Analytical thermal hydraulic model for oscillatory condensation of steam in presence of air

An analytical thermal hydraulic model has been developed from fundamental conservation laws, for the process of oscillatory condensation of steam in a pool of water, in presence of non-condensable gas (air). The oscillatory condensation phenomena addressed here is steam chugging, with an emphasis laid on studying the effect of small amount of air present in steam, on the phenomena. The objective of developing the model is to present an approximation of the real phenomena and to obtain an analytical solution. At the outset, a parametric study was conducted by using the developed model to capture and identify the salient features of steam chugging and compare the wave shapes obtained with those available in open literature. Subsequently, the effect of presence of air in steam was studied in detail using the non-condensable gas model. An attempt has been made to show numerically that the presence of a small amount of air in steam would effectively stabilize condensation and prevent inception of chugging. Typical results are presented in this paper to bring out the difference in oscillatory behavior due to presence and absence of non-condensable gas.