Enhancement of boiling heat transfer for R11 and R123 by appling uniform electric field

Electrohydrodynamic (EHD) heat transfer enhancement refers to a kind of heat transfer technique that can increase heat transfer efficiency greatly by coupling the flow and temperature field with a high-voltage, low-current electric field in a dielectric fluid medium. The experimental studies of EHD enhancement of boiling heat transfer with R11 and R123 in a uniform electric field are presented in this paper. The experiments were performed using a horizontal brass plate immersed in working fluid as the heat exchange surface. A brass mesh electrode was installed parallel above the plate in the test chamber in order to exert a uniform electric field on the fluid. The applied voltages varied from -25kV to +25kV for R11 and -20kV to +20kV for R123 in steps of 5 W. Relationships among high electric field voltage, heat flux, heat transfer coefficient, and enhancement ratio were obtained. The efficiency of EHD enhancement 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.