JP6716799B1 - Thermometer protection tube, temperature measuring instrument, steam piping structure, and installation method of thermometer protection tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermometer protection cylinder, a temperature measuring instrument, a steam piping structure, and a method for installing a thermometer protection cylinder capable of suppressing the generation of an unwelded portion in a portion to be welded. SOLUTION: The thermometer protection cylinder is a rod-like body extending in the direction of the axis X1 and has a tip end 11 side inserted into a through hole formed in a steam pipe, and a base end 12 side of the cylinder body 10 has an axis line X1. And a nozzle part 30 that is formed so as to expand in the radial direction orthogonal to the direction and that is arranged on the outer peripheral surface side of the steam pipe. The nozzle part 30 is a tip from the base end 12 side of the tube body 10. 11 from the outer peripheral side in the direction toward the 11 side, and from the end portion of the groove surface 31 on the cylinder body 10 side, in the direction from the tip 11 side to the base end 12 side of the cylinder body 10, the axis X1. A straight surface 32 that extends in the direction and that faces the outer peripheral surface of the tube body 10 with a gap therebetween and that is formed by the groove surface 31 and the straight surface 32 so as to project. Equipped with. [Selection diagram] Fig. 3

Description

The present disclosure relates to a thermometer protective cylinder, a temperature measuring instrument, a steam piping structure, and a method for installing a thermometer protective cylinder.

A large-scale boiler used in a power plant or the like has a furnace having a hollow shape and installed in the vertical direction, and a plurality of combustion burners are arranged on the furnace wall along the circumferential direction of the furnace. Further, in the boiler, a flue is connected vertically above the furnace, and a heat exchanger for generating steam is arranged in the flue. Then, the combustion burner injects a mixture of fuel and air (oxidizing gas) into the furnace to form a flame, and combustion gas is generated and flows into the flue. A heat exchanger is installed in a region in which the combustion gas flows, and superheated steam is generated by heating water or steam flowing in the heat transfer tube that constitutes the heat exchanger.

A thermometer for measuring a steam temperature is installed in a steam pipe used in a power plant having a boiler. At this time, in order to protect the thermometer from steam with high temperature and high pressure, the thermometer may be housed in a thermometer protection cylinder and installed in the steam pipe.

As a structure for installing the thermometer protection tube in the steam pipe, for example, a through hole is formed in the wall of the steam pipe, and a deep seat is formed so as not to reach the inner peripheral surface from the outer peripheral surface of the steam pipe around the through hole. There is a method in which a boring is performed, a thermometer protection tube is inserted into the through hole, and welding is performed so as to fill the deep counterbore.

Further, although not used as a thermometer protection cylinder, Patent Document 1 discloses an instrumentation nozzle (sampling nozzle) provided in a pipe of a power generation plant or the like. In the instrumentation nozzle of Patent Document 1, one end of the pipe and the stub are connected by welding, and the other end of the stub is connected by welding to the instrumentation nozzle.

JP, 9-311198, A

In the structure in which the thermometer protection tube is inserted into the through hole and the deep counterbore is welded, an unwelded portion of the weld may occur at the tip (bottom) of the deep counterbore. Further, the unwelded portion has a notch shape, and stress may be easily concentrated. Therefore, if the stress acting on the steam pipe due to the internal pressure concentrates on the notch-shaped unwelded portion, a crack may occur starting from the unwelded portion. As described above, when a crack is generated in a part of the steam pipe, the crack may spread to cause damage to the outer peripheral surface of the steam pipe, and steam may leak from the damaged portion. ..

Further, in the instrumentation nozzle disclosed in Patent Document 1, the instrumentation nozzle and the stub are welded in the form of so-called fillet welding, and the end of the R portion provided on the step (R portion, stub and In the vicinity of the boundary of the weld), there may be an unwelded part where the molten metal does not completely melt. Because of the structure of the instrumentation nozzle disclosed in Patent Document 1, the end of the R portion is the location where stress is most likely to be concentrated. Therefore, if there is an unwelded portion at such a location, the unwelded portion A crack may occur as a starting point. As described above, when a crack is generated in a part of the steam pipe, the crack may spread to cause damage to the outer peripheral surface of the steam pipe, and steam may leak from the damaged portion. ..

The present disclosure has been made in view of such circumstances, and a thermometer protective cylinder, a temperature measuring instrument, a steam pipe structure, and a thermometer that can suppress the generation of an unwelded portion in a portion to be welded. It is intended to provide a method of installing a protective cylinder.

In order to solve the above-mentioned subject, the following means is adopted for the installation method of the thermometer protection cylinder, the temperature measuring instrument, the steam piping structure, and the thermometer protection cylinder of the present disclosure.
That is, the thermometer protection cylinder according to one aspect of the present disclosure has a cylinder main body having a rod shape extending in the axial direction and having a tip end side inserted into a through hole formed in a steam pipe, and a base end side of the cylinder main body is A stub portion formed so as to expand in a radial direction orthogonal to the axial direction and arranged on the outer peripheral surface side of the steam pipe, and the stub portion from the base end side of the cylinder body. A groove surface that has been shrunk from the outer peripheral side in the direction toward the tip end side, and the axis in a direction from the tip end side of the cylinder body toward the base end side from an end portion of the groove surface on the cylinder body side. A straight surface that extends along the direction and that faces the outer peripheral surface of the tubular body with a gap therebetween and that has a groove portion formed to project by the groove surface and the straight surface. I have it.

Further, a temperature measuring instrument according to one aspect of the present disclosure includes a thermometer and the thermometer protection cylinder, and the cylinder body is bored in a direction from the end face of the base end toward the tip end side. The thermometer is inserted and fixed in the insertion hole.

