| Popis: |
A multi-evaporator hybrid loop heat pipe (ME-HLHP), with a unique design modification enabling sub-ambient operation in a warm laboratory setting, was developed and successfully tested at heat loads up to 600W and saturation temperatures up to 30K below local ambient. The ME-HLHP architecture, which utilizes a remote, cold-biased, flow-through reservoir (linked to a secondary ”sweepage” evaporator) to provide the operational robustness of a loop heat pipe (LHP) and the temperature controllability of a capillary pumped loop (CPL), has the same limitations that LHPs and CPLs do when trying to cool a component significantly below the temperature of its surroundings. In general, when a two-phase loop is operated in a warm environment, liquid returning to each evaporator must be protected from conductive, convective, and radiative heat leaks. If the liquid line is not sufficiently protected, a loss of subcooling may ensue that could lead to suboptimal loop performance, such as higher operating temperatures (due to autoregulation) in LHPs, higher than necessary sweepage power in HLHPs, or possible deprime in CPLs. To maximize loop robustness, a unique design feature known as the liquid cooled shield (LCS) was incorporated into the ME-HLHP architecture to protect the liquid return line from parasitic heat gains. This paper describes the background, design and test results of ME-HLHP for compact Laser applications. |
