JP7394742B2 - Protector, boiler equipment, and how to install the protector - Google Patents

Description

The present invention relates to a protector for protecting heat exchanger tubes, a boiler apparatus equipped with the protector, and a method for attaching the protector to the heat exchanger tubes.

Boiler systems that use coal as fuel have a problem in that ash generated during combustion adheres to heat exchanger tubes, reducing heat exchange efficiency. In order to solve such a problem, a boiler device is known that includes a soot blower device that injects steam into heat transfer tubes to remove ash.

However, there is a possibility that the heat transfer tubes may undergo erosion due to the steam injected from the soot blower device. Therefore, Patent Document 1 discloses a technique for avoiding erosion by attaching a protector to the surface facing the soot blower device. More specifically, the protector described in Patent Document 1 is attached and detached by screwing the tube body to an end member that is locked to the heat exchanger tube.

Japanese Patent Application Publication No. 2020-169742

The protector configured as described above deteriorates as it continues to receive steam injected from the soot blower device, so it is a consumable item that needs to be replaced periodically. In order to replace the protector described in Patent Document 1, it is necessary to unthread the existing tube body and end member and screw together a new tube body and end member. However, since the protector attached to the heat exchanger tube is very large, the above-mentioned replacement work requires a long time and skill. As a result, there is a problem that downtime of the boiler device becomes longer.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a protector that can shorten the downtime of a boiler device at the time of replacement.

In order to achieve the above object, the present invention provides a protector for protecting heat exchanger tubes of a boiler apparatus, which includes a cylindrical lower tube body that is fitted onto the heat exchanger tube, and a protector that protects a heat exchanger tube of a boiler device, and a cylindrical upper tube body that is fitted over the heat exchanger tube; and a support portion that supports the upper tube that is externally inserted into the lower tube from above, and the lower tube has a lower body that has a groove formed on its inner peripheral surface to receive the locking piece. The groove extending along the axial direction of the lower body part has a lower end open to allow the locking piece to enter, and an upper end closed to function as the locked part, The lower body portion includes a lower outer insertion portion located at the lower end of the lower tube body and having an inner diameter larger than an outer diameter size of the upper end of the upper tube body, and a lower outer insertion portion located above the lower outer insertion portion and having the groove. It is characterized by having a formed intermediate part .

According to the present invention, it is possible to reduce the downtime of the boiler device when replacing the protector. Note that problems, configurations, and effects other than those described above will be made clear by the description of the embodiments below.

FIG. 1 is an overall configuration diagram of a boiler device according to the present embodiment. The figure which shows the locking piece attached to a heat exchanger tube. FIG. 3 is a cross-sectional perspective view of the protector in an exploded state. FIG. 3 is a cross-sectional view showing two sets of protectors attached to the heat exchanger tubes. Flowchart of how to install the protector.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram of a boiler apparatus 1 according to an embodiment of the present invention. As shown in FIG. 1, the boiler device 1 mainly includes a furnace 2 that burns fuel, a combustion gas passage 3 that is a flow path for combustion gas generated in the furnace 2, and a soot blower device 4. The furnace 2 and the combustion gas passage 3 are suspended from suspension rods and suspension beams (not shown) of the boiler steel frame. In the following description, the furnace 2 side of the boiler device 1 will be referred to as the can front, and the outlet side of the combustion gas passage 3 will be referred to as the can rear.

The furnace 2 generates combustion gas by burning fuel with a burner (not shown). Combustion gas generated in the furnace 2 passes through the combustion gas passage 3, moves from the front of the can to the rear of the can, and is discharged to the outside of the boiler device 1. The fuel burned in the furnace 2 includes at least coal. However, in addition to coal, oil, gas, biomass fuel, etc. may also be included. When fuels containing coal are burned, ash is produced.

