In the method for determining the effective thermal conductivity of a two-phase heat transfer device, the heat flux Q transmitted by the two-phase heat transfer device is measured. Determine the effective length Lэф of the two-phase heat transfer device as the distance between the centers of the evaporation and condensation sections. Find the difference between the average values of the temperature Te of the surface in the evaporation section and the temperature Tc of the surface in the condensation section. Determine the cross-sectional area A of the two-phase heat transfer device.
The value of the effective thermal conductivity keff is determined as the ratio of the product of the heat flux by the effective length to the product of the difference between the average values of the temperature Te of the surface in the evaporation section and the temperature Tc of the surface in the condensation section by the cross-sectional area A. Additionally, the length L is measured and the volume V of the two-phase heat transfer device is determined. The cross-sectional area A of the two-phase heat transfer device is determined as the effective area Aeff of its cross-section, the value of which is determined as the ratio of the value of the volume V of the two-phase heat transfer device to the value of its length L by the ratio Aeff=V/L. The effective thermal conductivity of a two-phase heat transfer device is calculated by the following relation: keff=Q-Leff/Aeff-(Te-Tc).