JP5419667B2 - Heat transfer tube protector - Google Patents

Description

  The present invention relates to a heat transfer tube protection device that protects the outer peripheral surface of a heat transfer tube through which hot gas flows.

  Generally, in various heat exchangers such as boilers, air preheaters, and economizers, heat transfer tubes are arranged in the passages through which hot gas flows, and heat recovery is performed by exchanging heat between the hot gas and the fluid flowing in the heat transfer tubes. ing. In such a heat exchanger, the outer peripheral surface of the heat transfer tube may be worn by ash or soot contained in the hot gas.

  In addition, the ash and soot contained in the hot gas are highly sticky, and these adhere to and deposit on the outer peripheral surface of the heat transfer tube, resulting in a decrease in heat exchange performance. Many are equipped with a suit blower that sprays fluid such as compressed air to remove ash and soot. However, when the fluid is blown from the suit blower, there has been a problem that the outer peripheral surface of the heat transfer tube is worn by ash or soot. In addition to the suit blower, for example, the heat transfer tube installed in the fluidized bed of a fluidized bed boiler is rubbed by the movement of ash particles contained in the gas flow, and the outer peripheral surface of the heat transfer tube is thinned. It was easy.

  One of the factors that accelerate the thinning of the heat transfer tubes is corrosion called erosion / corrosion. In general, the surface of the heat transfer tube is covered with a protective coating formed of an oxide or the like. However, as described above, if the protective coating is partially peeled off due to the collision effect of particles contained in the gas flow, Then, metal and water droplets come into direct contact and corrode rapidly. This corrosion is one of the causes of heat transfer tube thinning problems, and the repair frequency must be increased as the heat transfer tube thinning rate increases.

  Therefore, in order to reduce the thinning rate of the heat transfer tube, a heat transfer tube protector 52 that protects the outer peripheral surface of the heat transfer tube 51a of the heat exchanger 50 is proposed and put into practical use as shown in FIG. FIG. 11 is a cross-sectional perspective view showing an attachment state of a conventional heat transfer tube protector 52. The heat transfer tube 51a is protected by installing a protector 52 having an arcuate cross section as a countermeasure against wear due to suit blower or gas flow, and erosion / corrosion.

However, when the protector 52 shown in FIG. 11 is a heat exchanger in which a plurality of heat transfer tubes 51a, 51b, 51c,... Are assembled, it is easy to install the protector 52 on the heat transfer tube 51a facing the outside. However, it is difficult to install the protector 52 in the heat transfer tubes 51b, 51c,... Located inside the heat exchanger 50.
In Patent Document 1 (Japanese Patent Application Laid-Open No. 2005-315439), a first protector that is attached to a heat transfer tube facing the outside by an attachment member, an internal heat transfer tube, and a connection member that is connected to the attachment member. A heat transfer tube protector including the second protector is disclosed.

JP 2005-315439 A

  However, since the protector for heat transfer tubes disclosed in Patent Document 1 has the second protector fixed to the connecting member, the second protector is easily caught by the heat transfer tube when the connecting member is inserted into the gap between the heat transfer tubes. The second protector could not be installed in the heat transfer tube located deep in the exchanger. For the same reason, it is difficult to install the second protector in a heat exchanger with a narrow gap between the heat transfer tubes, and skill is required for the attachment and removal of the protector.

  Therefore, in view of the problems of the prior art, the present invention has an object to provide a heat transfer tube protection device in which a protector can be easily attached and detached and can be attached to a heat transfer tube located inside a heat exchanger. To do.

In order to solve the above-described problems, the heat transfer tube protection device according to the first aspect of the present invention is provided in a horizontal heat exchanger in which a plurality of heat transfer tube straight tube portions are extended in a horizontal direction with gaps therebetween. In the heat transfer tube protection device for protecting the outer peripheral surface of the heat transfer tube straight tube portion, a plurality of elongated frames inserted between the plurality of heat transfer tube straight tube portions are connected in the longitudinal direction of the frame. A protector that covers the outer peripheral surface of the straight pipe portion of the heat transfer tube along the longitudinal direction, and a support shaft that is provided along the long side of the protector so that the protector rotates with the support shaft as a fulcrum. And a connecting member for connecting the protector to the frame, wherein a distance from the frame to the support shaft of the connecting member is larger than a thickness of the protector .

