KR20220001895A - Structure and method for intalling reheater for cfbc boiler - Google Patents

Abstract

In accordance with the present invention, an installation structure of a reheater includes the main tube part including the first and second main tubes connected to be consecutively joined in a flowing direction of steam to be heated in a heating space of a circulating fluidized bed combustion boiler. The installation structure includes a tube-shaped inlet-side sleeve which is installed on an outer wall of the heating space and through which the first main tube passes. The inlet-side sleeve includes first and second sleeve tubes connected to be consecutively joined, and the first sleeve tube and the first main tube are welded to be combined. The quality of the first sleeve tube contains no more than 0.07 wt% of carbon (C), no more than 0.75 wt% of silicon (Si), no more than 2.00 wt% of manganese (Mn), no more than 0.045 wt% of phosphorus (P), no more than 0.003 wt% of sulfur (S), no more than 10.5 wt% of nickel (Ni), and 18.0-20.0 wt% of chromium (Cr).

Description

Installation structure and method of reheater for circulating fluidized bed combustion boiler {STRUCTURE AND METHOD FOR INTALLING REHEATER FOR CFBC BOILER}

The present invention relates to a circulating fluidized bed combustion boiler, and more particularly, to a technology for installing a reheater for a circulating fluidized bed combustion boiler.

Circulating Fluidized Bed Combustion (CFBC) boiler is a boiler that completely burns solid fuel such as coal by continuously circulating heat. It has an eco-friendly circulation structure that can significantly reduce emissions.

A circulating fluidized bed combustion boiler in a power generation facility is provided with a reheater for reheating the high-temperature and low-pressure steam discharged from the high-pressure turbine as steam for medium and low-pressure turbines. As a tube used in the reheater, a tube of ASME standard SA213 T91 for high temperature use and a tube of SA213 T22 are mainly used.

In the case of using biomass containing a large amount of chlorine (Cl) as fuel in a circulating fluidized bed combustion boiler, sulfur (S) corrosion (0.02 mm/year) compared to excessive thickness reduction (0.6mm/year), the installation technology of the reheater is required in response to the changed material of the reheater tube along with the reheater tube made of a material with improved corrosion resistance to chlorine. do.

Republic of Korea Utility Model Publication No. 20-0328130 "Structure of heat exchanger tube arrangement of fluidized bed boiler" (2003.09.26.)

An object of the present invention is to provide an installation structure and method of a reheater for a circulating fluidized bed combustion boiler having excellent corrosion resistance to chlorine.

In order to achieve the object of the present invention, according to one aspect of the present invention, a first main tube and a second main tube connected to be continuously connected along the flow direction of the steam to be heated in the heating space of the circulating fluidized bed combustion boiler An installation structure of a reheater having a main tube portion including a tube, comprising: an inlet sleeve in the form of a tube installed on an outer wall of the heating space and through which the first main tube passes, wherein the inlet sleeve is continuously connected A first sleeve tube and a second sleeve tube are connected to each other, wherein the first sleeve tube and the first main tube are welded to each other, and the material of the first sleeve tube is carbon (C) 0.07 weight % or less, silicon (Si) 0.75 wt% or less, manganese (Mn) 2.00 wt% or less, phosphorus (P) 0.045 wt% or less, sulfur (S) 0.003 wt% or less, nickel (nickel) , Ni) 10.5 wt% or less, chromium (chromium, Cr) that contains 18.0 ~ 20.0 wt%, the installation structure of the reheater for a circulating fluidized bed combustion boiler is provided.

