Research on the Law and Mechanism of Condensation in High‐Temperature Steam Pipes

Abstract Desalination is crucial for addressing freshwater shortages, particularly in coastal cities. However, the specific mechanism and kinetics of droplet condensation in pipes remain unclear. This study employs a coupled VOF‐Lee model in Fluent to investigate steam condensation in a straight tube inclined at 10.00°, under constant wall temperature, steam flow rate, and temperature. The research analyzes droplet distribution, contact angle changes, and maximum droplet center pressure. Results show a positive correlation between droplet equivalent diameter and distance from the pipe inlet. As condensation stabilizes, this correlation remains, while the maximum droplet center pressure negatively correlates with droplet size. When the equivalent diameter exceeds 3.50 mm, the maximum center pressure stabilizes at 60.00 Pa. Additionally, droplets with diameters between 1.50 and 3.50 mm maintain a contact angle of 80.00°, reducing downward flow and lowering condensation efficiency. The study further supports droplet jumping and fusion theory. Industrially, enhancing condensation conditions in the early stage can increase the proportion of droplets exceeding 3.5 mm, improving overall condensation efficiency.