According to the first aspect of the present invention, the protector is rotated with the support shaft of the connecting member as a fulcrum. Therefore, when the protector is attached, the protector is folded to the frame side so that the heat transfer tube is not caught by the straight pipe portion. A protector can be inserted into the heat exchanger. In addition, when the protector reaches the mounting position, the protector is rotated and opened, and the protector can be easily installed up to the heat transfer tube straight tube portion located inside the heat exchanger by contacting the heat transfer tube straight tube portion. It becomes possible. Furthermore, when removing the protector, the protector is folded to the frame side by pulling out the frame, so that the protector can be easily removed.

The heat transfer tube protection device according to the first aspect of the present invention is a heat transfer tube protection device provided in a horizontal heat exchanger in which the plurality of heat transfer tube straight tube portions are horizontally extended, A plurality of protectors are connected in the longitudinal direction of the frame.
When the heat transfer tube protection device is provided in the horizontal heat exchanger, the frame is disposed in a substantially vertical direction, and the protector is disposed in a substantially horizontal direction. Therefore, since the protector can be rotated by its own weight when the protective device is attached / detached, the protector can be attached and detached more easily. Furthermore, since a plurality of protectors are attached in the longitudinal direction of the frame, it is possible to protect the plurality of heat transfer tube straight tube portions with one protection device.

The heat transfer tube protection device according to the first aspect of the present invention further includes a locking member that locks the protector in a state where the protector is erected along the frame.
Thus, by providing the locking member, when the protector is folded and the frame is inserted, the protector is prevented from opening due to its own weight and being caught by the heat transfer tube straight tube portion and cannot be inserted. The locking member is configured to be able to release the locking when the frame reaches the protector mounting position.

The second protection device of the heat transfer tube of the present invention, instead of providing the locking member, wherein a distance from the frame to the support shaft of the coupling member and greater than the thickness of the protector And
Thereby, when the protector is erected, the protector is inclined from the upper side in the vertical direction to the frame side, so that the protector is prevented from being opened and attached to the heat transfer tube straight tube portion when the heat transfer tube protection device is attached. When the protector is installed, the protector can be opened by tilting the upper part of the frame to the heat transfer tube straight tube side or giving an impact to the frame.

Furthermore, in the first invention or the second invention, the protector is preferably formed of a flat plate.
As a result, when the protector is folded, the protector becomes substantially parallel to the frame and easily passes through the gaps between the plurality of heat transfer tube straight tube portions. Moreover, since it is a flat plate, cost can be held down cheaply.

Furthermore, it is preferable that the protector is formed of an arcuate plate whose short side is curved along the outer peripheral surface of the heat transfer tube straight tube portion.
Thus, by forming a protector with a circular-arc-shaped board, the protection area of the heat exchanger tube straight pipe part by a protector becomes large, and protection property improves. Moreover, since the protector is curved, it is difficult for ash and soot to accumulate on the upper surface of the protector, and a decrease in heat exchange efficiency due to the ash and soot can be prevented.

At this time, it is more preferable that the curvature of the short side of the protector is smaller than the curvature of the outer peripheral surface of the heat transfer tube straight tube portion.
Thus, when the curvature of the short side of the protector is smaller than the curvature of the outer peripheral surface of the heat transfer tube straight tube portion, a gap is formed between the heat transfer tube straight tube portion and the protector with the protector installed, and the heat transfer tube straight tube Since the heat transfer area of the pipe portion is increased, the heat exchange efficiency can be maintained high.