In order to achieve the object of the present invention, according to another aspect of the present invention, a first main tube and a second main tube connected to be continuously connected along the flow direction of the steam to be heated in the heating space of the circulating fluidized bed combustion boiler A method of installing a reheater having a main tube portion having a tube, comprising: a sleeve preparation step of preparing a tube-shaped inlet sleeve manufactured by continuously welding a first sleeve tube and a second sleeve tube; a tube welding step of welding the first main tube to only the first sleeve tube among the first sleeve tube and the second sleeve tube while the first main tube passes through the inlet sleeve; and a wall welding step of welding and bonding the inlet sleeve to the outer wall of the heating space, wherein the material of the first sleeve tube is carbon (C) 0.07 wt% or less, silicon (Si) 0.75 Weight % or less, manganese (Mn) 2.00 wt% or less, phosphorus (P) 0.045 wt% or less, sulfur (S) 0.003 wt% or less, nickel (nickel, Ni) 10.5 wt% or less, chromium ( chromium, Cr) containing 18.0 to 20.0 wt%, a method of installing a reheater for a circulating fluidized bed combustion boiler is provided.

According to the present invention, all of the objects of the present invention described above can be achieved. Specifically, the portion in contact with the combustion gas containing chlorine (Cl) component in the tube of the reheater is made of nickel-chromium alloy steel containing nickel (Ni) and chromium (Cr) with improved corrosion resistance to chlorine component, In the inlet sleeve that surrounds the inlet tube of the reheater and is joined to the outer wall of the heating space, the part welded to the tube of the reheater is made of a material having a coefficient of thermal expansion similar to that of the tube of the reheater, so thermal stress is minimized for structural safety can improve

1 is a view showing a schematic configuration of a circulating fluidized bed combustion boiler to which a reheater installation structure according to an embodiment of the present invention is applied.
2 is a side view illustrating a state in which the reheater for the circulating fluidized bed combustion boiler shown in FIG. 1 is installed in the reheater installation structure according to an embodiment of the present invention.
FIG. 3 is a view showing the configuration of a tube structure in the reheater shown in FIG. 2 .
4 is an enlarged side view of the installation part of the inlet sleeve in FIGS. 2 and 3 .
FIG. 5 is a perspective view of the inlet sleeve shown in FIG. 4 ;
6 is a flowchart schematically illustrating a method of installing a reheater for a circulating fluidized bed combustion boiler according to an embodiment of the present invention.

Hereinafter, the configuration and operation of the embodiment of the present invention will be described in detail with reference to the drawings.

1 shows a schematic configuration of a circulating fluidized bed combustion boiler to which a reheater installation structure according to an embodiment of the present invention is applied. 1, the circulating fluidized bed combustion boiler 10 separates and collects solids from a combustion furnace 11 in which fluidized bed combustion of solid fuel is performed, and combustion exhaust gas discharged from the combustion furnace 11. The solid content separator 12, the heat transfer unit 13 where heat exchange is performed by the combustion exhaust gas discharged from the solid content separator 12, and the heat transfer unit 13 are installed to heat the combustion exhaust gas to heat the steam discharged from the high-pressure turbine. A reheater 100 for reheating is provided. The solids collected in the solid content separator 12 are supplied to the combustion furnace 11 and recycled. The object of the present invention is the installation structure of the reheater 100, and the remaining components are made of the technology used in a conventional circulating fluidized bed combustion boiler, so only the installation structure of the reheater 100 and the reheater 100 is detailed explain in detail. In the present embodiment, it is described that the reheater 100 is installed in the heat transfer unit 13 as shown in FIG. 1 , but the present invention is not limited thereto.

2 is a side view showing a state in which the reheater 100 for a circulating fluidized bed combustion boiler is installed in the reheater installation structure according to an embodiment of the present invention. Referring to FIG. 2 , the reheater 100 includes an inlet header 110 , an outlet header 120 , and a ash formed between the inlet header 110 and the outlet header 120 . and a hot air tube structure 130 . In this embodiment, it is described that the reheater 100 is installed in the heat transfer unit (13 in FIG. 1 ) so that the inlet header 110 is positioned below and the outlet header 120 is positioned above, as shown in the present embodiment. The invention is not limited thereto.

