JP7066572B2 - Temporary piping system for boiler blow-out and boiler blow-out method - Google Patents

Description

The present invention relates to a blowout of an exhaust heat recovery steam generator having a main steam system and a reheat steam system, and more particularly to a blowout of a reheat steam system.

There is a so-called combined cycle power generation facility that generates steam from the exhaust gas of a gas turbine by heat exchange and drives the steam turbine to generate electricity using the steam. FIG. 5 is a block diagram showing a configuration example of a plant of a general combined cycle power generation facility 100.

As shown in FIG. 5, in the combined cycle power generation facility 100, a generator 4, a steam turbine 3, and a gas turbine 1 are provided, and the gas turbine 1 burns natural gas or the like to generate electricity in the generator 4. .. There is also an example in which a generator is installed in each of a steam turbine and a gas turbine to generate electricity.

The high-temperature exhaust gas generated by the power generation combustion in the gas turbine 1 is sent to the exhaust heat recovery boiler 2. In the exhaust heat recovery boiler 2, the heat supply from the condenser 5 is converted into steam by the heat recovery from the high temperature gas, and is ventilated to the steam turbine 3. The steam that has worked in the steam turbine 3 is restored in the condenser 5, and the restored water is sent to the exhaust heat recovery boiler 2 again.

Before the steam is ventilated to the steam turbine 3 for the exhaust heat recovery boiler 2 that has been constructed, the foreign matter in the exhaust heat recovery boiler 2 is removed by using the fluid force of the steam generated in the exhaust heat recovery boiler 2. The blowing out, which is driving, is performed. This is intended to prevent foreign matter from being brought into the steam turbine 3 and damaging the blades of the steam turbine 3.

Some exhaust heat recovery steam generators 2 have a reheat steam system that reheats the steam that has worked in the steam turbine 3. In the exhaust heat recovery boiler 2 having such a reheated steam system, when the blowout of the reheated steam system is carried out, the superheated steam generated in the main steam system is used.

Specifically, a pipe for flowing steam from the main steam system to the reheated steam system by bypassing the steam turbine 3 is temporarily installed. In addition, a pipe will be temporarily installed to discharge the steam that has passed through the reheated steam system to the outside of the system. Then, the superheated steam generated in the superheater of the main steam system is flowed into the reheated steam system through the temporary pipe, and the reheated steam system is blown out by the fluid force (see, for example, Patent Document 1). ..

Japanese Patent No. 6044765

During normal operation, steam after working in the steam turbine 3, that is, low-temperature steam flows through the connection pipe (low-temperature reheat steam pipe) at the inlet of the reheat steam system into which the overheated steam of the main steam system flows. .. Therefore, when considering only normal operation, the material is not required to have high heat resistance.

However, when the gas temperature generated by the gas turbine 1 is high, the temperature of the superheated steam generated by the superheater of the main steam system becomes even higher. Therefore, in such a case, the temperature of the steam flowing into the reheated steam system at the time of blow-out may be higher than the maximum temperature of the steam flowing through the low-temperature reheated steam pipe during normal operation.

In particular, in the large combined cycle power generation facility 100, for example, the steam system of the exhaust heat recovery boiler 2 is configured by a triple pressure system of a high pressure system, a medium pressure system, and a low pressure system to improve the efficiency of exhaust heat recovery. .. Further, as a high-pressure superheater, it may be configured in two stages, primary and secondary. In the exhaust heat recovery boiler 2 having such a configuration, the superheated steam generated by the high-pressure superheater (in the case of the high-pressure system having two stages, the high-pressure secondary superheater) is used for the blow-out of the reheated steam system. This steam temperature is likely to greatly exceed the temperature of the steam flowing through the low temperature reheat steam pipe during normal operation.

Therefore, the maximum operating temperature of the low-temperature reheat steam pipe is determined in consideration of the short-term operation of blowing out before normal operation, and it is necessary to select a material that can withstand this. This results in excessive quality during normal operation, leading to higher costs.

