JP2005180902A - Boiler device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable boiler device capable of uniformly transmitting the mass of a back stay to a vertical strap so as not to cause an excessive stress to an upper vertical pipe. <P>SOLUTION: The boiler device comprises a number of vertical straps arranged vertically over the whole circumference of a furnace wall, and a number of back stays 5 arranged in the horizontal direction of the furnace wall, the intersections of the vertical straps 3 with the back stays 5 being connected by support members 6. A part of the intersections of the vertical straps 3 with the back stays 5 is laid in a non-constrained state without connection by the support members 6. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a boiler apparatus such as a boiler for large-capacity thermal power generation, and more particularly to a mass support structure for a furnace wall.

  In the latest large-capacity thermal power generation boilers, a spiral spiral membrane wall is used to equalize heat absorption in the boiler furnace wall (hereinafter sometimes referred to simply as the furnace wall) at the furnace wall outlet. Yes. In other words, in the conventional boiler, the furnace wall consisting of vertical pipes was provided in the entire height direction, but the unbalance of heat absorption generated in the circumferential direction of the furnace wall increased in the height direction of the furnace wall. Problems such as deformation may occur.

  For this reason, the lower furnace wall, which is particularly prone to unbalance, is arranged in a spiral shape so that the tube direction is inclined with respect to the height direction of the furnace. A structure with a vertical wall has been adopted for the furnace wall.

  The furnace wall is a so-called membrane wall in which steel pipes and flat steel are alternately formed into a panel shape by fillet welding. In addition, since combustion occurs in the furnace wall, in addition to measures to prevent deformation in the width direction due to the furnace pressure, it is necessary to take measures to absorb heat elongation in the height direction of the furnace due to thermal elongation. In the horizontal direction of the furnace wall, a support member called a horizontal backsteer is provided apart from the furnace wall to ensure the rigidity as the furnace wall and to cope with thermal expansion.

  FIG. 10 shows a schematic perspective view of a boiler apparatus to which the present invention is applied. FIG. 7 shows a support structure of the lower furnace wall by the upper furnace wall to which the present invention is applied.

  The boiler body is hung from a ceiling ceiling beam in a structure called a boiler building consisting of steel columns and beams (not shown), but in this case, a furnace consisting of a spiral tube compared to a furnace wall consisting of a vertical tube Since the wall bears the mass of the wall in the transverse direction of the tube, the mass that can be partially burdened is limited. For this reason, a plurality of suspension members called vertical straps 3 are provided in the height direction for the lower furnace wall 24 made of a spiral tube, and one fulcrum is provided on the upper furnace wall 15 made of a vertical tube over the entire circumference of the furnace wall. The other fulcrum is distributed over the entire lower furnace wall 24 to reduce the partial mass burden on the lower furnace wall 24.

  In addition, since the horizontal backstep 5 is arranged in a plurality of directions in the horizontal direction of the furnace wall so as to surround the furnace wall, it is necessary to bear this mass, but for this mass, a support member called a major link 6 is used. It is transmitted to the vertical straps 3 arranged in the height direction of the entire circumference of the boiler, and further transmitted to the vertical pipe of the upper furnace wall. That is, the vertical strap 3 is configured to transmit the mass of the lower furnace wall 24, the horizontal backstep 5, and the member connecting the horizontal backstep 5 and the vertical strap 3 to the upper furnace wall 15.

  In FIG. 7, reference numeral 1 in the figure denotes a vertical pipe constituting an upper furnace wall 15 made of a vertical wall of the furnace walls, and 2 denotes a lower furnace wall 24 made of a spiral membrane wall connected to the vertical pipe 1. The spiral tube 3 is vertically arranged over the entire circumference of the lower furnace wall 24 made of a spiral membrane wall, and a number of vertical straps provided with fulcrums on the upper furnace wall 15 made of the vertical wall 4 are parallel to the vertical strap 3. The vertical backstage 5 is arranged in the horizontal direction of the lower furnace wall 24 composed of the spiral membrane wall, and 6 is a major backstage 5 arranged between the vertical strap 3 and the horizontal backstage 5. The link, 7 is a minor link provided between the vertical strap 3 and the vertical backste-4 12 support pin, 13 support, 14 is a corner link.