As described above, since the protector of the heat transfer tube according to the present invention is configured so that the protector rotates with the support shaft of the connecting member as a fulcrum, the heat transfer tube is folded by folding the protector to the frame side when the protector is attached. The protector can be smoothly inserted into the heat exchanger without being caught by the straight pipe portion. In addition, when the protector reaches the mounting position, the protector is rotated and opened, and the protector can be easily installed up to the heat transfer tube straight tube portion located inside the heat exchanger by contacting the heat transfer tube straight tube portion. It becomes possible. Furthermore, when removing the protector, the protector is folded to the frame side by pulling out the frame, so that the protector can be easily removed.
Furthermore, the protection device for a heat transfer tube according to the first aspect of the present invention includes a locking member, so that when the protector is folded and the frame is inserted, the protector opens due to its own weight and is caught by the heat transfer tube straight tube portion. It can be prevented that it cannot be inserted.
Furthermore, in the heat transfer tube protection device according to the second aspect of the present invention, the distance from the frame to the support shaft of the connecting member is made larger than the thickness of the protector, so that when the protector is erected, the protector is Since it inclines to the flame | frame side, when attaching the protective device of a heat exchanger tube, it can prevent that a protector opens and is caught in a heat exchanger tube straight pipe part.

It is a perspective view of the protection device of a heat exchanger tube concerning the basic composition of the present invention. It is the sectional view on the AA line of FIG. It is a B direction arrow line view of FIG. It is a C direction arrow directional view of FIG. (A)-(D) is a figure explaining 1st Embodiment of 1st this invention . (A)-(D) are figures explaining 2nd Embodiment of 1st this invention . It is sectional drawing which shows one Embodiment of 2nd this invention . (A) is a perspective view of the protection apparatus of the heat exchanger tube which shows the modification of FIG. 5 , (B) is the DD sectional view taken on the line of (A). It is the DD sectional view taken on the line of the protection device of the heat exchanger tube of FIG. 8 (A) containing a locking member. (A) is a side view which shows an example of the heat exchanger with which a protective device is attached, (B) is a cross-sectional perspective view which shows the heat exchanger tube straight tube | pipe part area | region of a heat exchanger. It is a cross-sectional perspective view which shows the attachment state of the conventional heat exchanger tube protector.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
FIG. 10A is a side view showing an example of a heat exchanger to which a protection device is attached, and FIG. 10B is a cross-sectional perspective view showing a heat transfer tube straight pipe region of the heat exchanger. The heat transfer tube protection device according to the present invention is detachably attached to a heat transfer tube straight tube region 25 of a horizontal heat exchanger 20 as shown in FIG. 10, for example.

  The heat exchanger 20 includes a plurality of heat transfer tube straight tube portions 21 arranged in a row (heat transfer tube row 26) with a gap, and a plurality of heat transfer tube rows 26 arranged in parallel with a gap. ing. The plurality of heat transfer tube straight tube portions 21 may communicate with each other through bent portions at their end portions or may be connected via headers at the end portions.

  In the heat exchanger 20 of FIG. 10, in the heat transfer tube array 26 arranged in the vertical direction, the heat transfer tube straight tube portion 21 is connected to the other heat transfer tube straight tube portion 21 located above and below via a bent portion at the end thereof. In addition, the plurality of heat transfer tube rows 26 are connected to the upper header 22 and the lower header 23. The heat exchanger 20 is disposed in a hot gas passage 27 extending in the vertical direction. And the fluid which flows through the inside of the heat transfer tube straight tube portion 21 performs heat recovery by exchanging heat with the hot gas flowing through the hot gas passage 27 downward from above.

1 is a perspective view of a heat transfer tube protection device 1 according to the basic configuration of the present invention, FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, FIG. 3 is a view in the direction of arrow B in FIG. FIG. 3 is a view in the direction of arrow C in FIG. 2.
The heat transfer tube protection device 1 according to the basic configuration of the present invention mainly includes a long frame 2, a protector 3 that covers the outer peripheral surface of the heat transfer tube straight pipe portion 21, and a connection that connects the protector 3 to the frame 2. And a member 4.

  The frame 2 is formed in a long shape and is inserted between the plurality of heat transfer tube straight tube portions 21. The frame 2 is formed, for example, in a rod shape or a plate shape. When the frame 2 is formed in a plate shape having a narrow width (length with respect to the longitudinal direction of the protector 3) as shown in FIG. On the other hand, it is preferable to provide a plurality. Further, the frame 2 may be formed in a plate shape having a width equal to or close to the length of the heat transfer tube straight tube portion 21, and in this case, a rectifying effect of the hot gas can be obtained.

