Startup method of francis turbine and francis turbine

Patent metadata

Field	Value
Publication number	US-11566597-B2
Application number	US-202117351366-A
Country	US
Kind code	B2
Filing date	Jun 18, 2021
Priority date	Jun 19, 2020
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

A startup method of a Francis turbine according to an embodiment includes: a first rotation-speed increasing step in which a rotation speed of the runner is increased by opening the guide vane at a first opening; a second rotation-speed increasing step in which the increase in the rotation speed of the runner is accelerated by opening the guide vane at a second opening that is larger than the first opening after the first rotation-speed increasing step; and a rotation-speed regulating step in which the rotation speed of the runner is regulated to a rated rotation speed by opening the guide vane at a no-load opening after the second rotation-speed increasing step. The first opening is an opening that is half or less than the no-load opening.

First claim

The invention claimed is:

1. A startup method of a Francis turbine comprising a guide vane capable of regulating a flow rate of water to be guided to a runner, the startup method comprising:
a first rotation-speed increasing step in which a rotation speed of the runner is increased by opening the guide vane at a first opening;
a second rotation-speed increasing step in which the increase in the rotation speed of the runner is accelerated by opening the guide vane at a second opening that is larger than the first opening after the first rotation-speed increasing step; and
a rotation-speed regulating step in which the rotation speed of the runner is regulated to a rated rotation speed by opening the guide vane at a no-load opening after the second rotation-speed increasing step,
wherein the first opening is 50% or less than 50% of the no-load opening.

2. The startup method of a Francis turbine according to claim 1 , wherein:
in the first rotation-speed increasing step, the rotation speed of the runner reaches a first rotation speed; and
the first rotation speed is a rotation speed that is 30% or more of the rated rotation speed, or a difference between a peripheral speed of an outer circumferential part of the runner at the rated rotation speed and a peripheral speed of the outer circumferential part of the runner at the first rotation speed is 50 m/sec or less.

3. A Francis turbine comprising:
a runner;
a guide vane capable of regulating a flow rate of water to be guided to the runner; and
a control unit that controls the guide vane,
wherein the control unit controls the guide vane to perform:
a first rotation-speed increasing step in which a rotation speed of the runner is increased by opening the guide vane at a first opening;
a second rotation-speed increasing step in which the increase in the rotation speed of the runner is accelerated by opening the guide vane at a second opening that is larger than the first opening after the first rotation-speed increasing step; and
a rotation-speed regulating step in which the rotation speed of the runner is regulated to a rated rotation speed by opening the guide vane at a no-load opening after the second rotation-speed increasing step,
wherein the first opening is 50% or less than 50% of the no-load opening.

Assignees

• Toshiba Kk
• Toshiba Energy Systems & Solutions Corp

Inventors

• Nakazono Masahiko
• Shima Ryosuke

Classifications

• F03B15/005 Primary

  Starting, also of pump-turbines · CPC title

• F05B2220/32

  in water turbines · CPC title

• F03B3/02

  with radial flow at high-pressure side and axial flow at low-pressure side of rotors, e.g. Francis turbines {(rotors per se F03B3/125)} · CPC title

• F05B2270/101

  to control rotational speed (n) · CPC title

• F03B3/183 Primary

  Adjustable vanes, e.g. wicket gates · CPC title