KR102275074B1 - Lifting method for inner shell of liquefied gas tank using hydraulic pressure and reinforcement method of liquefied gas tank using tank lifting - Google Patents

Abstract

The present invention relates to a method for floating an inner tub of a liquefied gas tank using hydraulic pressure and a method for reinforcing a liquefied gas tank using floatation of an inner tub, which float an inner tub located in a liquefied gas tank for storing liquefied gas such as LNG using hydraulic pressure to inspect for a defect and reinforce the structure of the liquefied gas tank. The method for reinforcing a liquefied gas tank using floatation of an inner tub comprises: an actuator installation step (S120) of installing an actuator (33) along the circumference of the inner tub (18) of the liquefied gas tank (1); an inner tub bottom cutting step (S130) of cutting the circumference of the bottom of the inner tub (18); an inner tub floating step (S140) of extending the actuator (33) to lift the inner tub (18) so that a lower end of the circumference of the inner tub (18) is spaced apart from the bottom surface of the liquefied gas tank (1); an inner tub bottom extending step (S150) of forming a bottom plate (22) such that a bottom board (18c) of the inner tub (18), which is cut from the inner tub (18) and remaining in the liquefied gas tank (1), extends in a radial direction of the liquefied gas tank (1); a lower reinforcement step (S170) of laying leveling concrete (24) below the circumference of the inner tub (18) along a circumferential direction of the inner tub (18); an inner tub lowering step (S180) of lowering the inner tub (18); and a novel bottom installation step (S190) of installing a new bottom board (18c') in the inner circumference of the bottom of the inner tub (18).

Description

Floating method of inner tank in liquefied gas tank using hydraulic pressure and reinforcing method of liquefied gas tank using inner tank floating

In a liquefied gas tank using hydraulic pressure for reinforcing the structure of a liquefied gas tank, the present invention enables to check defects by lifting an inner tank located inside a liquefied gas tank for storing liquefied gas such as LNG using hydraulic pressure. It relates to a method for buoying an inner tank and a method for reinforcing a liquefied gas tank using the inner tank floating.

Liquefied natural gas (hereinafter referred to as 'LNG') used as household and industrial fuel is stored in a liquefied gas tank in a liquefied state, and is usually supplied to a consumer through a pipe in a gaseous state after vaporization.

The liquefied gas tank 100 storing the liquefied gas may have a structure as shown in FIG. 1 . An outer shape is formed by a floor slab 111 and an outer wall 112 made of concrete, and a blocking plate 113 for sealing the liquefied gas inside the outer wall 112 . An inner tub 118 made of a bonded material to store liquefied gas in an actual cryogenic state is installed therein. In order to support the load of the inner tub 118, leveling concrete 114 and A perlite concrete block 115 is provided along the circumference of the inner tank 118 . Foam glass 116 and dry sand 117 are filled inside the leveling concrete 114 and the pearlite concrete block 115 . Perlite 119a and fiber glass 119b are filled between the outer periphery of the inner tub 118 and the blocking plate 113 to insulate the periphery of the inner tub 118 .

After the liquefied gas tank 100 having such a structure is installed and used for the first time, inspection and repair are performed through a non-destructive test when the arrival of the durability life or the internal cracks due to abnormal operation are expected.

To this end, in order to inspect and repair cracks in the part that is difficult to confirm with the naked eye, for example, the lower part of the inner tank 118, cut the circumference of the lower bottom of the inner tank 118 and install a lifting device on the tank roof structure and then install the inner tank After lifting (118), the method of checking and repairing internal floor cracks was used. However, in this method, a part of the outer wall 112 or the loop has to be cut in order to bring in and take out the cut inner tank 118 and the like, and the cut inner tank 118 has to be restored by welding.

This has a problem of causing an increase in risk and an increase in the amount of work due to the lifting of a heavy object, and thus an increase in working time and cost.

