NUMERICAL-ANALYSIS OF COMPACT AIR CONDENSERS

The present work aims at analysing the thermal behaviour of the vapour flow inside the horizontal tube bundle of a cross-flow air condenser. It is pointed out that the steady-state air and water temperature dis tribution cannot be determined by means of analytical solutions, due t o the non-linearity of the problem. A model based on appropriate balan ce equations is introduced and a finite difference computer code is fo rmulated. This code, which reports a large number of correlations foun d in the literature, is used to evaluate the different flow patterns t hat characterise the two-phase flow condensation. It is also employed to calculate the local heat transfer coefficient, for both air and wat er side, and the pressure drop on the water side. The main results, re lated to the evaluation of the condenser's thermal-hydraulic behaviour (pressure and temperature of the condensing fluid), are presented and discussed in detail.