Further, a steam pipe structure according to an aspect of the present disclosure includes a steam pipe in which a through hole is formed, and the thermometer protection cylinder, wherein the thermometer protection cylinder has the tip end side of the cylinder main body as described above. The groove is inserted into a through hole and the groove is butted against the outer peripheral surface of the steam pipe, and a weld is formed between the groove surface of the groove and the outer peripheral surface of the steam pipe to form the steam. It is connected to the pipe.

Further, a method for installing a thermometer protection cylinder according to one aspect of the present disclosure, a cylinder main body having a rod shape extending in the axial direction and having a tip side inserted into a through hole formed in a steam pipe, and a base of the cylinder main body. An end side is formed so as to expand in a radial direction orthogonal to the axial direction, and a nozzle part arranged on the outer peripheral surface side of the steam pipe is provided, wherein the nozzle part is the base of the cylinder body. A groove surface that is shrunk from the outer peripheral side in a direction from the end side to the tip side, and a direction from the tip side of the cylinder body to the base end side from an end portion of the groove surface on the cylinder body side. And a straight surface that extends along the axial direction and that faces the outer peripheral surface of the cylindrical body with a gap therebetween and that is formed by the groove surface and the straight surface. A method of installing a thermometer protection cylinder having a tip portion, comprising: a first step of inserting the cylinder body into the through hole formed in the steam pipe; the groove portion of the nozzle part; A second step of forming a welded portion by welding the outer peripheral surface of the steam pipe.

According to the present disclosure, it is possible to provide a thermometer protection cylinder, a temperature measuring instrument, a steam piping structure, and a method for installing a thermometer protection cylinder that can suppress the generation of an unwelded portion in a portion to be welded.

It is a schematic diagram showing steam, condensate, and a water supply system in a boiler power plant. It is a side view of a thermometer protection cylinder concerning one embodiment of this indication. It is a longitudinal cross-sectional view of a thermometer protection cylinder according to an embodiment of the present disclosure. It is the figure which looked at the thermometer protection cylinder from the direction of arrow A shown in FIG. It is sectional drawing which looked at the thermometer protection cylinder inserted in the steam piping from the axial direction of the steam piping. It is sectional drawing which looked at the thermometer protection cylinder inserted in the steam piping from the direction orthogonal to the axial direction of the steam piping. It is sectional drawing which looked at the thermometer protection cylinder connected to the steam piping from the axial direction of the steam piping. It is sectional drawing which looked at the thermometer protection cylinder connected to the steam piping from the direction orthogonal to the axial direction of the steam piping. It is a reference drawing showing the concept of a stress concentration part.

[About boiler power plant]
First, a boiler power plant in which a thermometer protection tube according to an embodiment of the present disclosure is installed will be described with reference to FIG. 1.

FIG. 1 is a schematic diagram showing steam, condensate, and a water supply system in a boiler power plant.
The boiler power generation plant is connected to the heat exchangers 102, 103, 104 of the boiler, the steam turbine 110 that is rotationally driven by the steam generated by the boiler, and the steam turbine 110, and generates power according to the rotation of the steam turbine 110. And a generator 115.

The steam turbine 110 is composed of, for example, a high-pressure turbine 111, an intermediate-pressure turbine 112, and a low-pressure turbine 113, and steam from reheaters 105 and 106 described later flows into the medium-pressure turbine 112 and then flows into the low-pressure turbine 113. To do.

A condenser 114 is connected to the low-pressure turbine 113, and steam that rotationally drives the low-pressure turbine 113 is cooled by cooling water (for example, seawater) in the condenser 114 to be condensed water. The condenser 114 is connected to the economizer 107 via the water supply line L1.

The water supply line L1 is provided with, for example, a condensate pump (CP) 121, a low-pressure water supply heater 122, a boiler water supply pump (BFP) 123, and a high-pressure water supply heater 124.

A part of the steam that drives the steam turbines 111, 112, 113 is extracted into the low-pressure feed water heater 122 and the high-pressure feed water heater 124, and is used as a heat source for the high-pressure feed water heater 124 and the low-pressure feed water heater 122 via an extraction line (not shown). The water supplied and supplied to the economizer 107 is heated.

Hereinafter, a case where the boiler is a once-through boiler will be described as an example.
The economizer 107 is connected to each evaporation pipe of the furnace wall 101. When the feed water heated by the economizer 107 passes through the evaporation pipe of the furnace wall 101, it is radiated from the flame in the furnace to be heated and guided to the brackish water separator 126. The steam separated by the brackish water separator 126 is supplied to the superheaters 102, 103, 104, and the drain water separated by the brackish water separator 126 is fed to the condenser 114 via the drain water line L2. Be guided.

When the combustion gas flows through the combustion gas passage (flue) 13, the heat of the combustion gas is recovered by the superheaters 102, 103 and 104, the reheaters 105 and 106, and the economizer 107. On the other hand, the feed water supplied from the boiler feed water pump (BFP) 123 is preheated by the economizer 107 and then heated as it passes through each evaporation pipe of the furnace wall 101 to become steam, which is then introduced to the brackish water separator 126. Get burned.

The steam separated by the brackish water separator 126 is introduced into the superheaters 102, 103, 104 and superheated by the combustion gas.

The superheated steam generated by the superheaters 102, 103, 104 is supplied to the high-pressure turbine 111 via the steam line L3, and rotationally drives the high-pressure turbine 111.

The steam discharged from the high-pressure turbine 111 is introduced into the reheaters 105 and 106 via the steam line L4 and is again superheated. The reheated steam is supplied to the low-pressure turbine 113 via the steam line L5 and the intermediate-pressure turbine 112, and rotationally drives the intermediate-pressure turbine 112 and the low-pressure turbine 113.

