Abstract
Frost formation on the heat exchangers of low-temperature devices leads to a deterioration of the COP of the devices because frost acts as a thermally resistive layer. In the recent times, various energy-saving technologies are being sought, and advances in the technologies to reduce the frost formation are much needed. In order to reduce the frosting, it can be stated that the two quantities, the frost layer thickness and amount of frost, need to be reduced. However, an innovative method to do so has not surfaced so far. In the present work, with the aim of controlling the frost crystal formation and growth, micro-machining was done to form stripe shapes on the cooling surface, and the effects of their geometries on the frost formation were investigated. Further, the force required to scrape the frost from the cooling surface was measured, and the effect of the machined patterns/geometries on this force was also investigated. Results reveal that both the mass transfer due to the frost formation and the scrape-off force can be reduced by micro-machining the cooling surface. Thus, the possibility of controlling the frost formation and growth by micro-machining has been demonstrated.
