JP2020029977A - Temporary piping system for blowing-out of boiler and method for blowing out boiler - Google Patents

Abstract

To suppress cost increase using a simple configuration and enable blowing-out of a reheat steam system with efficiency, in a waste heat recovery boiler having a main steam system and a reheat steam system.SOLUTION: A temporary piping system for blowing-out of a boiler that blows a reheat steam system with the steam generated in a main steam system prior to the start of operation of the boiler equipped with the main steam system and the reheat steam system, comprises: a first temporary pipe 31 that supplies the superheated steam generated by a superheater 22 to the reheat steam system so as to bypass a steam turbine 3; a second temporary pipe 32 that discharges steam that has passed through a reheater 23 during blowing-out to the atmosphere; and a third temporary pipe 33 that flows part of the steam supplied to the superheaters 21 and 22 of the main steam system to a downstream side with respect to the outlet of the superheater 21 so as to bypass the superheaters 21 and/or 22.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a blow-out of an exhaust heat recovery boiler having a main steam system and a reheat steam system, and more particularly to a blow-out of a reheat steam system.

  There is a so-called combined cycle power generation facility in which steam is generated by heat exchange from exhaust gas of a gas turbine, and the steam is used to drive a steam turbine to generate power. FIG. 5 is a block diagram illustrating 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 power generator 4, a steam turbine 3, and a gas turbine 1 are provided, and the gas turbine 1 burns natural gas and the like to generate power using the power generator 4. . In some cases, a power generator is installed in each of the steam turbine and the gas turbine to generate power.

  High-temperature exhaust gas generated by power generation combustion in the gas turbine 1 is sent to the exhaust heat recovery boiler 2. In the waste heat recovery boiler 2, by recovering heat from the high-temperature gas, feed water sent from the condenser 5 is converted into steam, and the steam is passed through the steam turbine 3. The steam that has worked in the steam turbine 3 is condensed in the condenser 5, and the condensed water is sent to the exhaust heat recovery boiler 2 again.

  Before the steam is passed through the steam turbine 3 to the exhaust heat recovery boiler 2 whose construction has been completed, foreign matter in the exhaust heat recovery boiler 2 is removed using the fluid force of the steam generated in the exhaust heat recovery boiler 2. Driving, blowing out, is performed. This aims at preventing foreign matters from being brought into the steam turbine 3 and damaging the blades of the steam turbine 3.

  Some of the exhaust heat recovery boilers 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 reheat steam system, when performing blowing out of the reheat steam system, superheated steam generated in the main steam system is used.

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

Japanese Patent No. 6044765

  During normal operation, the connection pipe (low-temperature reheat steam pipe) at the inlet of the reheat steam system into which the superheated steam of the main steam system flows flows the steam after work in the steam turbine 3, that is, the low-temperature steam flows. . Therefore, when only normal operation is considered, high heat resistance is not required for the material.

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

  In particular, in the large-sized combined cycle power generation facility 100, for example, the steam system of the exhaust heat recovery boiler 2 is configured by a high-pressure system, a medium-pressure system, and a low-pressure system in a triple-pressure system to improve the efficiency of the exhaust heat recovery. . Further, the superheater of the high pressure system may be configured in two stages, primary and secondary. In the exhaust heat recovery boiler 2 having such a configuration, the superheated steam generated in the superheater of the high pressure system (or the high pressure secondary superheater when the high pressure system has two stages) is used for blowing out the reheat steam system. This steam temperature is likely to greatly exceed the temperature of 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-time operation of blowing out before the 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.

  In addition, the blowing out is performed under steam conditions that are equal to or more than the maximum generated dynamic pressure with respect to the planned steam condition in which the dynamic pressure generated during normal operation of the exhaust heat recovery boiler 2 becomes largest. As a result, foreign substances that may be scattered during the normal operation of the heat recovery steam generator 2 are discharged to the outside of the heat recovery steam generator 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 at the time of blowing out of the main steam system is 34,000 [N / m2] or more. Pressure. Further, if the maximum generated dynamic pressure, which is the planned steam condition of the reheat steam system, is 8,500 [N / m2], the steam flowing at the time of blowing out the reheat steam system is 8,500 [N / m2] which is higher than the maximum generated dynamic pressure. N / m2] or more.

