2results about How to "Increase heat transfer limit" patented technology

The utility model provides a multi-loop parallel pulsating heat pipe heat dissipation device, which belongs to the technical field of heat dissipation, and comprises a multi-loop parallel pulsating heat pipe assembly and a plurality of fins, the multi-loop parallel pulsating heat pipe assembly comprises a laminated heat pipe flat pipe assembly and an end connector, the stacked heat pipe flat pipe assembly comprises a plurality of micro-channel heat pipe flat pipes and a plurality of flat pipe expansion pieces, and the flat pipe expansion pieces and the micro-channel heat pipe flat pipes are alternately arranged in the width direction of the micro-channel heat pipe flat pipes to form the stacked heat pipe flat pipe assembly. The stacked heat pipe flat pipe assembly is bent for multiple times to form a snakelike structure with parallel middle pipe sections and opposite head and tail end openings, the end connector is in a fishbone shape, the end connector is connected with the head and tail end openings of the stacked heat pipe flat pipe assembly to form a closed structure, and a plurality of fins are arranged between the parallel middle pipe sections of the stacked heat pipe flat pipe assembly. According to the utility model, the dry-out failure risk of the pulsating heat pipe under high load is reduced, and the heat transfer limit of the heat pipe and the stability and reliability of the heat dissipation device are improved.

This invention provides an ultrathin vapor chamber based on an asymmetric capillary structure with a wettability gradient, and relates to an improved method for an ultrathin vapor chamber with an asymmetric distribution of hydrophilic-phobic composite capillary structures. The vapor chamber includes a sealed, flat cavity filled with a working fluid. Its innovation lies primarily in the construction of the capillary structures distributed on the upper and lower shell plates of the cavity. The upper shell plate comprises a hydrophilic surface with superhydrophilic microstructures exhibiting strong capillary forces, while the lower shell plate comprises a smooth hydrophobic surface without capillary structures and a hydrophilic surface with superhydrophilic microstructures exhibiting strong capillary forces. The superhydrophilic microstructures with strong capillary forces are uniformly distributed on the surface of the upper shell plate, while those on the lower shell plate are distributed in the edge region of the plate surface, with the central region being a smooth hydrophobic surface without capillary structures, forming a wettability gradient structure. Compared to traditional ultrathin heat spreaders with uniformly symmetrical capillary structures, this invention designs a continuous wettability gradient in the lower shell plate, allowing steam to rise vertically without obstruction in the central region. Meanwhile, the condensate formed by steam condensation flows back laterally efficiently through the superhydrophilic structure at the edge of the lower shell plate. During the gradual change of capillary force, the paths of steam and liquid are separated, thus achieving the synergy of steam diffusion and liquid reflux within a single thin cavity.