Experimental investigation on thermal performance of phase change material coupled with closed-loop oscillating heat pipe (PCM/CLOHP) used in thermal management

Combining the high heat capacity of the PCM with the high thermal conductivity of the OHP can overcome the shortcomings of PCM itself, such as paraffin wax coupled with closed-loop oscillating heat pipe (CLOHP). In this paper, CLOHPs with different turns were designed, manufactured and tested, and then a comprehensive investigation on the thermal performance of paraffin wax coupled with CLOHP under different supplied heating power (10-80 W) was performed experimentally. The results showed that when the whole width was constant, difficult or unstable oscillation tended to occur in the CLOHPs with less turns. The number of the turn had great influence on the start-up temperature and the oscillation stability of the CLOHPs, so it needs to be selected carefully according to the actual situation. The paraffin wax/CLOHP system showed much better dynamic thermal performance in the heating process and much better static thermal performance in the cooling process than those of the paraffin wax system. Limited by the heat transfer capability of the CLOHP and the conductivity of the PCM, the PCM could not be maintained in the state of solid-liquid coexistence when the heating power exceeded a threshold.