The inlet header 110 is disposed outside the side of the heat transfer unit ( 13 in FIG. 1 ) where the reheater 100 is installed. A reheater tube structure 130 is connected to the inlet header 110 . The reheat target steam discharged from the high-pressure turbine is supplied to the reheater tube structure 130 through the inlet header 110 . The inlet header 110 is in the form of a tube, and is disposed to extend generally in a horizontal direction.

The exit header 120 is disposed on the outside of the side of the heat transfer unit (13 in FIG. 1 ) in which the reheater 100 is installed, above the input guess header 110 . A reheater tube structure 130 is connected to the outlet header 110 . The steam discharged from the reheater tube structure 130 is collected and discharged to the outlet side header 120 . The outlet header 120 is in the form of a tube, and is disposed to extend generally in a horizontal direction.

The reheater tube structure 130 is formed between the inlet header 110 and the outlet header 120 . The reheater tube structure 130 communicates with the inlet header 110 and the outlet header 120 and includes a plurality of tube structures 140 that are arranged to extend in parallel.

The plurality of tube structures 140 are arranged to extend in parallel, and each communicates with the inlet header 110 and the outlet header 120 . The tube structure 140 provides a vapor passage through which the vapor flows. The steam introduced through the inlet header 110 is reheated while flowing to the outlet header 120 through the vapor passage. Each of the plurality of tube structures 140 passes through the inlet sleeve 101 from the inlet header 110 side, and passes through the outlet sleeve 109 from the outlet header 110 side. The inlet sleeve 101 and the outlet sleeve 109 constitute a reheater installation structure according to an embodiment of the present invention.

3 is an enlarged view of the configuration of the tube structure 140 in more detail. 2 and 3 , the tube structure 140 is formed by connecting a plurality of tubes in series, and includes a first header tube 150 extending from the inlet header 110 and an outlet header. A second header-side tube 160 extending from 120 , a main tube portion 170 extending between the first header-side tube 150 and the second header-side tube 160 , and the first header side A first connecting tube 180 connecting between the tube 150 and the main tube 170 and a second connecting tube connecting between the second header side tube 160 and the main tube 170 ( 190) is provided.

The first header-side tube 150 extends along the steam flow direction from the inlet-side header 110 so that an end thereof is connected to the first connection tube 180 . One end of both ends of the first header-side tube 150 is connected to communicate with the inlet header 110 from the outside of the heat transfer unit (13 in FIG. 1), and the other end is formed from the outside of the heat transfer unit (13 in FIG. 1). 1 It is connected so as to be connected to the connection tube 180 . In this embodiment, the first header-side tube 150 has an outer diameter of 44.5 mm and a minimum wall thickness (MWT) of 3.81 mm, and its material is ASME (American Society of Mechanical Engineers) standard SA213 T11. described as being

The second header-side tube 160 extends from the outlet-side header 120 in a direction opposite to the flow of steam so that an end thereof is connected to the second connection tube portion 190 . One end of both ends of the second header side tube 160 is connected to communicate with the outlet header 120 from the outside of the heat transfer unit (13 in FIG. 1), and the other end is connected to the outside of the heat transfer unit (13 in FIG. 1). It is connected so as to be connected to the 2 connection tube portion 190 . In this embodiment, the second header-side tube 160 has an outer diameter of 44.5 mm and a minimum thickness of 3.81 mm, and the material of the ASME standard SA213 T91 is described as being used.

The main tube portion 170 extends between the first header side tube 150 and the second header side tube 160 . The main tube portion 170 occupies most of the length section in the entire length section of the tube structure 140 . One end of both ends of the main tube unit 170 is connected to the first connection tube 180 from the outside of the heat transfer unit (13 in FIG. 1), and the other end is connected to the second end outside the heat transfer unit (13 in FIG. 1). It is connected so as to be connected to the connection tube part 190 . Both ends of the main tube portion 170 protrude to the outside while forming a substantially right angle with the outer wall W of the heat transfer unit (13 in Fig. 1), and the inlet sleeve 101 and the outlet sleeve coupled to the outer wall W ( 109) is passed. In the present embodiment, one end connected to the first connecting tube 180 in the main tube unit 170 is located below the other end connected to the second connecting tube unit 190 . In this embodiment, it will be described that combustion exhaust gas flows from top to bottom in the inner space of the heat transfer unit (13 in FIG. 1), which is a heating space. Accordingly, it becomes a high-temperature region with a higher temperature as it goes upward in the inner space of the heat transfer unit ( 13 in FIG. 1 ). Among both ends of the main tube 170, the inlet end connected to the first connecting tube 180 passes through the inlet sleeve 101, and the second connecting tube 109 and the outlet end are connected to the outlet sleeve ( 109) is passed.