The rotating shafts of the steam turbines 111, 112, 113 rotationally drive the generator 115 to generate electric power. The steam discharged from the low-pressure turbine 113 is cooled by the condenser 114 to become condensed water, and is sent to the economizer 107 again via the water supply line L1.

A plurality of thermometers for measuring the steam temperature are installed in the steam piping 50 constituting each steam line of the boiler power plant as described above. For example, the thermometer is installed at a point P on each steam line in the figure. The location P in the figure is an example, and not all installation locations are shown.

When installing the thermometer in the steam pipe 50, the thermometer is housed in the thermometer protection cylinder 1 in order to protect the thermometer from the temperature and pressure of the steam flowing inside the steam pipe 50, the force exerted by the fluid, and the like. Then, the steam pipe 50 is installed. For the thermometer, for example, a thermocouple or a resistance temperature detector is used.

[About thermometer protection tube]
Next, the thermometer protection cylinder 1 will be described with reference to FIGS. 2 to 4.
FIG. 2 is a side view of the thermometer protection cylinder 1. FIG. 3 is a vertical cross-sectional view of the thermometer protection cylinder. FIG. 4 is a view of the thermometer protection cylinder viewed from the direction of arrow A shown in FIG.

The thermometer protection cylinder 1 is made of metal (for example, chromium-containing alloy steel). Preferably, the thermometer protection cylinder 1 is made of the same or similar material as the steam pipe 50 described later.

As shown in FIG. 2 and FIG. 3, the thermometer protection cylinder 1 includes a cylinder body 10 that extends in the direction of the axis X1 and has a slight amount of taper on the tip 11 side, and a nozzle part 30 formed integrally with the cylinder body 10. It has and.
The term "integral" as used herein means that they are continuously formed of the same material and are not divided as members.

The outer diameter of the cylinder body 10 is set to a dimension that allows insertion with a small gap (for example, about 1 mm) between the inner diameter of a through hole 51 formed in the steam pipe 50 described later, and is set to, for example, about Φ30 mm to Φ70 mm. There is.

A thermometer insertion hole (insertion hole) 15 into which a thermometer (not shown) is inserted is bored from the end face (upper face in the figure) on the base end 12 side toward the tip 11 side inside the cylinder body 10. Has been done.
The thermometer insertion hole 15 is closed on the front end 11 side and is open on the end face on the base end 12 side. As a result, a thermometer such as a thermocouple can be inserted from the end face on the proximal end 12 side and fixed on the distal end 11 side. As a result, the thermometer protection cylinder 1 having the thermocouple inserted therein functions as a temperature measuring instrument.

On the base end 12 side of the cylinder body 10, the nozzle part 30 is expanded so that the cylinder body 10 projects to the outside in the radial direction (hereinafter, simply referred to as “radial direction”) orthogonal to the axis X1 direction. Has been formed.
As shown in FIGS. 5 to 8 to be described later, the thermometer protection cylinder 1 is configured such that the cylinder body 10 is inserted inside the steam pipe 50 into the through hole 51 provided in the steam pipe 50. Is installed in a state in which the tip 11 of the is protruding inside the steam pipe 50. On the other hand, the nozzle part 30 is arranged outside the steam pipe 50. At this time, by forming the welded portion 60 by welding between the groove surface 31 formed on the nozzle part 30 and the outer peripheral surface of the steam pipe 50, the thermometer protection cylinder 1 is joined to the steam pipe 50. And fixed.

The outer diameter of the nozzle part 30 is larger than the inner diameter of a through hole 51 formed in the steam pipe 50 described later, and is, for example, about Φ50 mm to Φ150 mm. This is for separating the welded portion 60 from the through hole 51 formed in the steam pipe 50.

A groove surface 31 and a straight surface 32 are formed in a lower portion (a portion facing a steam pipe 50 described later) of the nozzle portion 30.

The groove surface 31 is an inclined surface whose diameter decreases from the outer peripheral surface of the nozzle part 30 toward the cylinder body 10 side in the direction from the base end 12 to the tip 11 of the cylinder body 10. The groove surface 31 has an acute angle relationship with a straight surface 32 described later. The groove surface 31 is formed in an annular shape in the circumferential direction centering on the axis X1 from the outer peripheral surface of the nozzle part 30 toward the tip 11 on the cylinder body 10 side (see FIG. 4).

The straight surface 32 is connected to the tip of the groove surface 31 (the end portion of the groove surface 31 on the cylinder body 10 side) in the vicinity of the connecting portion between the nozzle part 30 and the cylinder body 10, and The surface extends along the axis X1 in the direction from the tip 11 to the base 12, and is formed in an annular shape in the circumferential direction centered on the axis X1 (see FIG. 4). At this time, the straight surface 32 faces the cylindrical outer peripheral surface of the cylinder body 10 near the connecting portion with the nozzle part 30 in parallel or substantially parallel to each other with a gap. The straight surface 32 preferably has a length dimension in the direction of the axis X1 of 2 mm or more and 5 mm or less. This is a dimension necessary for forming an annular groove portion 35 described later.

The gap between the cylindrical outer peripheral surface of the tube main body 10 near the nozzle part 30 and the connecting portion and the straight surface 32 facing it is uniquely determined by the radius of the round surface 34 described later.

The base end of the straight surface 32 (the end on the base end 12 side of the cylinder body 10) whose tip is connected to the groove surface 31 is folded back through the semi-circular round surface 34 so that the cylinder body 10 has a shape. Is connected to the outer peripheral surface of.