  As described above, since the burden mass of the spiral tube 2 is limited compared to the vertical tube 1, the mass of the backstays 4, 5, etc. is transmitted to the vertical strap 3 via the measure link 6, and the mass is further increased. It is structured to be transmitted to the vertical tube 1 through the vertical strap 3.

  FIG. 8 is a view showing an arrangement state of the major links 6 in the spiral membrane wall support structure in the conventional boiler apparatus. This figure has shown the arrangement | positioning condition of the support structure in the furnace side wall 25, and the dashed-dotted line 8 in the figure has shown the furnace front wall, and the dashed-dotted line 9 has shown the furnace rear wall. As shown in the figure, major links 6 are provided at or near the intersections of the vertical straps 3 arranged in the vertical direction of the furnace wall and the horizontal backstages 5 arranged in the horizontal direction of the furnace wall. Each major link 6 mechanically connects and fixes all the intersections of the vertical strap 3 and the horizontal back stay 5 to ensure the rigidity of the horizontal back stay 5 and to deform in the width direction due to the furnace pressure or the like. To prevent. Further, with respect to thermal elongation, a minor link 7 is connected between the horizontal backstays 5 in the height direction instead of being connected and fixed by the major link 6 to reduce rigidity and follow the thermal elongation.

  FIG. 9 is a schematic configuration diagram of the boiler device, and FIG. 10 is a schematic perspective view of the boiler device. Reference numeral 10 in the figure denotes a hopper wall, which is composed of a spiral tube 2 as shown in FIG. Reference numerals 11a and 11b denote superheaters suspended from the top of the furnace, that is, the furnace ceiling far above the hopper wall 10.

  FIG. 11 is a perspective view showing a support structure of the hopper wall 10. As shown in this figure, in the case of the support structure of the hopper wall 10, the hopper wall 10 is a clinker discharge portion at the bottom of the furnace, and therefore, the furnace front wall and the furnace rear wall corresponding to the hopper wall 10. Is inclined toward the inside of the furnace, so that the direction of thermal expansion is different from that of the furnace wall provided above the hopper wall 10, so that the vertical strap 3 is connected to the upper furnace wall side as in FIG. Are arranged in the hopper wall 10 without being connected.

  Further, although the furnace side wall is not inclined, it is necessary to make an overall adjustment together with the front and rear walls of the furnace, so that the vertical strap 3 is provided separately from the furnace wall directly above the hopper wall 10 as described above. Yes. In addition, since the cross-sectional area is particularly reduced on the side wall, the number of the holes is reduced toward the furnace bottom.

  As shown in FIG. 9, the hopper wall 10 receives a furnace pressure 16 during operation of the boiler device in addition to its own weight 20 in the same manner as the furnace wall above the hopper wall 10. Further, the hopper wall 10 receives an impact force 18 when the clinker 17 attached to the superheaters 11a and 11b falls. Further, when the ash 19 generated by the combustion of fuel accumulates on the hopper wall 10, the weight is applied to the hopper wall 10. Thus, the hopper wall 10 is swollen or deformed due to its own weight 20, the furnace pressure 16, the drop impact force 18 of the clinker 17, the weight of the accumulated ash 19, and the like.

  FIG. 12 is a diagram schematically showing how to apply a load such as the furnace pressure 16 and deformation of the hopper wall 10 during boiler operation. A load such as the furnace pressure 16 is transmitted to the vertical strap 3, the minor link 7, the vertical backstay 4 and the horizontal backstay 5 via the hopper wall 10.

