KR101241278B1 - Tube support for harp module of the heat recovery steam generator - Google Patents

Abstract

PURPOSE: A tube supporting unit for a half module of a heat recovery steam generator is provided to efficiently prevent the entire deformation of a half module by designing to fully manage a self-load of a tube in a large size. CONSTITUTION: A tube supporting unit(4) for a half module of a heat recovery steam generator comprises a band(43), a board ring(44), a vertical plate(42), and a substrate(41). The band is adhered by being coupled in a supported unit of the tube. The board ring supports the tube supporting unit while being coupled on an upper part of the band. The vertical plate is adhered to an inner surface to face an outer surface. An outer lower part of the substrate is adhered to the upper part of the substrate. The substrate is installed in the outer lower part of the band and the lower part of the vertical plate and comprises a beam-shaped supporting unit. A top board ring and the board ring are integrally formed between the substrates.

Description

Tube Support for Harp Module of the Heat Recovery Steam Generator}

The present invention, in the heat recovery boiler (HRSG) for power generation to recover the heat remaining in the high-temperature exhaust gas in the power plant to support the tubes of the half module (Harp Module) installed in the heat recovery boiler with stability. Therefore, the present invention relates to a tube support for a half module of a heat recovery boiler, which is effective for relieving the vibration and stress of a tube caused by turbulence of exhaust gas.

Heat recovery steam generator (HRSG) is a device that recovers the exhaust heat or waste heat energy of 500 ~ 700 ℃ which is discharged after generating electricity from steam turbine or gas turbine of thermal power plant. When the exhaust gas passes through the heat recovery boiler, steam is generated by heat exchange. The steam drives the steam turbine to produce power.

The heat exchange takes place in the half module of the heat recovery boiler. The half module arranges the plurality of tubes in a plurality of rows along the direction in which the exhaust gas flows. The tube may be a fin tube with heat dissipation fins advantageous for heat exchange.

During the heat exchange, the tube is shaken by the turbulence of the exhaust gases. Therefore, the half module is provided with a tube support for preventing the shaking of the tube.

The tube support of the general structure for the half module of the heat recovery boiler was a flat band made of steel. Since the flat band has a low thermal stress and a weak bearing force on the tube, the flat band has a disadvantage of sagging due to its own weight over time.

Considering this point, the tube support for a half module disclosed in Patent No. 650253. The tube support is a strip steel sheet formed with a constant pitch of S-shaped expandable corrugations circumscribed in the comb direction on the outer surface of the tube, and is supported by a four-point support method by a pair of tube supports that occupy the circumference of the tube by half. In other words, the area supporting the tube is only a small portion, and the support force of the tube against the turbulence of the exhaust gas is small, which is unstable. The accumulation of stress caused by the shaking of the tube may damage the tube and ultimately shorten the life.

Furthermore, in the field of array recovery boiler, which is the trend of large-scale design and fabrication, the half module has a high design difficulty of the tube support, considering the specifications of the tube support for closely arranging and supporting a plurality of tubes having 2 to 3 nozzles.

Recently, as the design of the array recovery boiler becomes larger, the nozzles installed in the half module increase and the size increases. In particular, in order to install a half module applied to a benson type recovery boiler, it is necessary to take a separate sure measure to reduce or eliminate the stress of the tube support.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tube support for a half module of a heat recovery boiler in which a half module of a large heat recovery boiler can sufficiently cope with large self-weight and turbulence of exhaust gas.

In order to achieve the above object, the present invention provides a band that covers the support of the tube, a plate ring to be inserted into the upper end of the band to reinforce, and the inner surface to face the symmetrical to the outer surface of the band and the bottom is attached to the upper surface of the substrate It proposes a tube support for the half module of the array recovery boiler consisting of a vertical plate for the ribs, and a substrate that forms a beam-like support against the outer surface of the lower end of the band and the lower end of the vertical plate.

The substrate includes one plate ring and the same type plate ring formed integrally between both substrates.

According to the present invention, a thick steel tube supporter for supporting a large half module, which is a heavy-weight body manufactured to meet a large array recovery boiler, can cope with its own weight even if the tube is large, thereby preventing deformation of the tube and the entire half module. It is also advantageous for the long term safe operation of the half module.

