WO2020054011A1

WO2020054011A1 - Steam-pipe temperature measurement device, steam-pipe temperature measurement method

Info

Publication number: WO2020054011A1
Application number: PCT/JP2018/033921
Authority: WO
Inventors: 西田　秀高
Original assignee: 中国電力株式会社
Priority date: 2018-09-13
Filing date: 2018-09-13
Publication date: 2020-03-19

Abstract

A steam-pipe temperature measurement device according to the present invention includes: an optical fiber for measuring the temperature of the surface of a steam pipe inside which steam obtained through heat exchange between water to be supplied to a boiler and a combustion gas circulates; a first cover that is mounted so as to surround the steam pipe, with the optical fiber sandwiched between the first cover and the steam pipe, such that the optical fiber is brought into close contact with the steam pipe along the longitudinal direction of the steam pipe, at a first position where the temperature of the surface of the steam pipe is measured; a heat pipe for cooling the optical fiber; and a second cover that is mounted so as to surround the steam pipe, with the optical fiber and the heat pipe sandwiched between the second cover and the steam pipe, such that, at a second position adjacent to the first position, the optical fiber is adjacent to the steam pipe along the longitudinal direction of the steam pipe, and the heat pipe surrounds the optical fiber along the longitudinal direction of the steam pipe.

Description

Steam pipe temperature measuring device, steam pipe temperature measuring method

The present invention relates to a steam pipe temperature measuring device and a steam pipe temperature measuring method.

For example, in a boiler for power generation in a thermal power plant, a steam pipe (for example, a superheater or a reheater) for circulating steam obtained by heat-exchanging water supplied from a condenser with combustion gas is installed. Have been. The steam pipe is composed of a boiler tube containing heat-resistant steel (for example, low alloy steel) as a component. However, if the steam pipe is continuously used at a high temperature exceeding the design standards, the outer circumferential surface of the steam pipe will increase with the progress of creep damage. Of the steam pipe or the thickness of the steam pipe may be reduced. Therefore, inspections are being conducted to prevent the accident caused by the deterioration of the steam pipe by grasping the combustion state of the boiler and the remaining life of the steam pipe from the measurement result of the surface temperature of the steam pipe (for example, Patent Reference 1).

JP 2013-190229 A

場合 When grasping the boiler combustion state and the remaining life of the steam pipe, it is necessary to measure the surface temperature of the steam pipe over a wide range and obtain the temperature distribution of the surface temperature of the steam pipe.

For example, a thermocouple may be used as a means for measuring the surface temperature of a steam pipe. However, when a thermocouple is used, only the surface temperature in a narrow range of the steam pipe can be measured, so that it is difficult to obtain the temperature distribution of the surface temperature of the steam pipe.

Therefore, an object of the present invention is to provide a temperature measuring device capable of reliably measuring the surface temperature of a steam pipe over a wide range.

The main invention for solving the above-mentioned problems is an optical fiber for measuring a surface temperature of a steam pipe in which steam obtained by heat-exchanging water supplied to a boiler with a combustion gas circulates, and the steam pipe. At a first position where the surface temperature is measured, the optical fiber is attached so as to surround the steam pipe with the optical fiber interposed therebetween so that the optical fiber is in close contact with the steam pipe along the longitudinal direction of the steam pipe. 1 cover, a heat pipe for cooling the optical fiber, and a second position adjacent to the first position, wherein the optical fiber is adjacent to the steam pipe along a longitudinal direction of the steam pipe and the heat pipe A second pipe is mounted so as to surround the optical fiber and the heat pipe so as to surround the optical fiber along a longitudinal direction of the steam pipe. It includes a bar, a.

の他 Other features of the present invention will be apparent from the accompanying drawings and the description of this specification.

According to the present invention, it is possible to reliably measure the surface temperature of the steam pipe over a wide range.

It is a figure showing an example of the whole composition of the thermal power plant in which the temperature measuring device of the steam pipe concerning this embodiment is used. It is a perspective view showing a situation before attaching the 1st cover used for the temperature measuring device concerning this embodiment to a straight pipe part of a steam pipe. It is a perspective view showing signs that a 1st cover used for a temperature measuring device concerning this embodiment has been attached to a straight pipe part of a steam pipe. It is sectional drawing which shows the mode after attaching the 1st cover used for the temperature measuring apparatus which concerns on this embodiment to the straight pipe part of a steam pipe. It is a perspective view showing a situation before attaching the 1st cover used for the temperature measuring device concerning this embodiment to the curved pipe part of a steam pipe. It is a perspective view showing signs that a 1st cover used for a temperature measuring device concerning this embodiment is attached to a curved pipe part of a steam pipe. It is sectional drawing which shows the mode after attaching the 1st cover used for the temperature measuring apparatus which concerns on this embodiment to the curved pipe part of a steam pipe. It is a perspective view showing a situation before attaching the 2nd cover used for the temperature measuring device concerning this embodiment to a straight pipe part of a steam pipe. It is a perspective view showing signs that a 2nd cover used for a temperature measuring device concerning this embodiment has been attached to a straight pipe part of a steam pipe. It is sectional drawing which shows the mode after attaching the 2nd cover used for the temperature measuring device which concerns on this embodiment to the straight pipe part of a steam pipe. It is a perspective view showing the situation before attaching the 2nd cover used for the temperature measuring device concerning this embodiment to the curved pipe part of a steam pipe. It is a perspective view showing signs that a 2nd cover used for a temperature measuring device concerning this embodiment is attached to a curved pipe part of a steam pipe. It is sectional drawing which shows the mode after attaching the 2nd cover used for the temperature measuring device which concerns on this embodiment to the curved pipe part of a steam pipe. It is a schematic diagram which shows an example of the steam pipe installed in a boiler. It is a schematic diagram which shows an example when the temperature measuring device which concerns on this embodiment is installed in a boiler.

