Ways to improve thermal uniformity inside a refrigerator

In a directly cooled refrigerator, the maximal temperature difference of the cooled air increases with the height of the chamber, which is the main problem for producing a large volume refrigerator. In order to improve the temperature uniformity inside the chamber, two kinds of refrigerators are studied in this paper by the computational fluid dynamics (CFD) software Star-CD and experimental methods. For the fully natural convective refrigerator, the calculated results show that the clearance between shelves and the back-wall and the clearance between the shelves and door play an important role in temperature distributions. When reducing both clearances, temperature variation will decline and more uniform temperature distributions will be achieved. In order to further improve the temperature uniformity, another kind of directly cooled refrigerator is put forward, in which a disturbing axial fan and an air duct are added. How to improve the airfield in this kind of refrigerator is studied, and the calculated results show that the flow direction of air from the air duct to the chamber has obvious effects on the temperature field and flow field. Comparison of the two kinds of refrigerators shows that temperature uniformity in the new kind of refrigerator is better than that of the first kind of refrigerator.