Analysis of the Physical Characteristics of Helical Heat Exchangers for Reducing CO2 Emissions into the Atmosphere

This research aims to analyze heat transfer behavior and evaluate the potential for reducing carbon dioxide emissions of elliptical cross-section helical coil heat exchangers. The study employs experimental testing and computational fluid dynamics (CFD) simulations under constant surface temperature conditions. The investigation focuses on the influence of physical characteristics, particularly the percent ovality (δ) and the hydraulic diameter to coil diameter ratio □(D_h/D_coil ) on heat transfer efficiency. Empirical results demonstrate that helical coils with high δ values (66.67%) and smaller surface areas exhibit higher heat transfer coefficients and Nusselt numbers. A mathematical model in the form of Nu=0.0327〖De〗^0.8595 〖Pr〗^0.4 was developed, achieving a correlation coefficient of 99.04%. Furthermore, exergy analysis reveals that the optimized design can reduce carbon dioxide emissions by up to 175.54 kg per year per unit, assuming 8-hour daily operation. These findings can be applied to the development of high-efficiency, environmentally friendly air conditioning systems for buildings and residences, aligning with greenhouse gas emission reduction targets set by the Paris Agreement.