、 At least the following matters will be made clear by the description in this specification and the accompanying drawings.

=== Example of Overall Configuration of Thermal Power Plant ===
FIG. 1 is a diagram illustrating an example of an overall configuration of a thermal power plant in which the steam pipe temperature measuring device according to the present embodiment is used.

The thermal power plant 1 includes a boiler 2, a steam generator 3, a water cooling wall 4, a steam valve 5, a high-pressure turbine 6, a medium-pressure turbine 7, a low-pressure turbine 8, a reheater 9, a condenser 10, a feedwater pump 11, and a power generator. Machine 12.

The boiler 2 is a heat exchange device that mixes fuel (for example, pulverized coal) supplied from the outside with air and generates combustion gas, and uses the heat of the combustion gas to convert water into steam. The boiler 2 houses a steam generator 3, a water cooling wall 4, and a reheater 9. The steam generator 3 includes a economizer (not shown) that preheats water supplied from the condenser 10 and a superheater (not shown) that further heats saturated steam supplied from the water cooling wall 4 to superheated steam. ). The water cooling wall 4 forms the housing of the boiler 2 and supplies the superheated water to the superheater as saturated steam. The steam valve 5 is a regulating valve that controls the flow rate of superheated steam generated by the steam generator 3.

The rotating shafts 13 of the high-pressure turbine 6, the medium-pressure turbine 7, and the low-pressure turbine 8 are the same, and are connected to the rotating shaft 14 of the generator 12. Superheated steam (first steam) generated by the steam generator 3 is supplied to the high-pressure turbine 6 via the steam valve 5. The high-pressure turbine 6 expands the first steam and supplies the expanded steam (second steam) to the reheater 9 in the boiler 2. The reheater 9 reheats the second steam and supplies it to the medium-pressure turbine 7 as reheated steam (third steam). The medium-pressure turbine 7 expands the third steam and supplies the expanded steam (fourth steam) to the low-pressure turbine 8. The low-pressure turbine 8 expands the fourth steam.

(4) The condenser 10 condenses the exhaust gas after the low-pressure turbine 8 expands the fourth steam and converts the exhaust gas into condensate water. The feedwater pump 11 pressurizes the condensed water generated by the condenser 10 and returns the condensed water to the steam generator 3 in the boiler 2 as feedwater.

The generator 12 is driven by power generated when the fourth steam expands so that electric power is generated.

The surface temperature of a superheater tube (steam tube) constituting the superheater included in the steam generator 3 and a reheater tube (steam tube) constituting the reheater 9 are measured by the temperature measuring device according to the present embodiment. The details will be described later. For convenience of explanation, in the following description, the superheater tube and the reheater tube will be referred to as a steam tube 15.

=== Temperature measuring device ===
<First cover>
FIG. 2 is a perspective view showing a state before the first cover used in the temperature measuring device according to the present embodiment is attached to the straight pipe portion of the steam pipe. FIG. 3 is a perspective view showing a state after the first cover used in the temperature measuring device according to the present embodiment is attached to the straight pipe portion of the steam pipe. FIG. 4 is a cross-sectional view showing a state after the first cover used in the temperature measuring device according to the present embodiment is attached to the straight pipe portion of the steam pipe. 2 to 4 show an example of the first cover. That is, the first cover may have any shape as long as it can be attached to the straight pipe portion of the steam pipe including the features of the present invention.

The first cover 100 is mounted on the straight pipe portion of the steam pipe 15 via the optical fiber 110 such that the optical fiber 110 is in close contact with the surface of the straight pipe portion of the steam pipe 15. The first cover 100 is formed using an alloy steel (for example, stainless steel (SUS304 or SUS316)).

The optical fiber 110 is attached by the first cover 100 so as to be in close contact with the surface of the steam pipe 15 along the longitudinal direction of the steam pipe 15 in order to measure the surface temperature of the steam pipe 15. When pulse light is incident on the optical fiber 110, the pulse light travels while slightly scattering in the optical fiber 110. Since the Raman scattered light (Stokes light and anti-Stokes light), which is one of the scattered lights, has a temperature dependency, the temperature of the object can be measured by detecting the Raman scattered light. That is, the surface temperature of the steam pipe 15 can be measured by bringing the optical fiber 110 into close contact with the surface of the steam pipe 15. The diameter of the optical fiber 110 is, for example, about 0.2 mm. Since a temperature measuring method using the temperature dependency of Raman scattered light is well known, its description is omitted.

The first cover 100 includes a cover body 1001 and

flanges

1002A and 1002B. The thickness of the first cover 100 is, for example, about 2 to 3 mm.

The cover body 1001 has a cylindrical shape having a diameter slightly larger than the diameter of the steam pipe 15. On the inner peripheral surface of the cover body 1001, the optical fiber 110 is accommodated along the longitudinal direction of the steam pipe 15 in order to adhere the optical fiber 110 to the surface of the steam pipe 15 along the longitudinal direction of the steam pipe 15. Groove 1001C is formed. The groove 1001C is formed on the cover body 1001, for example, on the opposite side of the

flanges

1002A and 1002B. When the first cover 100 is installed in the boiler 2, when the combustion gas hits the

flanges

1002A and 1002B, the flow of the combustion gas is disturbed. Therefore, the

flanges

1002A and 1002B are located downstream of the combustion gas (the side where the combustion gas hits). The first cover 100 is installed so as to face the opposite side. The groove 1001C has such a depression that the optical fiber 110 is in close contact with the surface of the steam pipe 15. The cover main body 1001 has end faces 1001A and 1001B along the longitudinal direction of the steam pipe 15 so that one gap is formed along the longitudinal direction of the steam pipe 15. The

flanges

1002A and 1002B are formed to extend from the end faces 1001A and 1001B so as to be away from the steam pipe 15, respectively. The

flanges

1002A and 1002B have a plurality of

holes

1003A and 1003B, respectively, along the longitudinal direction of the steam pipe 15. The plurality of

holes

1003A and 1003B communicate with each other such that the bolt 1004 is screwed with the nut 1005.

