The influence of plate corrugations geometry scale factor on performance of plate heat exchanger as condenser of vapour from its mixture with noncondensing gas

Abstract

The condensation of steam from a steam-air mixture is studied experimentally at three samples of Plate Heat Exchanger (PHE) channel. For three test samples corrugations are similar but differ in scale with the height 5, 7.5 and 10 mm. The results of tests are compared to calculations with one dimensional mathematical model of the process. The identification of correlations for local heat and mass transfer coefficients, as also friction factor in condensing two-phase flow, is made by comparison of computed results with tests data. The correlations for condensing two-phase flow are based on single-phase correlations for considered channels. For mass transfer coefficients, the best results are obtained using a stagnant film model for accounting transverse mass flux influence. For the prediction of pressure losses in two-phase condensing flow, the correlation with Lockhart-Martinelli parameters is used for zones of low liquid flow rates. For other channelzones are proposed its combination with an equation based on a dispersed annular model of flow structure. The presented equations can be used for calculation of heat and mass transfer intensity and pressure losses in two-phase condensing flow when designing PHE for condensation of steam from its mixture with air by local process parameters.