The main tube part 170 is formed to extend in a zigzag shape in the internal space (heating space) of the heat transfer part (13 of FIG. 1) in contact with the combustion exhaust gas. Specifically, the main tube portion 170 extends horizontally long from the end connected to the first connection tube 180 and then is bent to slightly extend upward, and then bent in the opposite horizontal direction to extend long and then bent to extend upward Then, it is bent again in the horizontal direction to extend long, then is bent to extend upward, and again is bent in the opposite horizontal direction to extend long and is connected to the second connection tube part 190 . That is, the main tube unit 170 is configured such that the steam to be heated flows in a direction substantially perpendicular to the flow direction of the combustion exhaust gas in the heating space repeatedly while flowing in the direction of flow of the combustion exhaust gas and discharged.

The main tube unit 170 includes a first main tube 171 and a second main tube 175 that are continuously connected along the flow direction of the heating target steam flowing therein. That is, in the heating space, the first main tube 171 is located in a relatively low temperature region, and the second main tube 175 is located in a relatively high temperature region. In this embodiment, both main tubes 171 and 175 have an outer diameter of 44.5 mm and a minimum thickness of 3.81 mm. The first main tube 171 passes through the inlet sleeve 101 , and the second main tube 175 passes through the outlet sleeve 109 . The inlet sleeve 101 and the outlet sleeve 109 are attached to the outer wall W of the heat transfer unit (13 in FIG. 1) while protecting the first main tube 171 and the second main tube 175 that are subjected to internal pressure, respectively. combined to prevent leakage of combustion exhaust gases.

The first main tube 171 is a nickel-chromium alloy steel, carbon (C) 0.07 to 0.13 wt% or less, silicon (Si) 0.30 wt% or less, manganese (Mn) 1.00 wt% or less, phosphorus ( phosphorus, P) 0.040 wt% or less, sulfur (S) 0.010 wt% or less, nickel (Ni) 7.5 to 10.5 wt%, chromium (Cr) 17.0 to 19.0 wt%, niobium (Nb) 0.30 to 0.60 wt%, copper (Cu) 2.5 to 3.5 wt%, nitrogen (N) 0.05 to 0.12 wt%, aluminum (aluminum, Al) 0.003 to 0.030 wt%, boron (B) 0.001 to 0.010% by weight.

The second main tube 175 is a nickel-chromium alloy steel, carbon (C) 0.10 wt% or less, silicon (Si) 0.50 wt% or less, manganese (Mn) 0.50 wt% or less, phosphorus (phosphorus, P) 0.015 wt% or less, sulfur (S) 0.015 wt% or less, nickel (Ni) 58.00 wt% or more, chromium (Cr) 20.00 ~ 23.00 wt%, molybdenum (Mo) 8.00 ~ 10.00 wt%, aluminum (Al) 0.40 wt% or less, titanium (Titanium, Ti) 0.40 wt% or less, iron (iron, Fe) 5.00 wt% or less, cobalt (Co) 1.0 wt% or less, niobium , Nb) + tantalum (Ta) 3.15 to 4.15% by weight.

The second main tube 175 disposed in the high temperature region contains a large amount of nickel (Ni) and chromium (Cr), and the first main tube 171 disposed in the low temperature region is also made of a material containing nickel and chromium. Corrosion resistance to chlorine contained in the combustion exhaust gas of the main tube portion 170 was significantly improved. In the case of the present invention, the corrosion rate is 0.1mm/year in the same combustion environment using biomass as fuel, whereas the existing ASME standard SA213 T22 tube and ASME standard SA213 T91 tube are connected. The corrosion rate is 0.6mm/year.

