Experimental Study of Underground Irrigation by Condensation of Humid Air in Perforated Pipes

A small scale Condensation Irrigation (CI) system was constructed to investigate the flow patterns of water, air and heat in the soil surrounding a perforated pipe from which water, heat and humid air was transferred. A 0.2 m long cross-section of sand and pipe was used to emulate a two-dimensional section of a CI system. Under these downscaled conditions, the mean irrigation rate in the sand box was 1.03 mm d-1. The major heat transfer mechanism in the sand profile was gas advection, which greatly reduced the sand temperature around the pipe.Nearly 50% of the vapour leaving the airflow inside the pipe, was transported to the sand surface by gas advection.Godkänd; 2012; 20121105 (jeli