When the maximum outer diameter of the nozzle part 30 is 150 mm and the thickness dimension (thickness in the radial direction from the straight surface 32 to the outermost peripheral surface of the nozzle part 30) is 25 mm, for example, the round surface 34 has a radius dimension. Is preferably 3 mm or more and 10 mm or less. The lower limit of 3 mm of the radius is the minimum value of the range of dimensions that can be easily manufactured, and the upper limit of 10 mm is the maximum value of the range of dimensions that satisfies the life (for example, 240,000 hours). The radius of the round surface 34 is determined so that the straight surface 32 is located radially outside the inner diameter of the through hole 51 formed in the steam pipe 50 described later within the above range of dimensions.

The grooved surface 31 and the straight surface 32, which is formed as described above and faces the outer peripheral surface of the cylinder body 10 with a gap therebetween, protrudes in a V-shape at the lower part of the nozzle part 30. The groove portion 35 is formed. The groove portion 35, like the groove surface 31 and the straight surface 32, is formed in an annular shape in the circumferential direction around the axis X1. The groove portion 35 is formed so as to project toward the steam pipe 50 side when being installed in the steam pipe 50. As a result, it is possible to improve the penetration of the molten metal during welding with the steam pipe 50, and it is possible to suppress the generation of unwelded portions in the portions to be welded. The root surface 33 may be formed between the groove surface 31 and the straight surface 32 at the tip of the groove portion 35.

[About steam piping structure]
Next, the structure of the steam pipe 50 in which the thermometer protection cylinder 1 is installed will be described with reference to FIGS. 5 to 9.
FIG. 5 is a cross-sectional view of the thermometer protection cylinder 1 inserted into the steam pipe 50 and before being welded to the steam pipe 50, as seen from the axial direction of the steam pipe 50. That is, FIG. 5 is a cross-sectional view in which the circumferential direction of the steam pipe 50 is visible. FIG. 6 is a cross-sectional view of the thermometer protection cylinder 1 inserted into the steam pipe 50 and before being welded to the steam pipe 50 as seen from a direction orthogonal to the axial direction of the steam pipe 50. That is, FIG. 6 is a cross-sectional view in which the longitudinal direction (axial direction) of the steam pipe 50 is visible. FIG. 7 is a cross-sectional view of the thermometer protection cylinder 1 connected to the steam pipe 50 by welding as seen from the axial direction of the steam pipe 50. FIG. 8 is a cross-sectional view of the thermometer protection cylinder 1 connected to the steam pipe 50 by welding as seen from a direction orthogonal to the axial direction of the steam pipe 50. FIG. 9 is a reference diagram showing the concept of the stress concentration part.

As shown in FIGS. 5 and 6, the thermometer protection cylinder 1 is inserted from the tip 11 in the direction of the axis X1 into the through hole 51 formed in the steam pipe 50 that constitutes the steam line (L3 to L5 in FIG. 1). (First step).

The steam pipe 50 is a pipe through which high-temperature and high-pressure steam flows. The wall thickness of the steam pipe 50 is, for example, 25 mm to 130 mm. A through hole 51 for inserting the thermometer protection cylinder 1 is formed in the steam pipe 50.

The through hole 51 is a straight tubular hole that penetrates the pipe wall of the steam pipe 50 in the thickness direction thereof, and connects the outside and the inside of the steam pipe 50.

In the thermometer protection cylinder 1 inserted into the through hole 51, an annular groove portion 35 formed by the groove surface 31 and the straight surface 32 and protruding toward the steam pipe 50 is butted against the outer peripheral surface of the steam pipe 50. .. As a result, a groove for welding is formed between the groove 35 and the outer peripheral surface of the steam pipe 50.
The thermometer protection cylinder 1 is held with a predetermined gap (route interval) secured between the groove portion 35 and the steam pipe 50 that are butted to each other. The route interval is, for example, 2 mm to 7 mm.

At this time, since the straight surface 32 is located radially outside of the inner diameter of the through hole 51 with respect to the direction of the axis X1, the outer peripheral surface of the steam pipe 50 is located radially inward of the tip of the groove portion 35. It exists (part B surrounded by a dotted square in FIGS. 5 and 6). The outer peripheral surface of the steam pipe 50 from the tip of the annular groove 35 to the through hole 51 is a portion for receiving the molten metal that flows out from the gap between the tip of the groove 35 and the outer peripheral surface of the steam pipe 50 at the start of welding. Function as. Further, by welding the groove portion 35 to the outer peripheral surface of the steam pipe 50 so as to be welded, it is possible to improve the penetration of the molten metal at the start of welding. As a result, it is possible to suppress the generation of an unwelded portion in the portion to be welded and suppress the generation of a discontinuous weld penetration shape.

The dimension (projection amount) on the tip 11 side of the cylinder body 10 protruding from the inner peripheral surface of the steam pipe 50 is controlled to be 63.5 mm or more and 100 mm or less. In other words, the dimension of the cylinder body 10 in the direction of the axis X1 is set so that the protrusion amount falls within the above range.

By setting the protrusion amount to 100 mm or less, it is possible to prevent the tip 11 of the cylinder body 10 from protruding more than necessary from the inner peripheral surface of the steam pipe 50, and keep the tip 11 of the cylinder body 10 away from the main stream of steam. The influence of steam on the mainstream can be reduced. Therefore, the diameter of the cylinder body 10 can be increased to secure the strength of the thermometer protection cylinder 1, and the durability against steam erosion can be improved. The lower limit of the protrusion amount of 63.5 mm is a dimension defined by the standard (ASME PTC 19.3 TW).

