Study of Meandering Closed-Loop Heat-Transport Device : Vapor-Plug Propagation Phenomena

Abstract

In the present paper, heat transport rates and fluid flow patterns of the meandering closed-loop heat-transport device (MCL-HTD) were experimentally and analytically investigated by using water as an operating liquid. MCL-HTD consists of a closed-looped-tube meandering between heating and cooling parts with operating liquid of a volume fraction in it. First, the effective thermal conductivity of the MCL-HTD was measured, which showed much higher value than that of copper. Next, observation of fluid flow in the MCL-HTD was conducted, and a simple periodic flow pattern appeared at a high value of volume fraction of liquid. This periodic flow pattern was numerically analyzed by a model, and the flow pattern induced liquid flow from the heating to cooling parts or contrariwise. Such liquid flow results in large temperature differences between the liquid and tube wall at the heating and cooling parts.