  However, the blowing out of the reheat steam system uses the steam generated from the main 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 blowing out the reheat steam system is significantly larger than the blowing pressure of the main steam system or the maximum generated dynamic pressure.

  Therefore, when blowing out the reheat steam system, an excessive dynamic pressure higher than the original dynamic pressure required for blowing out the main steam system is applied in the main steam system. As a result, foreign matter that has not been scattered when the main steam system is blown out is scattered from the main steam system to the reheat steam system, resulting in a longer blowout time.

  The prolonged blowing out time has led to enormous consumption of utilities such as fuel and pure water required to perform the blowing out.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in a waste heat recovery boiler having a main steam system and a reheat steam system, an increase in cost is suppressed with a simple configuration, and blowing out of the reheat steam system is efficiently performed. The purpose is to provide technology that enables

  The present invention provides a main steam system that superheats steam generated in an evaporator with a superheater and supplies the superheated steam generated by the superheater to a steam turbine, and reheats steam extracted from the steam turbine. Prior to the start of operation of a boiler having a reheat steam system for reheating and supplying the reheat steam to the steam turbine, a blowing-out operation for blowing the reheat steam system with steam generated in the main steam system. In the temporary piping system for blowing out of the boiler used at the time, the first temporary piping that supplies the superheated steam generated by the superheater to the reheat steam system by bypassing the steam turbine, and at the time of the blowing out A second temporary pipe that discharges 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 passed through the superheater. Scan to be characterized by and a third temporary piping to flow to flow after the outlet of the superheater.

  Further, according to the present invention, in the above-described method for blowing out a boiler using the temporary piping system for blowing out a boiler, the supply of steam from the superheater and the reheater to the steam turbine is interrupted, and The heating steam generated by the heater is supplied to the reheat steam system via the first temporary pipe, and a part of the steam before being supplied to the superheater is passed through the third temporary pipe. Then, by supplying to the first temporary pipe, it is mixed with the superheated steam supplied to the reheat steam system via the first temporary pipe, and the mixed steam flows into the reheater. Accordingly, the reheater is blown, and the steam after blowing the reheater is discharged to the atmosphere via the second temporary pipe.

  Advantageous Effects of Invention According to the present invention, in a waste heat recovery boiler having a main steam system and a reheat steam system, it is possible to suppress a rise in cost with a simple configuration and to efficiently blow out the reheat steam system. Problems, configurations, and effects other than those described above will be apparent from the following description of the embodiments.

It is a figure showing the system composition also at the time of blowing out of the waste heat recovery boiler of the embodiment of the present invention. It is explanatory drawing for demonstrating the blowing-out operation | movement of the waste heat recovery boiler of embodiment of this invention. It is a figure which shows the system configuration | structure of the waste-heat recovery boiler of the modification of embodiment of this invention. It is a figure which shows the system configuration of the exhaust-heat recovery boiler of other modification of embodiment of this invention. It is a plant configuration diagram of a combined cycle power generation facility.

  An example of the exhaust heat recovery boiler 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 a combined cycle power generation facility 100 shown in FIG.

  FIG. 1 is a system configuration diagram of an exhaust heat recovery boiler 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, the exhaust heat recovery boiler 2a includes, as main steam systems, a high-pressure system 41 that is a high-pressure system, an intermediate-pressure system 42 that is an intermediate-pressure system, and a low-pressure system that is a low-pressure system. A reheating system 44 is provided as a reheating steam system.

  Each steam system of the main steam system includes a superheater, an evaporator, and a 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 the low-pressure superheater 11, the low-pressure evaporator 10, and the low-pressure economizer 8. The medium pressure system 42 includes the medium pressure superheater 17, the medium pressure evaporator 16, and the 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 of the evaporators (low-pressure evaporator 10, medium-pressure evaporator 16, and 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 for supplying water from the condenser 5 to the low-pressure economizer 8 is connected to an 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 that supplies the 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 12 is provided with the high / medium pressure water supply pump 12.

