An experimental study of boiling heat transfer enhancement of mesh-on-fin tubes

This study investigated a new enhanced boiling surface made by wrapping wire mesh on low-fin tubes. Pool boiling performance of the new enhanced tubes was tested with refrigerant 134a at 5, 10, and 26.67°C saturation temperature for 6-48 kW/m ² heat flux. Brass or copper mesh of 80, 100, or 120 mesh per inch was wrapped around finned tubes of 42, 50, or 60 FPI (fins per inch). The fin heights were either 0.2 mm or 0.4 mm. The test results show that mesh-covered fin tubes yielded significantly enhanced boiling performance. The influence of fin geometry is more pronounced with mesh than without mesh. The preferred mesh size decreases with decreasing heat flux. The surface made by wrapping brass mesh of 100 mesh per inch on 60 FPI tube having 0.4 mm fin height yielded the best boiling performance. It enhanced the boiling heat transfer coefficient by 3-8 fold at 5-26.7°C as compared with the smooth tube.