A Study of R-113 Pool Flashing under Rapid Depressurization : 1st Report. Fundamental Experiment for Flashing Phenomena and Boiling Conditions

Abstract

The purpose of this paper is to investigate the fundamental features of R-113 pool flashing under rapid depressurization. Blowdown flashing of R-113 is initiated by the electro-magnetic valve opening and outflow of vapor from a pyrex glass vessel through the top orifice of designated diameter From the experimental results, it is remarked that the measured pressure variation in the vessel is characterized by a rapid decrease from the initial conditions to a level corresponding to the inception of flashing far below the saturation pressure and sevemal types of recovery by flashing. A two phase mixture yielded by its boiling spreads down from the vicinity of the free surface to the bottom of vessel. Furthermore, superheat limit of liquid R-113 under depressurization depends mainly on the depressurization rate in the present experiments. This limit of superheat corresponds to Gibbs number ; G_b≅22, according to the results of application of heterogeneous nucleation theory to our measured data.