JP5603906B2 - Extended spherical LNG storage tank - Google Patents

Description

  The present invention relates to an extended spherical LNG storage tank and a method of manufacturing the same, and more particularly, in a configuration of a connection tank portion that increases the LNG storage capacity, a connection portion of the connection tank portion, the upper tank portion, and the lower tank portion is slowly formed. While reducing the stress concentration applied to the connecting tank part, the LNG load is increased, and a plurality of plate pieces are welded and assembled to form a connecting tank part, thereby improving the manufacturing efficiency of the connecting tank part. The present invention relates to an extended spherical LNG storage tank that is formed thicker toward the lower portion and reduces stress concentration, and a method for manufacturing the same.

  As shown in FIG. 1, the spherical LNG storage tank 9 normally mounted on the LNG carrier 100 has the same size and secures the minimum visible distance 102 on the bow side required for the safe voyage of the LNG carrier 100. The ship's control line of sight 103 is determined by the height of the ship's cockpit 101 and the height of the spherical LNG storage tank 9 on the bow side.

  Therefore, the spherical LNG storage tank on the rear side of the spherical LNG storage tank 9 installed at the bow can be further expanded to the height of the steering line of sight 103.

  That is, when the cylindrically inserted LNG storage tank 11 extended in the height direction is disposed behind the LNG storage tank provided at the bow and is gradually disposed higher up to the ship's control line of sight 103, The LNG storage capacity can be increased as compared with the LNG carrier in which the spherical LNG storage tank 9 is arranged without change.

  FIG. 3 is a view showing a structure in which a conventional cylinder is inserted to increase the capacity of the LNG storage tank. The cylindrical insertion LNG storage tank 11 is installed to connect hemispherical upper tank part 20 and lower tank part 30 with the same radius of curvature and the upper tank part 20 and lower tank part 30 to increase the LNG storage capacity. And a support skirt 50 that is connected to the hull and supports the cylindrical insertion LNG storage tank 11 is installed according to the equator portion 45 having the edge of the cylindrical connection tank portion 40a.

  However, when the length of the cylindrical connecting tank portion 40a is excessively increased in order to increase the loading capacity, the longitudinal tank of the cylindrical connecting tank portion 40a is vertically formed to have a certain curvature. There is a problem that a stress concentration phenomenon occurs in the connection portion between the portion 20 and the lower tank portion 30 and the cylindrical connection tank portion 40a.

  The present invention was created to solve the conventional problems as described above, and slowly forms the connection part of the LNG storage tank mounted on the LNG carrier and the joint part of the upper tank part and the lower tank part. While increasing the storage capacity of the LNG storage tank, the stress concentration phenomenon applied to the joint portion is alleviated, and the connecting tank portion is combined with a plurality of plate pieces to facilitate manufacture and processing. An object of the present invention is to provide an extended spherical LNG storage tank and a method for manufacturing the same, which make the manufacturing operation quick and simple.

  In order to achieve the above object, the present invention provides an upper tank part and a lower tank part having a radius of curvature R, and a connecting tank part provided between the upper tank part and the lower tank part to increase the LNG storage capacity. In the LNG storage tank including the connection tank portion, a plurality of plate pieces having different thicknesses and a equator portion are combined, and the plate pieces become thicker from the upper tank portion side toward the lower tank portion side. Among the plate pieces having different thicknesses, the plate piece closest to the lower tank part is thicker than the lower tank part.

  The connecting tank portion extends from an arbitrary point on the center line passing through the center point of the connecting tank portion in the width direction, past the center of curvature of the upper tank portion and the lower tank portion, and is extended to the upper tank portion and the lower tank portion. It is characterized by being formed by an arc (C3) having an intersection with the arc as a start point and an end point, and a distance from the arbitrary point to the intersection as a radius of curvature R1.

  Further, the connecting tank portion is located on the arc of the lower tank portion starting from an arbitrary point located on the arc of the upper tank portion, but the end point is one point that is symmetric with the starting point. Although formed by a parabola, the inclination of the tangent to the parabola at the start point and the end point is formed by the same parabola (C3) as the inclination of the tangent to the upper tank part and the lower tank part at the same position. .

