Abstract
This paper presents the experimental study on the compressed air production from open channel flow with cross-flow water turbine. The water turbine combined with air compressor of linear-crank type is developed for utilizing unused small-scale hydropower at the existing water-use facilities to produce the compressed air. The compressed air is available for water aeration in order to restore the water quality in dam lakes. The turbine performance tests were carried out on two forms of the runner setting where the runner is lying or standing on the channel bed. Examinations are made on the effects of the water discharge on water elevation around the water turbine, the amount of compressed air and the efficiency of the system. The experimental results show that the lying turbine produces a larger amount of compressed air than the standing turbine when the hydropower of effective head exceeds 100 W. When the hydropower becomes less than 100 W, the standing turbine works well with high efficiency. The lying turbine has higher efficiency in a high hydropower range and keeps good efficiency in wide range of hydropower.
