| 摘要 |
PURPOSE:To make it possible to operate a multi-stage hydraulic machine with the total efficiency being mainained to be high, by controlling the water inlet opening edegree of the lowest pressure stage movable guide vanes to be less than that of the other stage movable guide vanes. CONSTITUTION:When the control turning point A which is set within a range from 50 to 70% of the output power P is not exceeded, high pressure stage movable guide vanes 15 are subjected to the open-and-close control along the output characteristic curve B, and low pressure stage movable guide vanes 16 are subjected to the open-and-close control along the output characteristic curve C. When the control turning point A is exceeded, all stage movable guide vanes 15, 16 are simultaneously controlled along the output characteristic curve D. With this arrangement, in a load reduction range, the water-head alotting rate of the lowest stage increases while the opening degree of the lowest pressure stage movable guide vanes 15 is controlled to be always less than the opening degree of the other movable guide vanes 15, and operation is made in a stable range in which the unit rotational speed is small and which is near the highest efficiency. |
