Control of Frost Accumulation on a Horizontal Cold Plate Using DC Electric Fields

With the rapid advancement and expansion of affordable electronics and their applications to computer-driven process control, the prospects for electronically controllable heat transfer surfaces utilizing electric fields are very encouraging. The effects of DC electric fields on frost crystal growth with wire and flat-plate insulated electrodes were studied in this paper. Results showed that the electrode geometry played a major role in the frost control process. Up to 39% frost reduction was obtained when an insulated plate electrode was used with an applied voltage of 17kV, while in similar experiments only 22% frost reduction was obtained using a wire electrode. The plate temperature varied from −20°C to −40°C, while the air temperature was varied from 0°C to −10°C with air relative humidity ranging from 45% to 90%. Both natural and forced convection (Reynolds number = 5,000) conditions were considered in this study. The average power consumption for these experiments was 31 mW. The main findings of this study suggest that the presence of a DC electric field can greatly affect both the frost crystal growth pattern and mass accumulation on a cold plate. For the first time, the ice surface’s electrical properties and basic electrostatics were used to explain the main findings in this paper. Numerical simulation results of the electric fields utilizing a state-of-the-art commercial software were in agreement with the experimental findings from this study. The effect of charge accumulation on the dielectric coating of the electrodes is also addressed.