Steam turbine exhaust chamber and steam turbine system

Patent metadata

Field	Value
Publication number	US-11022003-B2
Application number	US-201916273364-A
Country	US
Kind code	B2
Filing date	Feb 12, 2019
Priority date	Mar 8, 2018
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A steam turbine exhaust chamber defining therein an exhaust passage through which steam having passed through a last-stage blade of a steam turbine is introduced to a condenser includes: a casing including an outer peripheral wall portion formed on an outer peripheral side of the exhaust passage; a bearing cone disposed on a radially inner side of the outer peripheral wall portion; and at least one bypass passage carrying a part of steam flowing through the exhaust passage from a high-pressure portion of the exhaust passage to a low-pressure portion of the exhaust passage or to the condenser, The at least one bypass passage includes a high-pressure-side opening formed in the bearing cone and a low-pressure-side opening facing steam having a lower pressure than steam facing the high-pressure-side opening.

First claim

The invention claimed is:

1. A steam turbine exhaust chamber defining therein an exhaust passage through which steam having passed through a last-stage blade of a steam turbine is introduced to a condenser, the steam turbine exhaust chamber comprising:
a casing including an outer peripheral wall portion formed on an outer peripheral side of the exhaust passage;
a bearing cone disposed on a radially inner side of the outer peripheral wall portion; and
at least one bypass passage carrying a part of steam flowing through the exhaust passage from a high-pressure portion of the exhaust passage to a low-pressure portion of the exhaust passage or to the condenser,
wherein the at least one bypass passage is formed along an outer surface of the bearing cone, the outer surface of the bearing cone facing opposite to the outer peripheral wall portion, and
wherein the at least one bypass passage includes a high-pressure-side opening communicating with the exhaust passage on an opposite-condenser side and a low-pressure-side opening communicating with the exhaust passage on the condenser side, the opposite-condenser side being opposite to the condenser side.

2. The steam turbine exhaust chamber according to claim 1 ,
wherein the high-pressure-side opening communicates with the exhaust passage in a downstream portion of the bearing cone and the low-pressure-side opening communicates with the exhaust passage in an upstream portion of the bearing cone
wherein when the steam turbine exhaust chamber is divided in a circumferential direction, the condenser side is adjacent to the condenser and the opposite-condenser side is a side opposite to the condenser side apart from the condenser.

3. The steam turbine exhaust chamber according to claim 1 ,
wherein the low-pressure-side opening is an axial end seal portion disposed upstream of the high-pressure-side opening in a flow direction of the bearing cone, and the axial end seal portion is formed between a base portion of the last-stage blade and an upstream end of the bearing cone in the flow direction.

4. The steam turbine exhaust chamber according to claim 3 ,
wherein when the steam turbine exhaust chamber is divided in a circumferential direction, the condenser side is a side adjacent to the condenser and the opposite-condenser side is a side opposite to the condenser side apart from the condenser.

5. The steam turbine exhaust chamber according to claim 1 ,
wherein the casing further includes an inner peripheral wall portion disposed on a radially inner side of the bearing cone, and
wherein at least a part of the at least one bypass passage is formed by the outer surface of the bearing cone and an inner surface of the inner peripheral wall portion.

6. The steam turbine exhaust chamber according to claim 1 ,
wherein the low-pressure-side opening is formed in the condenser.

7. The steam turbine exhaust chamber according to claim 1 , further comprising a stop valve for opening and closing the at least one bypass passage.

8. A steam turbine system comprising:
a steam turbine including the steam turbine exhaust chamber according to claim 1 ;
a boiler for combusting a fuel to generate steam;
a generator for generating electric power by the steam turbine; and
a separation detection device for detecting separation of steam flowing through the exhaust passage.

9. The steam turbine system according to claim 8 ,
wherein the separation detection device includes a pressure sensor disposed on an inner surface of the bearing cone.