Further, the blowing out is carried out under the steam condition in which the maximum generated dynamic pressure is equal to or higher than the planned steam condition in which the dynamic pressure generated inside the exhaust heat recovery boiler 2 becomes the largest during the normal operation. As a result, foreign matter that may be scattered during the normal operation of the exhaust heat recovery boiler 2 is discharged to the outside of the exhaust heat recovery boiler 2.

As an example, if the maximum generated dynamic pressure, which is the planned steam condition of the main steam system, is 34,000 [N / m2], the steam flowing during the blowout of the main steam system is 34,000 [N / m2] or more. It needs to be pressure. If the maximum generated dynamic pressure, which is the planned steam condition of the reheated steam system, is 8,500 [N / m2], the steam flowing during the blowout of the reheated steam system is 8,500 [N / m2], which is equal to or higher than the maximum generated dynamic pressure. N / m2] or more.

However, the steam generated from the main steam system is used for the blow-out of the reheated steam system. When the dynamic pressure in the reheat steam system is 8,500 [N / m2] or more, the dynamic pressure in the main steam system is 51,000 [N / m2] or more. That is, the dynamic pressure generated in the main steam system when the reheated steam system is blown out is significantly larger than that at the time of blowing out the main steam system or the maximum generated dynamic pressure.

Therefore, when the reheated steam system is blown out, an excessive dynamic pressure higher than the original dynamic pressure required for blowing out the main steam system is applied to the main steam system. As a result, foreign matter that did not scatter when the main steam system was blown out is scattered from the main steam system to the reheated steam system, resulting in a longer blow-out time.

Due to the prolonged blow-out time, the consumption of utilities such as fuel and pure water required to carry out the blow-out is also enormous.

The present invention has been made in view of the above circumstances, and in an exhaust heat recovery boiler having a main steam system and a reheat steam system, a simple configuration suppresses an increase in cost and efficiently blows out the reheat steam system. The purpose is to provide the technology that makes it possible.

The present invention reheats a main steam system in which superheater generates superheater and supplies superheated steam generated by the superheater to a steam turbine, and steam extracted from the steam turbine. A blow-out operation in which the superheated steam system is blown by the steam generated in the main steam system prior to the start of operation of the boiler equipped with the superheated steam system that is reheated in the steam turbine and supplied to the steam turbine. In the temporary piping system for blow-out of the boiler used at the time, the first temporary pipe that bypasses the steam turbine and supplies the superheated steam generated by the superheater to the reheated steam system, and at the time of the blow-out. A second temporary pipe that releases the steam that has passed through the reheater to the atmosphere and a part of the steam supplied to the superheater of the main steam system are bypassed from the superheater and from the outlet of the superheater. It is characterized by being provided with a third temporary pipe that flows to the wake.

Further, according to the present invention, in the boiler blow-out method using the above-mentioned temporary boiler blow-out piping system, the supply of steam from the superheater and the reheater to the steam turbine is cut off, respectively, and the superheat is performed. The heated steam generated by the boiler is supplied to the reheated steam system via the first temporary pipe, and a part of the steam before being supplied to the superheater is supplied via the third temporary pipe. Then, by supplying it to the first temporary pipe, it is mixed with the superheated steam supplied to the reheated steam system via the first temporary pipe, and the mixed steam flows into the reheater. This is characterized in that the reheater is blown and the steam after blowing the reheater is released to the atmosphere via the second temporary pipe.

According to the present invention, in an exhaust heat recovery boiler having a main steam system and a reheat steam system, it is possible to suppress an increase in cost with a simple configuration and efficiently blow out the reheat steam system. Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

It is a figure which shows the system structure including the time of blowing out of the exhaust heat recovery boiler of embodiment of this invention. It is explanatory drawing for demonstrating the blow-out operation of the exhaust heat recovery boiler of embodiment of this invention. It is a figure which shows the system structure of the exhaust heat recovery boiler of the modification of embodiment of this invention. It is a figure which shows the system structure of the exhaust heat recovery boiler of another modification of the embodiment of this invention. It is a plant block diagram of the combined cycle power generation equipment.

