JP6551621B1 - Steam pipe temperature measuring device, steam pipe temperature measuring method - Google Patents

Abstract

SOLUTION: An optical fiber for measuring a surface temperature of a steam pipe in which steam obtained by heat exchange of water supplied to a boiler with a combustion gas is circulated as a temperature measuring device of steam pipe, and the light And a cover that is mounted so as to surround the steam pipe with the optical fiber interposed therebetween so that the fiber is in close contact with the steam pipe along the longitudinal direction of the steam pipe.

Description

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

  For example, a steam pipe (for example, a superheater or a reheater) for circulating steam obtained by heat exchange of water supplied from a condenser with combustion gas is installed in a boiler for power generation in a thermal power plant It is done. The steam pipe is composed of a boiler tube made of heat-resistant steel (for example, low alloy steel), but if it is used continuously at high temperature beyond the design standard, the outer surface of the steam pipe along with the progress of creep damage. May cause deformation such as expansion of the steam pipe or reduction in the thickness of the steam pipe. Therefore, 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, an inspection is performed to prevent an accident caused by the deterioration of the steam pipe in advance (for example, patent Reference 1).

JP, 2013-190229, A

  When grasping the combustion state of the boiler 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 to 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 the steam pipe. However, when a thermocouple is used, it is difficult to obtain the temperature distribution of the surface temperature of the steam pipe because only a narrow surface temperature in the steam pipe can be measured.

  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 present invention for solving the above-mentioned problems is to measure the surface temperature of a steam pipe in which steam obtained by heat exchange between water supplied to a boiler and combustion gas is measured as a temperature measuring device for steam pipe. of the optical fiber, so that the optical fiber is in close contact with the steam pipe along the longitudinal direction of the steam pipe, and a cover which is mounted to surround the steam pipe across the optical fiber, wherein The cover has a gap along the longitudinal direction of the steam pipe, and a groove recessed along the longitudinal direction of the steam pipe so as to accommodate the optical fiber when mounted on the steam pipe. A cover body having a cylindrical shape surrounding the steam pipe, and a flange formed by sandwiching the gap at both ends of the cover body and tightened by bolts so that the cover body is in close contact with the steam pipe The groove is formed on the opposite side of the cover body from the flange, and the optical fiber and the cover are installed in the boiler such that the flange faces the downstream side of the combustion gas The

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

  According to the present invention, the surface temperature of the steam pipe can be reliably measured over a wide range.

It is a figure which shows an example of the whole structure of the thermal power plant in which the temperature measuring apparatus of the steam pipe which concerns on this embodiment is used. It is a perspective view which shows a mode before mounting | wearing the straight pipe part of a steam pipe with the temperature measurement apparatus which concerns on this embodiment. It is a perspective view which shows a mode after mounting | wearing the straight pipe part of a steam pipe with the temperature measurement apparatus which concerns on this embodiment. It is sectional drawing which shows a mode after attaching the temperature measurement apparatus which concerns on this embodiment to the straight pipe part of a steam pipe. It is a perspective view which shows the mode before attaching the other temperature measuring apparatus which concerns on this embodiment to the curved pipe part of a steam pipe. It is a perspective view which shows a mode after mounting the other temperature measuring apparatus which concerns on this embodiment to the curved pipe part of a steam pipe. It is sectional drawing which shows a mode after attaching the other temperature measuring apparatus which concerns on this embodiment to the curved pipe part of a steam pipe.

  At least the following matters will be made clear by the present specification and the description of the accompanying drawings.

=== An example of the overall configuration of a 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 cooled wall 4, a steam valve 5, a high pressure turbine 6, an intermediate pressure turbine 7, a low pressure turbine 8, a reheater 9, a condenser 10, a feed water pump 11, and power generation. It is comprised including the machine 12.

  The boiler 2 is a heat exchange device that mixes a fuel (for example, coal in the form of pulverized coal) supplied from the outside with air to generate a combustion gas, and converts water into water vapor using the heat of the combustion gas. The boiler 2 contains a steam generator 3, a water cooling wall 4, and a reheater 9. The steam generator 3 includes an economizer (not shown) for preheating water supplied from the condenser 10 and a superheater (not shown) for further heating saturated steam supplied from the water cooling wall 4 into superheated steam. And is included. The water cooling wall 4 forms a housing of the boiler 2 and supplies preheated water as saturated steam to the superheater. The steam valve 5 is an adjustment valve that controls the flow rate of superheated steam generated by the steam generator 3.

  The rotary shafts 13 of the high-pressure turbine 6, the intermediate-pressure turbine 7, and the low-pressure turbine 8 are the same and are coupled to the rotary 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 intermediate pressure turbine 7 as reheated steam (third steam). The intermediate 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.