10. The steam turbine system according to claim 8 ,
wherein the separation detection device includes a vibration detection device disposed on the outer surface of the bearing cone.

11. The steam turbine system according to claim 8 ,
wherein the separation detection device includes an output detection device for detecting an output power of the generator.

12. The steam turbine system according to claim 8 ,
wherein the separation detection device includes a calculation device for calculating efficiency of the steam turbine based on a measurement result of a measurement tool provided to the steam turbine system.

13. The steam turbine system according to claim 8 further comprising:
a storage device storing criterion data indicating a separation state and a non-separation state of the steam flowing through the exhaust passage obtained by computational fluid analysis; and
a separation determination device determining whether the steam flowing through the exhaust passage is separated, based on the criterion data and a detection result of the separation detection device.

14. The steam turbine system according to claim 8 further comprising a separation prevention device for preventing separation of the steam flowing through the exhaust passage,
wherein the separation prevention device includes a controller for controlling an opening and closing operation of a main steam valve of the steam turbine or adjusting an amount of a fuel to be input to the boiler, based on a detection result of the separation detection device.

15. The steam turbine system according to claim 8 further comprising a separation prevention device for preventing separation of the steam flowing through the exhaust passage,
wherein the separation prevention device includes a controller for controlling an opening and closing operation of a stop valve for opening and closing the at least one bypass passage.

16. A steam turbine exhaust chamber defining therein an exhaust passage through which steam having passed through a last-stage blade of a steam turbine is introduced to a condenser, the steam turbine exhaust chamber comprising:
a casing including an outer peripheral wall portion formed on an outer peripheral side of the exhaust passage;
a bearing cone disposed on a radially inner side of the outer peripheral wall portion; and
at least one bypass passage carrying a part of steam flowing through the exhaust passage from a high-pressure portion of the exhaust passage to a low-pressure portion of the exhaust passage or to the condenser,
wherein the at least one bypass passage includes a high-pressure-side opening communicating with the exhaust passage on an opposite-condenser side and a low-pressure-side opening communicating with the exhaust passage on the condenser side when the steam turbine exhaust chamber is divided in a circumferential direction into the condenser side adjacent to the condenser and the opposite-condenser side opposite to the condenser side apart from the condenser, and
wherein the high-pressure-side opening communicates with the exhaust passage in a downstream portion of the bearing cone and the low-pressure-side opening communicates with the exhaust passage in an upstream portion of the bearing cone.

17. A steam turbine exhaust chamber defining therein an exhaust passage through which steam having passed through a last-stage blade of a steam turbine is introduced to a condenser, the steam turbine exhaust chamber comprising:
a casing including an outer peripheral wall portion formed on an outer peripheral side of the exhaust passage;
a bearing cone disposed on a radially inner side of the outer peripheral wall portion; and
at least one bypass passage carrying a part of steam flowing through the exhaust passage from a high-pressure portion of the exhaust passage to a low-pressure portion of the exhaust passage or to the condenser,
wherein the at least one bypass passage includes a high-pressure-side opening communicating with the exhaust passage on an opposite-condenser side and a low-pressure-side opening

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• NISHIKAWA Toyoharu
• Sugishita Hideaki
• Matsumoto Kazuyuki
• Kuwamura Yoshihiro
• Nakanishi Kei

Classifications

• F01D25/24

  Casings (modified for heating or cooling F01D25/14); Casing parts, e.g. diaphragms, casing fastenings (casings for rotary machines or engines in general F16M {; special arrangements in stators dealing with breaking-off of part of rotor F01D21/045}) · CPC title

• F01D25/30 Primary

  Exhaust heads, chambers, or the like · CPC title

• F01D17/105 Primary

  by passing part of the fluid · CPC title

• F05D2220/31

  in steam turbines · CPC title

• F02C9/18

  by bleeding, bypassing or acting on variable working fluid interconnections between turbines or compressors or their stages {(F02C3/113 takes precedence)} · CPC title