In addition, a corner protection made of a material capable of blocking the liquefied gas at very low temperature is not installed around the inner lower portion of the aged liquefied gas tank 100 when the liquefied gas overflows, so when the liquefied gas overflows, the blocking film 113 ) There were concerns about stability due to low-temperature brittle fracture.

On the other hand, the following prior art document discloses a technology related to 'a membrane-type LNG tank, a maintenance method therefor, and a workbench device used therein'.

KR 10-2010-0102265 A

The present invention was invented to solve the above problems, and by cutting the circumference of the bottom of the bottom of the inner tank of the liquefied gas tank that needs inspection, the inner tank is lifted with hydraulic pressure so that the bottom part of the inner tank can be inspected and reinforced. An object of the present invention is to provide a method for flotation of an inner tank in a liquefied gas tank using hydraulic pressure and a method for reinforcing a liquefied gas tank using an inner tank float.

Another object of the present invention is to enable the bottom of the existing liquefied gas tank to be used as a bottom plate to prevent gas leakage, and to install a new bottom of the inner tub to improve stability in a liquefied gas tank using hydraulic pressure. An object of the present invention is to provide a method for flotation of an inner tub and a method for reinforcing a liquefied gas tank using flotation of the inner tub.

Another object of the present invention is to provide a method for flotation of an inner tank in a liquefied gas tank using hydraulic pressure such that a corner protection is formed inside a liquefied gas tank in which a corner protection is not formed, and a method for reinforcing a liquefied gas tank using the inner tank floating will be.

The method for flotation of an inner tank in a liquefied gas tank using hydraulic pressure according to the present invention for achieving the above object is a method for flotation of an inner tank in which a liquefied gas is stored inside an outer wall, along the circumference of the inner tank A hydraulic actuator that expands and contracts in the vertical direction of the inner tank is installed at intervals, and the actuator is simultaneously extended to float the inner tank.

A bracket is installed in the inner tank, and both ends of the actuator are fixed to the bracket and the bottom of the liquefied gas tank.

It is characterized in that the bracket is installed on the outer surface of the inner tank at intervals along the circumference of the inner tank.

The actuator is fixed to the bracket with a fixing bolt.

A support is interposed between the lower end of the actuator and the bottom of the liquefied gas tank.

The inner tub is characterized in that after separating the bottom plate formed along the perimeter of the bottom from the bottom plate positioned inside the bottom plate, the inner tub is lifted.

On the other hand, the method for reinforcing a liquefied gas tank using the inner tank flotation includes an actuator installation step of installing an actuator along the circumference of the inner tank of the liquefied gas tank, an inner tank bottom cutting step of cutting the circumference of the bottom of the inner tank, and extending the actuator an inner tank lifting step of lifting the inner tank so that the lower end of the circumference of the inner tank is spaced apart from the bottom surface of the liquefied gas tank, and the bottom plate of the inner tank cut from the inner tank and left of the liquefied gas tank in the radial direction of the liquefied gas tank An inner tub floor extension step of extending to form a bottom plate, a lower reinforcement step of laying leveling concrete below the circumference of the inner tub along the circumferential direction of the inner tub, a lowering step of lowering the inner tub, and the inner tub It characterized in that it comprises a new floor installation step of installing a new floor plate on the inside of the perimeter of the floor.

Before the actuator installation step, it characterized in that it further comprises a heat insulating material removal step of removing the insulating material (perlite) filled between the inner tank and the outer wall of the liquefied gas tank.

The actuator is characterized in that it is a hydraulic actuator that expands when pressurized oil is supplied.

In the actuator installation step, a bracket is installed on the outer surface of the inner tank, and both ends of the actuator are installed at the bottom of the bracket and the liquefied gas tank.

The actuator installation step is characterized in that the actuator is installed at a gap around the outer periphery of the inner tub.

The inner tub bottom cutting step is characterized in that the bottom plate formed along the bottom circumference of the inner tub and the bottom plate positioned inside the bottom perimeter plate are separated.

