RESUMO

This paper presents the results of an investigation of heat transfer and hydrodynamics during the condensation of water vapor in a narrow gap condenser of a loop heat pipe. The length of the condenser was 80 mm. The cross section measured 40 × 1.1 mm. Instrumental investigations and visual observations of the condensation process in the condenser with and without longitudinal guide insertions were carried out. The investigations were conducted at a condenser cooling temperature from 60 to 95° C. During all operating parameters a stratified two-phase flow and film condensation were observed. The temperature field in the condenser and the heat-transfer coefficients were measured. The heat-transfer coefficients in the condenser without the insertions were in the range from 21 to 46 kW/(K·m²), with the insertions from 42 to 88 kW/(K·m²).