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Loop Heat Pipe (LHP) technology has advanced to the point that LHPs are baselined for thermal control systems in many spacecraft applications. These applications typically utilize a loop heat pipe with a single evaporator. However, many emerging applications involve heat sources with large thermal footprints, or multiple heat sources that would be better served by LHPs with multiple evaporators. Dual evaporator LHPs with separate reservoirs for each evaporator have been successfully developed, but the volume and weight of such systems become impractical as the number of the evaporators increase to more than three or four. Other investigators have proposed systems containing several evaporators that are coupled to a common reservoir with a conduit to contain a capillary link (secondary wick). This approach places several restrictions on the relative location of the evaporators due to the limitation of the capillary link.

In typical loop heat pipe (LHP) applications, the LHP design calls for a dedicated evaporator and a dedicated condenser. Applications exist for reversible loop heat pipes (LHPs), which can transport heat in either direction. In the reversible LHP design, two evaporator pumps are plumbed together, one which acts as an evaporator while the other acts as a condenser. The two pumps can reverse roles, simply by reversing the temperature gradient across the loop. Thus, either pump can be used as an evaporator or a condenser, depending upon the environment. Reversible LHPs can be used to share heat between components, or to cross-strap opposing spacecraft radiators. A reversible LHP was built and tested to demonstrate feasibility and to characterize its performance capabilities and attributes. The device was tested by either alternately heating each evaporator electrically or by inducing a temperature difference between the two ends of the device.

Loop Heat Pipe (LHP) technology has advanced to the point that LHPs are baselined for thermal control systems in many spacecraft applications. These applications typically utilize a loop heat pipe with a single evaporator. However, many emerging applications involve heat sources with large thermal footprints, or multiple heat sources that would be better served by LHPs with multiple evaporators. Other investigators have proposed systems containing several evaporators that are coupled to a common reservoir; however, this approach places severe restrictions on the relative locations of the evaporators. This paper describes a multiple evaporator loop heat pipe, with a separate reservoir for each evaporator, which can accommodate payloads with large or spatially separated heat sources.