In the step of extending the inner tank floor, a new floor plate is installed from the circumference of the existing floor plate of the inner tank to the inner surface of the outer wall of the liquefied gas tank, and a portion in contact with the new floor plate and the existing inner tank floor plate is joined, the floor plate characterized by forming

Between the step of extending the inner tank floor and the step of reinforcing the lower part, a corner protection installation step of installing a corner protection formed at a predetermined height along the inner surface of the outer wall from the floor slab and surrounded by the floor plate is characterized in that it comprises a .

In the lower reinforcement step, leveling concrete is installed below the circumference of the inner tank, and dry sand is filled in the leveling concrete.

The new floor installation step is characterized in that the new floor plate is joined to the bottom plate formed along the perimeter of the bottom of the inner tub.

According to the method for flotation of the inner tank in the liquefied gas tank using hydraulic pressure of the present invention having the above configuration and the method for reinforcing the liquefied gas tank using the inner tank flotation, by checking the lower portion by lifting the inner tank using hydraulic pressure, the liquefied gas tank It can reduce the time and cost required for inspection and maintenance.

In addition, the bottom of the existing liquefied gas tank can be used as a bottom plate to prevent gas leakage, and the bottom of the inner tank is newly installed, so that stability is improved.

In addition, it is possible to prevent leakage of the liquefied gas overflowing from the inner tank by forming a corner protection that was not present in the conventional liquefied gas tank.

1 is a partial cross-sectional view showing the configuration of a conventional liquefied gas tank.
Figure 2 is a cross-sectional view showing the circumference of the bottom of the inner tank after removing the insulating material (perlite) filled between the outer wall of the liquefied gas tank and the inner tank according to the reinforcement method of the liquefied gas tank using the inner tank flotation according to the present invention.
Figure 3 is a cross-sectional view showing a state in which a hydraulic actuator is installed on the outer periphery of the inner tank according to the reinforcement method of the liquefied gas tank using the inner tank lifting according to the present invention.
Figure 4 is a cross-sectional view showing a floating state after cutting the circumference of the inner tank bottom according to the reinforcement method of the liquefied gas tank using the inner tank flotation according to the present invention.
Figure 5 is a cross-sectional view showing a state of reinforcing the lower structure according to the reinforcement method of the liquefied gas tank using the inner tank flotation according to the present invention.
6 is a cross-sectional view illustrating a state in which leveling concrete is laid below the circumference of the inner tank according to the method for reinforcing a liquefied gas tank using inner tank flotation according to the present invention, and dry sand is installed inside the leveling concrete.
Figure 7 is a cross-sectional view showing a state of installing a new floor according to the reinforcement method of the liquefied gas tank using the inner tank flotation according to the present invention.
8 is a flowchart illustrating a method for reinforcing a liquefied gas tank using an inner tank flotation according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings, a method for flotation of an inner tank in a liquefied gas tank using hydraulic pressure according to the present invention and a method for reinforcing a liquefied gas tank using the inner tank flotation will be described in detail.

The liquefied gas tank 1 has a form in which an inner tank 18 made of a material such as 9% nickel steel is installed in a space formed by a floor slab 11 made of concrete or the like and an outer wall 12 .

A lower portion of the inner tub 18 is provided with leveling concrete 14 , a concrete block 15 , and dry sand 17 on a bottom surface of the inner tub 18 .

In addition, a blocking plate 13 for preventing gas leakage is installed on the inner surface of the outer wall 12 and the floor slab 11 .

In order to insulate the liquefied gas between the outer side of the inner tank 18 and the inner side of the outer wall 12, an insulating material such as perlite or fiber glass is filled.

As the life of the liquefied gas tank 1 approaches, it is necessary to check the inner tank 18 that substantially accommodates the liquefied gas and to check the soundness of the gas barrier plate 13 .

