Pressure Drops in Supercritical Boilers : 1st Report, Static Characteristics of Friction Pressure Drop

Static and dynamic characteristics of pressure drop in supercritical pressure boilers were studied. In this paper, experimental results of static pressure drop of CO2 at supercritical and relatively high subcritical pressures in a heated test tube were presented, and effects of various factors such as flow rate, heat flux, inlet temperature, and pressure were discussed. The calculated results by numerical integration using the friction coefficient of single phase flow agreed with the experimental results. The experimental results were well correlated by the dimensionless expression of pressure drop previously reported. This means that the results obtained by this CO2 experiment will be also applicable to the case of working fluid of H2O. Mean friction coefficients of supercritical fluid in the whole tube length were shown and an empirical equation of the coefficient for the heat flux was proposed.