An example of the exhaust heat recovery steam according to the embodiment of the present invention will be described. The exhaust heat recovery boiler of the present embodiment is used, for example, in the combined cycle power generation facility 100 shown in FIG.

FIG. 1 is a system configuration diagram of the exhaust heat recovery steam generator 2a of the present embodiment.

The exhaust heat recovery boiler 2a includes a main steam system and a reheat steam system. As shown in FIG. 1, as the main steam system, the exhaust heat recovery boiler 2a has a high-pressure system 41 which is a high-pressure steam system, a medium-pressure system 42 which is a medium-pressure steam system, and a low-pressure system which is a low-pressure steam system. A system 43 is provided, and a reheat system 44 is provided as a reheat steam system.

Each steam system of the main steam system includes a superheater, an evaporator, and an economizer in order from the upstream side to the downstream side of the exhaust gas flow path through which the exhaust gas from the gas turbine 1 flows. Specifically, the low-pressure system 43 includes a low-pressure superheater 11, a low-pressure evaporator 10, and a low-pressure economizer 8. Further, the medium pressure system 42 includes a medium pressure superheater 17, a medium pressure evaporator 16, and a medium pressure economizer 14. The high-pressure system 41 includes a high-pressure secondary superheater 22, a high-pressure primary superheater 21, a high-pressure evaporator 20, and a high-pressure economizer 18. Each evaporator (low pressure evaporator 10, medium pressure evaporator 16, high pressure evaporator 20) has a steam drum (low pressure drum 9, medium pressure drum 15, high pressure drum 19) for temporarily storing the generated steam. Is provided.

A condensate line 27 that supplies water from the condenser 5 to the low-pressure economizer 8 is connected to the inlet of the low-pressure economizer 8. The condensate line 27 is provided with a condensate pump 6 and a low-pressure water supply pump 7.

At the outlet of the low-pressure economizer 8, a high-medium-pressure water supply line 28 for supplying water heated by the low-pressure economizer 8 to the medium-pressure economizer 14 and the high-pressure economizer 18 is provided. The high / medium pressure water supply line 28 is provided with a high / medium pressure water supply pump 12.

An economizer recirculation line 13 is further provided at the outlet of the low pressure economizer 8 to recirculate the water supplied by the low pressure economizer 8 to the inlet of the low pressure economizer 8. The economizer recirculation line 13 is provided with an economizer recirculation pump 29.

The exhaust gas from the gas turbine 1 is sent from the high-pressure secondary superheater 22 of the high-pressure system 41, which is the first steam system, to the low-pressure economizer 8 of the low-pressure system 43 installed at the last flow portion, and each steam during that time. The system carries out heat recovery of the retained heat of the exhaust gas.

On the other hand, the water restored by the condenser 5 is sent to the water supply inlet of the exhaust heat recovery boiler 2a via the condenser pump 6 and the low-pressure water supply pump 7. The water supply supplied to the exhaust heat recovery boiler 2a becomes steam by heat exchange with the exhaust gas while flowing in the order of the low pressure system 43, the medium pressure system 42, and the high pressure system 41, and is supplied to the steam turbine 3.

At this time, in the high-pressure system 41 of the main steam system, the steam generated in the high-pressure evaporator 20 is supplied to the high-pressure primary superheater 21 and the high-pressure secondary superheater 22 via the high-pressure drum 19, and through the main steam pipe 24. Is supplied to the steam turbine 3.

The reheating system 44 reheats the steam that has worked in the steam turbine 3.

In order to realize this, the reheat system 44 includes a reheater 23, a low temperature reheat steam tube 25, and a high temperature reheat steam tube 26. The low-temperature reheat steam pipe 25 connects the steam turbine 3 and the inlet of the reheater 23, and supplies the steam worked in the steam turbine 3 to the reheater 23. The high-temperature reheat steam pipe 26 connects the outlet of the reheater 23 and the steam turbine 3, and supplies the steam reheated by the reheater 23 to the steam turbine 3.