Then, after covering the cover main body 1001 on the steam pipe 15 while widening the gap between the

flanges

1002A and 1002B against the rigidity of the first cover 100, the bolt 1004 is inserted into the plurality of

holes

1003A and 1003B, and the bolt 1004 is inserted. When the nut 1005 is tightened, the gap between the

flanges

1002A and 1002B disappears, and the cover main body 1001 is attached in close contact with the steam pipe 15.

When the water supplied from the condenser 10 is heat-exchanged with the combustion gas in the boiler 2, the temperature of the combustion gas is, for example, about 1200 ° C., and the temperature of the steam circulating in the steam pipe 15 is, for example, about 600 ° C. . Since the optical fiber 110 does not directly contact the combustion gas with the first cover 100, the temperature of the optical fiber 110 is affected only by the surface temperature of the steam pipe 15. Therefore, the temperature of the optical fiber 110 is suppressed to less than 700 ° C., and the surface temperature of the steam pipe 15 can be reliably obtained. Information on the surface temperature of the steam pipe 15 is taken into an external monitoring device (not shown) via a network, and a temperature distribution is obtained. Furthermore, since the first cover 100 surrounds the steam pipe 15, the creep strength of the steam pipe 15 can be improved.

FIG. 5 is a perspective view showing a state before the first cover used in the temperature measuring device according to the present embodiment is attached to the curved pipe portion of the steam pipe. FIG. 6 is a perspective view showing a state after the first cover used in the temperature measuring device according to the present embodiment is attached to the curved pipe portion of the steam pipe. FIG. 7 is a cross-sectional view illustrating a state after the first cover used in the temperature measuring device according to the present embodiment is attached to the curved pipe portion of the steam pipe. 5 to 7 show an example of the first cover. That is, the first cover may have any shape as long as it can be attached to the curved pipe portion of the steam pipe including the features of the present invention.

The first cover 200 is mounted on the curved portion of the steam pipe 15 via the optical fiber 110 such that the optical fiber 110 is in close contact with the surface of the steam pipe 15. The first cover 200 is formed using an alloy steel (for example, stainless steel (SUS304 or SUS316)).

The optical fiber 110 is attached by the first cover 200 so as to be in close contact with the surface of the steam pipe 15 along the longitudinal direction (the shape of the curved pipe portion) of the steam pipe 15 in order to measure the surface temperature of the steam pipe 15. .

The first cover 200 includes the cover main body 2001 and the

flanges

2002A and 2002B. The thickness of the cover 200 is, for example, about 2 to 3 mm.

The cover body 2001 has a diameter slightly larger than the diameter of the steam pipe 15 and has a cylindrical shape according to the curvature of the steam pipe 15. On the inner peripheral surface of the cover body 2001, the optical fiber 110 is accommodated along the longitudinal direction of the steam pipe 15 in order to make the optical fiber 110 adhere to the surface of the steam pipe 15 along the longitudinal direction of the steam pipe 15. Is formed. The groove 2001C is formed, for example, on the opposite side of the cover body 2001 from the

flanges

2002A and 2002B. When the first cover 200 is installed in the boiler 2, if the combustion gas hits the

flanges

2002A and 2002B, the flow of the combustion gas is disturbed. Therefore, the

flanges

2002A and 2002B are positioned downstream of the combustion gas (the side where the combustion gas hits). The first cover 200 is installed so as to face the opposite side. In addition, when the first cover 200 is mounted on a curved portion of the steam pipe 15 disposed in the boiler 2, the

flanges

2002A and 2002B have various shapes such that they always face the downstream side of the combustion gas. Is prepared in advance. The groove 2001C has such a depression that the optical fiber 110 is in close contact with the surface of the steam pipe 15. The cover main body 2001 has end faces 2001A and 2001B along the longitudinal direction of the steam pipe 15 so that one gap is formed along the longitudinal direction of the steam pipe 15. The

flanges

2002A and 2002B are formed to extend from the end faces 2001A and 2001B so as to be away from the steam pipe 15, respectively. The

flanges

2002A, 2002B have a plurality of

holes

2003A, 2003B, respectively, along the longitudinal direction of the steam pipe 15. The plurality of

holes

2003A and 2003B communicate with each other so that the bolt 2004 is screwed with the nut 2005. Then, after covering the cover main body 2001 on the curved pipe portion of the steam pipe 15 while widening the gap between the

flanges

2002A and 2002B against the rigidity of the first cover 200, the bolts 2004 are inserted into the plurality of

holes

2003A and 2003B. Then, when the bolt 2004 and the nut 2005 are tightened, the gap between the

flanges

2002A and 2002B disappears, and the cover main body 2001 is attached to the curved pipe portion of the steam pipe 15 in close contact.

(4) Since the optical fiber 110 does not directly contact the combustion gas with the first cover 200, the temperature of the optical fiber 110 is affected only by the surface temperature of the steam pipe 15. Therefore, the temperature of the optical fiber 110 is suppressed to less than 700 ° C., and the surface temperature of the curved portion of the steam pipe 15 can be reliably obtained. Information on the surface temperature of the steam pipe 15 is taken into an external monitoring device (not shown) via a network, and a temperature distribution is obtained. Furthermore, since the first cover 200 surrounds the steam pipe 15, the creep strength of the steam pipe 15 can be improved.

The steam pipe 15 has a shape in which a straight pipe portion and a curved pipe portion are continuous. Therefore, when measuring the surface temperature of the straight pipe portion and the curved pipe portion of the steam pipe 15, the first cover 100 is attached to the straight pipe portion of the steam pipe 15, and the first cover 200 is attached to the curved pipe portion of the steam pipe 15. You only have to attach it. Further, the cover 220 may be double mounted on the curved pipe portion of the steam pipe 15 to reinforce the curved pipe section of the steam pipe 15.