In this embodiment, the temperature of the gas in the environment in which the main tube unit 170 is used (that is, the combustion gas in the portion where the main tube unit 170 is located in the heat transfer unit 13) is about 870 ° C. It is explained that the concentration of chlorine component contained in the gas is about 3000 PPM.

The first connection tube 180 is disposed outside the heat transfer unit ( 13 of FIG. 1 ) to connect the first header side tube 150 and the first main tube 171 . Both ends of the first connection tube 180 are respectively welded to the first header side tube 150 and the first main tube 171 . The first connecting tube 180 is made of ASME standard SA213 T11, which is the same material as the first header side tube 150 . The first connecting tube 180 and the first main tube 171, which are of different materials, are welded and connected in a factory, and the first connecting tube 180 and the first header side tube, which are easy to weld at a site with poor working conditions, are used. Homogeneous welding for 150 is made. The first connecting tube 180 has an outer diameter of 44.5 mm and a minimum thickness of 3.81 mm.

The second connecting tube unit 190 is disposed outside the heat transfer unit (13 of FIG. 1 ) to connect the second header side tube 160 and the second main tube 175 . Both ends of the second connection tube portion 190 are respectively welded to the second header side tube 160 and the second main tube 175 . The second connecting tube unit 190 includes a 2A connecting tube 191 and a 2B connecting tube 195 that are continuously connected by welding.

The 2A connecting tube 191 is continuously connected to the second main tube 175 by welding. The 2A connection tube 191 is made of the same material as the first main tube 171 , and has an outer diameter of 44.5 mm and a minimum thickness of 3.81 mm. As the 2A connection tube 191 uses the same material as the first main tube 171 , there is no need for dissimilar welding in the field, and it is possible to prevent premature creep damage and oxidative peeling caused by existing materials.

The 2B connection tube 195 is continuously connected to the second header tube 160 by welding. 2B connection tube 195 is made of ASME standard SA213 TP347H material, has an outer diameter of 44.5mm and a minimum thickness of 3.81mm.

A feature of the present invention is the inlet sleeve 101 constituting the reheater installation structure. 3, 4 and 5, the inlet sleeve 101 is in the form of a tube surrounding the first main tube 171, and the passage 105 formed in the inlet sleeve 101 is connected to the first main tube ( 171) is combined as it passes. The inlet sleeve 101 is welded to and coupled to the outer wall W so that the first main tube 171 passes through the outer wall W at a position where the first main tube 171 passes the outer wall W of the heat transfer unit (13 in FIG. 1 ). In this embodiment, the inlet sleeve 101 will be described as having an outer diameter of 54 mm and a minimum thickness of 3.87 mm. The inlet sleeve 101 is a form in which the first sleeve tube 102 and the second sleeve tube 103 having the same outer diameter (54 mm) and minimum thickness (3.87 mm) are welded and continuously connected. In this embodiment, the first sleeve tube 102 and the second sleeve tube 103 will be described as having the same length. The first main tube 101 is welded to and coupled to the first sleeve tube 102 among the first sleeve tube 102 and the second sleeve tube 103, and the outer wall W of the heat transfer unit (13 in FIG. 1) is welded to the second sleeve 103 of the first sleeve tube 102 and the second sleeve tube 103 .

The first sleeve tube 102 is a nickel-chromium alloy steel, carbon (C) 0.07 wt% or less, silicon (Si) 0.75 wt% or less, manganese (Mn) 2.00 wt% or less, phosphorus (phosphorus, P) 0.045 wt% or less, sulfur (S) 0.003 wt% or less, nickel (nickel, Ni) 10.5 wt% or less, and chromium (Cr) 18.0 to 20.0 wt%. The first sleeve tube 102 having this chemical composition has a coefficient of thermal expansion similar to that of the first main tube 171 welded together, as can be seen from Tables 1 and 2 below. Therefore, the thermal stress due to the difference in the amount of thermal expansion can be minimized. Table 1 below shows the coefficient of thermal expansion according to the temperature of the material of the first sleeve tube 102 , and Table 2 shows the coefficient of thermal expansion according to the temperature of the material of the first main tube 101 .