  The protector 3 is formed in a long shape so as to cover the outer peripheral surface of the heat transfer tube straight tube portion 21 along the longitudinal direction. This protector 3 may be formed so as to cover at least the upstream side in the hot gas flow direction of the outer peripheral surface of the heat transfer tube straight tube portion 21. Furthermore, the protector 3 is preferably formed of a flat plate having a flat cross-sectional shape. By forming the protector 3 with a flat plate, the protector 3 becomes substantially parallel to the frame 2 when the protector 3 is folded, and it is easy to pass through the gaps between the plurality of heat transfer tube straight tube portions 21. Moreover, since it is a flat plate, cost can be held down cheaply.

As shown in FIG. 3, the connecting member 4 includes a support shaft 4 a provided along the long side of the protector 3, and connects the protector 3 to the frame 2 so that the protector 3 rotates around the support shaft 4 a. To do. For example, a hinge is used as the connecting member 4.
The frame 2, the protector 3, and the connecting member 4 described above are formed of a material having heat resistance equal to or higher than the hot gas temperature.

  In the heat transfer tube protection device 1 having such a configuration, the frame 2 is attached to a fixed portion 28 such as a component of the heat exchanger. At this time, the frame 2 may be fixed to the fixing portion 28 by welding, or may be fixed by a fastening member such as a bolt, but is fixed by a fastening member in order to make the protection device 1 detachable. It is preferable to do.

Further, in the heat transfer tube protection device 1 of this basic configuration , it is preferable to connect a plurality of protectors 3 to one frame 2, and thereby, a plurality of heat transfer tubes 26 (see FIG. 10). Each of the protectors 3 can be installed at a time on the heat pipe straight pipe portion 21. At this time, among the heat transfer tube straight tube portions 21 of the heat exchanger, the most upstream heat transfer tube straight tube portion 21 with respect to the hot gas flow direction faces the hot gas passage and is easy to attach the protector 3. The protector 8 may be attached to. For example, as shown in FIGS. 2 and 4, a protector 8 separate from the protection device 1 is installed in the most upstream heat transfer tube straight tube portion 21, and the protector 8 is fixed to a long support member 9. .

As described above, according to the present basic configuration , the protector 3 rotates with the support shaft 4a of the connecting member 4 as a fulcrum. Therefore, when the protector 3 is attached, the protector 3 is folded to the frame 2 side, thereby heat transfer tubes. The protector 3 can be smoothly inserted into the heat exchanger 20 without being caught by the straight pipe portion 21. Further, when the protector 3 reaches the attachment position, the protector 3 is rotated and opened, and is brought into contact with the heat transfer tube straight tube portion 21, so that the heat transfer tube straight tube portion 21 positioned inside the heat exchanger 20 can be easily obtained. It becomes possible to install the protector 3 in the. Furthermore, when the protector 3 is removed, the protector 3 is folded to the frame 2 side by pulling out the frame 2, so that the protector 3 can be easily removed.

5 and 6 show a heat transfer tube protection device 1 provided with a locking member.
It is preferable that the heat transfer tube protection device 1 of the present embodiment further includes locking members 5 and 7 that lock the protector 3 in a standing state along the frame 2. The state in which the protector 3 is erected along the frame 2 is a state in which the long side 3a on the free end side of the protector 3 is located above the support shaft 4a of the connecting member 4 and in the vicinity of the frame 2, that is, the protector. 3 is a state folded to the frame 2 side.
Moreover, it is preferable to further include an angle regulating member 6 that regulates the angle so that the protector 3 is not tilted to the frame side from the vertical direction or the vertical direction when the protector 3 stands on the frame 2. The angle restricting member 6 is configured by a protrusion formed on the frame 2, for example.

5A to 5D are views for explaining a first example of a method for attaching and detaching the protection device 1.
The locking member 5 shown in FIG. 5A is formed in a U-shape, and can be accommodated inside the locking member 5 in a state where the protector 3 is erected along the frame 2. ing. When attaching the heat transfer tube protection device 1, the protector 3 is stood up and housed in the locking member 5 together with the frame 2, and the locking member 5 is placed between the heat transfer tube row 26 a and the heat transfer tube row 26 b from above. Insert frame 2.