  In the conventional boiler apparatus, the hopper wall 10 is also mechanically connected and fixed at all intersections of the vertical strap 3 and the horizontal backstage 5 by the major links 6 as in FIG.

As for this type of boiler apparatus, for example, the following patent documents can be cited.
JP 54-103901 A JP-A-60-82702 JP 62-66005 A

  However, even in a large-capacity thermal power generation boiler with a spiral wall at the bottom and a vertical wall at the top, the mass of the backstay is not uniformly transmitted to the vertical strap due to the difference in thermal expansion mainly due to the temperature difference. It has been found. Due to this non-uniformity of the burden mass, excessive stress is generated on the support member such as the vertical strap and the upper vertical tube that supports the mass, so it tends to be over-designed and the non-uniformity of the burden mass cannot be resolved. Has the problem of leading to tube leaks.

  An object of the present invention is to provide a highly reliable boiler apparatus that eliminates the drawbacks of the prior art and can transmit the mass of the backstay to the vertical strap evenly.

In order to achieve the above object, the first means of the present invention includes a plurality of vertical straps arranged in the height direction of the boiler furnace wall and a plurality of backstays arranged in the horizontal hand direction of the boiler furnace wall. In the boiler device for connecting the intersection of the vertical strap and the back stay with a support member,
A part of the intersecting portions of the vertical strap and the backstay is not connected by the support member to form an unconstrained structure.

  According to a second means of the present invention, in the first means, the furnace wall comprises a lower furnace wall comprising a spiral tube connected to an upper furnace wall comprising a vertical tube, and the mass of the lower furnace wall and the backstay Is configured to be transmitted to the upper furnace wall made of the vertical pipe through the support member and a vertical strap.

  According to a third means of the present invention, in the first means, the furnace wall has a lower furnace wall made of a spiral tube connected to the upper furnace wall made of the vertical tube, and a boiler connected to the lower furnace wall. The lower furnace wall, the hopper wall and the mass of the back stay arranged in the horizontal direction of both of the furnace walls through the support member and a vertical strap. It is characterized in that it is structured to be transmitted to the upper furnace wall consisting of tubes.

  The present invention is configured as described above, can equalize the vertical strap burden mass, can be optimally designed for the support member, and reduce the possibility of tube leakage, thereby reducing the reliability of the boiler device. Can be improved.

  Next, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 7, in a large capacity thermal power generation boiler having a spiral membrane wall on the furnace wall, the burden mass of the spiral tube 2 is limited, so the mass of the backstays 4 and 5 is a support called a major link 6. It is transmitted through a member to a vertical strap 3 disposed around the entire circumference of the boiler and finally transmitted to the vertical pipe 1 on the upper furnace wall.

  However, in the conventional boiler apparatus, since the unbalance for heat absorption generated in the circumferential direction of the furnace wall increases in the height direction of the furnace wall, the lower furnace wall is relaxed as a spiral wall as shown in FIG. However, local imbalances still exist. In particular, in recent years when it is required to shorten the boiler start-up time, a phenomenon has occurred in which imbalance increases due to rapid start-up.

  For this reason, as shown in FIG. 8, conventionally, the measure links 6 are installed on all the straps at each level. Therefore, the difference in thermal expansion due to the temperature imbalance is increased, and the horizontal backstage 5 disposed in the horizontal direction is increased. On the other hand, a phenomenon occurs in which a level difference occurs in the major links 6 arranged at the same level or in the vicinity. As a result, when the vertical strap 3 that does not bear the mass of the backstays 4 and 5 is generated, an excessive stress is relatively applied to a part of the vertical straps 3 to damage the major link 6 and finally bear the mass. This may lead to damage to the upper vertical tube 1 that is damaged.