The combustion gas passage 3 is provided with a primary superheater 6, a secondary superheater 7, and a tertiary superheater 8 as heat exchangers for recovering the heat of the combustion gas. The primary superheater 6, the secondary superheater 7, and the tertiary superheater 8 are a group of pipes (an assembly of a plurality of heat transfer tubes) through which steam passes. As the steam passes through the primary superheater 6, secondary superheater 7, and tertiary superheater 8, heat exchange is performed with the combustion gas, and superheated steam superheated to a predetermined temperature is supplied to the turbine.

In this embodiment, the primary superheater 6 is of the so-called "horizontal type", and the secondary superheater 7 and the tertiary superheater 8 are of the so-called "hanging type". In order to increase the contact area with combustion gas, the secondary superheater 7 and the tertiary superheater 8 have a plurality of heat transfer tubes extending in the vertical direction arranged in the left-right direction (the depth direction in FIG. 1). The structure is as follows.

Here, if the ash contained in the combustion gas adheres to the surface of the heat exchanger tube, the heat exchange efficiency will decrease. Therefore, in the boiler device 1 according to the present embodiment, the soot blower device 4 is used to remove the ash adhering to the surface of the heat exchanger tubes. The soot blower device 4 is a device that injects steam toward a heat transfer tube, and includes, for example, a soot blower tube, a nozzle, and a steam supply source.

The soot blower tube is a steam passageway that extends in a direction (for example, in the left-right direction) that intersects with the direction in which the heat transfer tubes extend. The soot blower tube is configured to be able to advance and retreat in the extending direction while rotating (rotating). The nozzle is provided at the tip of the soot blower tube and injects steam. The steam supply source supplies steam at a predetermined pressure to the nozzle through the soot blower tube. Note that since the specific configuration of the soot blower device 4 is already well known, detailed explanation will be omitted.

In the boiler device 1 according to this embodiment, the soot blower devices 4 having the above configuration are provided at a plurality of locations at predetermined intervals. Therefore, the heat exchanger tubes located near the movement locus of the soot blower tube are exposed to high-pressure steam injected from the nozzle, and therefore erosion may occur.

Therefore, in this embodiment, the heat exchanger tubes 9 are protected by extrapolating the protector 20 onto the heat exchanger tubes 9. FIG. 2 is a diagram showing the locking pieces 10 and 11 attached to the heat exchanger tube 9. FIG. 3 is a cross-sectional perspective view of the protector 20 in an exploded state.

As shown in FIG. 2, locking pieces 10 and 11 are attached to the outer surface of the heat exchanger tube 9. The locking pieces 10 and 11 protrude radially outward from a part of the outer surface of the heat exchanger tube 9. Moreover, the locking pieces 10 and 11 are arranged at the same height position. Furthermore, the locking pieces 10 and 11 are arranged at positions spaced apart in the circumferential direction of the heat exchanger tube 9. The locking pieces 10 and 11 according to this embodiment are provided at two locations on the outer peripheral surface of the heat exchanger tube 9 at an interval of 180°.

That is, as shown by the broken line in FIG. 2(A), the diameter φ ₁ of the virtual circle passing through the protruding ends of the locking pieces 10 and 11 is larger than the outer diameter dimension φ ₀ of the heat exchanger tube 9. Note that the number of locking pieces is not limited to the above-mentioned example, and may be one or more. Moreover, the mounting interval of the locking pieces in the circumferential direction of the heat exchanger tube 9 is not limited to the above-mentioned example. However, it is desirable that the locking pieces be provided at equal intervals in the circumferential direction of the heat exchanger tube 9.

When viewed in plan from the radial direction of the heat exchanger tube 9, the locking pieces 10 and 11 have a rectangular outer shape having an upper side (upper end), a lower side (lower end), a left side (left end), and a right side (right end). Further, the inner surfaces of the locking pieces 10 and 11 facing the heat exchanger tube 9 have an arc shape along the outer surface of the heat exchanger tube 9. However, the specific shape of the locking pieces 10 and 11 is not limited to the example shown in FIG. 2 .

