Performance and energy consumption study of a dual-evaporator loop heat pipe for chip-level cooling

The dual-evaporator loop heat pipe (DeLHP) exhibits more applications than a single-evaporator loop heat pipe in a chip-level cooling field. However, increasing the evaporators leads to a complex pipeline structure. This study focuses on developing and investigating a new parallel structure for the DeLHP. Experimental research was conducted to analyze the startup characteristics of DeLHP under single-load and dual-load conditions, and its operational characteristics under various variable power conditions. Numerical simulation was employed to analyze the fluid distribution and flow characteristics. The results indicate that heating the evaporator near the vapor pipeline achieves faster startup and more stable temperatures under a single load. Under dual loads, DeLHP exhibits a faster startup compared to a single load. When the thermal load near the vapor pipeline is greater than the load on the evaporator near the liquid pipeline, DeLHP starts faster and maintains a lower stable temperature. Under a maximum total load of 300 W, the heating surface temperature stabilizes below 80 ℃. The numerical simulation results indicate that when evaporator 1 near the liquid pipeline is individually heated, the temperatures, vapor fractions, and fluid velocities of the two evaporators are more balanced. The power usage effectiveness reaches a minimum value of 1.09 at 150 W. These research findings provide reliable and substantive support for the performance optimization of DeLHPs in practical applications.