JP2019168149A - Protective tube support structure of temperature reducer - Google Patents

Abstract

To suppress displacement to the pipe axis direction of a protective tube, the displacement that is caused by abrasion of an outer circumferential surface of a pin and an inner face of a hole-shaped pin locking part.MEANS FOR SOLVING THE PROBLEM: A pin 9 is provided to a header 1 in a fixing manner, and is protruded to the inside in the tube diameter direction. A hole-shaped pin locking part 10 is provided to a protective tube 3 in a fixed manner, and can be locked to the pin 9. The movement in the pipe axis direction and the movement in the peritubular direction of the protective tube 3 to the header 1 are regulated by that the pin locking part 10 is locked to the pin 9. The outer circumferential surface of the pin 9 has a taper-shaped inclined outer surface 12 that is reduced in diameter or increased in diameter toward the inside in the tube diameter direction. The inner face of the pin locking part 10 is opposed with the inclined outer surface 12 of the pin 9, and has a taper-shaped inclined inner surface 18 that is reduced in diameter or increased in diameter toward the inside in the tube diameter direction.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a protective tube support structure for a temperature reducer that reduces the temperature of high-temperature steam.

  Patent Document 1 describes a temperature reducer used as an overheat reducer for a boiler for a thermal power plant. In this desuperheater, a protective cylinder is provided in the steam mother pipe through which high-temperature steam flows, keeping a distance from the steam mother pipe, and water is sprayed from a spray nozzle inserted in the protective cylinder to reduce the temperature of the high-temperature steam. The A support pin is attached to the steam mother pipe by welding, a hole through which the support pin passes is provided in the protective cylinder, and the protective cylinder is supported by the steam mother pipe by the support pin.

Japanese Patent No. 3060415

  In the temperature reducer described in Patent Document 1, the protective cylinder vibrates in the axial direction of the support pin (pin) with respect to the steam mother pipe (mother pipe) (fluid direction of the mother pipe) by the fluid vibration of the protective cylinder, The inner peripheral surface of the hole of the protective cylinder (the inner surface of the hole-shaped pin locking portion) slides on the outer peripheral surface of the pin, and the outer surface of the pin and the inner surface of the hole-shaped pin locking portion are When worn, the protective cylinder may be displaced downstream (one side in the pipe axis direction) with respect to the mother pipe. On the downstream side of the pin, the coolant supply pipe for supplying water to the spray nozzle passes through the supply pipe insertion hole of the protective cylinder, so that the coolant supply pipe is inserted through the supply pipe due to the displacement of the protective cylinder in the tube axis direction. There is a risk of being damaged by being pressed by the inner peripheral surface of the hole.

  Then, an object of this invention is to suppress the displacement to the pipe-axis direction of the protection cylinder resulting from abrasion of the outer peripheral surface of a pin, and the inner surface of a hole-shaped pin latching | locking part.

  In order to achieve the above object, the first aspect of the present invention is to arrange a protective cylinder spaced from the main pipe radially inward of the main pipe through which high-temperature steam flows, and to eject a low-temperature fluid into the protective cylinder. A protective cylinder support structure for a desuperheater that lowers the temperature of high-temperature steam, which is fixedly provided with respect to a mother pipe and protrudes inward in the radial direction of the pipe, and is provided fixedly with respect to the protective cylinder. A hole-shaped pin locking portion that can be locked to the pin.

  The movement of the protective cylinder relative to the mother pipe in the tube axis direction and the movement in the pipe circumferential direction are regulated by the pin locking portion being locked to the pin. The outer peripheral surface of the pin has a tapered inclined outer surface that decreases or increases in diameter toward the inner side in the tube radial direction. The inner surface of the pin locking portion is opposed to the inclined outer surface of the pin, and has a tapered inclined inner surface that is reduced in diameter or expanded toward the inner side in the tube radial direction.