<Second cover>
FIG. 8 is a perspective view showing a state before the second cover used in the temperature measuring device according to the present embodiment is attached to the straight pipe portion of the steam pipe. FIG. 9 is a perspective view showing a state after the second cover used in the temperature measuring device according to the present embodiment is attached to the straight pipe portion of the steam pipe. FIG. 10 is a cross-sectional view showing a state after the second cover used in the temperature measuring device according to the present embodiment is attached to the straight pipe portion of the steam pipe. 8 to 10 show an example of the second cover. That is, the second cover may have any shape as long as it can be attached to the straight pipe portion of the steam pipe, including the features of the present invention. For convenience of explanation, FIG. 8 shows a self-excited heat pipe in which thin tubes are connected in a ring shape.

As shown in FIGS. 1 to 7, when measuring the surface temperature of the steam pipe 15 using the optical fiber 110, the temperature of the optical fiber 110 is reduced to about 600 ° C. by the close contact of the optical fiber 110 with the steam pipe 15. As a result, the measurable distance of the optical fiber 110 to the steam pipe 15 is limited to about 10 m. Therefore, when it is desired to extend the measurable distance of the optical fiber 110 with respect to the steam pipe 15 to 10 m or more, the optical fiber 110 is cooled and the temperature of the optical fiber 110 is reduced at a position adjacent to the position where the surface temperature of the steam pipe 15 is measured. It is necessary to provide a lowering device.

The second cover 300 prevents the optical fiber 110 from being exposed in the boiler 2 at a position adjacent to the position where the first cover 100 (200) is attached to the steam pipe 15 (the optical fiber 110 is not exposed to combustion gas). The optical fiber 110 is attached to the straight pipe portion of the steam pipe 15 via the optical fiber 110 and the heat pipe 500 so that the optical fiber 110 is cooled while maintaining the state of being bonded to the first cover 100 (200). The second cover 300 is formed using an alloy steel (for example, stainless steel (SUS304 or SUS316)).

The heat pipe 500 is a heat exchanger that cools the optical fiber 110 by exchanging heat with the optical fiber 110. The heat pipe 500 is a device that performs heat exchange by repeatedly circulating a refrigerant that is sealed in a long tube (having a diameter of about 0.5 mm) that condenses and evaporates. In the heat pipe 500, the method of circulating the refrigerant may be either self-excited or separately-excited, but any method is well-known (for example, Japanese Patent Application Laid-Open No. 2011-144900), and the detailed description thereof will be omitted. Omitted.

When the second cover 300 is attached to the straight pipe portion of the steam pipe 15, the optical fiber 110 is separated from the surface of the steam pipe 15 by a small distance along the longitudinal direction of the steam pipe 15 so as to be adjacent to the steam pipe 15. The heat pipe 500 is disposed so as to surround the optical fiber 110 at a small distance from the surface of the steam pipe 15 along the longitudinal direction of the steam pipe 15. For example, the heat pipe 500 is folded back so as to surround the optical fiber 110 within a range covered by the second cover 300.

The second cover 300 includes a cover main body 3001 and

flanges

3002A and 3002B. The thickness of the second cover 300 is, for example, about 1 mm. When the second cover 300 is installed in the boiler 2, when the combustion gas hits the

flanges

3002A and 3002B, the flow of the combustion gas is disturbed. Therefore, the

flanges

3002A and 3002B are positioned downstream of the combustion gas (the side where the combustion gas hits). The second cover 300 is installed so as to face the opposite side.

The cover body 3001 has a cylindrical shape having a diameter slightly larger than the diameter of the steam pipe 15. The cover main body 3001 has end faces 3001A and 3001B along the longitudinal direction of the steam pipe 15 so that one small gap is formed along the longitudinal direction of the steam pipe 15. The

flanges

3002A and 3002B are formed to extend from the end faces 3001A and 3001B so as to be away from the steam pipe 15, respectively. The

flanges

3002A and 3002B have a plurality of

holes

3003A and 3003B, respectively, along the longitudinal direction of the steam pipe 15. The plurality of

holes

3003A and 3003B communicate with each other such that the bolt 3004 is screwed with the nut 3005. Then, after covering the cover main body 3001 over the steam pipe 15 while widening the gap between the

flanges

3002A and 3002B against the rigidity of the second cover 300, the bolt 3004 is inserted into the plurality of

holes

3003A and 3003B to insert the bolt 3004. When the nut 3005 is tightened, the gap between the

flanges

3002A and 3002B disappears, and the cover main body 3001 is attached to the steam pipe 15 in close contact. At this time, the

flanges

3002A and 3002B are in close contact with each other, and the combined thickness of the

flanges

3002A and 3002B is greater than the thickness of the cover main body 3001. Therefore, it is possible to secure a space 3001C for housing the optical fiber 110 and the heat pipe 500 inside the

flanges

3002A and 3002B. The space 3001C is a space having a cylindrical shape formed along the longitudinal direction of the steam pipe 15 inside the

flanges

3002A and 3002B. The flange 3002A has a semi-cylindrical groove 3001D on the surface in close contact with the flange 3002B, and the flange 3002B has a semi-cylindrical groove 3001E on the surface in close contact with the flange 3002A. The space 3001C is formed by overlapping the

grooves

3001D and 3001E when the

flanges

3002A and 3002B are brought into close contact.

In the space 3001C, the optical fiber 110 is arranged near the center along the longitudinal direction of the steam pipe 15, and the heat pipe 500 is arranged around the optical fiber 110 along the longitudinal direction of the steam pipe 15. For example, the heat pipe 500 includes a pair of heat pipes, one of which is folded back to surround the optical fiber 110, and the other of which surrounds the optical fiber 110 in a direction orthogonal to the one of the heat pipes. So that it is folded back. As described above, the optical fiber 110 is surrounded by the heat pipe 500 without contacting the surface of the steam pipe 15, so that the optical fiber 110 is effectively cooled. Further, since the second cover 300 surrounds the steam pipe 15, the creep strength of the steam pipe 15 can be improved.