Thereafter, as shown in FIGS. 7 and 8, a welded portion 60 is formed by depositing molten metal between the groove surface 31 and the outer peripheral surface of the steam pipe 50 by welding to form the thermometer protection cylinder 1 and the steam pipe. 50 is connected (second step).

When forming the welded portion 60, it is preferable that the position of the weld toe 61 is located radially outside of the position of the outer peripheral surface of the nozzle part 30 in the direction of the axis X1. The weld toe 61 is an outer end in the radial direction of a portion of the welded portion 60 that is in contact with the steam pipe 50. With this configuration, as shown in FIG. 8, the welding toe 61 can be positioned at a distance outside the stress concentrating portion 53 generated inside the pipe material of the steam pipe 50 in the longitudinal direction.

The stress concentrating portion 53 will be described below with reference to FIG.
Tensile stress σf is applied to the long side of a virtual plate 70 having a through hole 71 and extending in the longitudinal direction. At this time, as is known, with respect to the stress σy acting on the center line of the flat plate 70, the maximum stress σmax occurs near the longitudinal direction of the through hole 71 (so-called stress concentration). The maximum stress σmax is approximately three times the tensile stress σf generated at the through hole point 72.

A hoop stress acts on the steam pipe 50 in the circumferential direction of the through hole 51 due to the internal pressure of the steam flowing through the steam pipe 50. When the phenomenon of stress concentration shown in FIG. 9 is applied to the steam pipe 50, the hoop stress is shown in FIG. Thus, in the axial direction (longitudinal direction) of the steam pipe 50, the stress concentrating portion 53 is generated inside the pipe material of the steam pipe 50 and near the through hole 51.

In the present embodiment, the position of the welding toe 61 is radially outside with respect to the direction of the axis X1 in the radial direction with respect to the stress concentration portion 53 generated inside the pipe material of the steam pipe 50. A part of the existing stress can be carried by the nozzle part 30. Thereby, the stress concentration generated in the welded portion 60 near the groove surface 31 and the straight surface 32 can be relaxed, and the strength of the welded portion 60 can be secured and the service life can be extended.

According to this embodiment, the following effects are exhibited.
Since the nozzle part 30 has the straight surface 32 that faces the groove surface 31 and the outer peripheral surface of the cylinder body 10 with a gap therebetween, the circle projected by the groove surface 31 and the straight surface 32. An annular groove 35 can be formed. Thus, by welding the groove portion 35 to the outer peripheral surface of the steam pipe 50 so as to weld the molten metal at the start of welding, it is possible to improve the penetration of the molten metal so that the portion to be welded has an unwelded portion. The occurrence of discontinuous weld penetration shapes is suppressed. Thereby, even when a load is applied, it is possible to prevent stress from concentrating and causing a crack to occur.
In addition, the gap between the straight surface 32 and the outer peripheral surface of the cylinder body 10 is a radial direction with respect to the axis X1 direction when the cylinder body 10 is inserted into the through hole 51 and the groove surface 31 is abutted against the steam pipe 50. Since the straight surface 32 is set to be positioned outside the through hole 51, the circle formed by the straight surface 32 and the groove surface 31 when the thermometer protection cylinder 1 is butted against the steam pipe 50. The outer peripheral surface of the steam pipe 50 exists by the distance from the tip of the annular groove 35 to the through hole 51. The outer peripheral surface of the steam pipe 50 from the tip of the groove portion 35 to the through hole 51 is formed from the gap between the tip of the annular groove portion 35 protruding to the steam pipe 50 at the start of welding and the outer peripheral surface of the steam pipe 50. Since it functions as a receiving portion for the molten metal flowing out, it is possible to further improve the penetration of the molten metal.
By improving the penetration of the molten metal in this way, it is possible to suppress the generation of unwelded parts in the parts to be welded, and when stress is applied, stress concentrates on the unwelded parts and It is possible to suppress the initiation and extension of cracks starting from the welded portion.

In addition, since the round surface 34 that connects the straight surface 32 and the outer peripheral surface of the cylinder body 10 in a semi-circular shape is formed, stress concentration at the connecting portion between the straight surface 32 and the outer peripheral surface of the cylinder body 10 is reduced. Can be suppressed.

Moreover, since the protrusion amount of the cylinder body 10 is set to 63.5 mm or more and 100 mm or less, the tip 11 of the cylinder body 10 can be separated from the central axis of the steam pipe 50. That is, the tip 11 of the cylinder body 10 can be kept away from the mainstream. As a result, the influence of the cylinder body 10 on the main flow (blocking of the flow, etc.) is suppressed. Further, since the influence on the mainstream is suppressed by the amount of protrusion, the cylinder body 10 can be made thicker by that amount, and the strength of the thermometer protection cylinder 1 can be improved. In addition, the durability of steam to erosion can be improved.
If the amount of protrusion of the cylinder body 10 is large, it is conceivable to reduce the diameter of the cylinder body 10 in order to suppress the influence on the mainstream. However, the strength of the thermometer protection cylinder 1 is reduced by reducing the diameter of the cylinder body 10.

Further, in the thermometer protection cylinder 1, since the welded portion 60 is formed between the groove surface 31 of the nozzle portion 30 and the outer peripheral surface of the steam pipe 50 and connected to the steam pipe 50, the welded portion 60 All can be formed on the outer peripheral surface of the steam pipe 50. As a result, the presence or absence of defects in the welded portion 60 can be inspected by a nondestructive method, so that the welded portion 60 can be easily inspected. Further, since all of the welded portions 60 to be inspected are formed on the outer peripheral surface of the steam pipe 50, the inspection accuracy is improved. In addition, since the amount of molten metal can be reduced as compared with the case where a spot facing is provided on the steam pipe 50 and welding is performed with the thermometer protection cylinder, the number of man-hours required for mounting or replacing the thermometer protection cylinder 1 is reduced. Can be reduced.