Temperature 0-100℃ 0-315℃ 0-538℃ coefficient of thermal expansion 17.2 17.8 18.4

Temperature R.T.-300℃ R.T.-400℃ R.T.-500℃ R.T.-600℃ R.T.-700℃ R.T.-800℃ coefficient of thermal expansion 17.5 17.8 18.1 18.4 18.6 18.8

The second sleeve tube 103 is made of a material of ASME standard SA213 T22. The second slab tube 103 is coupled to the outer wall W by welding while passing through a through hole (not shown) formed in the outer wall W of the heat transfer unit (13 in FIG. 1 ). In this embodiment, the material of the outer wall (W) is of ASME standard SA387 Grade 11.

6 is a flowchart illustrating a method of installing a reheater for a circulating fluidized bed combustion boiler according to an embodiment of the present invention. Referring to FIG. 6 , in the method of installing a reheater for a circulating fluidized bed combustion boiler according to an embodiment of the present invention, the sleeve preparation step of preparing the inlet sleeve 101 having the configuration as shown in FIG. 4 ( S10 ) And, a tube welding step (S20) of welding the first main tube (171 in FIG. 4) to the inlet sleeve 101, and attaching the inlet sleeve 101 to the outer wall of the heat transfer unit (13 in FIG. 1) ( It includes a wall welding step (S30) of welding to W).

In the sleeve preparation step (S10), the inlet sleeve 101 of the configuration as shown in FIG. 4 described above is prepared. In the sleeve preparation step (S10), the inlet sleeve 101 is manufactured by welding the first sleeve tube 102 and the second sleeve tube 103 at the factory rather than the installation site of the circulating fluidized bed combustion boiler (10 in FIG. 1). performed by becoming

In the tube welding step (S20), the first main tube (171 in FIG. 4) is welded and coupled to the inlet sleeve 101 prepared through the sleeve preparation step (S10). The tube welding step (S20) is performed by welding the first main tube 171 and the inlet sleeve 101 at the factory rather than the installation site of the circulating fluidized bed combustion boiler (10 in FIG. 1). Specifically, in the tube welding step (S20), the first main tube 171 and the first main tube 171 and the inlet sleeve 101 are inserted in the passage 105 of the inlet sleeve 101 so that the first main tube 171 passes. 1 The sleeve tube 102 is welded.

In the wall welding step (S30), the inlet sleeve 101 coupled with the first main tube 171 through the tube welding step (S20) is welded to and coupled to the outer wall W of the heat transfer unit (13 in FIG. 1 ) . Specifically, in the wall welding step (S30), the inlet sleeve 101 is inserted into a through hole (not shown) formed in the outer wall W, and at this time, the second sleeve tube 103 section of the inlet sleeve 101 Located on the outer wall (W), the second sleeve tube 103 is welded to the outer wall (W). The entire first sleeve tube 102 of the inlet sleeve 101 is located in the inner space of the outer wall W, which is a heating space, and the second slip tube 103 of the inlet sleeve 101 forms the outer wall W. It is placed between the inner space and the outer space.

Although the present invention has been described through the above examples, the present invention is not limited thereto. The above embodiments may be modified or changed without departing from the spirit and scope of the present invention, and those skilled in the art will recognize that such modifications and changes also belong to the present invention.