  Therefore, in the first embodiment of the present invention, as shown in FIG. 1, in a large capacity thermal power generation boiler having a spiral membrane wall, the vertical strap 3 arranged in the vertical direction of the spiral membrane wall and the horizontal strap 3 are arranged in the horizontal direction. Instead of arranging the major links 6 at all the intersections of the horizontal backstays 5, every other major link 6 is arranged in a staggered manner as shown in the figure. Therefore, the vertical strap 3 and the horizontal backstay 5 are not mechanically connected to each other at the place where the major link 6 at the intersection is not arranged, and is an unconstrained portion. Therefore, in this first embodiment, every other major link 6 and non-restraining portion are staggered.

  Thus, by providing a part of the non-restraining portion at the intersection, when a plurality of thermal straps 3 are arranged in the circumferential direction of the furnace wall, a vertical strap 3 that does not bear a mass is generated. Therefore, the strap bears an equal mass as a whole, and it becomes possible to reduce the possibility of the optimum design of the support member and the tube leak.

  FIG. 2 is a diagram showing a second embodiment of the present invention, FIG. 3 is a diagram showing a third embodiment of the present invention, and FIG. 4 is a diagram showing a fourth embodiment of the present invention. The embodiment in which the arrangement state of the link 6 and the unconstrained part is different is shown. In addition, in each embodiment, arrangement | positioning of the major link 6 and the non-restraining part does not deviate partially, and it is necessary to arrange | position with sufficient balance seeing from the whole boiler.

  The provision of the non-restraining portion in this way is applied not only to the vertical wall 15 made of a vertical pipe constituting a part of the furnace wall but also to the hopper wall 10. When applied to the hopper wall 10, the support structure installed outside the hopper wall 10 also has a vertical strap 3, a minor link 7, a vertical back stay 4, a horizontal back stay 5, etc. as shown in FIG. 11. ing.

  The vertical strap 3 is attached to the hopper wall 10 with a support 13 and a support pin 12 fixed to the hopper wall 10 by welding. This vertical strap 3 is provided from the same technical idea as that provided on the lower furnace wall, but in addition to this, in the hopper wall 10, the load received by the hopper wall 10, that is, when the furnace pressure 16 and the clinker 17 are dropped. It is also necessary to cope with the impact force 18 generated, the weight of the ash 19 and the like. In the hopper wall 10 in particular, the conventional rigid structure cannot absorb the impact force 18 and is likely to cause deformation of the support member and damage to the furnace wall. As a result, it becomes a flexible structure and can cope with an impact force.

  A vertical back stay 4 is installed on the upper and lower surfaces of the horizontal back stay 5, and a minor link 7 is interposed between the vertical back stay 4 and the vertical strap 3. The load received by the vertical strap 3 is transmitted to the vertical back stay 4 via the minor link 7, and the load is supported by the hopper wall 10 via the horizontal back stay 5 and the corner link 14.

  That is, a series of support structures provided on the hopper wall 10 may be provided by being connected to the vertical strap 3 on the lower furnace wall side. However, since the hopper wall 10 is formed toward the inside of the furnace, The structure of the hopper wall 10 is complicated due to the difference in the direction of thermal elongation of the hopper, and the height of the hopper wall 10 is as small as, for example, about 10% with respect to the height of the furnace wall of the entire furnace. As shown in FIG. 11, the corner link 14 may temporarily receive it on the side wall, and the hopper wall 10 as a whole may bear the mass on the entire lower furnace wall.

  FIG. 5 is a diagram schematically showing the load transmission path. The vertical strap 3, the minor link 7, the vertical back stay 4 and the horizontal back stay 5 are elastic bodies, and their spring constants are K1, K2, K3 and K4.

  The vertical strap 3 and the minor link 7 and the minor link 7 and the vertical back stay 4 are connected by a pin, and the diameter of the pin is between the vertical strap 3 and the minor link 7 and the minor link 7 and the vertical back stay 4. The gaps 21 and 22 are provided by the difference in the diameter of the pin hole into which the pin is inserted. The code | symbol 23 in FIG. 5 is a furnace inner surface.