In addition, since the weld toe 61 of the welded portion 60 is located radially outward of the outer peripheral surface of the nozzle part 30 with respect to the direction of the axis X1, the inside of the pipe material of the steam pipe 50 and the vicinity of the through hole 51. It is possible to position the weld toe 61 of the welded portion 60 on the outer side in the radial direction with respect to the stress concentrating portion 53 that occurs at. As a result, the welded portion 60 is configured to cover the stress concentrated portion 53, and a part of the stress generated in the stress concentrated portion 53 can be carried by the nozzle part 30. As a result, the yield strength of the welded portion 60 can be improved. Further, the stress concentration generated in the welded portion 60 near the groove surface 31 and the straight surface 32 can be relaxed, and the strength of the welded portion 60 can be secured and the service life can be extended.

The embodiment described above is understood as follows, for example.
That is, the thermometer protection cylinder (1) according to one aspect of the present disclosure has a rod shape extending in the direction of the axis (X1), and the tip end (11) side is a through hole (51) formed in the steam pipe (50). The cylinder main body (10) to be inserted and the base end (12) side of the cylinder main body (10) are formed so as to expand in a radial direction orthogonal to the axis (X1) direction, and the steam pipe (50) And a nozzle part (30) arranged on the outer peripheral surface side, the nozzle part (30) extending from the base end (12) side of the tube body (10) toward the tip (11) side. Direction from the outer peripheral side in the direction, from the end of the groove surface (31) on the side of the cylinder body (10), from the side of the tip (11) of the cylinder body (10). A straight surface (32) extending along the axis (X1) in the direction toward the base end (12) and facing the outer peripheral surface of the cylinder body (10) with a gap therebetween. However, it is provided with a groove portion (35) formed so as to project by the groove surface (31) and the straight surface (32).

According to the thermometer protection cylinder (1) according to this aspect, the nozzle part (30) has the cylinder body from the outer peripheral side in the direction from the base end (12) side to the tip (11) side of the cylinder body (10). The groove surface (31) that has been shrunk to the (10) side, and the end portion of the groove surface (31) on the cylinder body (10) side, from the tip (11) side of the cylinder body (10) to the base end (12). ) Side and a straight surface (32) that extends along the axis (X1) direction and faces the outer peripheral surface of the cylinder body (10) with a gap therebetween. A groove portion (35) protruding from the nozzle part (30) can be formed by the (31) and the straight surface (32). Thus, the protruding groove portion (35) is abutted against the outer peripheral surface of the steam pipe (50) and welded, so that the molten metal can be favorably melted at the start of welding. Further, since a gap is provided between the straight surface (32) and the outer peripheral surface of the cylinder body (10), the outer periphery of the steam pipe (50) abutted against the tip of the protruding groove portion (35). The position on the surface can be extended to the cylinder body (10) side from the groove portion (35) by the amount of the gap. As a result, the outer peripheral surface of the steam pipe (50) extending to the cylinder body (10) side with respect to the protruding groove portion (35) has a distal end of the groove portion (35) and the steam pipe (50) at the start of welding. Since it functions as a portion for receiving the molten metal flowing out from the gap with the outer peripheral surface of the metal, the penetration of the molten metal can be further improved, and the generation of unwelded portions can be suppressed.
By improving the penetration of the molten metal in this way, it is possible to suppress the occurrence of discontinuous weld penetration shapes such as unwelded parts in the parts to be welded, and in the event that a load is applied. It is possible to prevent stress from concentrating and cracks from starting and extending from the unwelded portion.

Further, in the thermometer protection cylinder (1) according to one aspect of the present disclosure, a welded portion (60) is formed in the groove portion (35) with the outer peripheral surface of the steam pipe (50). ..

According to the thermometer protection cylinder (1) of this aspect, since the welded portion (60) is formed in the groove portion (35) with the outer peripheral surface of the steam pipe (50), the groove portion is formed. (35) and the outer peripheral surface of the steam pipe (50) can be welded and connected.

Further, in the thermometer protection cylinder (1) according to one aspect of the present disclosure, in the gap between the straight surface (32) and the outer peripheral surface of the cylinder body (10), the cylinder body has the through hole ( 51) and the groove portion (35) is butted against the outer peripheral surface of the steam pipe (50), the straight surface (32) is located outside the through hole (51) in the radial direction. It is set to be located.

With the thermometer protection cylinder (1) according to this aspect, the cylinder body (10) is inserted into the through hole (51) in the gap between the straight surface (32) and the outer peripheral surface of the cylinder body (10). Setting so that the straight surface (32) is located outside the through hole (51) in the radial direction of the thermometer protection cylinder (1) when the groove portion (35) is butted against the steam pipe (50). Therefore, when the thermometer protection cylinder (1) is butted against the steam pipe (50), a through hole is formed from the tip of the groove (35) protruding by the straight surface (32) and the groove surface (31). The steam pipe (50) exists for the distance up to (51). The outer peripheral surface of the steam pipe (50) from the tip of the groove portion (35) to the through hole (51) is a gap between the tip of the groove portion (35) and the outer peripheral surface of the steam pipe (50) at the start of welding. Since it functions as a receiving part for the molten metal flowing out from the molten metal, it is possible to further improve the melting of the molten metal, and a discontinuous weld-melting shape occurs in which there is an unwelded part in the portion to be welded. Can be suppressed.