The locking pieces 10 and 11 are welded to the heat exchanger tube 9 with their inner surfaces aligned with the heat exchanger tube 9. More specifically, among the upper, lower, left, and right sides of the locking pieces 10 and 11, only the left and right sides are welded with the welding materials 10l, 10r, 11l, and 11r, and the upper and lower sides are not welded. However, the method of attaching the locking pieces 10 and 11 to the heat exchanger tube 9 is not limited to the above-mentioned example.

As shown in FIG. 3, the protector 20 according to the present embodiment includes a lower tube body 30 and an upper tube body 40 having a cylindrical shape (more specifically, a cylindrical shape). The lower tube body 30 and the upper tube body 40 are made of stainless steel for piping, such as SUS309 and SUS310STP. Further, the lower tube body 30 and the upper tube body 40 are formed, for example, by machining a tube material or a bar material.

In this way, by configuring the lower tube body 30 and the upper tube body 40 seamlessly, the health of the protector 20 is improved. Furthermore, since the protector 20 can be realized with a simple configuration, manufacturing costs can be reduced.

The lower tube body 30 includes a lower body portion 31 and a support portion 32. The lower body portion 31 is a portion exposed to the outside when the protector 20 is attached to the heat exchanger tube 9. The support portion 32 is a portion that is covered by the upper tube body 40 (more specifically, an upper outer insertion portion 42 described later) and supports the upper tube body 40 when the protector 20 is attached to the heat exchanger tube 9. be.

The lower body portion 31 and the support portion 32 are adjacent to each other in the axial direction of the lower tube body 30. The outer diameter dimension φ ₂ of the support portion 32 is set smaller than the outer diameter dimension φ ₃ of the lower body portion 31 . That is, on the outer circumferential surface of the lower tube body 30, a continuous step in the circumferential direction is formed between the lower body portion 31 and the support portion 32.

The lower body portion 31 includes an intermediate portion 33 and a lower outer insertion portion 34 that are adjacent to each other in the axial direction. The intermediate portion 33 is a portion that connects the support portion 32 and the lower extrapolation portion 34. The lower outer insertion portion 34 is a portion that is inserted into the upper tube body 40 of the protector 20 of another set when the protector 20 is attached to the heat exchanger tube 9.

The inner diameter dimension φ ₅ of the intermediate portion 33 is larger than the inner diameter dimension φ ₄ of the support portion 32 and smaller than the inner diameter dimension φ ₆ of the lower outer insertion portion 34 . That is, on the inner circumferential surface of the lower tube body 30, a continuous step in the circumferential direction is formed between the support portion 32 and the intermediate portion 33 and between the intermediate portion 33 and the lower outer insertion portion 34. Further, the inner diameter dimensions φ ₄ , φ ₅ , and φ ₆ of the lower tube body 30 are larger than the outer diameter dimension φ ₀ of the heat exchanger tube 9. That is, the lower tube body 30 can be inserted into the heat exchanger tube 9.

More specifically, as shown in FIG. 4, the lower tube body 30 is inserted into the heat exchanger tube 9 with the support portion 32 facing upward (in other words, the lower external insertion portion 34 facing downward). That is, when the lower tube body 30 is attached to the heat exchanger tube 9, the support portion 32 is located at the upper end of the lower tube body 30, and the lower outer insertion portion 34 is located at the lower end of the lower tube body 30.

Furthermore, a groove 35 is formed in the inner circumferential surface of the intermediate portion 33 . The groove 35 has a shape and size that can receive the locking piece 10, and is recessed radially outward from the inner circumferential surface of the intermediate portion 33. Further, the groove 35 extends in the axial direction of the lower tube body 30. Then, the lower end of the groove 35 (that is, the lower outer insertion part 34 side) is opened to allow the locking pieces 10 and 11 to enter. Further, the upper end of the groove 35 (that is, the side of the support portion 32) is closed and functions as a locked portion 36.

