Two-Phase Flow Heat Exchangers

Abstract

Approximately 60% of heat exchangers in industrial use are working in a twophase flow mode. They are used in the power and process industry as well as in air conditioning, in refrigerating, and in food production. Mostly the latent heat of evaporation of a vapour-liquid mixture is used to improve the transport capacity and also to enhance the heat transfer process. After discussing different criteria and possibilities classifying two-phase flow heat exchangers, their design and application, some examples of modern design in heat exchangers with phase change, are presented. Finally thermo- and fluiddynamic phenomena are briefly discussed which have major influence on the design and the operational performance of two-phase flow heat. exchangers. The paper intends to give an introduction to the followin'lj'1ectures and papers dealing with the design of special two-phase flow heat exchangers and their heat transfer calculation in detail.