Experimental and analytical study of thermohydraulic performance of a novel loop heat pipe with an innovative active temperature control method

In this study, a novel type of LHP is innovated, fabricated, and its performance is assessed by numerous experiments. Compared to conventional LHPs, this novel design has some modifications in its evaporator and reservoir configuration. This particular type has a simpler and less costly fabrication procedure compared to other LHPs and it yields acceptable performance. Additionally, a novel method is introduced to control the temperature distribution in the system. A steel ball is placed in the evaporator to actively control the operating temperature. The ball is moved by two magnets installed outside of the evaporator. Moreover, a steady-state one-dimensional mathematical model of the fabricated LHP is developed and compared with experiments. This model is derived based on the energy balance equations in the horizontally installed setup. The average difference between modeling and experiment in calculation of evaporator casing temperature at different positions of the steel ball, from position No. 1 to position No. 5, is 2.2%, 3.7%, 2.5%, 3.8%, and 4.3%, respectively. Therefore, the modeling results are in good agreement with experimental data. In addition, the model can predict the effect of steel ball displacement on the variation of energy and fluid flow. Finally, the effects of heat sink temperature, ambient temperature and porosity of wick on the performance of LHP are studied by the validated model.