As shown in FIG. 5B, when the frame 2 is inserted up to the installation position of the protector 3, the locking member 5 is removed. By removing the locking member 5, the protector 3 is opened in the direction of the arrow in the figure by the weight of the long side 3a on the free end side. At this time, since the protector 3 is inclined toward the heat transfer tube straight tube portion 21 side from the vertical direction by the angle regulating member 6, the protector 3 is surely opened by removing the locking member 5.
Next, as shown in FIG. 5 (C), the frame 2 is pushed in the lateral direction toward the heat transfer tube straight tube portion 21 side (in the direction of the arrow in the figure) where the protector 3 is installed, and the protector 3 is placed on the heat transfer tube straight tube portion 21. Install. When the protector 3 is installed at an appropriate position, the frame 2 is fixed to the fixing portion 28 (see FIG. 2) of the heat exchanger.

  As shown in FIG. 5 (D), when removing the heat transfer tube protection device 1, the frame 2 and the fixing portion 28 are fixed and then moved in the lateral direction opposite to the side to which the protector 3 is connected. And pull it up. Since the protector 3 is folded downward by its own weight when the frame 2 is pulled up, the frame 2 can be easily pulled out together with the protector 3 from between the heat transfer tube row 26a and the heat transfer tube row 26b.

6A to 6D are diagrams illustrating a second example of a method for attaching and detaching the protection device 1.
The locking member 7 shown in FIG. 6A is formed of a string-like body or a thread-like body, and one end is connected to the long side 3 a on the free end side of the protector 3. When the heat transfer tube protection device 1 is installed, the frame 2 is connected to the rows of the heat transfer tube straight tube portions 21 in a state where the long side 3a on the free end side of the protector 3 is suspended by the locking member 7 so that the protector 3 stands. Insert between.

As shown in FIG. 6B, when the frame 2 is inserted up to the installation position of the protector 3, the locking member 7 is cut. By cutting the locking member 7, the protector 3 is opened in the direction of the arrow in the figure by the dead weight of the long side 3a on the free end side.
Next, as shown in FIG. 6C, the frame 2 is pushed into the heat transfer tube straight tube portion 21 side where the protector 3 is installed, and the protector 3 is installed on the heat transfer tube straight tube portion 21. When the protector 3 is installed at an appropriate position, the frame 2 is fixed to the fixing portion 28 (see FIG. 2) of the heat exchanger.
As shown in FIG. 6 (D), when removing the heat transfer tube protection device 1, the frame 2 and the fixing portion 28 are released and then moved in the lateral direction opposite to the side to which the protector 3 is connected. And pull it up.

  Thus, by providing the locking members 5 and 7, when the protector 3 is folded and the frame 2 is inserted, the protector 3 is prevented from being opened and cannot be inserted from the gap between the heat transfer tube rows 26. Further, by using the U-shaped locking member 5 as shown in FIG. 5, the locking member 7 can be used repeatedly. Moreover, as shown in FIG. 6, the cost can be reduced by using the locking member 7 formed of a string-like body or a thread-like body.

  FIG. 7 is a cross-sectional view showing a configuration example of the connecting member 4. As shown in the figure, the distance D from the frame 2 to the support shaft 4a of the connecting member 4 is determined from the thickness d of the protector 3 as means for preventing the protector 3 from opening when the heat transfer tube protection device 1 is attached. A larger configuration may be used. Thereby, when the protector 3 is erected, the protector 3 is inclined to the frame 2 side from the upper side in the vertical direction. Therefore, the protector 3 is opened when the heat transfer tube protection device 1 is attached, and is caught by the heat transfer tube straight tube portion 21. To prevent. When the protector 3 is installed, the protector 3 can be opened by tilting the upper portion of the frame 2 toward the heat transfer tube straight tube portion 21 side or applying an impact to the frame 2.

Next, a modification of the heat transfer tube protection device shown in FIG. 5 will be described with reference to FIGS. 8A is a perspective view of a heat transfer tube protection device showing a modification of FIG. 5 , FIG . 8B is a sectional view taken along the line DD of FIG. 9A, and FIG. It is the DD sectional view taken on the line of the protection apparatus of the heat exchanger tube of A).

