Loop thermosyphons for cooling of electronics

Recent innovations to loop thermosyphon (LTS) design are anticipated to have a significant impact on electronics thermal solutions. Future electronics systems including high-density desktop computers, multi-processor rack mounted servers, and telecommunications cabinets are reaching volumetric thermal densities beyond the limits of direct air-cooling. Therefore, alternative cooling solutions need to be developed, for example, using loop thermosyphons. This paper presents experimental data obtained on two innovative loop thermosyphons with capillary structures that are prime candidates for electronics cooling solutions to replace typical air-cooled systems, where commercially available heat pipes cannot be used due to the high power and transport length limitations. The performance characteristics of the two loop thermosyphons with capillary structures are discussed: (a) with a horizontal square U-tube evaporator and (b) with horizontal transport lines and a flat evaporator heated from both sides.