Heat Transfer Characteristics of an Earth Probe Model for a Ground-Source Heat Pump. Experiments on Forced Convection Boiling Heat Transfer in a Vertical Double Tube:the Case of Small Flow Rate.

Abstract

An experimental investigation was conducted to determine the heat transfer characteristics of HCFC-22 for a two-phase double tube connected to a heat pump. This study focussed on the forced convection boiling heat transfer of small flow rate in a double tube. It was clarified that the quality at the dry-out point increases as mass velocity increases, and that the heat transfer coefficient of two-phase flow is about 30 times as large as that of the liquid single-phase laminar flow. Furthermore, it was found that the heat transfer performance of the double tube is superior to that of a single tube.