Design and Verification Experiment of Small Loop Heat Pipe with Two Evaporators and Two Condensers Part І－Under Atmospheric Condition

Abstract

In this work, a small multiple loop heat pipe with two evaporators and two condensers was designed and fabricated for thermal vacuum test with the working fluid ammonia. Then the verification experiment was conducted under atmospheric condition. The pressurized test was also done to make future thermal vacuum experiment plausible. The primary wick was made of stainless steel. Secondary wick and flow regulator were also employed in this small multiple loop heat pipe to improve its operating characteristics. Two kinds of verification tests were carried out in atmospheric condition with the working fluid acetone. In the test that two evaporators were heated, both of the evaporators were found to start up at 10/10 W and transport 160 W in total (80 W from each evaporator to each radiator) for about 1.5 m. In another test that only one evaporator was heated, one evaporator transported 80 W for 1.5 m, while the other evaporator transported 120 W for 1.5 m. Since ammonia will be used as the working fluid in the thermal vacuum test which is to be performed in the future, the pressurized test was performed and verified that the small multiple loop heat pipe can tolerate ammonia's high saturation pressure.