Effect of Air Velocity, Surface Temperature, and Absolute Humidity on Frosting Phenomena under Condition of Electric Field

The correlation of effect of electric field and environmental parameters on frosting phenomena was studied. The investigation was based on experiments with a forced air stream on the cold plate surface under several frosting conditions. The effect of electric field, defrosting phenomena, was evaluated from frost formation rate and mass transfer coefficient, which was derived from the amount of frost remained on the cold plate surface. The results obtained were as follows ; (1)Under large difference of absolute humidity, the reduction rate of frost formation rate obtained by forming the electric field appeared at nearly constant rate and was independent of the difference of absolute humidity, but it disappeared where the difference of absolute humidity was small. (2)The mass transfer coefficient under the electric field became small as temperature of the cold plate surface became lower. (3)The reduction rate of mass transfer coefficient occured by forming the electric field decreased as air velocity increased. (4)The mass transfer coefficient under the electric field decreased proportionally as the field strength were strength end from 0 k V /cm, but became not to vary beyond a field strength, which depended on temperature of the cold plate surface.