To this end, in the present invention, the inner tank 18 is checked by lifting the inner tank 18 , and the structure supporting the lower portion of the inner tank 18 is reinforced, and the liquefied gas is installed by installing a corner protection 21 . By increasing the protective performance of the tank (1), the stability is also improved.

8 shows a method for reinforcing a liquefied gas tank using an inner tank flotation according to the present invention.

The insulating material removal step S110 is a process of removing the insulating material filled between the outer wall 12 and the inner tub 18 . When the liquefied gas is filled in the inner tub 18 between the outer wall 12 and the inner tub 18, pearlite, fiber glass, etc. are filled in order to insulate the liquefied gas from the outside, and the inner tub 18 is floated. In order to do this, first remove the insulating material.

In the actuator installation step (S120), the actuator 33 is installed along the circumference of the inner tank 18 of the liquefied gas tank 1 (refer to FIG. 3). The actuator 33 is installed at a gap around the outer periphery of the inner tank 18 .

Here, the actuator 33 is preferably a hydraulic actuator that expands when pressurized oil is supplied.

Along the circumference of the inner tank 18, a hydraulic actuator 33 that expands and contracts in the vertical direction of the inner tank 18 is installed at intervals, and the actuator 33 is simultaneously extended to expand the inner tank 18. boost

Meanwhile, a bracket 31 is installed in the inner tank 17 to install the actuator 33 . That is, the bracket 31 is installed on the outside of the side plate 18a in the inner tank 18 , and both ends of the actuator 33 are fixed to the bracket 31 and the bottom of the liquefied gas tank 1 . At this time, by installing the brackets 31 on the outer surface of the inner tub 18 at intervals along the circumference of the inner tub 18 , the actuator 33 may be installed along the perimeter of the inner tub 18 . The actuator 33 and the bracket 31 are fixed with a fixing bolt 32 .

A support 35 is installed between the lower end of the actuator 33 , that is, the end of the piston rod 34 drawn out from the actuator 33 and the bottom of the liquefied gas tank 1 .

In the inner tank bottom cutting step (S130), in order to float the inner tank 18, the side plate 18a of the inner tank 18 is separated from the bottom (refer to FIG. 3). At this time, the inner tub 18 has a bottom peripheral plate 18b formed of a thick plate along the circumference of the inner tub 18 at the lower end of the side plate 18a, and the bottom peripheral plate 18b A bottom plate 18c is formed therein to a thickness thinner than the bottom plate 18b, and a portion where the bottom plate 18b and the bottom plate 18c come into contact is cut. For example, the portion indicated by A in FIG. 2 is separated by a welding gun or the like. As the bottom plate 18b and the bottom plate 18c are separated, the side plate 18a of the inner tub 18 is substantially separated from the bottom of the inner tub 18 so that the side plate of the inner tub 18 is floated. this becomes possible

In the lifting of the inner tank ( S140 ), the hydraulic actuator 33 is extended to lift the inner tank 18 from the bottom (see FIG. 4 ).

The actuator 33 is installed on the outer surface of the inner tub 18, ie, the outer surface of the side plate 18a, at intervals along the periphery of the inner tub 18. Since the inner tub 18 is heavy, a plurality of the actuators 33 are provided at intervals, and the actuators 33 are simultaneously stretched so that the inner tub 18 is floated.

In this way, when the inner tub 18 is floated, the bottom portion of the floated inner tub 18 may be inspected with the naked eye or using equipment. As the inner tub 18 is lifted, it is possible to inspect a portion that is difficult to see while the inner tub 18 is installed.

In the inner tank floor extension step (S150), a new floor plate is additionally installed from the circumference of the existing floor plate 18c of the inner tank 18 to the inner surface of the outer wall 12, and the existing floor plate 18c and the new floor The parts where the plates are in contact are joined together. By bonding the existing bottom plate 18c and the new bottom plate to each other, it becomes the bottom plate 22 of the liquefied gas tank 1 . The bottom plate 22 prevents gas from leaking to the double bottom of the liquefied gas tank 1 together with the blocking plate 13 .

