Reversible Counter-Rotating Type Hydroelectric Unit for Tidal Power Station

摘要

To cope with the warming global environments, the authors haveproposed the counter-rotating type hydroelectric unit. This unit maytake place of the traditional bulb type turbines, and is suitable for notonly the hydropower on the land but also the tidal power in the ocean.This paper discusses the effects of the setting angles of the front and therear runner blades on the turbine performances, and presents theoptimum setting angles at the on-cam operation, which is applicable tothe gradual change of the tidal head at the large power station. Themaximum output or the maximum efficiency is got at the larger unitdischarge with the decrease of not only the blade number but also theblade setting angle. The on-cam hill chart gives the optimum bladesetting angles to operate the unit at the specified efficiency or output.Besides, the runner blades were modified to get the fruitful output fromnot only the rising but also the falling tides at the power station with thedam/weir/sluice. The performances against the relative rotational speedhave almost the same profiles as those of the normal runners and themaximum hydraulic efficiency is compared favorably with that of thenormal runners.