Portable Refrigerator

FIG. 1 is a front view of a portable refrigerator showing the new design;

FIG. 2 is a back view thereof;

FIG. 3 is a left-side view thereof;

FIG. 4 is a right-side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof;

FIG. 7 is a top-right perspective view thereof; and,

FIG. 8 is a back, left-side and bottom perspective view thereof.

The areas within the broken lines illustrate portions of the portable refrigerator that are not part of the claimed design. The broken lines themselves do not form any part of the claimed design.