A study on effective use of heat transfer additives in the process of steam condensation

It is well known that the additives in absorption chillers play a significant role in increasing absorber performance. Realizing that the additives in absorption chillers circulate throughout the system including the condensers, we investigated the effect of additives in the condenser. Reported herein are the results of the experimental and theoretical investigations done by using effective heat transfer additives for enhancing heat transfer coefficient in condensation of steam over a horizontal copper (99.9% Cu, 0.1% P) tube surface. By using effective additives, the condensation heat transfer coefficient can be enhanced as much as 1.47 times when compared to filmwise condensation. The steam condensation, which occurred in our experiments while using effective additives, was mostly pseudo-dropwise like. In our experiments, we noted that the use of heat transfer additive such as 2-ethoxyethanol for steam condensation was highly effective. This increase in heat transfer coefficient can be attributed to concept of Marangom effect. It is understood that this surface convection is caused by local variations in the interfacial tension. So far there has been very little noted literature available on the theoretical aspect of surface tension effect on enhancing heat transfer rate in steam condensation. In the current research we try to explain the surface tension effect for enhancing beat transfer rate in steam condensation using effective heat transfer additives. (c) 2006 Elsevier Ltd and IIR. All rights reserved.