Thermal performance of LHSU for electronics under steady and transient operations modes

•A lower base temperature of LHSU is achieved at ψPCM=1.0.•n-Eicosane gains higher increase in temperature after 120mins resulting reduces the latent heating duration.•A maximum enhancement in operation time is found at lower input as 124.75mins at 1.6kW/m2.•A maximum enhancement ratio of 6.20 is obtained at input flux of 1.6kW/m2 for SPT of 40 °C.•Increasing the operation cycles resulting decrease the base temperature of PCM based LHSU. This experimental study investigates the effect of passive cooling of electronic devices using a latent heat storage unit (LHSU) filled with n-eicosane as phase change material (PCM),under steady-state and transient heating operations. A pin–fin heat sink of square configuration, made of aluminum, pin-fins acted as a thermal conductivity enhancers (TCEs), is used to augment the rate of heat transfer through n-eicosane which has low thermal conductivity. A range of input heating loads from 1.2–2.8kW/m2 with an interval of 0.4kW/m2 are applied at the base of LHSU, filled at three different volumetric fractions of n-eicosane, to quantify the steady-state and transient heat transfer characteristics for different operation modes for reliable passive cooling of electronics. The results are reported under two phases i.e. steady-state and transient heating, and thermal performance of LHSU is elucidated in terms of enhancement in operation time, enhancement ratio, effect of PCM amount and various usage modes under different heating loads.