1 is a state diagram of the installation of the present invention half module
FIG. 2 is a front view of FIG. 1
3 is an exploded view of the tube support according to one embodiment
4 is a copper assembly diagram
Figure 5 is an installation example of the tube by the tube support
Figure 6 is an illustration of a variant substrate for a tube support according to another embodiment

As shown in Figures 1 and 2, the half module 1 for a large array recovery boiler is upright so that several tubes 2 of the same type are arranged in a row or in a plurality of rows along the direction of the gas discharged from the array recovery boiler. Water and gas are separated from the introduction tube (2a) via the final tube (2b) of the rear half module (1a) in turn, and in this process, the agglomerated water in each tube (2) is discharged separately and only the gas is discharged. It is discharged to the atmosphere via the final tube (2b).

The upper part of all the tubes 2 is supported by a tube support 4 specially manufactured on the steel structure 3 installed on the ground.

In FIG. 3, the tube support 4 is composed of a substrate 41, a vertical plate 42, a band 43, and a plate ring 44. The board 41 is mounted on the horizontal beam of the steel structure installed using steel such as H-beam to install the separator, and is fastened by bolts or bolt-nuts to stabilize the posture of the entire support. The inner surface 41a is an arc surface corresponding to the outer diameter of the band 43, and the plate surface close to the outer end is perforated with a fastening hole 41b mounted on the horizontal beam of the steel structure for tube installation and fastened with a bolt or bolt-nut. The fastening hole 41b is a long hole suitable for preventing the bias of the load of the tube, which may be caused by the substrate 41 not maintaining the position correctly on the horizontal beam of the steel structure. The long axis of the long hole corresponds to the longitudinal direction of the transverse beam.

The vertical plate 42 is attached to the outer surface of each band 43 symmetrically to increase the strength to prevent deformation and at the same time the tube support 4 through the coupling of the substrate 41 and the plate ring 44 to the band 43 ) Rib to increase the overall rigidity, the inner surface of each vertical plate 42 is longitudinally attached to the outer surface of the band 43, the upper end to the bottom surface of the plate ring 44 and the lower end to the upper surface of the substrate 41 Attached. The attachment means may use welding or another attachment means.

The height of the vertical plate 42 is set to the length between the upper surface of the substrate 41 and the bottom surface of the plate ring 44 in the band 43 fitted to expose the lower and upper ends of the upper surface of the substrate 41 and the plate ring 44 slightly. As a result, the bonding state of the substrate 41 and the plate ring 44 to the band 43 is secured.

Band 43 is used to combine the two semi-circular pipes facing each other by dividing the tubular body as shown in Figure 3, so that the gap (W) is widened when the inner diameter of the band is formed smaller than the outer diameter of the tube to cover the outer surface of the tube Configure. In addition, only one of the bands 43 may be vertically cut and configured to be elastically stretched.

When the band 43 is attached to the tube 2, the wrapping force is good, and the strength of the supported portion of the tube 2 is increased to increase the ability to cope with stress. The band may also use a steel short tube whose inner diameter is equal to the outer diameter of the tube.

The plate ring 44 covers the upper end of the band 43 covered by the supported portion of the tube 2 to increase the stress against deformation of the upper end and to stabilize the posture of the band 43 surrounded by the tube 2.

The inner surface 41a of each substrate 41 is welded to the lower end of the outer circumferential surface of the band 43. Specifically, the substrate 41 is attached to each other so that the lower end of the band 43 is slightly exposed. The lower surface of the vertical plate 42 is placed on the upper surface of each of the substrates 41, and the inner surface of the vertical plate 42 is brought into contact with the outer surface of the band 43 to be welded to the substrate 41 and the band 43 to be integrated. do.

Subsequently, the plate ring 44 is lowered to the upper end of the band 43 to sit on the upper end of the vertical plate 42. This slightly exposes the top of the band 43 over the plate ring 44. Welding in this state completes the tube support 4 of the aspect as shown in FIG. The above is an example of the assembly of the tube support 4, and the upper surface of the substrate 41 and the lower end of the vertical plate 42 are welded first, and the inner surface of the vertical plate 42 is welded to the outer surface of the band 43. You can also proceed in order.

In FIG. 5, the tube support 4 is seated by raising the band 43 to the bottom of the upper structure of the tube 2, and attaches the upper and lower ends of the band 43 to the outer surface of the tube 2 by welding. . The tube 2 equipped with the tube support 4 is lowered between the horizontal beams 31 of the steel structure 3 to saddle the substrate 41 of the tube support 4 on the horizontal beams 31, and then Fix the support to the horizontal beam 31 by the fastening means.