Further, the thermometer protection cylinder (1) according to one aspect of the present disclosure is configured to face the straight surface (32) of the groove portion (35) and the straight surface (32) with the gap therebetween. A round surface (34) is formed to connect the outer peripheral surface of the cylinder body (10) in a semi-circular shape.

According to the thermometer protection cylinder (1) according to this aspect, the round surface (34) that connects the straight surface (32) and the outer peripheral surface of the cylinder body (10) in a semicircular arc shape is formed. Thus, it is possible to suppress stress concentration at the connecting portion between the straight surface (32) and the outer peripheral surface of the cylinder body (10).

Further, in the thermometer protection cylinder (1) according to one aspect of the present disclosure, the dimension of the portion protruding from the inner peripheral surface of the steam pipe (50) along the axis (X1) direction is 63.5 mm or more and 100 mm or less. Is set.

According to the thermometer protection cylinder (1) according to this aspect, the cylinder main body (10) has a dimension of 63.5 mm or more along the axis (X1) direction of the portion protruding from the inner peripheral surface of the steam pipe (50). Since the length is set to 100 mm or less, the tip end (11) of the cylinder body (10) can be kept away from the central axis of the steam pipe (50). That is, the tip (11) of the cylinder body (10) can be kept away from the mainstream. As a result, the influence of the cylinder body (10) on the main flow (blocking of flow, etc.) is suppressed. Further, since the influence on the mainstream is suppressed by the amount of protrusion, the cylinder body (10) can be made thicker by that amount, and the strength of the thermometer protection cylinder (1) can be improved.

Further, a temperature measuring instrument according to one aspect of the present disclosure includes a thermometer and the thermometer protection cylinder (1), and the cylinder body (10) is the end surface of the base end (12) from the end surface. The thermometer has an insertion hole (15) formed in the direction toward the tip (11) side, and the thermometer is inserted and fixed in the insertion hole (15).

The temperature measuring instrument according to this aspect includes a thermometer and the thermometer protection cylinder (1), and the cylinder body (10) extends from the end face of the base end (12) toward the tip (11) side. Since the thermometer is inserted and fixed in the insertion hole (15), the temperature is measured while the thermometer is protected by the thermometer protection tube (1). can do.

Further, a steam pipe structure according to an aspect of the present disclosure includes a steam pipe (50) having a through hole (51) formed therein and the thermometer protection cylinder (1), and the thermometer protection cylinder ( 1), the tip end (11) side of the tube body (10) is inserted into the through hole (51), and the groove portion (35) is butted against the outer peripheral surface of the steam pipe (50). A welded portion (60) is formed between the groove surface (31) of the groove portion (35) and the outer peripheral surface of the steam pipe (50) and is connected to the steam pipe (50).

According to the steam piping structure of the present aspect, in the thermometer protection cylinder (1), the tip (11) side of the cylinder body (10) is inserted into the through hole (51) and the groove (35) is steamed. The welded portion (60) is formed between the groove surface (31) of the groove portion (35) and the outer peripheral surface of the steam pipe (50), and is connected to the steam pipe (50). Therefore, the entire welded portion (60) can be formed on the outer peripheral surface of the steam pipe (50). Accordingly, the presence or absence of defects in the welded portion (60) can be inspected by a nondestructive method, so that the welded portion (60) can be easily inspected. Further, since all of the welded portions (60) to be inspected are formed on the outer peripheral surface of the steam pipe (50), the inspection accuracy is improved.
In addition, since the amount of molten metal can be reduced as compared with the case where a spot facing is provided on the steam pipe (50) and welding is performed with the thermometer protection cylinder, work at the time of mounting or replacement of the thermometer protection cylinder is possible. The number of steps can be reduced.

Moreover, in the steam piping structure according to an aspect of the present disclosure, the gap between the straight surface (32) and the outer peripheral surface of the tube body (10) has the straight surface (32) in the radial direction. It is set to be located outside the through hole (51).

According to the steam piping structure of this aspect, the gap between the straight surface (32) and the outer peripheral surface of the tube body (10) is such that the straight surface (32) is outside the through hole (51) in the radial direction. Since it is set so as to be located in the steam pipe (51), the distance from the tip of the groove portion (35) formed by the straight surface (32) and the groove surface (31) to the through hole (51). 50) will exist. The outer peripheral surface of the steam pipe (50) from the tip of the groove portion (35) to the through hole (51) is a gap between the tip of the groove portion (35) and the outer peripheral surface of the steam pipe (50) at the start of welding. Since it functions as a receiving portion of the molten metal flowing out from the molten metal, the molten metal can be more favorably melted.

Further, in the steam pipe structure according to one aspect of the present disclosure, in the welded portion (60), an end portion (61) on the outer side in the radial direction of a portion in contact with the steam pipe (50) is the nozzle part ( 30) is located outside the outer peripheral surface in the radial direction.

According to the steam pipe structure of this aspect, in the welded portion (60), the radially outer end portion (61) of the portion in contact with the steam pipe (50) is positioned more radially than the nozzle portion (30). Since it is located on the outer side, the end of the welded part (60) is radially outward of the stress concentration part (53) generated inside the pipe material of the steam pipe (50) and near the through hole (51). 61) can be located. As a result, a part of the stress generated in the stress concentration part (53) can be carried by the nozzle part (30). Therefore, the yield strength of the steam pipe (50) can be improved. In addition, the stress concentration generated in the welded portion (60) can be relaxed, and the strength of the welded portion (60) can be secured and the service life can be extended.