As described above, in the exhaust heat recovery boiler 2a whose construction has been completed, foreign matter in the exhaust heat recovery boiler 2a is brought into the steam turbine 3 before the steam is ventilated to the steam turbine 3 (before the start of normal operation). Blow out is performed so as not to damage the blades of the steam turbine 3. Steam generated by the evaporator is used for blowing out. That is, steam is generated from the exhaust heat recovery boiler 2a itself, and foreign matter is removed from the exhaust heat recovery boiler 2a using the fluid force of the steam.

However, the reheat system 44 does not have an evaporator. Therefore, as described above, the superheated steam of the main steam system is used for the blow-out of the reheat system 44. In order to realize this, the exhaust heat recovery boiler 2a of the present embodiment is provided with a temporary pipe for blowing out of the reheating system 44.

Hereinafter, the temporary piping system for blowing out of the exhaust heat recovery steam generator 2a of the present embodiment will be described with reference to FIG.

In the present embodiment, in order to send the superheated steam of the main steam system to the reheater 23 by bypassing the steam turbine 3, the superheater outlet (outlet of the high-pressure secondary superheater 22) and the reheated steam system are connected. The first temporary pipe 31 which is a temporary pipe is provided.

As shown in FIG. 1, the first temporary pipe 31 branches from the main steam pipe 24, is connected to the low temperature reheat steam pipe 25, and supplies steam from the main steam pipe 24 to the low temperature reheat steam pipe 25. The steam generated in the main steam system is flowed to the reheated steam system through the first temporary pipe 31, and blow-out is performed.

In addition, a second temporary pipe 32 is provided to release the steam that has passed through the reheater 23 to the atmosphere. As shown in FIG. 1, the second temporary pipe 32 branches from the high temperature reheat steam pipe 26 and is connected to the exhaust silencer 39. The steam that has passed through the reheat system 44 is released to the atmosphere through the exhaust silencer 39. This prevents the steam that has passed through the reheater 23 at the time of blow-out from being aerated to the steam turbine 3.

Further, in the present embodiment, in order to lower the temperature of the steam supplied from the main steam system to the reheating system 44, a part of the steam supplied to the superheater of the main steam system is bypassed by the superheater. A third temporary pipe that mixes with the steam supplied to the reheat system 44 is provided. In the present embodiment, the third temporary pipe 33 is connected to the first temporary pipe 31 from the outlet of the high pressure drum 19, for example, as shown in FIG.

Through the third temporary pipe 33, a part of the saturated steam at the outlet of the high pressure drum 19 before being superheated by the high pressure primary superheater 21 and the high pressure secondary superheater 22 is not overheated and the first temporary pipe 31 Is supplied to and mixed with the hot steam in the tube. As a result, the steam temperature flowing into the low temperature reheat steam pipe 25 from the first temporary pipe 31 is reduced.

The temporary pipes (31, 32, 33) for blowing out are used only at the time of blowing out.

Further, in carrying out the blow-out, first, the blow-out is performed in the main steam system by a known method, and then the blow-out of the reheat system 44 is performed.

For example, a first isolation valve (not shown) on the steam turbine 3 side of the main steam pipe 24 on the steam turbine 3 side of the branch point of the first temporary pipe 31 and a second temporary pipe 32 of the high temperature reheat steam pipe 26. A second isolation valve (not shown) is provided on the steam turbine 3 side of the branch point. Further, temporary shutoff valves (not shown) are provided in the first temporary pipe 31, the second temporary pipe 32, and the third temporary pipe 33, respectively.

After the blow-out of the main steam system is completed, the blow-out of the reheat system 44 is started. At the time of blowing out of the reheating system 44, first, the first shutoff valve and the second shutoff valve are closed, the steam from the high pressure secondary superheater 22 flows into the steam turbine 3, and the reheater 23 Is cut off from the inflow of steam into the steam turbine 3.

Then, each temporary isolation valve is opened, and the steam generated by the high-pressure evaporator 20 is supplied to the reheat system 44. The steam supplied at this time shall be equal to or higher than the maximum generated dynamic pressure of the reheating system 44. This is usually greater than the maximum dynamic pressure of the main steam system.

