Experiment and predictions of capillary limits for integrated plate heat pipes

摘要

The capillary effect of grooves in the integrated plate heat pipe was investigated experimentally. Various capillary grooves, having 0.5, or 1.0 mm depth were made in 1.25 mm or 2.5 mm pitch on an aluminum or brass plate to form integrated plate heat pipes with a gap of 0.5-to-2.5 mm. Temperatures were measured to determine the thermal resistance. Visualization experiments were also conducted to observe the liquid-vapor interface in the capillary grooves through a glass cover plate. Capillary grooves of trapezoidal or triangular shape of 30, 45, or 60 degree groove angle were tested. Methanol or HFC4310 was the working fluid with 25-to-75% charge volume fractions for the aluminum heat pipes, and water was charged in the brass heat pipes with 1 3-to-50% volume fractions. The effects of groove angle, charge volume fraction, gap size, and working were found experimentally. A predictive correlation of maximum heat transport capacity (Q{sub}(max)) was developed, and it predicted the present brass-water heat pipe performance within ±30%.