  The outlet of the low-pressure economizer 8 is further provided with a economizer recirculation line 13 for recirculating feed water heated 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.

  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 stream. The system recovers the heat retained in the exhaust gas.

  On the other hand, the water condensed by the condenser 5 is sent to the water supply inlet of the exhaust heat recovery boiler 2a via the condensate pump 6 and the low-pressure water supply pump 7. The feedwater supplied to the exhaust heat recovery boiler 2a becomes steam by heat exchange with 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 is transmitted through the main steam pipe 24. And supplied to the steam turbine 3.

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

  To realize this, the reheating system 44 includes the reheater 23, the low-temperature reheat steam pipe 25, and the high-temperature reheat steam pipe 26. The low-temperature reheat steam pipe 25 connects the steam turbine 3 to the inlet of the reheater 23, and supplies the steam that has 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 that has been completed, the foreign matter in the exhaust heat recovery boiler 2a is brought into the steam turbine 3 before ventilating the steam into the steam turbine 3 (before starting normal operation). Blowing out is performed so as not to damage the blades of the steam turbine 3. The 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, the superheated steam of the main steam system is used for blowing out the reheat system 44 as described above. In order to realize this, the exhaust heat recovery boiler 2a of the present embodiment is provided with a temporary piping for blowing out the reheating system 44.

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

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

  As shown in FIG. 1, the first temporary pipe 31 branches off 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 passed through the first temporary pipe 31 to the reheat steam system, and blowing out is performed.

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

  Furthermore, in this 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 to the superheater. A third temporary pipe for mixing with steam supplied to the reheating 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 heated by the high-pressure primary superheater 21 and the high-pressure secondary superheater 22 is not overheated, and the first temporary pipe 31 is not heated. And mixed with the hot steam in the tube. Thereby, the temperature of the steam flowing from the first temporary pipe 31 to the low-temperature reheat steam pipe 25 is reduced.

  In addition, each temporary piping (31, 32, 33) for blowing out is used only at the time of blowing out.

  When performing the blowing out, first, in the main steam system, the blowing out is performed by a known method, and then, the blowing out of the reheating system 44 is performed.

  For example, a first shut-off valve (not shown) of the main steam pipe 24 on the steam turbine 3 side from the branch point of the first temporary pipe 31 is connected to the second temporary pipe 32 of the high-temperature reheat steam pipe 26. A second shutoff valve (not shown) is provided on the steam turbine 3 side of the branch point. Further, a temporary shutoff valve (not shown) is provided in each of the first temporary pipe 31, the second temporary pipe 32, and the third temporary pipe 33.

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

  Then, each temporary shut-off valve is opened, and the steam generated in the high-pressure evaporator 20 is supplied to the reheating system 44. The steam supplied at this time is equal to or higher than the maximum generated dynamic pressure of the reheating system 44. This is typically greater than the maximum generated dynamic pressure of the main steam system.

  Thereby, when the reheating system 44 is blown out, the steam superheated by the high-pressure secondary superheater 22 is cooled to a low temperature through the main steam pipe 24 and the first temporary pipe 31 as shown by a thick line in FIG. 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 through 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 blowing out is discharged from the outlet of the reheater 23 to the atmosphere 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 superheated in the high-pressure system 41 is mixed with the superheated steam for blowing out in the reheating system 44. Then, the steam whose temperature has dropped after mixing is caused to flow into the low-temperature reheat steam pipe 25. For this reason, at the time of design, the material for the low-temperature reheat steam pipe 25 does not consider the passing steam temperature at the time of blowing out, so that the steam for blowing out exceeds the maximum operating temperature of the pipe and damages the pipe. The likelihood is reduced.

  Further, the flow rate of the steam passing through the high-pressure system 41 is reduced by the third temporary pipe 33. As the fluid force of the high-pressure system 41 decreases, the dynamic pressure also decreases, so that 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 in from the high-pressure system 41. Can also be suppressed. Therefore, the blowing-out of the reheater 23 can be performed with steam having a small amount of foreign matter scattered, and the blowing-out time can be reduced.