FIG. 11 is a perspective view showing a state before the second cover used in the temperature measuring device according to the present embodiment is mounted on the curved pipe portion of the steam pipe. FIG. 12 is a perspective view showing a state after the second cover used for the temperature measuring device according to the present embodiment is attached to the curved pipe portion of the steam pipe. FIG. 13 is a cross-sectional view showing a state after the second cover used in the temperature measuring device according to the present embodiment is attached to the curved pipe portion of the steam pipe. FIGS. 11 to 13 show examples of the second cover. That is, the second cover may have any shape as long as it can be attached to the curved portion of the steam pipe, including the features of the present invention. For convenience of explanation, FIG. 11 shows a self-excited heat pipe in which thin tubes are connected in a ring shape.

The second cover 400 prevents the optical fiber 110 from being exposed in the boiler 2 at a position adjacent to the position where the first cover 100 (200) is attached to the steam pipe 15 (the optical fiber 110 is not exposed to combustion gas). The optical fiber 110 is attached to the curved portion of the steam pipe 15 via the optical fiber 110 and the heat pipe 500 so as to cool the optical fiber 110 while maintaining the state of being bonded to the first cover 100 (200). The second cover 400 is formed using an alloy steel (for example, stainless steel (SUS304 or SUS316)).

When the second cover 400 is attached to the bent portion of the steam pipe 15, the optical fiber 110 is separated from the surface of the steam pipe 15 by a small distance along the longitudinal direction of the steam pipe 15 so as to be adjacent to the steam pipe 15. The heat pipe 500 is disposed so as to surround the optical fiber 110 at a small distance from the surface of the steam pipe 15 along the longitudinal direction of the steam pipe 15. For example, the heat pipe 500 is folded and disposed so as to surround the optical fiber 110 within a range covered by the second cover 400.

The second cover 400 includes a cover body 4001 and

flanges

4002A and 4002B. The thickness of the second cover 400 is, for example, about 1 mm. When the second cover 400 is installed in the boiler 2, the flow of the combustion gas is disturbed when the combustion gas hits the

flanges

4002A and 4002B. Is opposite to the second cover 400. Also, when the second cover 400 is attached to a curved portion of the steam pipe 15 arranged in the boiler 2, the

flanges

4002A and 4002B have various shapes such that they always face the downstream side of the combustion gas. Is prepared in advance.

The cover main body 4001 has a diameter slightly larger than the diameter of the steam pipe 15 and has a cylindrical shape corresponding to the curvature of the steam pipe 15. The cover main body 4001 has end faces 4001A and 4001B along the longitudinal direction of the steam pipe 15 so that one small gap is formed along the longitudinal direction of the steam pipe 15. The

flanges

4002A and 4002B are formed to extend from the end faces 4001A and 4001B so as to be away from the steam pipe 15, respectively. The

flanges

4002A and 4002B have a plurality of

holes

4003A and 4003B, respectively, along the longitudinal direction of the steam pipe 15. The plurality of

holes

4003A and 4003B communicate with each other so that the bolt 4004 is screwed with the nut 4005. Then, after covering the cover main body 4001 on the steam pipe 15 while widening the gap between the

flanges

4002A and 4002B against the rigidity of the second cover 400, the bolt 4004 is inserted into the plurality of

holes

4003A and 4003B, and the bolt 4004 is inserted. When the nut 4005 and the nut 4005 are tightened, the gap between the

flanges

4002A and 4002B disappears, and the cover main body 4001 is attached to the steam pipe 15 in close contact. At this time, the

flanges

4002A and 4002B are in close contact with each other, and the combined thickness of the

flanges

4002A and 4002B is greater than the thickness of the cover body 4001. Therefore, it is possible to secure a space 4001C for housing the optical fiber 110 and the heat pipe 500 inside the

flanges

4002A and 4002B. The space 4001C is a space having a columnar shape formed along the longitudinal direction of the steam pipe 15 inside the

flanges

4002A and 4002B. The flange 4002A has a semi-cylindrical groove 4001D on the surface in close contact with the flange 4002B, and the flange 4002B has a semi-cylindrical groove 4001E on the surface in close contact with the flange 4002A. The space 4001C is formed by overlapping the grooves 4001D and 4001E when the

flanges

4002A and 4002B are brought into close contact.

In the space 4001C, the optical fiber 110 is arranged near the center along the longitudinal direction of the steam pipe 15, and the heat pipe 500 is arranged around the optical fiber 110 along the longitudinal direction of the steam pipe 15. For example, the heat pipe 500 includes a pair of heat pipes, one of which is folded back to surround the optical fiber 110, and the other of which surrounds the optical fiber 110 in a direction orthogonal to the one of the heat pipes. So that it is folded back. As described above, the optical fiber 110 is surrounded by the heat pipe 500 without contacting the surface of the steam pipe 15, so that the optical fiber 110 is effectively cooled. Furthermore, since the second cover 400 surrounds the steam pipe 15, the creep strength of the steam pipe 15 can be improved.

The steam pipe 15 has a shape in which a straight pipe portion and a curved pipe portion are continuous. Therefore, when cooling the optical fiber 110 in the straight pipe portion and the bent pipe portion of the steam pipe 15, the second cover 300 is attached to the straight pipe portion of the steam pipe 15, and the second cover 400 is attached to the bent pipe portion of the steam pipe 15. It should just be attached to. Further, the cover 220 may be double mounted on the curved pipe portion of the steam pipe 15 to reinforce the curved pipe section of the steam pipe 15.