If the load of the tube 2 is biased to one side on the transverse beam 31 of the steel structure 3, loosen the fastening means, correct the position of the tube 2, and then tighten it again to tighten the tube 2 due to the bias of the load. Eliminates postural instability.

FIG. 6 shows a modification in which the symmetrical substrate 41 is integrally formed on the left and right sides of the plate ring 44 and the same plate ring 45 through press or laser processing.

In other words, the plate ring 45 having the substrate 41 integrally formed on both sides of the ring ring formed in the shape of a ring like the upper plate ring 44. The band hole 45a is formed in the band hole 45a when the tube supporter is assembled. With the lower end fitted, the tube support thus assembled is more effective in relieving stress on the supported portion of the tube 2.

Any type of tube support 4 can withstand the burden and movable load caused by the increased load even if the half module is designed to be large for the large array recovery boiler.

For reference, the specification-specific analysis of each member for disproving the effect of the tube supporter by this invention is illustrated.

[Interpretation Condition]

Tube: 10 "× SCH.120. SA335-P91 [HRH]

Plate Ring: 20t / SA335-P22

Band: 20t / SA335-P22

Board: 20t / SA335-P22

Vertical plate: 20t / SA335-P22

Static load: 16,000 kg (= HRH half weight: 32,000 kg. Interpreted as two-point support)

        Actual HRH is three point support.

The stress generated in the support by the load of the tube is 49.5 MPa, which is preferable because it is lower than the allowable stress (60% of the yield stress). SA387-22 yield strength at 570 ℃ is 150MPa → 49.5MPa <90MPa (150MPa × 0.6)

The stress generated in the base material by the load of the tube is 29.7 MPa, which is lower than the allowable stress. The yield strength of SA335-P91 at 575 ° C. ranges from 87 MPa to 29.7 MPa <87 MPa.

[Analysis of Abnormal State, ie, Uneven Load Distribution]

The stress generated on the tube support by the load of the tube is 70 MPa, which is good because it is lower than the allowable stress (60% of the yield stress). SA387-22 yield strength at 570 ℃ is 150MPa → 70MPa <90MPa (150MPa × 0.6)

The stress generated in the base material by the load of the tube is 40.1 MPa, which is lower than the allowable stress. The yield stress of SA335-P91 at 575 ° C. ranges from 87 MPa to 40 MPa <87 MPa.

[Interpretation Condition]

Tube: 24 "× 61t SA335-P22

Plate Ring: 20t / SA335-P22

Band: 20t / SA335-P22

Board: 30t / SA335-P22

Vertical plate: 20t / SA335-P22

Static load: 30,000 kg (= separator weight approx. 20,000 kg)

The maximum stress generated on the support by the load of the tube is 61.57 MPa, which is good because it is lower than the allowable stress (60% of the yield stress). The yield strength of SA387-22 at 475 ° C. ranges from 225 MPa to 61.57 MPa <135 MPa (225 MPa × 0.6).

The stress generated in the base material by the load of the tube is 93.3 MPa, which is lower than the allowable stress. The yield stress of SA335-P22 at 475 ° C. ranges from 100 MPa to 93.3 MPa <100 MPa.

1: half module
2: tube
3: steel structure
4: tube support
41: substrate
41a: inside
41b: Fastener
42: vertical plate (in place of rib)
43: band
44,45: Fanring

Claims (4)

As a support for the half module tube installed in the heat recovery boiler,
A tubular band fitted to the supported portion of the tube;
A plate ring fitted to the upper end of the band and reinforced;
Vertical plates for replacing ribs attached to the inner surface of the band so as to be symmetrical to the outer surface of the band and attached to the upper surface of the substrate;
A substrate facing the outer surface of the lower end of the band to the lower end of the vertical plate to form a beam support; Tube support for the half module of the array recovery boiler comprising the. The half support tube support for an array recovery boiler according to claim 1, wherein an upper plate ring and an identical plate ring are integrally formed between the substrates. The half-module tube support according to any one of claims 1 to 3, wherein a long hole-type fastening hole for correcting the load bias of the tube tube is drilled on the substrate. The tube support for a half module of an array recovery boiler according to claim 1, wherein vertical cutouts are formed on both or one side of the band.

Images