JP6497936B2 - Nozzle reinforcement structure for low temperature storage tank - Google Patents

Description

  The present invention relates to a nozzle reinforcing structure for a low temperature storage tank.

  For example, a ground type LNG tank that is a low temperature storage tank has an inner tank, an outer tank, a PC liquid barrier, and a heat insulating material (such as foamed concrete or pearlite) filled between the inner tank and the outer tank, A plurality of nozzles (tube members) for filling and dispensing LNG to and from the LNG tank are attached so as to penetrate the inner tank roof and the outer tank roof.

Patent Document 1 describes a low-temperature storage tank having a parallel-shrink type membrane structure. In this low-temperature storage tank, a plurality of nozzles through which the nozzle penetrates the roof portion and the membrane structure from the viewpoint of ensuring the strength and airtightness of the membrane structure. The penetrating portion is disposed so as to satisfy a predetermined condition for corrugation of the membrane structure.
A plurality of nozzles extend upward through the inner tank roof and the outer tank roof, and then extend in the horizontal direction. Since external force due to wind load, seismic load and thermal contraction / expansion acts on the nozzle, and a torsional moment due to these external forces also acts, in the nozzle penetration part where the nozzle penetrates the inner tank roof, The nozzle is connected to the inner tank frame structure and the knuckle plate through the nozzle reinforcing structure.

  FIG. 6 is a diagram illustrating an example of a nozzle penetration portion 100 and a nozzle reinforcement structure 101 of a conventional LNG tank. The inner tank roof 200 includes an inner tank roof plate 201, an inner tank frame structure 202 joined to the inner tank roof plate 201, and a knuckle plate 203 on the outer peripheral side of the inner tank frame structure 202. 202 includes a plurality of arch rafter members 204, a plurality of ring members (not shown), and a circumferential reinforcing member 205.

  The nozzle penetrating portion 100 is provided in a rectangular region surrounded by a pair of arch rafter members 204, a circumferential reinforcing member 205, and a knuckle plate 203. The arch rafter member 204, the ring member, and the circumferential reinforcing member 205 are made of H-shaped steel having a pair of upper and lower flanges and a vertical web. The nozzle reinforcing structure 101 includes a pair of reinforcing members made of a steel member having an inverted T-shaped cross section that connects one annular flange member 104 fixed to the nozzle 103 and a pair of arch rafter members 204 to the flange member 104. The bone 105, the same reinforcing bone 106 that connects the flange member 104 to the circumferential reinforcing member 205, and the same reinforcing bone 107 that connects the flange member 104 to the nack plate 203 are included.

  The pair of reinforcing bones 105 are disposed in the circumferential direction, and are joined to the center of the span between the cross joint 206 and the cross joint 207. The reinforcing bone 106 is disposed in the radial direction, and is joined to the center portion of the span between the cross-shaped joint 206 and the cross-shaped joint 206.

JP 2003-287198 A

  In the nozzle reinforcing structure 101 shown in FIG. 6, the ends of the reinforcing bones 105 are joined to the center portion of the span of the arch rafter member. Therefore, for example, when an external force F acts on the nozzle 103, A bending moment acts on the circumferential reinforcing member 205 and a bending moment acts on the reinforcing bone 105. Similarly, when an external force perpendicular to the external force F acts on the nozzle, a bending moment acts on the pair of arch rafter members 204 and the circumferential reinforcing member 205, and a bending moment also acts on the reinforcing bones 106 and 107. When a torsional moment M acts on the nozzle 103, the torsional moment M disperses the bending moment at the center of the span where the ends of the reinforcing bones 105, 105, 106, 107 are joined. Is transmitted.

For this reason, the load conditions of the arch rafter member, the circumferential reinforcing member and the reinforcing bone become stricter. Therefore, in order to increase the rigidity and strength of the arch rafter member, the circumferential reinforcing member and the reinforcing bone, the size and thickness of these members are increased. Because it has to be, the production cost becomes expensive.
This invention is providing the nozzle auxiliary | assistant structure of the low temperature storage tank which can ease the load conditions of an arch rafter member, a circumferential direction reinforcement member, and a reinforcement bone.