  In the above configuration, since the vibration in the pin axial direction (tube diameter direction) of the protective cylinder with respect to the mother pipe is suppressed by contact (locking) between the inclined outer surface of the pin and the inclined inner surface of the pin locking portion, the pin locking portion The inner surface and the outer peripheral surface of the pin are less likely to wear, and displacement of the protective cylinder in the tube axis direction due to such wear can be suppressed. Accordingly, a supply pipe insertion hole is provided in the protective cylinder, and a low-temperature fluid is supplied to the spray nozzle in the protective cylinder by the coolant supply pipe inserted through the supply pipe insertion hole, and the low-temperature fluid is ejected from the spray nozzle into the protective cylinder. In the temperature reducer, it is possible to prevent damage to the coolant supply pipe due to unintended displacement of the protective cylinder in the pipe axis direction.

  A second aspect of the present invention is the protective cylinder support structure according to the first aspect, each having the pin and the pin locking portion, and spaced apart from each other in the radial direction of the mother pipe. A pair of locking support structures are provided.

  In the above configuration, for example, when the inclined outer surface of the pin is reduced in diameter toward the inner side in the tube radial direction and the inclined inner surface of the pin locking portion is increased in diameter toward the inner side in the tube radial direction, one of the pair of locking support structures On the other hand, the displacement of the protective cylinder to the inside in the pipe radial direction is suppressed. Therefore, the vibration in the pin axis direction (tube diameter direction) of the protective cylinder relative to the mother pipe can be suppressed from both sides in the pipe radial direction, and the vibration suppression effect of the protective cylinder can be enhanced.

  A third aspect of the present invention is the protective cylinder support structure of the first or second aspect, and includes a support plate fixed to the inner peripheral surface of the protective cylinder. The pin locking portion is a pin insertion hole that penetrates the protective cylinder and the support plate.

  In the above configuration, the range of the inclined inner surface in the tube diameter direction can be expanded by the thickness of the support plate, and the contact range between the inclined outer surface and the inclined inner surface can be expanded to enhance the vibration suppressing effect of the protective cylinder.

  ADVANTAGE OF THE INVENTION According to this invention, the displacement to the pipe-axis direction of the protection cylinder resulting from abrasion of the outer peripheral surface of a pin and the inner surface of a hole-shaped pin latching part can be suppressed.

It is a sectional side view which shows typically the schematic structure of the mother pipe and temperature reducer which concern on one Embodiment of this invention. It is a perspective view of the upstream end of the protection cylinder of FIG. It is a front view of the upstream end of the protection cylinder of FIG. FIG. 4 is a cross-sectional view taken along arrow IV-IV in FIG. 2. FIG. 5 is a cross-sectional view taken along line VV in FIG. 2. It is the figure which looked at the protection cylinder before fixing a support plate from the pipe radial direction inner side. It is the figure which looked at the protection cylinder after fixing a support plate from the pipe radial direction inner side. It is sectional drawing of the downstream end side of the protection cylinder of FIG. It is sectional drawing of a modification, (a) shows a 1st modification, (b) shows a 2nd modification, (c) shows a 3rd modification, (d) shows a 4th modification, respectively.

  A temperature reducer 2 according to an embodiment of the present invention will be described with reference to the drawings. The temperature reducer 2 of the present embodiment is used as an overheat reducer that reduces the temperature of high-temperature steam with a low-temperature fluid, such as a superheater or reheater of a boiler for a thermal power plant. In the following description, the pipe radial direction refers to the direction along the radial direction of the mother pipe 1 and the protective cylinder 3, and the pipe axis direction refers to the direction along the axial direction of the mother pipe 1 and the protective cylinder 3. The pipe circumferential direction means a direction along the circumferential direction of the mother pipe 1 and the protective cylinder 3.

  As shown in FIG. 1, high-temperature steam flows in the mother pipe (steam mother pipe) 1 from the upstream side to the downstream side (in the direction of arrow 30 in FIG. 1). The temperature reducer 2 provided in the mother pipe 1 includes a protective cylinder 3 and a spray nozzle 4, and the mother pipe 1 and the protective cylinder 3 are metal circular pipes. The outer diameter of the protective cylinder 3 is smaller than the inner diameter of the mother pipe 1, and the protective cylinder 3 is arranged in the mother pipe 1 (inside the radial direction of the mother pipe 1) away from the inner peripheral surface of the mother pipe 1. . The spray nozzle 4 is disposed in the protective cylinder 3 and sprays (sprays) a coolant (cooling water in the present embodiment). The protective cylinder 3 protects the mother pipe 1 by preventing direct injection of the coolant from the spray nozzle 4 to the mother pipe 1.

