Dynamic thermal heat pipes analysis: Thermal impedance in start-up condition

Heat dissipation is one of the most important issues for electronics development. Heat pipes are one of the most efficient heat transporting devices on the market. This paper presents a dynamic analysis of a heat pipe in start-up condition. Through a theoretical analysis, an appropriate RC thermal model is proposed. From the proposed RC model network, the temperature is calculated and the thermal impedance Nyquist plot is obtained. In order to validate the theoretical results several experimental measurements are conducted. In an arrangement including a heat pipe, a power step input is applied and the temperature is measured at the heat source. From the measured temperature, the thermal impedance Nyquist plot is calculated and is juxtaposed with the one calculated from the proposed RC model network. From the comparison, the proposed RC model network is validated and the observed phenomena from the experimental measurements are explained. Thermal impedance Nyquist plot obtained from the experiments was calculated.