As a result, when the reheating system 44 is blown out, as shown by the thick line in FIG. 2, the steam superheated by the high-pressure secondary superheater 22 is cooled to a low temperature via the main steam pipe 24 and the first temporary pipe 31. It flows into the reheat steam pipe 25. At this time, a part of the saturated steam at the outlet of the high-pressure drum 19 is supplied to the first temporary pipe 31 via the third temporary pipe 33 and mixed with the steam before flowing into the low-temperature reheat steam pipe 25. .. The steam superheated by the high-pressure secondary superheater 22 and a part of the saturated steam at the outlet of the high-pressure drum 19 are mixed in the first temporary pipe 31, and the reheater 23 is passed through the low-temperature reheat steam pipe 25. And blows out foreign matter in the reheater 23. The steam after blow-out is released to the atmosphere from the outlet of the reheater 23 via the high-temperature reheat steam pipe 26, the second temporary pipe 32, and the exhaust silencer 39.

As described above, according to the present embodiment, the third temporary pipe 33 is provided, and the low-temperature steam before being overheated by the high-pressure system 41 is mixed with the superheated steam for blowing out of the reheating system 44. Then, the steam whose temperature has dropped after mixing is allowed to flow into the low-temperature reheat steam pipe 25. Therefore, at the time of designing, the steam for blow-out exceeds the maximum operating temperature of the pipe and damages the pipe even if the material of the low-temperature reheat steam pipe 25 does not consider the passing steam temperature at the time of blow-out. Possibility is reduced.

Further, the third temporary pipe 33 reduces the steam flow rate passing through the high pressure system 41. By reducing the fluid force of the high pressure system 41, the dynamic pressure also decreases, the amount of foreign matter scattered in the high pressure system 41 can be suppressed, and the amount of foreign matter scattered in the superheated steam flowing from the high pressure system 41 can be suppressed. Can also be suppressed. Therefore, the blow-out of the reheater 23 can be performed with steam having a small amount of foreign matter scattered, and the blow-out time can be shortened.

As described above, according to the present embodiment, in the exhaust heat recovery boiler 2a, a temporary pipe for bypassing the superheater is provided for a part of the steam supplied from the main steam system, and the cost is reduced. It is possible to suppress the rise and efficiently blow out the reheat system 44.

In the above embodiment, the exhaust heat recovery boiler 2a has been described by taking as an example the case of the triple pressure system of the high pressure system 41, the medium pressure system 42, and the low pressure system 43, but the present invention is not limited to this. For example, a double pressure system without a medium pressure system 42 may be used. Further, the main steam system does not have to be a multiple pressure system. As long as the saturated steam before overheating can be taken out from the steam drum of the main steam system and mixed with the steam in the first temporary pipe 31 that sends the superheated steam to the reheater 23, the configuration of the exhaust heat recovery boiler 2a itself does not matter.

<Modification example>
For example, in the case of the exhaust heat recovery boiler 2 having a configuration in which a plurality of high-pressure superheaters are provided (hereinafter referred to as a multi-stage configuration), the third temporary pipe may be provided so as to bypass the plurality of high-pressure superheaters. For example, the superheater may be bypassed by connecting from the inlet side of the high-pressure primary superheater 21 to the inlet side of any of the following superheaters. For example, FIG. 3 shows an example in which the high-pressure system 41 is a two-stage exhaust heat recovery steam generator 2b. As shown in this figure, the third temporary pipe 34 branches from the inlet side of the high-pressure primary superheater 21 and is connected to the outlet side thereof, that is, the inlet side of the high-pressure secondary superheater 22. In addition, the saturated steam to be bypassed is a part or all.

In the case of the tertiary configuration, the third temporary pipe 34 is connected to the middle of the high-pressure primary superheater 21 and the high-pressure secondary superheater 22 and the high-pressure secondary superheater 22 from the inlet side of the high-pressure primary superheater 21. Connected to one of the middle with a high pressure tertiary superheater. In the former case, the steam before superheating bypasses the high-pressure primary superheater 21, and in the latter case, it bypasses the high-pressure primary superheater 21 and the high-pressure secondary superheater 22. In the case of a quaternary configuration, connect to either the middle of the primary superheater and the secondary superheater, the middle of the secondary superheater and the tertiary superheater, or the middle of the tertiary superheater and the quaternary superheater. Will be done. The saturated steam to be bypassed is a part or all in both the tertiary configuration and the quaternary configuration.

