The present paper deals with a new defrosting method for application to a cold heat exchanger by means of a frost sublimation phenomenon. The frost sublimation phenomenon occurs under the condition of temperature below the triple point of water (0.01°C, 0.6105 kPa). The present experimental study has focused on the heat and mass transfer processes at a horizontal frost layer in a moist airflow. It is found that the mass flux from the frost layer increases with the increase of water vapor mass concentration difference between the frost and main moist air flow, main air flow velocity, and the infrared radiant heat intensity. Nondimensional correlations for mass transfer, heat transfer, and defrost completion time have been derived.
Issue Section:
Phase-Change and Multiphase Heat Transfer
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Kochs
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Ko¯rber
Ch.
Heschel
I.
Nunner
B.
1993
, “The Influence of the Freezing Process on Vapour Transport During Sublimation in Vacuum-Freeze-Drying of Macroscopic Samples
,” Int. J. Heat Mass Transfer
, Vol. 36
, No. 7
, pp. 1727
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.2.
Schmidt
E.
1934
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,” Forshung
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.3.
Inaba
H.
Otake
H.
Nozu
S.
1992
, “Fundamental Study on a Horizontal Frost Layer Melted From Above by Radiative Heat
,” Trans. JSME
, Vol. 58
, No. 555
, pp. 3373
–3381
.
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