The nozzle reinforcement structure for a low temperature storage tank according to claim 1 is a nozzle that penetrates the roof of the low temperature storage tank and extends vertically to the vicinity of the bottom, and is fixed to the roof for loading and discharging liquefied natural gas. In the nozzle reinforcing structure, a nozzle fixing frame part constituted by two radial fixing members extending in the radial direction and two circumferential fixing members extending in the circumferential direction on the roof, and an inner space of the nozzle fixing frame part are arranged. A flange member provided and fixed to the nozzle, and at least three of the four cross-shaped joints in which the two radial fixing members and the two circumferential fixing members are joined in a cross shape. And a plurality of reinforcing bones fixedly connected to the two intersecting joints.

  The nozzle reinforcing structure for a low temperature storage tank according to claim 2 is the invention according to claim 1, wherein the radial direction fixing member is an arch rafter member of an inner tank roof, and one circumferential direction fixing member is a circumferential direction reinforcing member of the inner tank roof. And one circumferential fixing member is a knuckle plate, and four reinforcing bones are provided as a plurality of reinforcing bones.

  The nozzle reinforcing structure for a low temperature storage tank according to claim 3 is the invention of claim 1 or 2, wherein the radial direction fixing member and the circumferential direction fixing member are each made of H-shaped steel having a pair of upper and lower flanges, The end is fastened with a plurality of bolts to a bracket joined to the cross joint.

According to the first aspect of the present invention, the nozzle fixing frame portion constituted by the two radial fixing members extending in the radial direction and the two circumferential fixing members extending in the circumferential direction on the roof, and the inner space of the nozzle fixing frame portion And a flange member fixed to a nozzle provided for loading and discharging liquefied natural gas, and the flange member, the two radial fixing members and the two circumferential fixing members are joined in a cross shape. A plurality of reinforcing bones fixedly connected to at least three of the four crossed joints formed, so that when an external force acts on the nozzle, the plurality of reinforcing bones are generated. It is transmitted to the cross-shaped joint portion of the nozzle fixing frame portion via an axial force. Since the bending moment due to the external force acting on the nozzle does not occur in this way, the load conditions of the radial direction fixing member, circumferential direction fixing member and reinforcing bone are remarkably eased, which is advantageous in terms of rigidity and strength. , Production costs can be reduced.

  When a torsional moment is applied to the nozzle, the torsional moment is dispersively transmitted to at least three crossed joints. However, since the crossed joints have sufficient rigidity and strength, There is no need for a structure that takes into account the twisting moment.

  According to invention of Claim 2, the said radial direction fixing member consists of the arch rafter member of an inner tank roof, and one circumferential direction fixing member consists of the circumferential direction reinforcement member of an inner tank roof, and one circumferential direction fixing member is Since it is composed of a knuckle plate and four reinforcing bones are provided as a plurality of reinforcing bones, the nozzle fixing frame portion is configured by the arch rafter member, the circumferential reinforcing member, and the knuckle plate, and the nozzle is strengthened by the four reinforcing bones. Can be reinforced.

  According to invention of Claim 3, the said radial direction fixing member and the circumferential direction fixing member are each comprised with the H-shaped steel which has a pair of upper and lower flanges, and the edge part of the said reinforcement bone is joined to the said cross-shaped junction part. Since it is fastened to the bracket with a plurality of bolts, it is possible to shorten the construction period when manufacturing the nozzle reinforcing structure.

It is sectional drawing of the ground type LNG tank concerning the Example of this invention. It is a bottom view of the principal part of the inner tank roof of an LNG tank. It is a bottom view of the principal part of an inner tank roof, and a nozzle reinforcement structure. It is a bottom view which shows the bracket of the nozzle reinforcement structure of FIG. It is a bottom view of the principal part of an inner tank roof, and a nozzle reinforcement structure. FIG. 6 is a view corresponding to FIG. 5 according to the prior art.

  EMBODIMENT OF THE INVENTION The form for implementing this invention is demonstrated based on an Example.

  As shown in FIG. 1, a ground type LNG tank 1, which is a low temperature storage tank, includes an inner tank 2, an outer tank 3, a PC liquid barrier 4, a heat insulating material 5 (foamed concrete) between the inner tank bottom plate 2a and the outer tank bottom plate 3a. The space between the inner tank side plate 2b and the outer tank side plate 3b and the powdery heat insulating material 6 (pearlite) filled in the space between the inner tank roof 2c and the outer tank roof 3c are provided.

