Investigation on Pulsating Heat Pipe (PHP) Heat Spreader Plate for Electronics Cooling

A Pulsating Heat Pipe (PHP) plate heat spreader was investigated as a high thermal performance alternative to a conventional conduction plate heat spreader. A 3U form factor card, i.e., 160 mm x 100 mm x 3.38 mm was selected for performance testing. The PHP heat spreader was additively manufactured with aluminum and charged with propylene. From performance analysis, it was determined that the PHP had 100% higher thermal conductance compared to the conduction plate when the condenser (plate heat rejection) temperature was below 0 °C. The maximum variation in thermal conductance observed through repeatable experiments was less than 10% with 95% confidence level. The PHP was capable of transporting more than 220 W of heat without dry-out at these conditions. However, when the condenser was maintained at 20 °C, the thermal performance improvement of PHP was 45% more than the conduction plate.