Active cooling is a technique for expanding the upper temperature limit of drilling measurement instruments. An innovative active cooling system, where a cooling device and a circuit compartment that requires cooling are located at the drill string central water eye, is proposed in this paper. The structure of three types thermal conductors that quickly transfers the heat of the chip to the refrigerator, is designed. The thermal conductivity of different structures is studied using numerical simulation methods. The research results indicate that the point-point cooling scheme that uses four small heat transfer arms to transfer heat separately is more optimal. The overall temperature inside the cabin increases, except for the chip. The environmental heat leakage is reduced by 1.2W, the cold end temperature is reduced by 23.4K, compared to the other two solutions. When the total thickness of the four heat transfer arms remains unchanged, increasing the thickness of the long heat transfer arm and decreasing the thickness of the short heat transfer arm slightly reduces the heat load of the refrigeration machine, but the temperature on the cold end of the refrigeration machine increases by 5K, and the temperature difference on the four chips narrows by 8.5K. Therefore, the use of a four claw heat transfer structure with variable thickness is the optimal choice.

Numerical investigation of the circuit compartment of the central water eye active cooling device