CPU Cooling of Desktop PC by Closed-end Oscillating Heat-pipe (CEOHP)

The CEOHP cooling module consisted of two main parts, i.e., the aluminum housing and the CEOHP. The house casing was designed to be suitable for CEOHP. The housing to drilling for insert the CEOHP. The CEOHP design employed copper tubes: Two sets of capillary tubes with an inner diameter of 0.002 m, an evaporator length of 0.05 and a condenser length of 0.16 m and each of which has six meandering turns. The evaporator section was embraced in the aluminum housing and attached to the thermal pad of Pentium 4 CPU, model SL 6 PB, 2.26 GHZ. While the condenser section was embraced in the cooling fin housing and cooled by forced convection. R134a was used as the working fluid with filling ratio of 50%. In the experiment, the CPU chip with a power of 58 W was 70°C. Fan speed of 2000 and 4000 rpm. It was found that, if fan speed increases the cooling performance increases. The CEOHP cooling module had better thermal performance than conventional heat sink.