线电极强化双肋片热沉对流换热实验研究

Experimental Study on Convection Heat Transfer Enhancement of Two-Finned Heat Sink by Wire Electrode

本文采用两渐扩肋片热沉作为集电极,肋片间隙内布置线电极产生电晕风以强化对流换热。实验研究了电极电压、加热功率、线基距和线电极半径对换热的影响。使用半径0.065mm和0.05mm的线电极,分别将对流换热系数提高到自然对流换热系数的1.6~3倍和1.8~3.3倍。较高的电极电压、较低的加热功率或较小的线电极半径可以获得更高的EHD强化比。给定电极电压和加热功率,线电极具有最佳位置,对应着最高的EHD强化比。另外,降低电极电压、增加线基距或增大线电极半径,可提高EHD系统的能效。本实验中EHD能耗很低,系统的性能系数(COP)可达64。

In this work,a heat sink with two divergent fins is used as a collecting electrode.A wire electrode is placed between the two fins to generate corona wind for enhancing convection heat transfer.The influences of the voltage,heating power,wire-base distance,and wire radius on heat transfer are studied experimentally.Depending on two wire radii of 0.065 mm and 0.05 mm,the convection heat transfer coefficients with EHD are 1.6~3 and 1.8~3.3 times that in natural convection,respectively.A higher voltage,lower heating power, or smaller wire radius can increase the EHD enhancement ratio.Given an electrode voltage and a heating power,there exists an optimum wire position corresponding to the maximum EHD enhancement ratio.In addition,decreasing the voltage,enlarging the wire-base distance,or increasing the wire radius can improve the energy efficiency of the EHD device.The EHD power consumption is very low and the coefficient of performance(COP) reaches 64.