Multi-stage hydraulic machine and control method for a multi-stage hydraulic machine
AssigneeTokyo Shibaura Denki Kabushiki Kaisha
InventorsSachio Tsunoda, Shinsaku Sato
Life of this patent
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Abstract
A multi-stage hydraulic machine comprises a rotatable shaft, a plurality of runners fixed to the shaft and arranged from a highest-pressure stage to a lowest-pressure stage, runner chambers which, respectively, house the runners, a return channel for connecting adjacent ones of the runner chambers with each other, movable wicket gates provided at least in the highest-pressure stage and capable of moving between a position in which the movable wicket gates block the channel and a position in which the movable wicket gates open the channel, a casing connected to the highest-pressure stage, and an inlet valve disposed between the casing and a penstock.
Claims8
A control method for a multi-stage hydraulic machine which comprises a rotatable shaft;
- a plurality of runners fixed to said shaft and arranged from a highest-pressure stage to a lowest-pressure stage;
- runner chambers which, respectively, house said runners;
- a return channel for connecting adjacent ones of said runner chambers with each other;
- movable wicket gates provided at least in said highest-pressure stage and capable of moving between a position in which said movable wicket gates block the channel and a position in which said movable wicket gates open the channel;
- a casing connected to said highest-pressure stage, and an inlet valve disposed between said casing and a penstock, said method comprising
- a first step of causing said movable wicket gates and said inlet valve to block the channel;
- a second step of feeding air to an upper portion of a draft tube which is connected to a lower portion of said lowest-pressure stage after the channel is substantially blocked by said movable wicket gates;
- a third step of discharging water in said return channel and said lowest-pressure stage runner chamber adjacent thereto through a lowest-pressure stage drain pipe after a water level in said draft tube is lowered to a predetermined value;
- a fourth step of discharging water in said highest-pressure stage runner chamber to said draft tube through a highest-pressure stage drain pipe after a pressure in said highest-pressure stage runner chamber is lowered below a predetermined pressure;
- and
- a fifth step of interrupting the operation of air-feeding in said second step after the water level in said draft tube is stabilized at a predetermined value.
The control method for a multi-stage hydraulic machine according to any one of the preceding claims, further comprising a seventh step of feeding the air to that part of said return channel which is located in a lower portion of the runner chamber of each stage, before said third step and after said second step.
A multi-stage hydraulic machine which comprises
- a rotatable shaft;
- a plurality of runners fixed to said shaft and arranged from a highest-pressure stage to a lowest-pressure stage;
- runner chambers which, respectively, house said runners;
- a return channel for connecting adjacent ones of said runner chambers with each other;
- movable wicket gates provided at least in said runner chamber of the highest-pressure stage and capable of moving between a position in which said movable wicket gates block the channel and a position in which said movable wicket gates open the channel;
- a casing connected to the runner chamber of the highest-pressure stage;
- an inlet valve disposed between said casing and a penstock;
- a draft tube connected to the runner chamber of the lowest-pressure stage;
- first air supply means connected to the upper portion of said draft tube, for feeding air thereto after said movable wicket gates substantially block the channel;
- a first drain pipe connected between the runner chamber of highest pressure-stage and the draft tube, having a first drain valve which is opened after a pressure in the runner chamber of the highest-pressure stage is lowered below a predetermined pressure;
- and
- a second drain pipe connected between the runner chamber of the lowest-pressure stage and the draft tube, having a second drain valve which is opened after a water level in said draft tube is lowered to a predetermined value.
Dependencies are inferred from the claim text.