The locked portion 36 is a portion that is locked by the locking piece 10 to fix the lower tube body 30 to the heat exchanger tube 9 when the lower tube body 30 is inserted into the heat exchanger tube 9 . The groove 35 and the locked portion 36 are provided in correspondence with the locking pieces 10 and 11, respectively. That is, the groove 35 and the locked portion 36 according to the present embodiment are provided at two locations on the inner peripheral surface of the lower tube body 30 at an interval of 180 degrees.

Here, the diameter φ ₁ of the virtual circle passing through the protruding ends of the locking pieces 10 and 11 is larger than the inner diameter dimensions φ ₄ and φ ₅ of the support portion 32 and the intermediate portion 33, and the inner diameter dimension φ ₆ of the lower outer insertion portion 34 smaller. That is, when the lower tube body 30 is externally inserted from above the heat exchanger tube 9, the locking pieces 10 and 11 pass through the lower externally inserted part 34 and reach the position of the locked part 36 along the groove 35. do. Thereby, the lower tube body 30 is attached to the heat exchanger tube 9.

The upper tube 40 is fitted onto the heat exchanger tube 9 above the lower tube 30 . The upper tube body 40 includes an upper body portion 41 and an upper outer insertion portion 42 that are adjacent to each other in the axial direction. When the protector 20 is attached to the heat exchanger tube 9, the upper body part 41 has a part of the upper end covered by the lower tube body 30 (more specifically, the lower outer insertion part 34) of the protector 20 of another set, The other part is the part exposed to the outside. The upper outer part 42 is a part that is fitted onto the support part 32 and supported by the tip of the support part 32 when the protector 20 is attached to the heat exchanger tube 9 .

The outer diameter dimension φ ₇ of the upper tube body 40 , the inner diameter dimension φ ₈ of the upper body portion 41 , and the inner diameter dimension φ ₉ of the upper outer insertion portion 42 are each constant in the axial direction of the upper tube body 40 . Further, the outer diameter dimension φ ₇ of the upper tube body 40 is larger than the outer diameter dimension φ ₂ of the support portion 32 and smaller than the outer diameter dimension φ ₃ of the lower body portion 31 . Further, the inner diameter dimension φ ₉ of the upper outer insertion portion 42 is larger than the inner diameter dimension φ ₈ of the upper body portion 41 . That is, on the inner circumferential surface of the upper tube body 40, a step 43 continuous in the circumferential direction is formed between the upper body portion 41 and the upper outer insertion portion 42.

Further, the outer diameter dimension φ ₂ of the support portion 32 is larger than the inner diameter dimension φ ₈ of the upper body portion 41 and smaller than the inner diameter dimension φ ₉ of the upper outer insertion portion 42 . As a result, when the upper tube body 40 is inserted from above into the heat exchanger tube 9 to which the lower tube body 30 is already attached, the upper outer insertion part 42 is inserted into the support part 32, and the step 43 is inserted into the support part 32. supported at the tip. On the other hand, the length of the upper extrapolation part 42 in the axial direction is shorter than the length of the support part 32 in the axial direction. Therefore, as shown in FIG. 4, when the upper tube body 40 is supported by the support part 32, there is a gap between the tip (lower end) of the upper outer insertion part 42 and the step between the lower body part 31 and the support part 32. A gap is formed.

Next, with reference to FIGS. 4 and 5, a method of attaching a plurality of protectors 20 according to the present embodiment to the heat exchanger tube 9 in an axial direction will be described. FIG. 4 is a sectional view showing a state in which two sets of protectors 20a and 20b are attached to the heat exchanger tube 9. FIG. 5 is a flowchart of the protector attachment method. The structure of the locking pieces 10a, 10b is the same as the locking piece 10 shown in FIG. 2, and the structure of the protectors 20a, 20b is the same as the protector 20 shown in FIG. 3.

