THERMAL HYDRAULIC BEHAVIOUR OF FEED-WATER PREHEATER THEORETICAL AND EXPERIMENTAL ANALYSIS
Accumulation of non-condensibles seriously affects the performance of feed water preheaters, thereby influencing also the availability of the plant, due to the consequences of extended tube corrosion in the presence of air blanketing. Only a detailed 2D or even 3D analysis of the steam flow, providing the spatial distribution of condensation rate, of pressure, and of the concentration of non-condensibles, may identify the adequacy of the equipment or system proposed for the extraction of non-condensibles. In the paper, the characteristics of the computer programs allowing the detailed, local analysis of .the condensing zone of feed water preheaters, are described, referring to heat exchangers with segmented baffles (C0ND3), with vertical or horizontal axis. The experimental results obtained during a first campaign of qualification of the computer programs are also reported, with a specific reference to a segmented-baffle type heat-exchanger. The fluid utilized in condensation is R12.