Miniature loop heat pipes-a promising means for cooling electronics

Loop heat pipes (LHPs) are highly efficient heat-transfer devices, which have considerable advantages over conventional heat pipes. Currently, miniature LHPs (MLHPs) with masses ranging from 10-20 g and ammonia and water as working fluids have been developed and tested. The MLHPs are capable of transferring heat loads of 100-200 W for distances up to 300 mm in the temperature range 50-100°C at any orientation in 1-g conditions. The thermal resistance for these conditions are in the range from 0.1 to 0.2 K/W. The devices possess mechanical flexibility and are adaptable to different conditions of location and operation. Such characteristics of MLHPs open numerous prospects for use in cooling systems of electronics and computer systems.