As shown in FIG. 8, the heat transfer tube protection device 11 mainly includes a long frame 12, a protector 13 that covers the outer peripheral surface of the heat transfer tube straight pipe portion 21, and a connecting member that connects the protector 13 to the frame 12. 14.
In this modification, the protector 13 is formed of a plate having a short side having an arc shape (circular arc shape). The protector 13 is preferably formed so as to cover at least the upstream side in the hot gas flow direction.

  The heat transfer tube protection device 11 may include a locking member as shown in FIGS. 5 and 6 described above. FIG. 9 shows a protective device 11 including a U-shaped locking member 15 as an example. In this modification, since the protector 13 is curved, the angle restricting member may not be provided.

  Thus, by forming the protector 13 with an arcuate plate, the protection area of the heat transfer tube straight tube portion 21 by the protector 13 is increased, and the protection is improved. Further, since the protector 13 is curved, it is difficult for ash and soot to accumulate on the upper surface of the protector 13, and a decrease in heat exchange efficiency due to the ash and soot can be prevented.

  The curvature of the short side of the protector 13 may be the same as the curvature of the outer peripheral surface of the heat transfer tube straight tube portion 21, but more preferably smaller than the curvature of the outer peripheral surface of the heat transfer tube straight tube portion 21. If the curvature of the short side of the protector 13 is smaller than the curvature of the outer peripheral surface of the heat transfer tube straight tube portion 21, a gap is formed between the heat transfer tube straight tube portion 21 and the protector 13 with the protector 13 installed, and the heat transfer tube Since the heat transfer area of the straight pipe portion 21 is increased, the heat exchange efficiency can be maintained high.

DESCRIPTION OF SYMBOLS 1, 11 Heat transfer tube protection device 2, 12 Frame 3, 13 Protector 4, 14 Connecting member 4a Support shaft 5, 7, 15 Locking member 6 Angle restricting member 8 Protector 9 Support member 20 Heat exchanger 21 Direct heat transfer tube Portion 22 Upper header 23 Lower header 25 Heat transfer tube straight tube region 26, 26a, 26b Heat transfer tube row 27 Hot gas passage 28 Fixed part

Claims (5)

In a heat transfer tube protection device that is provided in a horizontal heat exchanger in which a plurality of heat transfer tube straight tube portions are provided in a horizontal direction with a gap therebetween, and that protects the outer peripheral surface of the heat transfer tube straight tube portion,
An elongated frame inserted between the plurality of heat transfer tube straight tube portions;
A plurality of protectors that are coupled in the longitudinal direction of the frame and that cover the outer peripheral surface of the heat transfer tube straight pipe portion along the longitudinal direction;
A connecting member that includes a support shaft provided along the long side of the protector, and connects the protector to the frame so that the protector rotates around the support shaft ;
An apparatus for protecting a heat transfer tube , comprising: a locking member that locks the protector in a state where the protector is erected along the frame . In a heat transfer tube protection device that is provided in a horizontal heat exchanger in which a plurality of heat transfer tube straight tube portions are provided in a horizontal direction with a gap therebetween, and that protects the outer peripheral surface of the heat transfer tube straight tube portion ,
An elongated frame inserted between the plurality of heat transfer tube straight tube portions ;
A plurality of protectors that are coupled in the longitudinal direction of the frame and that cover the outer peripheral surface of the heat transfer tube straight pipe portion along the longitudinal direction;
Including a support shaft provided along the long side of the protector, and a connecting member for connecting the protector to the frame so that the protector rotates around the support shaft .
The heat transfer tube protection device according to claim 1, wherein a distance from the frame to the support shaft of the connecting member is larger than a thickness of the protector . The said protector is formed with the flat plate, The protection apparatus of the heat exchanger tube of Claim 1 or 2 characterized by the above-mentioned. 3. The heat transfer tube protection device according to claim 1 , wherein the protector is formed of an arc-shaped plate whose short side is curved along the outer peripheral surface of the heat transfer tube straight tube portion . The heat transfer tube protection device according to claim 4 , wherein a curvature of the short side of the protector is smaller than a curvature of an outer peripheral surface of the heat transfer tube straight tube portion .

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