=== Example of installation of temperature measurement device ===
FIG. 14 is a schematic diagram illustrating an example of a steam pipe installed in a boiler. FIG. 15 is a schematic diagram illustrating an example of a case where the temperature measuring device according to the present embodiment is installed in a boiler. For convenience of explanation, a steam pipe 15 such as a superheater pipe or a reheater pipe installed in the boiler 2 is schematically illustrated as a pipe in which a straight pipe portion (open portion) and a curved pipe portion (hatched portion) are continuous. Will be shown.

In order to obtain information on the surface temperature of the steam pipe 15 measured by the optical fiber 110, the optical fiber 110 is disposed along the longitudinal direction of the steam pipe 15, and both ends of the optical fiber 110 are connected to a measuring device (not (Shown). At this time, at least one of the

first covers

100 and 200 and at least one of the

second covers

300 and 400 are continuously connected to all the steam pipes 15 in the boiler 2 so that the optical fiber 110 is not exposed to the combustion gas. Attached to.

For example, in the boiler 2, straight pipe portions A, C, E, G, I and curved pipe portions B, D, F, H in the steam pipe 15 are alternately and continuously installed so that steam passes therethrough. It has been done. Then, an example of installation of the temperature measuring device when measuring the surface temperatures of the curved pipe portions B and D and the straight pipe portions C and G will be described. In the case of this installation example, in consideration of mounting the temperature measuring device on the existing steam pipe 15, the first cover 100 having a shape that can be mounted on the straight pipe portions C and G, and the straight pipe portion A , E, and I, a second cover 300 having a shape capable of being attached to the curved tube portions B and D, and a shape capable of being attached to the curved tube portions F and H. Is prepared in advance.

<Straight pipe part A>
The straight pipe part A is a part that cools the optical fiber 110 using the heat pipe 500. Therefore, the second cover 300 having the same length as the straight pipe portion A is prepared so that the optical fiber 110 is not exposed. Then, the optical fiber 110 and the heat pump 500 are accommodated in the space 3001C so that the heat pipe 500 surrounds the optical fiber 110 while the second cover 300 is attached so as to cover the entire straight pipe portion A. Here, since the straight pipe portion A is a portion communicating with the outside of the boiler 2, one end of the optical fiber 110 is taken out of the boiler 2. Further, the heat pipe 500 is connected so that the refrigerant is forcibly circulated through a pump 600 provided outside the boiler 2. Thereby, it is possible to secure a distance for cooling the optical fiber 110.

<Bent tube part B>
The curved tube portion B is a portion for measuring the surface temperature of the steam pipe 15 using the optical fiber 110. Therefore, the first cover 200 having the same length as the curved tube portion B is prepared so that the optical fiber 110 is not exposed. The optical fiber 110 extending from the straight pipe portion A is attached while the first cover 200 is mounted so as to cover the entire curved pipe portion B while being joined to the second cover 300 mounted on the straight pipe portion A. The optical fiber 110 is housed in the groove 2001C so as to be in close contact with the surface of the steam pipe 15.

<Straight pipe part C>
The straight pipe part C is a part for measuring the surface temperature of the steam pipe 15 using the optical fiber 110. Therefore, the first cover 100 having the same length as the straight pipe portion C is prepared so that the optical fiber 110 is not exposed. The optical fiber 110 extending from the curved tube portion B is attached while the first cover 100 is attached so as to cover the entire straight tube portion C while being joined to the first cover 200 attached to the curved tube portion B. The optical fiber 110 is housed in the groove 1001C so as to be in close contact with the surface of the steam pipe 15.

<Bent tube part D>
The curved tube portion D is a portion for measuring the surface temperature of the steam pipe 15 using the optical fiber 110. Therefore, the first cover 200 having the same length as the curved tube portion D is prepared so that the optical fiber 110 is not exposed. The optical fiber 110 extending from the straight pipe portion C is attached while the first cover 200 is mounted so as to cover the entire curved pipe portion D while being joined to the first cover 100 mounted on the straight pipe portion C. The optical fiber 110 is housed in the groove 2001C so as to be in close contact with the surface of the steam pipe 15.

<Straight pipe part E>
The straight pipe part E is a part that cools the optical fiber 110 using the heat pipe 500. Therefore, the second cover 300 having the same length as the straight pipe portion E is prepared so that the optical fiber 110 is not exposed. Then, the heat pipe 500 extends from the curved pipe portion D while attaching the second cover 300 so as to cover the entire straight pipe portion E while being joined to the first cover 200 attached to the curved pipe portion D. The optical fiber 110 and the heat pump 500 are housed in the space 3001C so as to surround the optical fiber 110. Since the straight tube portion E is sandwiched between the curved tube portions D and F, a pump installed outside the boiler 2 cannot be connected to the thin tube of the heat pipe 500. Therefore, the heat pipe 500 is annularly connected in the second cover 300 so as to generate self-excited pressure oscillation for circulating the refrigerant by repeatedly condensing and evaporating the refrigerant.

<Bent tube part F>
The curved pipe portion F is a portion that cools the optical fiber 110 using the heat pipe 500. Therefore, a second cover 400 having the same length as the curved tube portion F is prepared so that the optical fiber 110 is not exposed. Then, the heat pipe 500 extends from the straight pipe portion E while attaching the second cover 400 so as to cover the entire curved pipe portion F while being joined to the second cover 300 mounted on the straight pipe portion E. The optical fiber 110 and the heat pump 500 are housed in the space 4001C so as to surround the optical fiber 110. Since the curved pipe portion F is sandwiched between the straight pipe portions E and G, a pump installed outside the boiler 2 cannot be connected to the thin pipe of the heat pipe 500. Therefore, the heat pipe 500 is annularly connected in the second cover 400 so as to generate self-excited pressure oscillation for circulating the refrigerant by repeatedly condensing and evaporating the refrigerant.