  A supply pipe insertion hole 5 penetrating both of the mother pipe 1 and the protective cylinder 3 is formed, and a cooling liquid supply pipe 6 for supplying a cooling liquid to the spray nozzle 4 is inserted through the supply pipe insertion hole 5 to form the spray nozzle 4. Connected to. The supply pipe insertion hole 5 is formed on the upstream end part 3 a side between the upstream end part 3 a and the downstream end part 3 b of the protective cylinder 3, and the space between the coolant supply pipe 6 and the supply pipe insertion hole 5 is sealed. ing.

  As shown in FIGS. 2 and 3, the upstream end portion 3a of the protective cylinder 3 is supported by the mother pipe 1 by a pair (two) of locking support structures 7 each having the same configuration. The stop support structure 7 is arranged to be shifted by approximately 180 degrees so as to be spaced apart from each other in the pipe radial direction of the mother pipe 1. As shown in FIG. 8, the downstream end portion 3b of the protective cylinder 3 is supported on the mother pipe 1 by two pairs (four) of abutting support structures 8 that are similarly configured, and four abutting support structures. 8 are arranged so as to be shifted by approximately 90 degrees. In addition, the number of the latching support structures 7 and the contact support structures 8 is not limited to the above, and can be set arbitrarily.

  As shown in FIGS. 4 to 7, each locking support structure 7 includes a rod-shaped pin 9 and a hole-shaped pin locking portion 10. A pair of arc plates 11 made of a metal plate that is curved in a semicircular arc shape is fixed to the inner peripheral surface of the mother pipe 1 facing the outer peripheral surface of the upstream end 3 a of the protective cylinder 3 by welding. Most of the area over the entire circumference of the inner peripheral surface overlaps the arc plate 11 (see FIGS. 2 and 3).

  The pin 9 protrudes integrally from the inner surface of the circular arc plate 11 to the inner side in the pipe radial direction of the mother pipe 1. The pin 9 may be formed integrally with the arc plate 11 or may be fixed to the arc plate 11 by welding or the like. The pin 9 has a truncated cone shape that is reduced in diameter toward the inner side in the tube radial direction, and the outer peripheral surface of the pin 9 constitutes a tapered inclined outer surface 12 that is reduced in diameter toward the inner side in the tube radial direction.

  A first pin insertion hole 13 penetrating in the tube diameter direction is formed in the protective cylinder 3, and the pin 9 is inserted through the first pin insertion hole 13 and a second pin insertion hole 15 described later. The first pin insertion hole 13 has a long hole shape extending along the tube axis direction from the upstream end opening 14 opened at the upstream end of the protective cylinder 3 to the downstream side, and the pipe circumferential direction of the second pin insertion hole 15 Is set to a size that allows the pin 9 to move in the tube axis direction.

  A support plate 16 made of a metal plate is fixed to the inner peripheral surface of the protective cylinder 3 by welding so as to overlap the first pin insertion hole 13. The support plate 16 is formed with a second pin insertion hole 15 penetrating in the pipe radial direction so as to communicate with the downstream end portion 17 of the first pin insertion hole 13. The downstream end of the first pin insertion hole 13 is formed in the support plate 16. The inner surface of the portion 17 is continuous with the inner peripheral surface of the second pin insertion hole 15.

  The pin 9 is inserted through the downstream end 17 and the second pin insertion hole 15 of the first pin insertion hole 13, and the inner surface of the downstream end 17 of the first pin insertion hole 13 and the second pin insertion hole 15. This inner peripheral surface constitutes a pin locking portion 10 that is fixed to the protective cylinder 3 and can be locked to the pin 9. The movement of the protective cylinder 3 relative to the mother pipe 1 in the pipe axis direction and the movement in the pipe circumferential direction are restricted by the pin locking portion 10 being locked to the pin 9. The pair of locking support structures 7 allows the protection cylinder 3 to tilt (moving in the rotation direction) about the pair of pins 9.