First, an operator welds the left and right sides of the locking pieces 10a and 11a (the locking piece 11a is not shown in FIG. 4) to the outer surface of the heat exchanger tube 9 (S1). Next, the operator inserts the lower tube body 30a from above the heat exchanger tube 9 with the locking pieces 10a, 11a and the groove 35a (not shown in FIG. 4) facing each other (S2). As a result, the locked portion 36a is locked by the locking pieces 10a and 11a. Next, the operator extrapolates the upper tube body 40a from above the heat exchanger tube 9 (S3). As a result, the upper extrapolation part 42a is fitted onto the support part 32a, and the step 43a is supported at the tip of the support part 32a. That is, the lower tube body 30a and the upper tube body 40a are coupled by a so-called spigot structure.

Next, the operator determines whether all the protectors 20a, 20b have been attached to the heat exchanger tubes 9 (S4). Then, if the protector 20b has not been attached yet (S4: No), the operator transfers the locking pieces 10b, 11b (the locking piece 11b is not shown in FIG. 4) and the protector 20b using the above-mentioned procedure. Attach to heat tube 9 (S1 to S3).

At this time, as shown in FIG. 4, the operator must ensure that the lower end of the lower outer insertion part 34b is below the upper end of the upper body part 41a, and that the step between the intermediate part 33b and the lower outer insertion part 34b is lower than the upper body part. The vertical distance between the locking pieces 10a, 11a and the locking pieces 10b, 11b is adjusted so that the locking pieces 10a, 11a are located above the upper end of the locking piece 41a. As a result, a portion of the upper end of the upper body portion 41a is covered by the lower extrapolation portion 34b. That is, the upper tube body 40a and the lower tube body 30b are coupled by a so-called spigot structure. Further, a gap is formed between the step between the intermediate portion 33b and the lower outer insertion portion 34b and the upper end of the upper main body portion 41a.

According to the embodiment described above, the protector 20 can be attached to the heat exchanger tube 9 simply by sequentially extrapolating the lower tube body 30 and the upper tube body 40 to the heat exchanger tube 9 . As a result, the protector 20 can be easily replaced in a shorter time than a conventional protector in which a plurality of tube bodies are screwed together to be attached and detached. As a result, the downtime of the boiler device 1 when the protector 20 is replaced can be shortened.

Further, according to the above embodiment, by extrapolating the upper pipe body 40 to the lower pipe body 30, coal ash falling from above is prevented from entering between the lower pipe body 30 and the upper pipe body 40. It can be prevented. As a result, the gap between the lower tube body 30 and the upper tube body 40 connected by the spigot structure can be increased to some extent, so that the work of replacing the protector 20 becomes easier. Further, when a plurality of protectors 20a, 20b are attached to the heat exchanger tube 9, the same can be said between the upper tube body 40a and the lower tube body 30b.

Further, according to the above embodiment, when the step 43 is supported by the support section 32, a gap is formed between the lower end of the upper tube body 40 and the step between the lower body section 31 and the support section 32. Ru. This allows the lower tube body 30 and the upper tube body 40 to expand due to temperature rise. Further, when a plurality of protectors 20a, 20b are attached to the heat exchanger tube 9, the same can be said between the upper tube body 40a and the lower tube body 30b.

Further, according to the embodiment described above, since the plurality of locking pieces 10 and 11 are attached at equal intervals in the circumferential direction of the heat transfer tube 9, it is possible to prevent the lower tube body 30 (protector 20) from tilting. Further, according to the embodiment described above, only the left and right sides of the locking pieces 10 and 11 are welded to the heat exchanger tube 9, so the lower tube body 30 can be locked on the upper sides of the locking pieces 10 and 11 without play. However, in addition to the left and right sides of the locking pieces 10 and 11, the lower sides may be welded to the heat exchanger tube 9.