In the corner protection installation step ( S160 ), a corner protection formed at a predetermined height along the inner surface of the outer wall 12 from the floor slab 11 and surrounded by the floor plate 22 is installed (see FIG. 5 ). The corner protection 21 is not installed in the existing liquefied gas tank 1, but the corner protection 21 is newly installed through the corner protection installation step (S160), so that the liquefied gas in the inner tank 18 is Even if it overflows, it is possible to prevent leakage to the outside by the corner protection 21 .

In the lower reinforcement step (S170), as shown in FIG. 6, a new leveling concrete 24 is installed to support the circumference of the inner tank 18 under the bottom peripheral plate 18b of the inner tank 18. do. The leveling concrete 24 is newly installed below the bottom peripheral plate 18b of the inner tank 18 to support the lower circumference of the inner tank 18 .

In addition, in the lower reinforcement step (S170), the dry sand 27 is also newly filled in the inside of the leveling concrete 24.

The bottom plate 18c' of the inner tub 18 is newly installed by a new floor installation step (S190) to be described later. In order to support the lower portion of the inner tub 18, the leveling concrete 24 and the dry sand ( 27), the support structure of the inner tank 18 is strengthened and the stored liquefied gas is insulated.

In the lowering of the inner tank ( S180 ), the raised inner tank 18 is lowered for inspection of the liquefied gas tank 1 . The hydraulic actuator 33 provided in the circumferential direction of the inner tub 18 is contracted around the inner tub to lower the inner tub 18 . The bottom plate 18b of the inner tub 18 is lowered to be seated on the newly installed leveling concrete 24 .

In the new floor installation step ( S190 ), the bottom plate 18c ′ of the inner tub 18 is newly installed (see FIG. 7 ). In the inner tub 18, the bottom plate 18c is separated from the bottom perimeter plate 18b. In the state in which the inner tub 18 is lowered, a new bottom plate 18c is placed inside the bottom perimeter plate 18b. '), and the newly installed bottom plate 18c' is joined to the bottom plate 18b in the same manner as by welding. A new bottom plate 18c ′ is installed to seal the lower portion of the inner tank 18 , thereby storing liquefied gas.

1: liquefied gas tank 11: floor slab
12: outer wall 13: blocking plate
14: leveling concrete 15: concrete block
16: foam glass 17: dry sand
18: inner shell 18a: side plate
18b: bottom plate 18c, 18c': bottom plate
21: corner protection 22: bottom plate
24: leveling concrete 27: dry sand
31: bracket 32: fixing bolt
33: actuator 34: piston rod
35: support 100: liquefied gas tank
111: floor slab 112: exterior wall
113: blocking plate 114: leveling concrete
115: concrete block 116: foam glass
117: dry sand 118: inner shell
119a: pearlite 119b: fiber glass
S110: Insulation removal step S120: Actuator installation step
S130: inner tub bottom cutting step S140: inner tub floating step
S150: inner tank floor extension step S160: corner protection installation step
S170: lower reinforcement step S180: inner tank lowering step
S190 : New floor installation step

Claims (16)

