International. In a study by researchers from the Department of Mechanical and Aeronautical Engineering at the University of Pretoria in South Africa, numerical simulations of R134a condensation were made inside a smooth inclined tube.
The effects of different parameters such as saturation temperature, tube tilt angle, steam quality and mass flow, on variations in condensation heat transfer coefficient and pressure drop along the tube were investigated. The simulations were performed at a uniform heat flow of 5050 W / m2, mass flows of 100-400 kg / m2, saturation temperatures of 30-50 ° C, steam qualities of 0.1-0.9 and inclination angles of -90 to + 90 °.
The flow field was supposed to be three-dimensional, transient, and turbulent. The volume of the fluid model was used to solve the governing equations. Simulated results for condensation heat transfer coefficient and pressure drop showed a good correlation with the available experimental data.
The results also showed that the coefficient of condensation heat transfer and pressure drop along the tube increased with the decrease in saturation temperature and the increase in the flow and steam qualities of the mass. It was also determined that there was an optimal tilt angle range, -30 to -15 °, in which the condensation heat transfer coefficient reached a maximum value.
Source: www.sciencedirect.com