Furthermore, by employing the procedure shown in FIG. 5, a plurality of protectors 20a, 20b can be attached to the heat exchanger tube 9. Note that when replacing the protectors 20a, 20b in the procedure shown in FIG. 5, it is necessary to once remove the locking pieces 10b, 11b. Here, by reducing the number of welded parts of the locking pieces 10b, 11b to the heat transfer tube 9, the locking pieces 10b, 11b can be easily removed.

Note that the present invention is not limited to the embodiments described above, and includes various other modifications. For example, the above-described embodiments have been described in detail to explain the present invention in an easy-to-understand manner, and the present invention is not necessarily limited to having all the configurations described.

1 Boiler device 2 Furnace 3 Combustion gas passage 4 Soot blower device 6 Primary superheater 7 Secondary superheater 8 Tertiary superheater 9 Heat exchanger tubes 9a, 9b Stopper 10, 10a, 10b, 11, 11a, 11b Locking piece 10l, 10r, 11l, 11r Welding material 20, 20a, 20b Protector 30, 30a, 30b Lower pipe body 31, 31a, 31b Lower body part 32, 32a, 32b Support part 33, 33a, 33b Intermediate part 34, 34a, 34b Lower outer insertion part 35 Groove 36 Locked part 40, 40a, 40b Upper pipe body 41, 41a, 41b Upper body part 42, 42a, 42b Upper outer insertion part 43, 43a, 43b Step

Claims (6)

A protector for protecting heat exchanger tubes of a boiler equipment,
a cylindrical lower tube body inserted into the heat exchanger tube;
a cylindrical upper tube body that is fitted onto the heat exchanger tube above the lower tube body;
The lower tube body is
a locked part that is locked by a locking piece protruding from a part of the outer surface of the heat exchanger tube;
a support portion that supports the upper tube body and is externally inserted into the lower tube body from above ;
The lower tube body has a lower body portion in which a groove for receiving the locking piece is formed on the inner peripheral surface,
The groove extending along the axial direction of the lower body part has a lower end open to allow the locking piece to enter, and an upper end closed to function as the locked part,
The lower body portion is
a lower outer part located at the lower end of the lower tube and having an inner diameter larger than the outer diameter of the upper end of the upper tube;
an intermediate portion located above the lower extrapolation portion and in which the groove is formed;
A protector comprising : The protector according to claim 1,
The support part is located at the upper end of the lower tube body,
The upper tube body is
an upper outer insertion part located at the lower end of the upper tube body and having an inner diameter larger than an outer diameter of the support part;
an upper body portion located above the upper outer insertion portion and having an inner diameter smaller than an outer diameter of the support portion;
A protector characterized in that, when the upper extrapolation part is extrapolated onto the support part, a step between the upper extrapolation part and the upper main body part is supported by the tip of the support part. A furnace that burns fuel including coal,
a heat exchanger tube suspended on a flow path of combustion gas generated in the furnace;
a soot blower device that injects steam toward the heat transfer tube;
A boiler apparatus comprising: the protector according to claim 1 or 2 , which is fitted over the heat exchanger tube. The boiler device according to claim 3 ,
A boiler device characterized in that the locking pieces are formed on the outer surface of the heat exchanger tube at a plurality of positions spaced apart in a circumferential direction. The boiler device according to claim 3 or 4 ,
The boiler apparatus is characterized in that, among an upper end, a lower end, a left end, and a right end, only the left end and the right end of the locking piece are welded to the outer surface of the heat exchanger tube. A method for attaching a protector, comprising: attaching a plurality of protectors according to claim 1 or 2 side by side in the axial direction of the heat exchanger tube;
attaching the locking piece to the outer surface of the heat exchanger tube;
a step of extrapolating the lower tube body from above the heat exchanger tube and locking the locked portion to the locking piece;
A method for attaching a protector, comprising repeating the steps of extrapolating the upper tube from above the heat exchanger tube and supporting the upper tube inserted into the lower tube on the supporting portion.

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