  Further, the connecting tank portion is constituted by a combination of a plurality of plate pieces or the like. The connection tank part includes a first connection part and a second connection part separated into upper and lower parts, and an equator part connected to a lower part of the second connection part and provided with a support skirt. To do.

  In addition, the connection tank part is connected to the first connection part, the third connection part and the second connection part, and the lower part of the second connection part separated into an upper part, a central part and a lower part, and an equator in which a support skirt is installed. It is comprised from a part.

  The first connection part or the second connection part has a truncated cone shape in cross section.

  The connecting tank portion may be configured to further increase in thickness toward a lower direction.

  In addition, a plurality of plate pieces are combined to produce a hemispherical upper tank portion and a lower tank portion, and a plurality of plate pieces are combined to have a larger radius of curvature than the upper tank portion and the lower tank portion. Manufacturing a part, manufacturing a support skirt that is installed in the connecting tank part and fixed to the hull to support the tank, and connecting the connecting tank part to the upper part of the lower tank part, A pipe tower is installed vertically in the center of the tank part, a support skirt is joined along the periphery of the connecting tank part, and an upper tank part is joined to the upper part of the connecting tank part. And an assembly stage that is installed so as to be connected to the main body.

  The effect of the present invention that can be expected by the above configuration and operation is that the upper tank part, the lower tank part, and the connecting tank part are slowly formed, and the thickness of the connecting tank part is further lowered toward the lower part. By configuring it to be thicker, the stress concentration applied to the connection tank part is alleviated and at the same time the LNG load is increased, and a plurality of plate pieces are welded and assembled to form a connection tank part. It is a useful invention that can be manufactured very easily.

It is a figure which shows the mounting structure of a conventional spherical tank LNG carrier, and a steering line of sight. It is a figure which shows the LNG carrier ship carrying the conventional cylindrical insertion LNG storage tank. It is a figure which shows the conventional cylindrical insertion LNG storage tank. FIG. 2 is a diagram showing an LNG storage tank according to the present invention. It is a figure which shows notionally the structure of the connection tank part of the LNG storage tank by this invention. It is a figure which shows the expansion structure of the LNG storage tank by the Example of this invention. It is a figure which shows the expansion structure of the LNG storage tank by other Examples of this invention. It is a perspective view which shows the detail of the connection tank part by one Example of this invention. It is a front view which shows the detail of the installation state of the connection tank part by one Example of this invention. It is a perspective view which shows the detail of the connection tank part by the other Example of this invention. It is a front view which shows the detail of the installation state of the connection tank part by one Example of this invention. It is a figure which shows the change of the thickness of the connection tank part by this invention. It is a figure which shows the structural strength interpretation result of the connection tank part by this invention. It is a figure which shows the installation structure of the support skirt by this invention. It is a figure which shows the process of processing the plate piece which comprises the upper tank part and lower tank part of this invention. It is a figure which shows the process of a cover of the upper tank part and lower tank part of this invention. It is a figure which shows the process of a connection tank part using this invention. It is a figure which shows the process of a connection tank part using this invention. It is a figure which shows the assembly process of the LNG storage tank of this invention.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the configuration and operation of embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 4 is a view showing an LNG storage tank according to the present invention. An extended spherical LNG storage tank 10 according to an embodiment of the present invention includes an upper tank portion 20 and a lower tank portion 30 having a radius R formed by an arc, and larger than the radius R. As a circular arc having a radius, the upper tank is connected to the outer surface of the spherical surface of the upper tank portion 20 by welding, and the lower tank portion 30 is connected to the outer surface of the lower tank by welding and the lower portion of the connecting tank portion 40 is installed. The support skirt 50 is connected to the equator portion 45 and supports the extended spherical LNG storage tank 10 on the hull.

FIG. 5 is a diagram conceptually showing the structure of the connecting tank part of the LNG storage tank according to the present invention. The connecting tank part 40 circumscribes two circles (C1, C2) forming the upper tank part 20 and the lower tank part 30. The upper tank part 20 and the lower tank part 30 are connected to each other and formed according to an arc or a parabola (C3).

  As described above, the connecting portion of the connecting tank portion 40, the upper tank portion 20 and the lower tank portion 30 is configured to be sluggish so that the LNG load can be increased while relaxing the stress concentration applied to the connecting tank portion 40. It is a thing.