  As described above, according to the present embodiment, in the exhaust heat recovery boiler 2a, a part of the steam supplied from the main steam system is provided with the temporary pipe for bypassing the superheater, and the cost is reduced. The rise can be suppressed, and the blowing out of the reheating system 44 can be performed efficiently.

  In the above-described embodiment, the case where the exhaust heat recovery boiler 2a is a triple-pressure system of the high-pressure system 41, the medium-pressure system 42, and the low-pressure system 43 has been described as an example, but is not limited thereto. For example, a double (double) pressure system without the intermediate pressure system 42 may be used. Further, the main steam system need not be a multi-pressure system. The configuration of the exhaust heat recovery boiler 2a itself is not limited as long as saturated steam before superheating 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.

<Modification>
For example, in the case where the exhaust heat recovery boiler 2 has 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 one of the inlet sides of the subsequent superheater. For example, FIG. 3 shows an example in which the high-pressure system 41 is a two-stage exhaust heat recovery boiler 2b. As shown in the figure, the third temporary pipe 34 branches off from the inlet side of the high-pressure primary superheater 21 and is connected to its outlet side, that is, the inlet side of the high-pressure secondary superheater 22. Further, the saturated steam to be bypassed is part or all.

  In the case of the tertiary configuration, the third temporary pipe 34 is provided between 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. It is connected to one of the intermediate points with the 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, it is connected to one of the intermediate points between the primary and secondary superheaters, between the secondary and tertiary superheaters, and between the tertiary and quaternary superheaters. Is done. The saturated steam to be bypassed is part or all of the tertiary configuration and the quaternary configuration.

  Similarly, when the high-pressure system 41 has a multi-stage configuration, the third temporary pipe is bypassed from the inlet side of any one of the subsequent superheaters after the secondary to the first temporary pipe 31. You may connect. For example, FIG. 4 shows an example in which the high-pressure system 41 is a two-stage exhaust heat recovery boiler 2c. As shown in the 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. Further, the saturated steam to be bypassed is part or all.

  In this way, the third temporary pipe, when blowing out, allows a part or all of the steam of the main steam system before being supplied to the superheater to bypass the superheater and flow downstream from the outlet of the superheater. These modifications may be appropriately selected according to the configuration of the exhaust heat recovery boiler 2.

  Generally, the heat transfer tube panel of the exhaust heat recovery boiler 2 is installed such that the heat transfer tubes are arranged between the inlet header and the outlet header. The connecting pipe connected from the high-pressure drum 19 for separating 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. You. That is, in some cases, the 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 (the high-pressure primary superheater 21) to which the steam is first connected. In some cases, a flow path is formed. Each modification is appropriately selected according to the configuration of the exhaust heat recovery boiler 2 so that the length of the third temporary pipe branched is short and the pipe is simple. This simplifies the management of the temporary piping during blowing out, and can be expected to have a cost advantage.

  Further, in the above-described embodiment and the modified example, the drum type heat recovery steam generator has been described as an example, but the type of the heat recovery steam generator is not limited thereto. For example, a once-through type using a brackish water separator instead of the steam drum may be used. Further, in addition to a horizontal exhaust heat recovery boiler in which heat transfer tube panels are arranged in a horizontal direction, a vertical exhaust heat recovery boiler in which heat transfer tube panels are arranged in a vertical direction may be used. The scale of the power generation equipment, the configuration of the steam system, the arrangement of the water supply pumps, and the like are not particularly limited to the above-described embodiments and modifications, and may be determined according to the design and the like as long as the technical idea according to the present invention is not deviated. Various modifications are possible.