  By providing the gaps 21 and 22 at both ends of the minor link 7 as described above, the actual spring constant (spring characteristic) becomes a solid line shown in FIG. 6, and the spring constant decreases corresponding to the gaps 21 and 22.

Since the vertical strap 3, the minor link 7, the vertical back stay 4 and the horizontal back stay 5 are arranged in series from the load transmission path, these composite spring constants K are
1 / K = 1 / K1 + 1 / K2 + 1 / K3 + 1 / K4
It becomes.

  Accordingly, the composite spring constant can be set smaller than the conventional one, and the structure becomes flexible, so that these function as a cushioning material. Therefore, the impact force 18 to the hopper wall 10 generated when the clinker 17 falls is reduced, so that the strength and soundness of the hopper wall 10 can be enhanced. In addition, the impact force to the horizontal backstay 5 that ultimately receives the load can also be reduced, and the reliability of the boiler device can be improved.

  Although the case where the hopper wall 10 is configured by the spiral tube 2 has been described in the above embodiment, the present invention can also be applied to a boiler device that configures the hopper wall by a vertical tube.

FIG. 3 is a diagram showing an arrangement state of major links in the spiral membrane wall support structure according to the first embodiment of the present invention. It is a figure which shows the arrangement | positioning state of the major link in the spiral membrane wall support structure which concerns on 2nd Embodiment of this invention. It is a figure which shows the arrangement | positioning state of the major link in the spiral membrane wall support structure which concerns on 3rd Embodiment of this invention. It is a figure which shows the arrangement | positioning state of the major link in the spiral membrane wall support structure which concerns on 4th Embodiment of this invention. It is the figure which showed typically the transmission path of the load in the support structure of the hopper wall which concerns on embodiment of this invention. It is a spring characteristic figure in the support structure. It is a perspective view which shows the support structure of the vertical wall in a boiler apparatus. It is a figure which shows the arrangement | positioning state of the major link in the support structure. It is a schematic block diagram of a boiler apparatus. It is a schematic perspective view of a boiler apparatus. It is a perspective view which shows the support structure of the hopper wall in a boiler apparatus. It is the figure which showed typically how to apply the load in the hopper wall support structure, and a deformation | transformation of the hopper wall during boiler operation.

Explanation of symbols

  1: vertical pipe, 2: spiral pipe, 3: vertical strap, 4: vertical backstay, 5: horizontal backstay, 6: major link, 7: minor link, 8: front wall of furnace, 9: rear wall of furnace, 10 : Hopper wall, 11: superheater, 12: support pin, 13: support, 14: corner link, 15: vertical wall, 16: furnace pressure, 17: clinker, 18: impact force, 19: ash, 20: hopper wall Weight, 21, 22: gap, 23: furnace inner surface.

Claims (3)

A plurality of vertical straps arranged in the height direction of the boiler furnace wall and a plurality of back stays arranged in the horizontal hand direction of the boiler furnace wall, and a support member at the intersection of the vertical strap and the back stay In the boiler equipment to be connected,
A boiler device characterized in that a part of the intersecting portions of the vertical strap and the backstay is not connected by the support member and has a non-restraining structure. 2. The boiler apparatus according to claim 1, wherein the furnace wall is a lower furnace wall made of a spiral tube connected to an upper furnace wall made of a vertical pipe, and the mass of the lower furnace wall and the backstay is the support member and the vertical. A boiler device characterized in that it is structured to be transmitted to an upper furnace wall composed of the vertical pipe through a strap. 2. The boiler apparatus according to claim 1, wherein the furnace wall is provided at a bottom furnace wall connected to the lower furnace wall and a lower furnace wall connected to the upper furnace wall consisting of the vertical pipe. An upper furnace wall comprising a hopper wall, and the mass of the lower furnace wall, the hopper wall and the back stay arranged in the horizontal direction of both the furnace walls, and the vertical pipe via the support member and a vertical strap. Boiler device characterized by having a structure transmitted to

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