Studies on the Heat Transfer of Fluids at a Supercritical Pressure : 1st Report, A Proposition of Reference Values of Thermal Properties and Experiments with Supercritical Carbon-Dioxide

Abstract

A reference value of the thermal properties for a fluid at a supercritical pressure is proposed as, F=1/(tω-t∞)∫tωt∞F (t) dt where F : reference thermal property F (t) : thermal property as a function of temperature tω : wall temperature t∞ : bulk temperature. The heat transfer coefficient of a supercritical fluid can be determined by applying the reference value to an ordinary heat transfer formula for constant thermal properties. Experiments of heat transfer for carbon-dioxide at a supercritical pressure were made for three types of heat transfer, viz. (1) natural convection from a horizontal pipe, (2) natural convection from a vertical plate, and (3) forced convection from a circular pipe. The experimental result agrees with the proposed calculation.