The ornamental design for a heatdissipationdevice, as shown and described.
FIG. 1 is a perspective view of a heat dissipation device showing our new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left view thereof;
FIG. 5 is a right view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof; and,
FIG. 8 is a top perspective view thereof shown in a use configuration with environment.
The broken lines in the drawings depict portions of the heat dissipation device that form no part of claimed design. The broken lines in FIG. 8 depicting a heat radiator as environment form no part of the claimed design.