  The inner surface (the inner surface of the downstream end portion 17 of the first pin insertion hole 13 and the inner peripheral surface of the second pin insertion hole 15) of the pin locking portion 10 facing the inclined outer surface 12 of the pin 9 is the inclination of the pin 9. A tapered inclined inner surface 18 that expands toward the inner side in the tube diameter direction along the outer surface 12 is configured. Note that, in the inner surface of the first pin insertion hole 13, a region other than the downstream end portion 17 may be formed in a tapered shape similarly to the downstream end portion 17.

  In assembling the protective cylinder 3 to the mother pipe 1, the arc plate 11 is fixed to the protective cylinder 3, the upstream end of the protective cylinder 3 is inserted from the downstream end of the mother pipe 1, and the upstream end of the protective cylinder 3 is connected to the mother pipe 1. Move upstream. When the upstream end of the protective cylinder 3 approaches the pair of pins 9, the upstream end openings 14 of the two first pin insertion holes 13 are aligned with the pair of pins 9, respectively. While being inserted into the first pin insertion hole 13, the protection cylinder 3 is moved to a predetermined position where the pin 9 reaches the downstream end 17 of the first pin insertion hole 13. When the protective cylinder 3 is set at a predetermined position, the protruding tip (tip on the inner side in the pipe radial direction) of the pin 9 is inserted into the second pin insertion hole 15 and the support plate 16 is overlaid on the inner peripheral surface of the protective cylinder 3 for support. The plate 16 is fixed to the protective cylinder 3. Thus, in each of the pair of locking support structures 7, the protection tube in which the pin 9 is inserted through the pin locking portion 10 (the downstream end portion 17 of the first pin insertion hole 13 and the second pin insertion hole 15). It becomes an assembly state. The protruding tip of the pin 9 in the state where the protective cylinder is assembled is located in the vicinity of the inner end in the tube radial direction of the second pin insertion hole 15 (the inner surface in the tube radial direction of the support plate 16).

  As shown in FIG. 8, each contact support structure 8 includes a stud bolt 19. A reinforcing plate 20 is overlapped and fixed on the inner peripheral surface of the protective cylinder 3, and the stud bolt 19 is screwed into a female screw 21 penetrating the protective cylinder 3 and the reinforcing plate 19. When the protruding end of the stud bolt protruding from the outer peripheral surface of the protective cylinder 3 comes into contact with the inner peripheral surface of the mother pipe 1, the downstream end portion 3 b of the protective cylinder 3 is supported by the mother pipe 1. A stopper 25 is provided on the downstream side of the downstream end of the protective cylinder 3 so as to protrude from the mother pipe 1 inward in the pipe diameter direction and prevent the protective cylinder 3 from moving downstream.

  According to the present embodiment, the protective cylinder 3 tries to vibrate in the pin axis direction (the pipe radial direction of the mother pipe 1) with respect to the mother pipe 1 due to the fluid vibration of the protective cylinder 3. The vibration in the pin axis direction is suppressed by contact (locking) between the inclined outer surface 12 of the pin 9 and the inclined inner surface 18 of the pin locking portion 10. For this reason, the inner surface of the pin locking part 10 and the outer peripheral surface of the pin 9 are not easily worn, and displacement of the protective cylinder 3 in the tube axis direction due to such wear can be suppressed.

  Further, in one and the other of the pair of locking support structures 7, the displacement of the protective cylinder 3 toward the inner side in the pipe radial direction is suppressed, so that the pin axis direction of the protective cylinder 3 relative to the mother pipe 1 (the pipe radial direction) ) Can be suppressed from both sides in the tube diameter direction, and the vibration suppressing effect of the protective cylinder 3 can be enhanced.

  Further, since the range of the inclined inner surface 18 in the tube radial direction can be expanded by the thickness of the support plate 16, the contact range between the inclined outer surface 12 and the inclined inner surface 18 is expanded to enhance the vibration suppressing effect of the protective cylinder 3. be able to.

