressed in previous studies. Specifically, the design incorporates dual thermoelectric coolers integrated at the top and bottom of the circuit to establish bi-directional heat dissipation pathways, while insulating the surroundings to minimize the heat leakage from environment. The cooling performance of the proposed TCS was evaluated through both experiments and numerical simulations. The results indicate that the system can maintain the temperature of a 3 W heat source at 190.2 °C in a 230 °C environment. The numerical results from COMSOL simulations align well with experimental data, with a temperature error of less than 2.6 °C. It suggests that the overall coefficient of performance (COP) of the proposed TCS is 0.097 and an ambient heat leakage is 0.42 W. The proposed TCS demonstrates excellent temperature control performance, long-term stable operation capability, and broad application prospects.