Steam turbine plant and method for cleaning same

Patent metadata

Field	Value
Publication number	US-11873723-B2
Application number	US-202118024890-A
Country	US
Kind code	B2
Filing date	Jul 19, 2021
Priority date	Sep 18, 2020
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

This steam turbine plant comprises: a boiler; a steam turbine; a condenser; a condensate pump; a main steam line that is capable of guiding, to the steam turbine, steam generated in the boiler; a bypass line that is branched from the main steam line and is connected to the condenser; a condensate line that is capable of guiding, to the condensate pump, water in the condenser; a condensate outlet valve that is provided in the condensate line; a water supply line that is capable of guiding, to the boiler, water having a pressure which has been increased in the condensate pump; a first connection unit that is, in the condensate line, branched from a position which is closer to the condenser than the condensate outlet valve is; and a second connection unit that is, in the condensate line, branched from a position which is closer to the condensate pump than the condensate outlet valve is. The first connection unit has a first connection seating that is connectable with a first line. The second connection unit has a second connection seating that is connectable with a second line.

First claim

The invention claimed is:

1. A steam turbine plant comprising:
a boiler configured to generate steam;
a steam turbine configured to be driven by the steam from the boiler;
a condenser configured to convert the steam exhausted from the steam turbine to water;
a condensate pump configured to raise a pressure of the water from the condenser;
a main steam line configured to guide the steam generated in the boiler to the steam turbine;
a steam stop valve provided in the main steam line and configured to stop an inflow of the steam into the steam turbine;
a bypass line branched from a position closer to the boiler than the steam stop valve in the main steam line is and connected to the condenser;
a bypass valve provided in the bypass line;
a condensate line configured to guide the water inside the condenser to the condensate pump;
a condensate outlet valve provided in the condensate line;
a water supply line configured to guide the water whose pressure is raised by the condensate pump to the boiler;
a pure water supply apparatus including
a pure water tank configured to store pure water,
a pure water line configured to guide the pure water inside the pure water tank to the condenser,
a pure water pump provided in the pure water line, and
a pure water control valve provided closer to the condenser than the pure water pump in the pure water line is;

a first connection unit branched from a position closer to the condenser than the condensate outlet valve in the condensate line is;
a second connection unit branched from a position closer to the condensate pump than the condensate outlet valve in the condensate line is; and
a third connection unit branched from a position closer to the condenser than the pure water pump is and closer to the pure water tank than the pure water control valve in the pure water line is,
wherein the first connection unit has a first connection seat connectable to a first line,
the second connection unit has a second connection seat connectable to a second line, and
the third connection unit has a third connection seat connectable to the second line.

2. The steam turbine plant according to claim 1 ,
wherein the first connection seat, the second connection seat, and the third connection seat are all connection flanges.

3. The steam turbine plant according to claim 1 , further comprising:
an inertial filter installed closer to the boiler than the bypass valve in the bypass line is and configured to remove foreign substances contained in the steam flowing through the bypass line.

4. The steam turbine plant according to claim 1 , further comprising:
a wastewater treatment apparatus configured to purify the water from the water supply line;
a water supply blow line branched from the water supply line and configured to guide the water flowing through the water supply line to the wastewater treatment apparatus;
a water supply blow valve provided in the water supply blow line; and
a water quality detector connected to the water supply line and configured to detect water quality of the water flowing through the water supply line.

5. The steam turbine plant according to claim 1 , further comprising:
a blowing water recovery apparatus,
wherein the blowing water recovery apparatus includes
a blowing water tank configured to temporarily store the water from the condenser,
a blowing water line connecting the first connection seat and the blowing water tank and configured to guide the water from the condenser to the blowing water tank, and
a blowing water valve provided in the blowing water line, and

the first line is the blowing water line.

6. The steam turbine plant according to claim 4 , further comprising:
a blowing water recovery apparatus,
wherein the blowing water recovery apparatus includes
a blowing water tank configured to temporarily store the water from the condenser,
a blowing water line connecting the first connection seat and the blowing water tank and configured to guide the water from the condenser to the blowing water tank,
a blowing water valve provided in the blowing water line, and
a blowing water discharge line connecting the blowing water tank and the wastewater treatment apparatus and configured to guide the water inside the blowing water tank to the wastewater treatment apparatus, and

the first line is the blowing water line.

7. The steam turbine plant according to claim 1 , further comprising:
a temporary pure water line,
wherein the temporary pure water line is connectable to the second connection seat and the to third connection seat, as the second line.

8. The steam turbine plant according to claim 1 , further comprising:
a turbine protection plate,
wherein the condenser includes
a condenser casing into which the steam from the steam turbine and the steam from the bypass line are configured to flow, and
a heat transfer pipe group disposed inside the condenser casing and configured to include a plurality of heat transfer pipes, and

the turbine protection plate is provided closer to the steam turbine than a connection position between the condenser casing and the bypass line is, inside the condenser casing, and is configured to prevent the steam from the bypass line from flowing into the steam turbine.

9. The steam turbine according to claim 1 , further comprising:
a heat transfer pipe protection net,
wherein the condenser includes
a condenser casing into which the steam from the steam turbine and the steam from the bypass line are configured to flow, and
a heat transfer pipe group disposed inside the condenser casing and configured to include a plurality of heat transfer pipes, and
the heat transfer pipe protection net configured to cover at least a side into which the steam from the bypass line flows in the heat transfer pipe group.

10. A method for cleaning a steam turbine plant including a boiler configured to generate steam, a steam turbine configured to be driven by the steam from the boiler, a condenser configured to convert the steam exhausted from the steam turbine to water, a condensate pump configured to raise a pressure of the water from the condenser, a main steam line configured to guide the steam generated in the boiler to the steam turbine, a steam stop valve provided in the main steam line and configured to stop an inflow of the steam into the steam turbine, a bypass line branched from a position closer to the boiler than the steam stop valve in the main steam line is and connected to the condenser, a bypass valve provided in the bypass line, a condensate line configured to guide the water inside the condenser to the condensate pump, a condensate outlet valve provided in the condensate line, a water supply line configured to guide the water whose pressure is raised by the condensate pump to the boiler, and a pure water supply apparatus including a pure water tank configured to store pure water, and configured to supply the pure water inside the pure water tank into the condenser, the method comprising:
a preparation step; and
a blowing-out step,
wherein the preparation step includes
a blowing water recovery apparatus installation step of connecting a blowing water recovery apparatus having a blowing water tank configured to temporarily store the water from the condenser at a position closer to the condenser than the condensate outlet valve in the condensate line is, and
a temporary pure water line connection step of connecting a temporary pure water line to feed the water inside the pure water tank, at a position closer to the condensate pump than the condensate outlet valve in the condensate line, and

the blowing-out step includes
a blowing-out line setting step of closing

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Fujimura Daiki
• Niwa Takafumi
• Kuroshima Ayumu
• GOSHIMA Motohiro

Classifications

• F01D25/002 Primary

  Cleaning of turbomachines · CPC title

• F01D25/32 Primary

  Collecting of condensation water; Drainage {; Removing solid particles} · CPC title

• F05D2220/31

  in steam turbines · CPC title

• F05D2260/606

  Bypassing the fluid · CPC title

• F05D2260/607

  Preventing clogging or obstruction of flow paths by dirt, dust, or foreign particles · CPC title