In this LNG tank 1, a plurality of nozzles 10 for loading and discharging LNG are provided in a state of extending vertically through the inner tank roof 2c and the outer tank roof 3c to the vicinity of the bottom.
The lower part of the nozzle 10 is fixed to the inner tank side plate 2b by a V-shaped support member 11 in plan view, and the metal that is externally fitted to the nozzle 10 and joined to the nozzle 10 and the outer tank roof 3c outside the outer tank roof 3c. A cylindrical member 12 with a bellows is provided.

  FIG. 2 is a bottom view of the eight nozzle penetrating parts 13 through which the nozzles 10 penetrate the inner tank roof 2 in the vertical direction and the inner tank roof part in the vicinity thereof. As shown in FIG. The inner tank roof frame structure 20, the inner tank roof plate 14 on the upper surface of the inner tank roof frame structure 20, and the knuckle plate 15 (see FIG. 1) on the outer peripheral side of the inner tank roof frame structure 20. The inner tub roof frame structure 20 includes a plurality of arch rafter members 21 extending in the radial direction, a plurality of ring members 22 extending in the circumferential direction, and a circumferential reinforcing member 23.

  The nozzle penetration portion 13 is an inner space of a substantially rectangular nozzle fixing frame portion 24 composed of two radial fixing members 21A extending in the radial direction and two circumferential fixing members 23A, 15A extending in the circumferential direction. It is arranged at the center. Each of the radial direction fixing members 21 </ b> A is composed of the arch rafter member 21, one circumferential direction fixing member 23 </ b> A is composed of the circumferential direction reinforcing member 23, and one circumferential direction fixing member 15 </ b> A is composed of the knuckle plate 15.

The arch rafter member 21, the circumferential reinforcing member 23, and the ring member 22 are all made of H-shaped steel having a pair of upper and lower flanges and a vertical web.
The arch rafter member 21 as the radial direction fixing member 21 </ b> A is configured as a member having higher rigidity than the other arch rafter members 21, and the circumferential direction fixing member 23 </ b> A is configured on the inner peripheral side of the plurality of nozzle penetration portions 13. For this purpose, a highly rigid circumferential reinforcing member 23 is provided.

Next, the nozzle reinforcement structure 30 that reinforces the nozzle 10 in the nozzle penetration portion 13 will be described. As shown in FIGS. 3 to 5, the nozzle reinforcing structure 30 includes the nozzle fixing frame portion 24 and a pair of upper and lower annular flanges fixed to the nozzle 10 in an outer fitting manner in the inner space of the nozzle fixing frame portion 24. A member 31 and four reinforcing bones 32 and 33 that reinforce the nozzle 10 are provided.
These reinforcing bones 32 and 33 are arranged on a diagonal line of the nozzle fixing frame portion 24. The upper and lower flange members 31 are provided at the same height as the upper and lower flanges 21a of the radial fixing member 21A. The upper and lower flanges 32a and 33a of the reinforcing bones 32 and 33 are the same as the upper and lower flanges 21a of the radial fixing member 21A. It is provided at the same height position. The upper and lower flanges 21a of the radial fixing member 21A are provided at the same height as the upper and lower flanges 23a of the circumferential fixing member 23A.

  The inner end portion 32b of the reinforcing bone 32 is bolted or welded to the upper and lower flange members 31, and the outer end portion 32c is a cross shape in which the radial direction fixing member 21A and the circumferential direction fixing member 23A are joined in a cross shape. It is fixed to the joint portion 25. The inner end 33b of the reinforcing bone 33 is bolted or welded to the upper and lower flange members 31, and the outer end 33c is joined to the radial fixing member 21A and the circumferential fixing member 15A in a crossing manner. It is fixed to the part 26.

  The reinforcing bones 32 and 33 are each made of an H-shaped steel having a pair of upper and lower flanges 32a and 33a and a vertical web. A pair of upper and lower brackets 34 are joined to the intersecting joint portion 25 so as to protrude into the inner space of the nozzle fixing frame portion 24, and a pair of upper and lower brackets 35 are also joined to the intersecting joint portion 26. It joins so that it may protrude to 24 inner space. The upper surfaces of the upper and lower brackets 34 are at the same height as the lower surfaces of the upper and lower flanges 21a and 23a, and the upper surfaces of the upper and lower brackets 35 are at the same height as the lower surfaces of the upper and lower flanges 21a.

