The Role of Orifice and Noncondensable Gas Bubbles on Two-Phase Natural Circulation

Abstract

The role of orifice and non-condensable gas on the two-phase natural circulation in a horizontal heating-vertical condensing figure of zero loop has been studied experimentally. Experimental results show that, the flow observed during the natural circulation is oscillating flow. The frequency of oscillation, net flow rate and heat removal capability in vertical section, are significantly influenced by the presence of the non-condensable gas and the orifice in the loops. Possible mechanism leading to this experimental observation is discussed.