The ornamental design for a portablefireplace, as shown and described.
FIG. 1 is a perspective view of the portable fireplace of the present invention;
FIG. 2 is a top view of the portable fireplace of the present invention;
FIG. 3 is a front elevational view of the portable fireplace of the present invention;
FIG. 4 is a left side elevational view of the portable fireplace of the present invention;
FIG. 5 is a rear elevational view of the portable fireplace of the present invention;
FIG. 6 is a bottom view of the portable fireplace of the present invention; and,
FIG. 7 is a perspective view of the portable fireplace of the present invention shown from the left side with a lid of the fireplace in an open and stored position.
The broken lines in the figures represent unclaimed portions of the portable fireplace and form no part of the claimed design.