Experimental study of a dual-evaporator flat loop heat pipe with a triply periodic minimal surface wick structure

Triply periodic minimal surface (TPMS) structures have the potential to be applied in loop heat pipe wicks due to their ability to enhance heat and mass transfer. This study experimentally investigates a dual-evaporator flat loop heat pipe (DE-FLHP) with a TPMS-structured wick. The influence of the filling ratio, heating mode, cooling water inlet temperature (T _cool), and flow rate (m _cool) on the steady-state performance was examined. The evaporator and condenser temperature distributions, pressure variations, working fluid circulation characteristics, and thermal resistances were analyzed. Sobol sensitivity analysis was employed to quantify the contribution of each parameter to DE-FLHP behavior and the multi-parameter coupling effects. The results show that the DE-FLHP exhibits excellent thermal performance. A 50% filling ratio maintains stable liquid-vapor circulation at a lower saturation pressure and yields the lowest thermal resistance. Double-sided heating mode symmetrically redistributes the heat flux to form a uniform evaporator temperature field, reducing the evaporator temperature difference by 81.2% and decreasing the operating pressure by 15.9%. Increasing m _cool improves condenser heat transfer at low power, while evaporation limits performance at high power. Additionally, an increase in T _cool reduces the driving temperature difference between the evaporator and condenser, resulting in an average operating pressure increase of 12.7%. Sensitivity analysis indicates that heating power is the main factor affecting the performance of DE-FLHP, contributing over 92% to the variations in evaporator temperature and thermal resistance, while insufficient cooling capacity amplifies the adverse effects of high heat input. This study may provide guidance for the design optimization and practical operation of LHPs based on TPMS-structured wicks.