Similarly, when the high-pressure system 41 has a multi-stage configuration, the third temporary pipe is connected to the first temporary pipe 31 by bypassing the superheater from the inlet side of any of the secondary and subsequent superheaters. You may connect. For example, FIG. 4 shows an example in which the high-pressure system 41 is a two-stage exhaust heat recovery steam generator 2c. As shown in this figure, the third temporary pipe 35 branches from the outlet side of the high-pressure primary superheater 21, that is, the inlet side of the high-pressure secondary superheater 22, and is connected to the first temporary pipe 31. In addition, the saturated steam to be bypassed is a part or all.

In this way, at the time of blow-out, the third temporary pipe bypasses the superheater and wakes a part or all of the steam of the main steam system before being supplied to the superheater from the outlet of the superheater. These modifications may be appropriately selected depending on the configuration of the exhaust heat recovery steam 2.

Generally, the heat transfer tube panel of the exhaust heat recovery boiler 2 is installed so that the heat transfer tube is arranged between the inlet header and the outlet header. The connecting pipe connected from the high pressure drum 19 that separates water and steam to the header of the high pressure primary superheater 21 which is the first heat transfer tube panel is connected to either the inlet header or the outlet header for each exhaust heat recovery boiler 2. The header. That is, in some cases, a flow path is formed so that the steam flowing out of the high-pressure drum 19 flows downward from the top of the heat transfer tube panel (high-pressure primary superheater 21) to which the steam flows out first, and the steam flows upward from the bottom. In some cases, a flow path is formed. Each modification is appropriately selected so that the length of the third temporary pipe to be branched is short and the pipe is simple according to the configuration of the exhaust heat recovery boiler 2. This simplifies the handling of temporary piping at the time of blow-out, and can be expected to have a cost advantage.

Further, in the above-described embodiments and modifications, the drum-type exhaust heat recovery boiler has been described as an example, but the type of the exhaust heat recovery boiler is not limited to this. For example, a once-through type may be used in which a brackish water separator is used instead of the steam drum. Further, in addition to the horizontal type exhaust heat recovery boiler in which the heat transfer tube panels are arranged in the horizontal direction, a vertical type exhaust heat recovery boiler in which the heat transfer tube panels are arranged in the vertical direction may be used. The scale of the power generation facility, the configuration of the steam system, the arrangement of the water supply pumps, etc. are not particularly limited to the above-described embodiments and modifications, and are within a range that does not deviate from the technical idea of the present invention, depending on the design and the like. Various changes are possible.

1: Gas turbine 2: Exhaust heat recovery boiler, 2a: Exhaust heat recovery boiler, 2b: Exhaust heat recovery boiler, 2c: Exhaust heat recovery boiler, 3: Steam turbine, 4: Generator, 5: Water recovery device, 6 : Condensation pump, 7: Low pressure water supply pump, 8: Low pressure economizer, 9: Low pressure drum, 10: Low pressure evaporator, 11: Low pressure superheater, 12: High and medium pressure water supply pump, 13: Economizer recirculation line , 14: Medium pressure economizer, 15: Medium pressure drum, 16: Medium pressure evaporator, 17: Medium pressure superheater, 18: High pressure economizer, 19: High pressure drum, 20: High pressure evaporator, 21: High pressure Primary superheater, 22: High pressure secondary superheater, 23: Reheater, 24: Main steam pipe, 25: Low temperature reheat steam pipe, 26: High temperature reheat steam pipe, 27: Restoration line, 28: High medium pressure Water supply line, 29: Economizer recirculation pump,
31: 1st temporary piping, 32: 2nd temporary piping, 33: 3rd temporary piping, 34: 3rd temporary piping, 35: 3rd temporary piping, 39: exhaust silencer,
41: High pressure system, 42: Medium pressure system, 43: Low pressure system, 44: Reheat system,
100: Combined cycle power generation equipment

