The ornamental design for a modularrefrigerator, as shown and described.
FIG. 1 is a right front perspective view of the design of the modular refrigerator;
FIG. 2 is a front elevational view thereof. The ornamental design is not visible in a rear view, top plan view or bottom view; and,
FIG. 3 is a right side elevational view thereof, the left side elevational view being a mirror image.
Those portions of modular refrigerator in broken lines, specifically the surfaces of the modular refrigerator at the top and bottom edges of the door and surfaces extending back from the door including other surfaces of the modular refrigerator are not part of the claimed invention.