In addition, the method for installing the thermometer protection cylinder (1) according to one aspect of the present disclosure is a through-hole (rod) extending in the direction of the axis (X1) and having a tip (11) side formed in the steam pipe (50) ( 51) inserted into the cylinder main body (10) and the base end (12) side of the cylinder main body (10) are formed so as to expand in a radial direction orthogonal to the direction of the axis (X1). And a nozzle part (30) disposed on the outer peripheral surface side of the tube body (50), wherein the nozzle part (30) is provided from the base end (12) side of the tube body (10) to the tip (11). From the outer peripheral side in the direction toward the side, and from the end portion of the groove surface (31) on the cylinder body (10) side, the tip (11) of the cylinder body (10). ) Side toward the base end (12) side along the axis (X1) direction and a straight surface (32) facing the outer peripheral surface of the cylinder body (10) with a gap therebetween. And a method for installing a thermometer protection tube (1) having a groove portion (35) formed so as to protrude by the groove surface (31) and the straight surface (32). A first step of inserting the tube body (10) into the through hole (51) formed in the steam pipe (50), the groove portion (35) of the nozzle part (30), and the steam A second step of welding the outer peripheral surface of the pipe (50) to form a welded portion (60).

1 Thermometer protection tube 10 Tube body 11 Tip 12 Base end 15 Thermometer insertion hole (insertion hole)
30 nozzle part 31 groove surface 32 straight surface 33 root surface 34 round surface 35 groove part 50 steam pipe 51 through hole 53 stress concentration part 60 welded part 61 welding toe 70 flat plate 71 through hole 72 through hole point 101 furnace wall (Heat transfer tube)
102 First superheater (heat exchanger)
103 Second superheater (heat exchanger)
104 Third superheater (heat exchanger)
105 1st reheater (heat exchanger)
106 second reheater (heat exchanger)
107 economizer (heat exchanger)
111 High Pressure Turbine 112 Medium Pressure Turbine 113 Low Pressure Turbine 114 Condenser 121 Condensate Pump (CP)
122 Low pressure water heater 123 Boiler water supply pump (BFP)
124 High-pressure water heater 126 Brackish water separator L1 Water supply line L2 Drain water line L3 to L5 Steam line

Claims (10)

A cylinder main body that is a rod-shaped member that extends in the axial direction and whose tip side is inserted into a through hole formed in the steam pipe,
A base portion formed so that the base end side of the cylinder main body expands in a radial direction orthogonal to the axial direction, and a nozzle base portion arranged on the outer peripheral surface side of the steam pipe;
Equipped with
The nozzle part is
A groove surface that has been shrunk from the outer peripheral side in the direction from the proximal end side to the distal end side of the cylinder body,
From the end of the groove surface on the cylinder body side, extending along the axial direction in the direction from the tip end side to the base end side of the cylinder body, a gap is formed between the groove surface and the outer peripheral surface of the cylinder body. With a straight surface facing each other,
Have
A thermometer protection tube having a groove portion formed so as to project by the groove surface and the straight surface. The thermometer protection cylinder according to claim 1, wherein a weld is formed between the groove and the outer peripheral surface of the steam pipe. The gap between the straight surface and the outer peripheral surface of the cylinder body, in the radial direction, when the cylinder body is inserted into the through hole and the groove portion is butted against the outer peripheral surface of the steam pipe. The thermometer protection cylinder according to claim 1 or 2, wherein the straight surface is set so as to be located outside the through hole. The round surface which connects in a semi-circular shape between the straight surface of the groove and the outer peripheral surface of the cylinder body facing the straight surface with the gap provided therebetween is formed. The thermometer protection tube according to any one of 1. The said cylinder main body is set so that the dimension along the said axial direction of the part which protrudes from the inner peripheral surface of the said steam piping may be 63.5 mm or more and 100 mm or less. Thermometer protection tube. A thermometer,
A thermometer protection tube according to any one of claims 1 to 5,
Equipped with
The barrel main body has an insertion hole formed in a direction from the end face of the base end toward the distal end side,
The thermometer is a temperature measuring instrument inserted and fixed in the insertion hole. A steam pipe in which a through hole is formed,
A thermometer protection tube according to any one of claims 1 to 5,
Equipped with
In the thermometer protection cylinder, the tip side of the cylinder body is inserted into the through hole, the groove portion is abutted against the outer peripheral surface of the steam pipe, and the groove surface of the groove portion and the steam pipe. A steam piping structure having a weld formed between the steam piping structure and the outer peripheral surface of the steam piping. The steam piping structure according to claim 7, wherein the gap between the straight surface and the outer peripheral surface of the cylinder body is set such that the straight surface is located outside the through hole in the radial direction. Stuff. The steam pipe according to claim 7 or 8, wherein the welded portion has an outer end in the radial direction of a portion in contact with the steam pipe located outside the outer peripheral surface of the nozzle part in the radial direction. Structure. A cylinder main body that is a rod-shaped member that extends in the axial direction and whose tip side is inserted into a through hole formed in the steam pipe,
A base portion formed so that the base end side of the cylinder main body expands in a radial direction orthogonal to the axial direction, and a nozzle base portion arranged on the outer peripheral surface side of the steam pipe;
Equipped with
The nozzle part is
A groove surface that has been shrunk from the outer peripheral side in the direction from the proximal end side to the distal end side of the cylinder body,
From the end of the groove surface on the cylinder body side, extending along the axial direction in the direction from the tip end side to the base end side of the cylinder body, a gap is formed between the groove surface and the outer peripheral surface of the cylinder body. With a straight surface facing each other,
Have
A method of installing a thermometer protection tube comprising a groove portion formed so as to project by the groove surface and the straight surface,
A first step of inserting the tube body into the through hole formed in the steam pipe;
A second step of forming a welded part by welding between the groove part of the nozzle part and the outer peripheral surface of the steam pipe;
Installation method of thermometer protection tube including.

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