板式脉动热管的磁流体实验研究

Experimental study of magnetic fluid in plate pulsating heat pipe

脉动热管被认为是超高热流密度功耗的工况中最具前景的散热元器件之一,与逐渐发展成熟的纳米技术一同被广泛应用于电子散热设备中,因此探究纳米流体脉动热管的运行与热特性变化机理十分重要。通过采用外加磁场的方法来强化纳米磁流体脉动热管传热的实验研究,搭建了纳米磁流体脉动热管的传热测试可视化实验台。分别测量了在磁场为25、5、1、0 mT以及在2种不同磁场方向(脉动热管蒸发段的正后方与正下方)作用下,板式脉动热管的温度分布和传热速率,研究了纳米磁流体、热负载功耗、磁感应强度与磁铁摆放位置等因素对其换热性能的影响。实验结果表明,用四氧化三铁/乙醇纳米流体作为工作流体,在磁场作用下可以显著强化脉动热管的传热性能,其中置于脉动热管蒸发段正下方的永磁体能够更多地优化脉动热管的传热性能,这可为超高热流密度功耗的工况提供借鉴指导。

As a heat pipe occupying a place in the field of heat transfer,the PHP is widely used in electronic heat dissipation equipment,and regarded to be one of the heat dissipation components that have great development prospects under the conditions of extra high heat flow density and power consumption.With the maturity of nanotechnology,Nano fluid has also become an innovative research in the traditional field of heat dissipation and heat transfer.Therefore,it is extremely important to explore the change mechanism and change law of the operation and thermal characteristics of the pulsating heat pipe in different magnetic field environments.Through the use of an external magnetic field to strengthen the experimental research on the heat transfer of the nano-magnetic fluid pulsating heat pipe,a visualization experiment platform for heat transfer testing of the nano-magnetic fluid pulsating heat pipe was built.The temperature distribution and heat transfer rate of the plate-type pulsating heat pipe under the action of the magnetic field size of 25,5,1 and 0 mT anddifferent magnetic field directions are respectively measured.The influence of factors such as nano-magnetic fluid,heat load power consumption,magnetic induction intensity and magnet placement position on its heat transfer performance is studied.The experimental results show that the use of Fe3O4/ethanol nanofluid as the working fluid can significantly enhance the heat transfer performance of the pulsating heat pipe under the action of a magnetic field.Especially under high heat flux loading,this can provide a reference for the working conditions of ultra-high heat flux density and power consumption.