| 摘要 |
PURPOSE:To make a leak of water into a runner chamber eliminable in time of runner's starting in air, by installing a cylinder gate, capable of cutting off a flow passage entirely, in the flow passage at the upstream side of a runner. CONSTITUTION:A cylinder gate 18 is brought down to a fully-closed position, while a low pressure step movable guide vane 12 is fully opened. Next, a drain valve 28 is opened, while air feed and release valves 23 and 25 are fully opened, feeding both air feed and release pipes 22 and 24 with compressed air, and each water level of both a maximum pressure killing chamber 8 and a minimum pressure killing chamber 9 is pressed down to some extent. Like this, in time of runner's starting in air, a flow passage at the upstream side of a runner 2 in a maximum pressure step part of the cylinder gate 18 is made so as to be fully closed whereby the cylinder gate 8 is brought downward, so that a leak of water into a runner chamber from the side of a casing 13 comes to almost nothing. |
