EHD (electrohydrodynamic) enhancement of boiling heat transfer with R11 in plate surface

EHD (electrohydrodynamic) heat transfer enhancement refers to a kind of heat transfer technique which can increase heat transfer efficiency greatly by the coupling of the flow and temperature field with a high voltage, low current electric field in a dielectric fluid medium. An experimental study of EHD enhancement of boiling heat transfer with R11 in uniform electric field is presented in this paper. The experiments were performed by using a horizontal brass plate immersed in R11 as heat exchange surface. A brass mesh electrode was installed parallel above the plate in the test chamber in order to exert an uniform electric flied on the fluid. The applied voltages varied from -25kV to +25kV in steps of 5kV. Relationships among high electric field voltage, heat flux, heat transfer coefficient and enhancement factor was obtained. The efficiency of EHD enhancement by using positive and negative electric field was analyzed respectively. These results have laid a foundation for exploring the mechanism of EHD augmentation of boiling heat transfer.