Modeling the condensation heat transfer coefficient of alcohols in the presence of a non-condensing gas on horizontal plain and low-finned tubes

This study examines design methods for condensers with horizontal low-finned tubes in the presence of non-condensing gases, with the aim of applying them to the chemical industry. Although low-finned tubes can significantly enhance condensation heat transfer, research addressing their use in the chemical industry is scarce. Existing design methods are primarily validated for the condensation of refrigerants and water. This article discusses relevant calculation methods from the literature and addresses their suitability for designing heat exchangers in the chemical industry. The models are thoroughly derived and their performance is evaluated with a focus on available mass transfer correction factors, using heat transfer measurements with isopropanol in the presence of nitrogen, which are introduced in this study. For the first time, we demonstrate that an additional correction of the mass transfer coefficient is essential for precisely modeling the condensation heat transfer in the presence of a non-condensing gas. When an appropriate mass transfer correction is applied, the non-equilibrium model by Colburn and Drew 1937 aligns well with the experimental data. The diffusion layer model of Peterson et al. 1993, which is primarily used in nuclear engineering for the condensation of water in the presence of air, predicts comparable heat transfer coefficients. Thus, it provides a simpler yet reliable alternative for designing heat exchangers involving non-condensing gases in the chemical industry. • Measurement data on the impact of nitrogen on the condensation heat transfer. • Detailed derivation of the non-equilibrium model and the diffusion layer model. • Mass transfer correction is vital for accurate heat transfer modeling. • Good agreement between models and measurements.