A loop heat pipe (LHP) is a two-phase heat transfer device that uses the latent heat of vaporization of a working fluid for heat transfer. Due to their inherent robustness, LHPs are ideal candidates to meet the ever increasing thermal challenges facing the electronics and spacecraft industries. Through miniaturization, LHPs have the potential to efficiently transport, spread, and dissipate heat in advanced electronics packages where the heat dissipation is rapidly increasing with decreasing volume.; In this study, three LHPs were designed, manufactured, and tested to help gain the knowledge necessary for developing smaller and more efficient designs for use in future Canadian space missions. A detailed development process was discussed and included initial design criteria and selection, material preparation and treatment, assembly, evacuation, charging, and sealing. A series of tests were conducted to investigate the thermal performance characteristics of each unit. Tests were performed under ambient conditions to study the effect of fluid inventory on LHP start-up, steady-state operating temperature, effective thermal resistance, and overall heat transfer coefficient. Alternate configurations were investigated to measure the effect of orientation and periodic heating on thermal performance. LHP operation was also examined for temperature hysteresis during rapid power variations.; Numerical models were developed to aid in the design phase of the study by estimating the properties of various working fluids, calculating fluid inventory, and sizing the compensation chamber. The models also provide the foundation for future work on a 1-D steady state solver to predict operational characteristics such as steady-state temperatures, system pressure drop and mass flow rate for any given design.
展开▼