  The condenser 10 condenses the exhaust after the low pressure turbine 8 expands the fourth steam and converts it to condensed water. The feed water pump 11 boosts the condensate generated by the condenser 10 and returns it to the steam generator 3 in the boiler 2 as feed water.

  And the generator 12 is driven by the motive power which generate | occur | produces when 4th vapor | steam expands so that electric power may be produced | generated.

  The surface temperature of the superheater pipe (steam pipe) constituting the superheater included in the steam generator 3 and the reheater pipe (steam pipe) 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 pipe and the reheater pipe will be referred to as a steam pipe 15.

=== Temperature measuring device ===
FIG. 2 is a perspective view showing a state before the temperature measuring device according to the present embodiment is mounted on the straight pipe portion of the steam pipe. FIG. 3 is a perspective view showing a state after the temperature measuring device according to the present embodiment is mounted on the straight pipe portion of the steam pipe. FIG. 4 is a cross-sectional view showing a state after the temperature measuring device according to the present embodiment is mounted on the straight pipe portion of the steam pipe. The temperature measurement device is attached to the steam pipe so that the optical fiber is not exposed in the boiler.

  The temperature measuring device 100 is made of metal (e.g., SUS304, SUS316) attached to the straight pipe portion of the steam pipe 15 via the optical fiber 110 so that the optical fiber 110 adheres to the surface of the straight pipe portion of the steam pipe 15. Device of The temperature measurement device 100 is configured to include an optical fiber 110 and a cover 120.

  The optical fiber 110 is attached by a cover 120 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 pulsed light is incident on the optical fiber 110, the pulsed light travels while being slightly scattered in the optical fiber 110. Since Raman scattered light (Stokes light and anti-Stokes light), which is one of the scattered light, has temperature dependency, it is possible to measure the temperature of the object by detecting the Raman scattered light. That is, by bringing the optical fiber 110 into close contact with the surface of the steam pipe 15, it is possible to measure the surface temperature of the steam pipe 15. The diameter of the optical fiber 110 is, for example, about 0.2 mm. In addition, since the temperature measurement method using the temperature dependence of Raman scattered light is known, the description is abbreviate | omitted.

  The cover 120 includes a cover main body 1201 and flanges 1202A and 1202B. The thickness of the cover 120 is, for example, about 2 to 3 mm.

  The cover main body 1201 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 main body 1201, the optical fiber 110 is accommodated along the longitudinal direction of the steam pipe 15 in order to bring the optical fiber 110 into close contact with the surface of the steam pipe 15 along the longitudinal direction of the steam pipe 15. The groove 1201C is formed. The groove 1201C is formed, for example, on the opposite side of the flanges 1202A and 1202B in the cover main body 1201. When the temperature measuring device 100 is installed in the boiler 2, if the combustion gas hits the flanges 1202A and 1202B, the flow of the combustion gas is disturbed. The temperature measuring device 100 is installed so as to face the opposite side. The groove 1201 </ b> C has a depression that allows the optical fiber 110 to be in close contact with the surface of the steam pipe 15. The cover main body 1201 has end faces 1201A and 1201B 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 1202A and 1202B are formed to extend from the end surfaces 1201A and 1201B so as to be away from the steam pipe 15, respectively. The flanges 1202A and 1202B have a plurality of holes 1203A and 1203B along the longitudinal direction of the steam pipe 15, respectively. The plurality of holes 1203A and 1203B communicate with each other so that the bolt 1204 is screwed with the nut 1205. Then, the cover body 1201 is placed on the steam pipe 15 while widening the gap between the flanges 1020A and 1202B against the rigidity of the temperature measuring device 100, and then the bolt 1204 is inserted into the plurality of holes 1203A and 1203B. When the nut 1205 is tightened, the gap between the flanges 1202A and 1202B disappears, and the cover body 1201 is attached in close contact with the steam pipe 15.

  In the boiler 2, when the water supplied from the condenser 10 is heat exchanged with the combustion gas, 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. . The temperature of the optical fiber 110 is affected only by the surface temperature of the steam pipe 15 because the optical fiber 110 does not directly touch the combustion gas by the cover 120. 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 acquired. Information on the surface temperature of the steam pipe 15 is taken into an external monitoring device (not shown) via a network to obtain a temperature distribution. Furthermore, since the cover 120 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 another 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 another temperature measuring device according to the present embodiment is mounted on the curved pipe portion of the steam pipe. FIG. 7 is a cross-sectional view showing a state after another temperature measuring device according to the present embodiment is mounted on the curved pipe portion of the steam pipe. The temperature measuring device is attached to the steam pipe with such a length that the optical fiber is not exposed in the boiler.

