Startup characteristics of a dual compensation chamber loop heat pipe with an extended bayonet tube

Dual compensation chamber loop heat pipe (DCCLHP) is an advanced two-phase heat transfer device, which features an orientation-free operation in the terrestrial surroundings and promises great application potential in the aircraft thermal management. In this work, a DCCLHP with an extended bayonet tube was designed and fabricated, aiming to improve its startup performance especially at a small heat load. The startup characteristics of the DCCLHP in five different orientations was experimentally investigated and theoretically analyzed. According to the experimental results, some important conclusions have been drawn: 1) The DCCLHP with an extended bayonet tube could achieve successful startup under the heat load ranging from 10 to 100 W in the horizontal orientation, and no startup failure occurred. 2) The DCCLHP could start up successfully even at a small heat load of 10 W from -90° to +90° tilt angle in the terrestrial surroundings. 3) Different startup phenomena such as the unique change of the temperature overshoot were observed in the experiments. 4) Operating instability such as the temperature oscillation occurred during the startup process in the favorable directions.