Multiple loop heat pipe is a high-functional thermal transport device. This work was conducted to confirm the working performance of Multiple loop heat pipe under thermal vacuum ambience with the working fluid ammonia. Asmall multiple loop heat pipe with two evaporators and two ra- diators was designed and fabricated. Then thermal vacuum test was conducted. The heaters were fasten on both evaporators, both radiators, both compensation chambers. In the case that both evaporators were heated, the multiple loop heat pipe can transport 120/120 W for 1.5 m, in the case that only one evaporator was heated, evaporator 1 can transport 80 W for 1.5 m, while eva- porator 2 can transport 120 W for 1.5 m. Two flow regulators were installed near the confluence of liquid line to prevent uncondensed vapor penetrating into returning liquid when the tempera- ture difference exists between two radiators. In the case that the heat load at both evaporators were 40/40 W and one radiator was heated, the flow regulator1 can tolerate the 160 W of heat load which was supplied to radiator1 while the flow regulator2 can tolerate the 100 W of heat load which was supplied to radiator2. To demonstrate the multiple loop heat pipe’s startup behavior at lowheat load, each of the compensation chamber was preheated to change the initial distribution of liquid and vapor in the evaporator and compensation chamber, in the result, each evaporator can start up at 5W through preheating.
[1]
Ku, J. (1999) Operating Characteristics of Loop Heat Pipes. Proceeding of 29th International Conference on Environmental System, Denver, 12-15 July 1999.
http://dx.doi.org/10.4271/1999-01-2007
[2]
Baker, C., McCarthy, T. and Grob, E. (2004) Geoscience Laser Altimeter System (Glas) Loop Heat Pipes—An Eventful First Year On-Orbit. Proceeding of 34th International Conference on Environmental Systems, Colorado Springs, 18-22 July 2004.
[3]
Bienert, W.B., et al. (1997) The Proof-of-Feasibility of Multiple Evaporator Loop Heat Pipes. Proceedings of the Sixth European Symposium on Space Environmental Control Systems, Noordwijk, 20-22 May 1997, 393-398.
[4]
Hoang, T.T. and Ku, J. (2004) Mathematical Modeling of Loop Heat Pipes with Multiple Capillary Pumps and Multiple Condensers Part I-Steady State Simulations. Proceedings of the AIAA, 2nd International Energy Conversion Engi-neering Conference, Providence, 16-19 August 2004.
[5]
Hoang, T.T. and Ku, J. (2005) Mathematical Modeling of Loop Heat Pipes with Multiple Evaporators and Multiple Condensers. Proceedings of the 3rd International Energy Conversion Engineering Conference, San Francisco, 15-18 August 2005.
http://dx.doi.org/10.2514/6.2005-5682
[6]
Ku, J., Ottenstein, L. and Douglas, D. (2008) Multiple-Evaporator Miniature Loop Heat Pipe for Small Spacecraft Thermal Control. Proceedings of the 49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference, Schaumburg, 7-10 April 2008.