Influences of Pin Geometry and Inclination Angle on Condensation Heat Transfer Performance of Elliptical Pin-Fin Surface

In present study, a new type of three-dimensional pin-fin plate with elliptical cross-section was proposed. Steam condensation on the proposed plates with different geometric parameter was experimentally studied at atmospheric pressure. The effects of horizontal pin spacing, pin height and inclination angle on condensation heat transfer were investigated. The results showed that all the elliptical pin-fin plates exhibited substantially better performance than the flat plate. The highest enhancement ratio of 2.33 was achieved when the elliptical pin-fin plate was vertically placed. The geometric parameter and inclination angle showed a strong influence on the performance of elliptical pin-fin plate. The performance of elliptical pin-fin plate was enhanced when the pin height increased from 1.2mm to 2.0mm or the horizontal pin spacing increased from 1.2mm to 2.0mm. The strengthening effect of pin height became weaker with the increase of horizontal pin spacing. When the inclination angle increased from 0 degrees to 60 degrees, the heat flux and average condensation heat transfer coefficient decreased by 16 and 25%, respectively. With the increase of inclination angle, the gravity effect in the direction of condensate flow decreased, resulted in the deterioration of heat transfer. The results can provide reference for practical engineering applications and the further optimization design of pin-fin enhanced condensation structure.