  The ends of the pair of upper and lower flanges 32 a corresponding to the outer end 32 c of the reinforcing bone 32 are fastened to the pair of upper and lower brackets 34 of the intersecting joint 25 by a plurality of bolts 36. The ends of the pair of upper and lower flanges 33 a corresponding to the end 33 c are fastened to the pair of upper and lower brackets 35 of the intersecting joint 26 by a plurality of bolts 37.

Next, the operation and effect of the nozzle reinforcing structure 30 described above will be described.
The reinforcing bones 32 and 33 are disposed on the diagonal line of the nozzle fixing frame portion 24, the inner end portion 32 b of the reinforcing bone 32 is joined to the upper and lower flange members 31, and the outer end portion 32 c intersects with the bracket 34. 3 because the inner end portion 33b of the reinforcing bone 33 is bonded to the upper and lower flange members 31 and the outer end portion 33c is fixed to the intersecting joint portion 26 via the bracket 35. When the external force G as shown in FIG. 6 is applied in any direction, only the axial force acts on the reinforcing bones 32 and 33 as in the truss structure, and the radial direction fixing member 21A, the circumferential direction fixing member 23A, Since no bending moment acts on the reinforcing bones 32 and 33, the load conditions of these members can be remarkably reduced, and the size and thickness of these members can be reduced compared to those of the prior art, Production cost Is advantageous.

  Further, even when a torsional moment T acts on the nozzle 10, it is dispersively transmitted to the two cross joints 25 and the two cross joints 26 through the reinforcing bones 32 and 33. Since the joints 25 and 26 have sufficiently high rigidity, it is not necessary to reinforce the cross joints 25 and 26 against the torsional moment T.

  In addition, since the outer ends 32c and 33c of the reinforcing bones 32 and 33 are bolted to the corresponding brackets 34 and 35, the work period can be shortened compared to welding.

Next, an example in which the above embodiment is partially changed will be described.
1) Instead of the pair of upper and lower flange members 31, it is also possible to provide one flange member above or below. In this case, as the reinforcing bones 32 and 33, steel members having a T-shaped section or an inverted T-shaped section having a flange portion at substantially the same level as the flange member may be employed.

2) In the above embodiment, the four reinforcing bones 32 and 33 are provided. However, at least three reinforcing bones may be provided. In that case, three reinforcing bones can be arranged in a form in which any one of the four reinforcing bones 32 and 33 is omitted.
3) In addition, those skilled in the art can implement the invention in a form in which a partial change is added to the above embodiment, and the present invention includes such a change form.

DESCRIPTION OF SYMBOLS 1 LNG tank 2c Inner tank roof 3c Outer tank roof 10 Nozzle 13 Nozzle penetration part 15 Knuckle plate 15A Circumferential direction fixing member 21 Arch rafter member 21A Radial direction fixing member 21a Flange 23 Circumferential reinforcement member 23A Circumferential direction fixing member 23a Flange 24 Nozzle Fixed frame portion 25 Cross-shaped joint portion 26 Cross-shaped joint portion 30 Nozzle reinforcement structure 31 Flange members 32, 33 Reinforcement bones 32a, 33a Flange 32b, 33b Inner end portions 32c, 33c Outer end portions 34, 35 Bracket

Claims (3)

In the nozzle reinforcement structure that fixes the nozzle provided for loading and discharging the liquefied natural gas through the roof of the low temperature storage tank vertically extending to the vicinity of the bottom,
A nozzle fixing frame portion composed of two radial fixing members extending in the radial direction on the roof and two circumferential fixing members extending in the circumferential direction;
A flange member disposed in the inner space of the nozzle fixing frame and fixed to the nozzle;
A plurality of flange members fixedly connected to at least three cross-shaped joints among four cross-shaped joints in which the two radial fixing members and the two circumferential fixing members are joined in a cross shape. A nozzle reinforcement structure for a low temperature storage tank, comprising a reinforcing bone.  The radial fixing member is an inner tank roof arch rafter member, one circumferential fixing member is an inner tank roof circumferential reinforcing member, one circumferential fixing member is a knuckle plate, and a plurality of reinforcing bones The nozzle reinforcing structure for a cryogenic storage tank according to claim 1, wherein four reinforcing bones are provided.   The radial fixing member and the circumferential fixing member are each made of H-shaped steel having a pair of upper and lower flanges, and the end portions of the reinforcing bones are fastened with a plurality of bolts to a bracket joined to the intersecting joint portion. The nozzle reinforcing structure for a low-temperature storage tank according to claim 1 or 2, wherein