<Straight pipe part G>
The straight pipe part G is a part for measuring the surface temperature of the steam pipe 15 using the optical fiber 110. Therefore, the first cover 100 having the same length as the straight pipe portion G is prepared so that the optical fiber 110 is not exposed. The optical fiber 110 extending from the curved tube portion F is attached while the first cover 100 is attached so as to cover the entire straight tube portion G while being joined to the second cover 400 attached to the curved tube portion F. The optical fiber 110 is housed in the groove 1001C so as to be in close contact with the surface of the steam pipe 15.

<Bent tube part H>
The curved pipe portion H is a portion that cools the optical fiber 110 using the heat pipe 500. Therefore, the second cover 400 having the same length as the curved tube portion H is prepared so that the optical fiber 110 is not exposed. Then, the heat pipe 500 extends from the straight pipe portion G while attaching the second cover 400 so as to cover the entire curved pipe portion H while being joined to the first cover 100 mounted on the straight pipe portion G. The optical fiber 110 and the heat pump 500 are housed in the space 4001C so as to surround the optical fiber 110. Since the curved tube portion H is sandwiched between the straight tube portions G and I, a pump installed outside the boiler 2 cannot be connected to the thin tube of the heat pipe 500. Therefore, the heat pipe 500 is annularly connected in the second cover 400 so as to generate self-excited pressure oscillation for circulating the refrigerant by repeatedly condensing and evaporating the refrigerant.

<Straight pipe part I>
The straight pipe part I is a part that cools the optical fiber 110 using the heat pipe 500. Therefore, the second cover 300 having the same length as the straight pipe portion I is prepared so that the optical fiber 110 is not exposed. A space 3001C is attached so that the heat pipe 500 surrounds the optical fiber 110 while the second cover 300 is attached so as to cover the entire straight pipe portion I while being joined to the second cover 400 attached to the curved pipe portion H. Accommodates the optical fiber 110 and the heat pump 500. Here, since the straight pipe portion I is a portion communicating with the outside of the boiler 2, one end of the optical fiber 110 is taken out of the boiler 2. Further, the heat pipe 500 is connected so that the refrigerant is forcibly circulated through a pump 600 installed outside the boiler 2. Thereby, it is possible to secure a distance for cooling the optical fiber 110.

<Temperature of optical fiber at temperature measurement part>
The optical fibers 110 are located at portions (straight tube portions A, E, I and curved tube portions F, H) adjacent to the portions for measuring the surface temperature of the steam pipe 15 (curved tube portions B, D and straight tube portions C, G). Is cooled, the temperature of the optical fiber 110 which is in close contact with the portion for measuring the surface temperature of the steam pipe 15 decreases to, for example, about 300 ° C. Therefore, even when the entire length of the steam pipe 15 reaches several tens of meters, the surface temperature of the steam pipe 15 can be reliably obtained.

When the first cover 100 (200) and the second cover 300 (400) are continuously attached to the steam pipe 15, the optical fiber 110 extends from the straight pipe portion A to the straight pipe portion I in a longitudinal direction of the steam pipe 15. The grooves 1001C of the first cover 100, the grooves 2001C of the first cover 200, the spaces 3001C of the second cover 300, and the second cover 400 The first cover 100 (200) and the second cover 300 (400) are positioned at the positions of the groove 1001C (2001C) and the space 3001C (4001C) according to the shape of the steam pipe 15 so that the space 4001C communicates with the space 4001C. Needs to be appropriately changed.

=== Summary ===
As described above, the temperature measuring device according to the present embodiment is configured such that the steam obtained by heat-exchanging the water supplied to the boiler 2 with the combustion gas circulates through the steam pipe 15 (superheater tube or reheater). A heat pipe 500 for cooling the optical fiber 110 and a position for measuring the surface temperature of the steam pipe 15 (curved pipe portions B, D and At positions (straight tube portions A, E, I and curved tube portions F, H) adjacent to the straight tube portions C, E), the optical fiber 110 is adjacent to the steam tube 15 along the longitudinal direction of the steam tube 15. The cover 300 (400) is attached so as to surround the optical fiber 110 along the longitudinal direction of the steam pipe 15 so that the heat pipe 500 surrounds the steam pipe 15 with the optical fiber 110 and the heat pipe 500 interposed therebetween. And, equipped with a.

In other words, the temperature measuring device according to the present embodiment includes a steam pipe 15 (superheater tube or reheater tube) in which steam obtained by heat-exchanging water supplied to the boiler 2 with combustion gas circulates. At an optical fiber 110 for measuring the surface temperature and at a first position (curved pipe portions B and D and straight pipe portions C and E) where the surface temperature of the steam pipe 15 is measured, the optical fiber 110 is elongated along the length of the steam pipe 15. A first cover 100 (200) mounted to surround the steam pipe 15 with the optical fiber 110 interposed therebetween so as to be in close contact with the steam pipe 15 along the direction, and a heat pipe 500 for cooling the optical fiber 110. At a second position (straight tube portions A, E, I and curved tube portions F, H) adjacent to the first position, the optical fiber 110 is adjacent to the steam pipe 15 along the longitudinal direction of the steam pipe 15 and is heated. Pipe 500 So as to surround the optical fiber 110 in the longitudinal direction of the steam pipe 15 provided with a second cover 300 mounted to surround the steam pipe 15 across the optical fiber 110 and the heat pipe 500 (400), the.

According to the temperature measuring device of the present embodiment, even when the entire length of the steam pipe 15 reaches several tens of meters, it is possible to reliably acquire the surface temperature of the steam pipe 15, It is possible to improve the creep strength.

In the present embodiment, the first cover 100 (200) has a groove 1001C (2001C) recessed along the longitudinal direction of the steam pipe 15 so that the optical fiber 110 is accommodated when the first cover 100 (200C) is attached to the steam pipe 15. ).