  The temperature measuring device 200 is made of metal (for example, SUS304, SUS316) attached to the curved pipe portion of the steam pipe 15 via the optical fiber 210 so that the optical fiber 210 adheres to the surface of the curved pipe portion of the steam pipe 15. It is an apparatus. The temperature measurement device 200 is configured to include an optical fiber 210 and a cover 220.

  The optical fiber 210 is attached by a cover 220 so as to be in close contact with the surface of the steam pipe 15 along the longitudinal direction (the shape of a curved pipe portion) of the steam pipe 15 in order to measure the surface temperature of the steam pipe 15. Then, as in the case of the optical fiber 110, the surface temperature of the vapor pipe 15 can be measured by bringing the optical fiber 210 into close contact with the surface of the vapor pipe 15 and utilizing the temperature dependency of the Raman scattered light. The diameter of the optical fiber 210 is, for example, about 0.2 mm.

  The cover 220 includes a cover main body 2201 and flanges 2202A and 2202B. The thickness of the cover 220 is, for example, about 2 to 3 mm.

  The cover main body 2201 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. On the inner circumferential surface of the cover main body 2201, the optical fiber 210 is accommodated along the longitudinal direction of the steam pipe 15 in order to bring the optical fiber 210 into close contact with the surface of the steam pipe 15 along the longitudinal direction of the steam pipe 15. The groove 2201 C is formed. The groove 2201C is formed, for example, on the opposite side of the flanges 2202A and 2202B in the cover main body 2201. When the temperature measurement device 200 is installed in the boiler 2, if the combustion gas hits the flanges 2202A and 2202B, the flow of the combustion gas is disturbed, so the flanges 2202A and 2202B are on the downstream side of the combustion gas (the side where the combustion gas hits Is facing the opposite side, the temperature measuring device 200 is installed. In addition, when the temperature measurement device 200 is mounted on a curved pipe portion of the steam pipe 15 disposed in the boiler 2, a variation that exhibits various shapes such that the flanges 2202A and 2202B always face the downstream side of the combustion gas Is prepared in advance. The groove 2201 </ b> C has a depression that allows the optical fiber 210 to be in close contact with the surface of the steam pipe 15. The cover main body 2201 has end faces 2201 A and 2201 B 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 2202A and 2202B are formed to extend from the end faces 2201A and 2201B so as to be away from the steam pipe 15, respectively. The flanges 2202A and 2202B have a plurality of holes 2203A and 2203B along the longitudinal direction of the steam pipe 15, respectively. The plurality of holes 2203A and 2203B communicate with each other so that the bolt 2204 is screwed with the nut 2205. Then, after covering the cover main body 2201 on the curved pipe portion of the steam pipe 15 while widening the gap between the flanges 2020A and 2202B against the rigidity of the temperature measuring device 200, the bolts 2204 are inserted into the plurality of holes 2203A and 2203B. Then, when the bolt 2204 and the nut 2205 are tightened, the gap between the flanges 2202A and 2202B disappears, and the cover main body 2201 is closely attached to the curved pipe portion of the steam pipe 15.

  The temperature of the optical fiber 210 is affected only by the surface temperature of the steam pipe 15 because the optical fiber 210 does not directly touch the combustion gas by the cover 220. Therefore, the temperature of the optical fiber 210 is suppressed to less than 700 ° C., and the surface temperature of the curved pipe portion of the steam pipe 15 can be reliably acquired. Information on the surface temperature of the steam pipe 15 is taken into an external monitoring device (not shown) via a network to obtain a temperature distribution. Furthermore, since the cover 220 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 in the steam pipe 15, the cover 120 may be attached to the straight pipe portion of the steam pipe 15 and the cover 220 may be attached to the curved pipe portion of the steam pipe 15. . Alternatively, the cover 220 may be doubly attached to the curved pipe portion of the steam pipe 15 to reinforce the curved pipe portion of the steam pipe 15.

  As described above, the temperature measurement device 100 (200) according to the present embodiment includes the steam pipe 15 (superheater pipe) in which the steam obtained by heat-exchanging the water supplied to the boiler 2 with the combustion gas And the optical fiber 110 (210) for measuring the surface temperature of the reheater tube, and the optical fiber 110 so that the optical fiber 110 (210) adheres to the steam pipe 15 along the longitudinal direction of the steam pipe 15. And a cover 120 (220) mounted so as to surround the steam pipe 15 with (210) interposed therebetween. According to the present embodiment, the optical fiber 110 (210) is not directly exposed to the combustion gas by the cover 120 (220), and the temperature of the optical fiber 110 (210) is affected only by the surface temperature of the steam pipe 15, The temperature of the optical fiber 110 (210) is suppressed to less than 700 ° C., and the surface temperature of the steam pipe 15 can be reliably acquired. Furthermore, since the cover 120 (220) surrounds the steam pipe 15, the creep strength of the steam pipe 15 can be improved.