  Accordingly, the supply tube insertion hole 5 is provided in the protection cylinder 3, and the low temperature fluid is supplied from the spray nozzle 4 to the spray nozzle 4 in the protection cylinder 3 by the coolant supply pipe 6 inserted through the supply tube insertion hole 5. In the temperature reducer 2 in which a low-temperature fluid is jetted into the coolant 3, damage to the coolant supply pipe 6 due to unintentional displacement of the protective cylinder 3 in the tube axis direction (damage due to interference with the inner peripheral surface of the supply pipe insertion hole 5) ) Can be prevented.

  In addition, this invention is not limited to the above-mentioned embodiment and modification which were demonstrated as an example, If it is the range which does not deviate from the technical idea which concerns on this invention also except the above-mentioned embodiment etc. Various changes can be made according to the design and the like.

  For example, as shown in Modification 1 in FIG. 9A, the protruding tip of the pin 9 in the assembled state of the protective cylinder is connected to the inner end in the tube radial direction of the second pin insertion hole 15 (the inner side in the tube radial direction of the support plate 16). The cover plate 22 covering the protruding tip of the pin 9 may be fixed to the inside of the support plate 16 in the tube radial direction.

  9B, a part (base end side) of the outer peripheral surface of the pin 9 is the inclined outer surface 12, and the remaining region (tip end side) is along the tube radial direction. The inclined inner surface 18 and the inclined inner surface 24 may be provided on the inner surface of the pin locking portion 10 corresponding to the non-inclined outer surface 23. By providing the non-inclined outer surface 23 on the pin 9, it is possible to suppress the diameter reduction of the tip end portion of the pin 9, and to secure the rigidity of the pin 9. Further, the tip portion of the pin 9 can be formed with high accuracy, and the accuracy of the assembly position of the protective cylinder 3 with respect to the mother tube 1 is improved.

  Further, as shown in Modification 3 of FIG. 9C, the arc plate may be omitted and the pin 9 may be directly fixed to the mother pipe 1. As shown in Modification 4 of FIG. The inclined outer surface 12 of the pin 9 may have a tapered shape that expands toward the inside in the tube diameter direction, and the inclined inner surface 18 of the pin locking portion 10 may have a tapered shape that expands toward the inside in the tube diameter direction.

1: Mother pipe 2: Temperature reducer 3: Protection cylinder 3a: Upstream end 3b of protection cylinder: Downstream end of protection cylinder 4: Spray nozzle 5: Supply pipe insertion hole 6: Coolant supply pipe 7: Locking support Structure 8: Contact support structure 9: Pin 10: Pin locking part 11: Arc plate 12: Inclined outer surface 13: First pin insertion hole 14: Upstream end opening 15 of the first pin insertion hole 15: Second pin Insertion hole 16: Support plate 17: Downstream end 18 of the first pin insertion hole 18: Inclined inner surface 19: Stud bolt 20: Reinforcement plate 21: Female screw 22: Cover plate 23: Non-inclined outer surface 24: Non-inclined inner surface 25: Stopper

Claims (3)

A protective cylinder support for a desuperheater that lowers the temperature of the high-temperature steam by ejecting a low-temperature fluid into the protective cylinder by disposing a protective cylinder away from the main pipe in the radial direction of the main pipe through which high-temperature steam flows Structure,
A pin fixedly provided to the mother pipe and projecting inward in the radial direction of the pipe;
A hole-shaped pin locking portion fixed to the protective cylinder and lockable to the pin, and
The movement of the protective cylinder in the tube axis direction and the movement in the tube circumferential direction with respect to the mother pipe are regulated by the pin locking portion locking to the pin,
The outer peripheral surface of the pin has a tapered inclined outer surface that is reduced in diameter or expanded toward the inside in the tube radial direction,
The inner surface of the pin locking portion has a tapered inclined inner surface facing the inclined outer surface of the pin and reducing or expanding in diameter toward the inner side in the tube diameter direction. Tube support structure. The protective cylinder support structure according to claim 1,
A protective cylinder support structure for a desuperheater, characterized in that each includes the pin and the pin locking portion, and includes a pair of locking support structures that are spaced apart from each other in the radial direction of the mother pipe and face each other. . It is a protection cylinder support structure according to claim 1 or 2,
A support plate fixed to the inner peripheral surface of the protective cylinder,
The pin locking part is a pin insertion hole that penetrates the protective cylinder and the support plate.

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