In the present embodiment, the second cover 300 (400) is formed along the longitudinal direction of the steam pipe 15 so that the optical fiber 110 and the heat pipe 500 are accommodated when the second cover 300 (400) is mounted on the steam pipe 15. Space 3001C (4001C).

In the present embodiment, the first cover 100 (200) has a gap along the longitudinal direction of the steam pipe 15 and has a cylindrical cover body 1001 (2001) surrounding the steam pipe 15, and a cover body 1001 (200). 2001) and flanges 1002A (2002A) and 1002B (2002B) that are tightened by bolts so that the cover body 1001 (2001) is in close contact with the steam pipe 15. Similarly, the second cover 300 (400) has a gap along the longitudinal direction of the steam pipe 15 and has a cylindrical cover body 3001 (4001) surrounding the steam pipe 15 and both ends of the cover body 3001 (4001). And a flange 3002A (4002A) and 3002B (4002B) that are tightened by bolts so that the cover main body 3001 (4001) is in close contact with the steam pipe 15.

Also, in the present embodiment, the first cover 100 (200) and the second cover 300 (400) are formed from alloy steel. In particular, the first cover 100 (200) and the second cover 300 (400) are desirably formed from stainless steel.

In the present embodiment, the steam pipe 15 is a superheater pipe or a reheater pipe.

Note that the above-described embodiment is for the purpose of facilitating the understanding of the present invention, and is not for limiting and interpreting the present invention. The present invention can be modified and improved without departing from the spirit thereof, and the present invention also includes equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Thermal power plant 2 Boiler 3 Steam generator 6 High-pressure turbine 7 Medium-pressure turbine 8 Low-pressure turbine 9 Reheater 10 Condenser 12 Generator 15

Steam pipe

100, 200 First cover 110

Optical fiber

300, 400 Second cover 500

Heat pipes

1001, 2001, 3001, 4001

Cover bodies

1001A, 1001B, 2001A, 2001B, 3001A, 3001B, 4001A, 4001B End faces 1001C,

2001C Grooves

1002A, 1002B, 2002A, 2002B, 3002A, 3002B, 4002A,

4002B Flanges

1003A, 1003B , 2003A, 2003B, 3003A, 3003B, 4003A, 4003B

Multiple holes

1004, 2004, 3004, 4004

Bolts

1005, 2005, 3005, 4005

Door

3001C, 4001C space

Claims

A steam pipe temperature measuring device for measuring the surface temperature of a steam pipe in which steam obtained by heat-exchanging water supplied to a boiler with a combustion gas circulates through an optical fiber,
A heat pipe for cooling the optical fiber,
At a position adjacent to a position where the surface temperature of the steam pipe is measured, the optical fiber is adjacent to the steam pipe along a longitudinal direction of the steam pipe, and the heat pipe is located along a longitudinal direction of the steam pipe. A cover attached to surround the optical fiber and the steam pipe with the optical fiber and the heat pipe interposed therebetween,
A steam pipe temperature measuring device comprising:
An optical fiber for measuring the surface temperature of a steam pipe in which steam obtained by heat-exchanging water supplied to the boiler with combustion gas circulates,
At the first position where the surface temperature of the steam pipe is measured, the optical fiber is attached so as to surround the steam pipe with the optical fiber interposed therebetween so that the optical fiber is in close contact with the steam pipe along the longitudinal direction of the steam pipe. A first cover to be
A heat pipe for cooling the optical fiber,
At a second position adjacent to the first position, the optical fiber is adjacent to the steam pipe along a longitudinal direction of the steam pipe, and the heat pipe surrounds the optical fiber along a longitudinal direction of the steam pipe. A second cover attached to surround the steam pipe with the optical fiber and the heat pipe interposed therebetween;
A steam pipe temperature measuring device comprising:
The said 1st cover has the groove | channel recessed along the longitudinal direction of the said steam pipe so that the said optical fiber may be accommodated when it is attached to the said steam pipe. Steam pipe temperature measurement device.
The second cover has a space formed along a longitudinal direction of the steam pipe so that the optical fiber and the heat pipe are accommodated when the second cover is mounted on the steam pipe. The steam pipe temperature measuring device according to claim 2 or 3.
The first cover or the second cover includes:
A cover body having a gap along the longitudinal direction of the steam pipe and having a cylindrical shape through which the steam pipe is inserted;
The flange according to any one of claims 2 to 4, further comprising: flanges formed at both ends of the cover main body, the flanges being tightened by bolts so that the cover main body is in close contact with the steam pipe. Steam pipe temperature measurement device.
The steam pipe temperature measuring device according to any one of claims 2 to 7, wherein the first cover and the second cover are formed of an alloy steel.
The steam pipe temperature measuring device according to claim 6, wherein the first cover and the second cover are formed of stainless steel.
The steam pipe temperature measuring device according to any one of claims 2 to 7, wherein the steam pipe is a superheater pipe or a reheater pipe.
At a first position for measuring the surface temperature of a steam pipe in which steam obtained by heat-exchanging water supplied to the boiler with combustion gas circulates, an optical fiber for measuring the surface temperature of the steam pipe is provided. A first cover surrounding the steam pipe with the optical fiber interposed therebetween is attached so as to be in close contact with the steam pipe along the longitudinal direction of the steam pipe,
In a second position adjacent to the first position, the optical fiber is adjacent to the steam pipe along a longitudinal direction of the steam pipe, and a heat pipe for cooling the optical fiber is provided in a longitudinal direction of the steam pipe. Mounting a second cover that surrounds the steam pipe with the optical fiber and the heat pipe interposed therebetween so as to surround the optical fiber along the line.
The method for measuring the temperature of a steam pipe according to claim 9, wherein the first cover and the second cover are formed of an alloy steel.
The method according to claim 10, wherein the first cover and the second cover are formed of stainless steel.