1: gas turbine, 2: waste heat recovery boiler, 2a: waste heat recovery boiler, 2b: waste heat recovery boiler, 2c: waste heat recovery boiler, 3: steam turbine, 4: generator, 5: condenser, 6 : Condensate pump, 7: low pressure feed pump, 8: low pressure economizer, 9: low pressure drum, 10: low pressure evaporator, 11: low pressure superheater, 12: high and medium pressure feed 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: Condensate line, 28: High and medium pressure Water supply line, 29: economizer recirculation pump,
31: first temporary pipe, 32: second temporary pipe, 33: third temporary pipe, 34: third temporary pipe, 35: third temporary pipe, 39: exhaust silencer,
41: high pressure system, 42: medium pressure system, 43: low pressure system, 44: reheating system,
100: Combined cycle power generation equipment

Claims (8)

Superheated steam generated in the evaporator with a superheater, a main steam system for supplying superheated steam generated in the superheater to a steam turbine, and steam extracted from the steam turbine are reheated in a reheater. Prior to the start of operation of a boiler provided with a reheat steam system that supplies the steam turbine to the steam turbine, the reheat steam system is used in blowing out, which is an operation of blowing the reheat steam system with steam generated in the main steam system. In the temporary piping system for boiler blowing out,
A first temporary pipe that supplies the superheated steam generated by the superheater to the reheat steam system, bypassing the steam turbine,
A second temporary pipe that discharges steam that has passed through the reheater to the atmosphere during the blowing out,
Boiler blowing, characterized by comprising: a third temporary pipe that allows a part of steam supplied to the superheater of the main steam system to bypass the superheater and flow downstream from an outlet of the superheater. Temporary piping system for out. The temporary piping system for blowing out a boiler according to claim 1,
The temporary piping system for blowing out a boiler, wherein the third temporary piping is connected from the upstream of the superheater to the first temporary piping. The temporary piping system for blowing out a boiler according to claim 2,
The main steam system evaporator includes a steam drum for temporarily storing generated steam,
The temporary piping system for blowing out a boiler, wherein the third temporary piping is connected to the first temporary piping from a steam drum outlet of the main steam system. The temporary piping system for blowing out a boiler according to claim 2,
The main steam system includes a plurality of the superheaters,
The temporary piping system for boiler blowing-out, wherein the third temporary piping is connected to the first temporary piping from an inlet side of a predetermined one of the plurality of superheaters. The temporary piping system for blowing out a boiler according to claim 1,
The said temporary piping is connected from the inlet side of the said superheater to the outlet side of the said superheater, The temporary piping system for blowing out of a boiler characterized by the above-mentioned. The temporary piping system for blowing out a boiler according to claim 1,
The main steam system includes a plurality of the superheaters,
The third temporary pipe is, from among the plurality of superheaters, an exhaust gas flow path through which exhaust gas from the steam turbine flows, and the exhaust gas flow path from the superheater located at the most downstream side of the superheater. A temporary piping system for blowing out a boiler, wherein the temporary piping system is connected to an inlet side of any one of the superheaters disposed upstream of the boiler. The temporary piping system for blowing out a boiler according to claim 1,
The boiler is a high-pressure system having the superheater, the evaporator, and the economizer in order from the upstream side to the downstream side of an exhaust gas flow path through which exhaust gas from the steam turbine flows, as the main steam system. A system and a low-pressure system, wherein each of the evaporators is an exhaust heat recovery boiler to which a steam drum for temporarily storing generated steam is connected,
The first temporary pipe is a low-temperature pipe 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 the reheat steam pipe,
The second temporary pipe is connected to a high-temperature reheat steam pipe that supplies the steam reheated by the reheater to the steam turbine, and discharges steam that has passed through the reheater to the atmosphere,
The temporary piping system for boiler blow-out, wherein the third temporary piping is connected to the first temporary piping from an outlet of the steam drum of the high-pressure system. A method for blowing out a boiler using the temporary piping system for blowing out a boiler according to claim 1,
Cutting off the supply of steam from the superheater and the reheater to the steam turbine,
The heating steam generated by the superheater is supplied to the reheating steam system via the first temporary pipe, and a part of the steam before being supplied to the superheater is supplied to the third temporary pipe. By supplying to the first temporary pipe via, mixed with the superheated steam supplied to the reheat steam system via the first temporary pipe,
Blowing the mixed steam into the reheater to blow the reheater,
A method for blowing out a boiler, wherein the steam after blowing the reheater is discharged to the atmosphere via the second temporary pipe.

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