Enhanced boiling conditions during quenching by use of frost as a temporary heat transfer enhancer were determined experimentally. The frost coating was obtained by the application of air moisture on the previously cooled surface of a product. We found that heat transfer intensity can be adjusted by the change in coating structure characteristics. These characteristics, on the other hand, depend on frost formation parameters such as a temperature of the preliminarily cooled sample, an air temperature, a relative humidity, an air movement velocity and a frost formation time range. During the subsequent sample quenching in liquid nitrogen, a heat exchange enhancement was 10.2-12.4 when cooling down to the nitrogen's saturation temperature. By limiting the cooling temperature within the range of 90 K-110 K, the additional heat exchange enhancement increased 1.4-1.5 times.
|Number of pages||8|
|Journal||Applied Thermal Engineering|
|State||Published - 21 Jan 2013|
- Heat transfer
- Pool boiling