Simulation and Experimental Study of Ventilated Active Cooling for the Logging Tool Electronics Section

Passive thermal management systems are effective in slowing the rate of temperature rise of the logging tool electronics section. However, its excellent thermal insulation performance simultaneously leads to the slow cooling rate of the logging tool after operation, which seriously limits the efficiency of the instrument in rapid well transfer. This paper proposes an active cooling method based on unidirectional convective heat transfer of dry cold air, and establishes a numerical simulation model of transient active cooling with coupled flow, heat transfer and phase change, and carries out experimental study. The simulation results show that the maximum cooling rate of the circuit board is 3.6 °C/min, and the heat storage module completes the liquid-solid phase change and restores the heat storage function after cooling for 3.5 h. The experimental tests indicate that the average temperature of the electronics section of 190 °C can be cooled down to 25 °C in 3.5 h, under the condition that 20 °C dry cold air is continuously supplied from the small openings at a speed of 5 m/s. And the average error is only 9.4 °C, which verifies the feasibility of the method and the accuracy of the simulation. The research results demonstrate the ventilated active cooling method proposed in this study can efficiently solve the problem of slow heat dissipation in the internal system of the logging tool after high-temperature operation, and an autonomous cooling process can be designed based on this model.