EHD效应强化管内油的强制对流换热实验

本文以高粘性流体为实验工质,对水平光滑管内油的层流流动换热进行了直流高压电场强化（ＥＨＤ效应）实验研究。以实验方法调查了其换热系数强化率与外加电场强度、热流密度及流动速度,油温等因素的相关性。实验证实了外加直流高压电场能对管内层流强制对流换热起着很好的强化作用。验证了高粘性流体在ＥＨＤ效应下,综合换热性能同样有大幅度增加。

EXPERIMENTAL STUDY ON ENHANCEMENT OF FORCED CONVECTIVE HEAT TRANSFER IN TUBE BY EHD EFFECT

An experiment was performed for the laminar flow forced convective heat transfer of oil through horizontal uniform heated tube under direct current high voltage radial Electric Field. The effects of electric voltage applied, heat flux, flow velocity and temperatures of oil on the enhanced heat transfer were fully investigated. The experimental results show that: for low electric voltage applied (U <1.5 kV), the heat transfer enhancement ratio was low and almost not influenced by the heat flux. With increase of voltage applied, the heat transfer enhancement ratio increased rapidly. For high electric voltage applied, with increase of heat flux the heat transfer enhancement ratio decreased. In the experiment, the maximum heat transfer enhancement ratio was more than 9 times under 4.0 kV voltage applied.