  Further, in the present embodiment, the cover 120 (220) is a groove 1201C (which is recessed along the longitudinal direction of the steam pipe 15 so that the optical fiber 110 (210) is accommodated when attached to the steam pipe 15). 2201 C). According to this embodiment, it is possible to protect the optical fiber 110 (210) while being in close contact with the steam pipe 15.

  Also, in the present embodiment, the cover 120 (220) has a gap along the longitudinal direction of the steam pipe 15, and has a cylindrical cover body 1201 (2201) surrounding the steam pipe 15, and the cover body 1201 (2201). The flanges 1202A (2202A) and 1202B (2202B) are formed at both ends of the cover 120 and tightened by bolts 1204 (2204) and nuts 1205 (2205) so that the cover main body 1201 (2201) is in close contact with the steam pipe 15.

  Also, in the present embodiment, the cover 120 (220) is formed of alloy steel. In particular, the cover 120 (220) is preferably formed from stainless steel (SUS304 or SUS316).

  In addition, said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. The present invention can be modified and improved without departing from the gist thereof, and the present invention also includes the equivalents thereof. For example, the cover 120 (220) may be welded to the steam pipe 15 without providing the flanges 1202A (2202A) and 1202B (2202B).

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 100, 200 Temperature measuring device 110, 210 Optical fiber 120, 220 Cover 1201, 220 Cover Body 1201A, 1201B, 2201A, 2201B End face 1201C, 2201C Groove 1202A, 1202B, 2202A, 2202B Flange 1203A, 1203B, 2203A, 2203B Hole 1204, 2204 Bolt 1205, 2205 Nut

Claims (8)

An optical fiber for measuring the surface temperature of a steam pipe in which steam obtained by heat exchange between the water supplied to the boiler and the combustion gas is circulated;
And a cover mounted so as to surround the steam pipe with the optical fiber interposed therebetween so that the optical fiber adheres to the steam pipe along the longitudinal direction of the steam pipe .
The cover is
It has one gap along the longitudinal direction of the steam pipe, and a groove recessed along the longitudinal direction of the steam pipe so that the optical fiber is accommodated when the steam pipe is mounted. A cover body having a cylindrical shape surrounding the steam pipe;
And a flange formed at both ends of the cover main body with the gap interposed therebetween and tightened by a bolt so that the cover main body is in close contact with the steam pipe,
The groove is formed on the opposite side of the cover body from the flange;
The apparatus for measuring a temperature of a steam pipe, wherein the optical fiber and the cover are installed in the boiler such that the flange faces the downstream side of the combustion gas . The steam pipe temperature measuring device according to claim 1, wherein the cover is made of alloy steel. The steam pipe temperature measuring device according to claim 2 , wherein the cover is made of stainless steel. The said steam pipe is a superheater pipe | tube The temperature measurement apparatus of the steam pipe as described in any one of the Claims 1-3 characterized by the above-mentioned. The said steam pipe is a reheater crucible. The temperature measurement apparatus of the steam pipe as described in any one of the Claims 1-3 characterized by the above-mentioned. An optical fiber for measuring the surface temperature of the steam pipe in which the steam obtained by heat exchange between the water supplied to the boiler and the combustion gas is circulated adheres to the steam pipe along the longitudinal direction of the steam pipe. So as to attach a cover surrounding the steam pipe across the optical fiber ,
The cover is
It has one gap along the longitudinal direction of the steam pipe, and a groove recessed along the longitudinal direction of the steam pipe so that the optical fiber is accommodated when the steam pipe is mounted. A cover body having a cylindrical shape surrounding the steam pipe;
And a flange formed at both ends of the cover main body with the gap interposed therebetween and tightened by a bolt so that the cover main body is in close contact with the steam pipe,
The groove is formed on the opposite side of the cover body from the flange;
The method for measuring the temperature of a steam pipe, wherein the optical fiber and the cover are installed in the boiler such that the flange faces the downstream side of the combustion gas . The steam pipe temperature measuring method according to claim 6 , wherein the cover is made of alloy steel. The steam pipe temperature measuring method according to claim 7 , wherein the cover is made of stainless steel.

Images