Claims (8)

The steam generated in the evaporator is overheated by the superheater, and the main steam system that supplies the superheated steam generated by the superheater to the steam turbine and the steam extracted from the steam turbine are reheated by the reheater. It is used at the time of blowing out, which is an operation of blowing the reheated steam system with the steam generated in the main steam system prior to the start of operation of the boiler equipped with the reheated steam system supplied to the steam turbine. In the temporary piping system for blow-out of the boiler
A first temporary pipe that bypasses the steam turbine and supplies the superheated steam generated by the superheater to the reheated steam system.
A second temporary pipe that releases steam that has passed through the reheater to the atmosphere at the time of blowing out, and
Boiler blowing characterized by comprising a third temporary pipe that bypasses the superheater and allows a part of steam supplied to the superheater of the main steam system to flow to the wake from the outlet of the superheater. Temporary piping system for out. In the temporary piping system for blowing out of the boiler according to claim 1,
The third temporary pipe is a temporary piping system for blowing out of a boiler, characterized in that the front flow of the superheater is connected to the first temporary pipe. In the temporary piping system for blowing out of the boiler according to claim 2,
The main steam system evaporator is equipped with a steam drum for temporarily storing the generated steam.
The third temporary pipe is a temporary pipe system for blowing out of a boiler, characterized in that the steam drum outlet of the main steam system is connected to the first temporary pipe. In the temporary piping system for blowing out of the boiler according to claim 2,
The main steam system includes a plurality of the superheaters.
The third temporary pipe is a temporary piping system for blowing out of a boiler, characterized in that the third temporary pipe is connected to the first temporary pipe from the inlet side of a predetermined superheater among the plurality of superheaters. In the temporary piping system for blowing out of the boiler according to claim 1,
The third temporary piping system is a temporary piping system for blowing out of a boiler, which is connected from the inlet side of the superheater to the outlet side of the superheater. In the temporary piping system for blowing out of the boiler according to claim 1,
The main steam system includes a plurality of the superheaters.
The third temporary pipe is the exhaust gas flow path from the superheater from the inlet side of the superheater arranged at the most downstream side of the exhaust gas flow path through which the exhaust gas from the steam turbine flows among the plurality of the superheaters. Temporary piping system for blow-out of a boiler, characterized in that it is connected to the inlet side of any of the superheaters located on the upstream side of the boiler. In the temporary piping system for blowing out of the boiler according to claim 1,
The boiler is a high-pressure system having the superheater, the evaporator, and the coal-saving device in order from the upstream side to the downstream side of the exhaust gas flow path through which the exhaust gas from the steam turbine flows, and the medium pressure, respectively, as the main steam system. It is an exhaust heat recovery boiler provided with a system and a low pressure system, and a steam drum for temporarily storing generated steam is connected to each of the evaporators.
The first temporary pipe is a low temperature that supplies steam extracted from the steam turbine to the reheater from a main steam pipe that supplies the superheated steam generated by the superheater of the high pressure system to the steam turbine. Connected to a reheat steam tube,
The second temporary pipe is connected to a high-temperature reheat steam pipe that supplies steam reheated by the reheater to the steam turbine, and releases steam that has passed through the reheater to the atmosphere.
The third temporary pipe is a temporary pipe system for blowing out of a boiler, characterized in that the third temporary pipe is connected to the first temporary pipe from the outlet of the steam drum of the high pressure system. In the boiler blow-out method using the temporary boiler blow-out piping system according to claim 1.
The supply of steam from the superheater and the reheater to the steam turbine is cut off, respectively.
The heated steam generated by the superheater is supplied to the reheated steam system via the first temporary pipe, and a part of the steam before being supplied to the superheater is partially supplied to the third temporary pipe. By supplying to the first temporary pipe via the above, it is mixed with the superheated steam supplied to the reheated steam system via the first temporary pipe.
The reheater is blown by flowing the mixed steam into the reheater.
A method for blowing out a boiler, which comprises releasing steam after blowing the reheater to the atmosphere via the second temporary pipe.

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