In the liquefied gas tank consisting of an outer wall and an inner tank, in the inner tank flotation method of floating the inner tank in which liquefied gas is stored inside the outer wall,
A hydraulic actuator that expands and contracts in the vertical direction of the inner tank along the circumference of the inner tank is installed at intervals,
Simultaneously extending the actuator to float the inner tub in the interior of the outer wall,
The inner tub separates the bottom plate formed along the perimeter of the bottom from the bottom plate that is located inside the bottom plate and is formed thinner than the bottom plate, and then floats the inner tub,
Hydraulic pressure characterized in that a new bottom plate is installed from the circumference of the existing bottom plate of the inner tank to the inner surface of the outer wall of the liquefied gas tank, and a portion in contact with the new bottom plate and the existing inner tank bottom plate is joined to form a bottom plate A method of flotation using the inner tank. According to claim 1,
Install a bracket on the inner tank,
A method for flotation using hydraulic pressure, characterized in that both ends of the actuator are fixed to the bracket and the bottom of the liquefied gas tank. 3. The method of claim 2,
The inner tank buoyancy method using hydraulic pressure, characterized in that by installing brackets at intervals along the circumference of the inner tank on the outer surface of the inner tank. 4. The method of claim 3,
The actuator is a tubular buoyancy method using hydraulic pressure, characterized in that it is fixed to the bracket with a fixing bolt. 3. The method of claim 2,
An internal tub flotation method using hydraulic pressure, characterized in that a support is interposed between the lower end of the actuator and the bottom of the liquefied gas tank. delete An actuator installation step of installing an actuator along the circumference of the inner tank of the liquefied gas tank;
an inner tub bottom cutting step of cutting the circumference of the bottom of the inner tub;
An inner tank buoyancy step of elongating the actuator to lift the inner tank from the inside of the outer wall so that the lower end of the circumference of the inner tank is spaced apart from the bottom surface of the liquefied gas tank;
an inner tank bottom extension step of forming a bottom plate cut from the inner tank and extending the bottom plate of the inner tank remaining of the liquefied gas tank in a radial direction of the liquefied gas tank;
A lower reinforcement step of laying leveling concrete below the circumference of the inner tank along the circumferential direction of the inner tank;
an inner tub lowering step of lowering the inner tub;
Including a new floor installation step of installing a new floor plate in the inner perimeter of the bottom of the inner tank,
The inner tub bottom cutting step cuts a portion in contact with the bottom plate and the bottom plate formed with a thickness thinner than the bottom plate,
In the inner tank bottom extension step, a new bottom plate is installed from the periphery of the existing bottom plate of the inner tank to the inner surface of the outer wall of the liquefied gas tank, and a portion in contact with the new bottom plate and the existing inner tank bottom plate is joined, and the bottom plate is formed. Reinforcement method of a liquefied gas tank using an inner tank flotation, characterized in that it forms. 8. The method of claim 7,
Before the actuator installation step,
The method of reinforcing a liquefied gas tank using an inner tank flotation further comprising the step of removing a heat insulating material filled between the outer wall of the liquefied gas tank and the inner tank. 8. The method of claim 7,
The actuator is a method of reinforcing a liquefied gas tank using an inner tank flotation, characterized in that it is a hydraulic actuator that expands when pressurized oil is supplied. 8. The method of claim 7,
The actuator installation step is,
Install a bracket on the outer surface of the inner tank,
Reinforcement method of a liquefied gas tank using an inner tank flotation, characterized in that the bracket and the bottom of the liquefied gas tank are installed so that both ends of the actuator are positioned. 8. The method of claim 7,
The actuator installation step is,
Reinforcing method of a liquefied gas tank using an inner tank flotation, characterized in that the actuator is installed at a distance around the outer periphery of the inner tank. 8. The method of claim 7,
The inner bath bottom incision step,
A method of reinforcing a liquefied gas tank using an inner tank flotation, characterized in that the bottom plate formed along the bottom circumference of the inner tank and the bottom plate positioned inside the bottom plate are separated. delete 8. The method of claim 7,
Between the inner tank floor extension step and the lower reinforcement step,
A method of reinforcing a liquefied gas tank using an inner tank flotation, comprising the step of installing a corner protection formed at a predetermined height along the inner surface of the outer wall from the floor slab and surrounded by the floor plate. 8. The method of claim 7,
The lower reinforcement step is
Laying leveling concrete below the circumference of the inner tank,
Reinforcement method of a liquefied gas tank using an inner tank flotation, characterized in that filling the inside of the leveling concrete with dry sand. 8. The method of claim 7,
The new floor installation step is a method of reinforcing a liquefied gas tank using an inner tank flotation, characterized in that bonding the new floor plate to the bottom plate formed along the bottom circumference of the inner tank.

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