测井仪电子短节通气主动冷却仿真与实验研究

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

被动式热管理系统有效延缓了测井仪电子短节的温升速率,但其优异的隔热性能同时导致作业完成后冷却缓慢,制约了快速转井的效率。该文提出了基于干燥冷空气单向对流换热的主动冷却方法,建立了流动、传热及相变耦合的瞬态主动冷却过程数值仿真模型,并开展了实验研究。仿真结果显示电路板最大降温速率为3.6℃/min,且储热模块在冷却3.5 h后完成液-固相变,恢复储热功能。实验结果表明,在以5 m/s的速度持续从小开口侧通入20℃干燥冷空气条件下,3.5 h即可将电子短节平均温度从190℃冷却至25℃,平均误差仅为9.4℃,验证了方案的可行性及仿真的准确性。研究结果表明,该研究所提出的通气主动冷却方法可以高效解决高温作业后测井仪电子短节散热缓慢的难题,并且基于该模型可设计自主调节的冷却工艺。

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℃/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℃ can be cooled down to 25℃ in 3.5 h,under the condition that 20℃ 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℃,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.