100: reheater for circulating fluidized bed combustion boiler
101: inlet sleeve
102: first sleeve tube
103: second sleeve tube
109: exit sleeve
110: entry header
120: exit header
130: reheater tube structure
140: tube structure
150: first header side tube
160: second header side tube
170: main tube part
171: first main tube
175: second main tube
180: first connection tube
190: second connection tube part

Claims (8)

An installation structure of a reheater having a main tube portion having a first main tube and a second main tube connected to be continuously connected along a flow direction of a steam to be heated in a heating space of a circulating fluidized bed combustion boiler, the reheater comprising:
It is installed on the outer wall of the heating space and includes an inlet sleeve in the form of a tube through which the first main tube passes,
The inlet sleeve includes a first sleeve tube and a second sleeve tube connected to be continuously connected,
The first sleeve tube and the first main tube are joined by welding,
The material of the first sleeve tube is carbon (C) 0.07 wt% or less, silicon (Si) 0.75 wt% or less, manganese (Mn) 2.00 wt% or less, phosphorus (P) 0.045 wt% % or less, sulfur (S) 0.003 wt% or less, nickel (nickel, Ni) 10.5 wt% or less, chromium (Cr) 18.0 to 20.0 wt% or less,
Installation structure of reheater for circulating fluidized bed combustion boiler. The method according to claim 1,
The material of the first main tube is carbon (C) 0.07 to 0.13 wt% or less, silicon (Si) 0.30 wt% or less, manganese (Mn) 1.00 wt% or less, phosphorus (P) 0.040 wt% or less, sulfur (S) 0.010 wt% or less, nickel (Ni) 7.5 to 10.5 wt%, chromium (Cr) 17.0 to 19.0 wt%, niobium (Nb) 0.30 to 0.60 wt% %, copper (Cu) 2.5 to 3.5 wt%, nitrogen (N) 0.05 to 0.12 wt%, aluminum (aluminum, Al) 0.003 to 0.030 wt%, boron (B) 0.001 to 0.010 wt% which contains,
Installation structure of reheater for circulating fluidized bed combustion boiler. The method according to claim 1,
wherein the second sleeve tube is welded to the outer wall;
Installation structure of reheater for circulating fluidized bed combustion boiler. 4. The method according to claim 3,
The entirety of the first sleeve tube is located in the heating space,
The second sleeve tube is positioned inside and outside the heating space with the outer wall interposed therebetween,
Installation structure of reheater for circulating fluidized bed combustion boiler. 4. The method according to claim 3,
The material of the second sleeve tube is that of ASME standard SA213 T22,
The material of the outer wall is that of ASME standard SA387 Grade 11,
Installation structure of reheater for circulating fluidized bed combustion boiler. A method of installing a reheater having a main tube portion having a first main tube and a second main tube connected to be continuously connected along a flow direction of a steam to be heated in a heating space of a circulating fluidized bed combustion boiler, the reheater comprising:
A sleeve preparation step of preparing a tube-shaped inlet sleeve manufactured by welding the first sleeve tube and the second sleeve tube to be continuously connected;
a tube welding step of welding the first main tube to only the first sleeve tube among the first sleeve tube and the second sleeve tube while the first main tube passes through the inlet sleeve; and
a wall welding step of welding and joining the inlet sleeve to an outer wall of the heating space;
The material of the first sleeve tube is carbon (C) 0.07 wt% or less, silicon (Si) 0.75 wt% or less, manganese (Mn) 2.00 wt% or less, phosphorus (P) 0.045 wt% % or less, sulfur (S) 0.003 wt% or less, nickel (nickel, Ni) 10.5 wt% or less, chromium (Cr) 18.0 to 20.0 wt% or less,
Installation method of reheater for circulating fluidized bed combustion boiler. 7. The method of claim 6,
The wall welding step is performed by welding the outer wall and the inlet sleeve in a state where the inlet sleeve is inserted into the through hole formed in the outer wall,
Installation method of reheater for circulating fluidized bed combustion boiler. 8. The method of claim 7,
In the wall welding step, the whole of the first sleeve tube is located in the heating space, and the second sleeve tube is arranged to be located inside and outside the heating space with the outer wall therebetween,
Installation method of reheater for circulating fluidized bed combustion boiler.

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