  FIG. 6 is a view showing an expanded structure of an LNG storage tank according to an embodiment of the present invention. An extended spherical LNG storage tank 10 according to an embodiment of the present invention has a radius around points 0 and 0 ′ as shown in FIG. The upper tank part 20 and the lower tank part 30 forming an arc as R, and the upper tank part 20 is welded and connected to the outside of the spherical surface of the upper tank part 20 as an arc having a radius R1 larger than the radius R, and the spherical surface of the lower tank part 30 It is comprised from the connection tank part 40 by which the lower stage is weld-connected outside.

  At this time, the connection tank unit 40 is formed at a contact point E with the upper tank unit 20 so that the inclination of the end point of the connection tank unit 40 is slowly formed as an arc like the inclination of the arc of the upper tank unit 20 at the contact point E. It is connected to the contact point G with the tank unit 30.

  That is, the tangential slope 80 of the arc of the upper tank portion 20 at the contact E is the same as the tangential slope 80 of the connection tank portion 40 and the tangential slope 80 of the connection tank portion 40. The tangential slope 80 of the arc is the same as the tangential slope 80 of the connecting tank portion 40.

  Therefore, the connecting tank portion 40 is an arc formed by the radius R1 with the point E as the start point and the point G as the end point.

  On the other hand, the radius R1 of the connecting tank portion 40 is past the center point 0 of the arc of the upper tank portion 20 from any one point J of the line segment AB that is a center line passing through the center point of the connecting tank portion 40 in the width direction. The upper tank portion 20 extends to the arc, that is, the point of contact E, and the radius R1 of the connecting tank portion 40 is a line segment JE.

  Further, the contact point G with the lower tank part 30 is located at a point symmetrical with respect to the contact point E and the line segment AB which is the center line of the connection tank part 40, so that the lower tank part 30 and the connection tank part 40 are located. Have the same tangent slope 80 on the contact G.

  On the other hand, the contact F is a symmetrical point of the contact E with respect to the line segment CD that is the central axis of the LNG storage tank 10, and the contact H is a contact that is centered on the line segment AB that is the center line in the width direction of the connection tank unit 40. This is a vertical symmetry point of F.

  Eventually, the upper tank portion 20 of the extended spherical LNG storage tank 10 has an arc EF (curvature radius R), the lower tank portion 30 has an arc GH (curvature radius R), and the connecting tank portion 40 has an arc EG (curvature radius R1) and The extended spherical LNG storage tank 10 has a circular arc FH (curvature radius R1) and is formed by mutual coupling such as the circular arc. In addition, at the points E, F, H, and G where the two arcs meet, the two arcs have the same tangent slope.

  On the other hand, FIG. 7 is a view showing an extended structure of an LNG storage tank according to another embodiment of the present invention. The connecting tank portion 40 starts from an arbitrary point S located on the arc of the upper tank portion 20 as the starting point. It is formed by a parabola whose end point is one point U on the arc of the lower tank 30 at a position symmetrical to S.

  This is because the connecting tank portion 40 appears as a parabola according to a quadratic equation. At this time, the slope 80 of the tangent to the parabola at the start point S and the end point U is the tangent to the upper tank portion 20 and the lower tank portion 30 at the same position. It is formed the same as the inclination 80, and the center line of this parabola is a line segment AB.

  In the embodiment as described above, the connecting tank part 40 is slowly connected to the upper tank part 20 and the lower tank part 30 because the tangential slopes 80 of the arcs and parabolas and the upper tank part and the lower tank part are the same. Thus, the storage capacity of the LNG storage tank can be increased, the stress concentration of the connection tank unit 40 can be reduced, and the safety of the LNG storage tank can be improved.

  Further, the support skirt 50 for fixing the extended spherical LNG storage tank 10 to the hull is connected to the equator portion 45 installed on the connection tank portion 40 so as to safely support the LNG storage tank 10 and fixed to the hull. desirable.

  FIG. 8 is a perspective view illustrating details of the connection tank portion according to the embodiment of the present invention, and FIG. 9 is a front view illustrating details of the installation state of the connection tank portion according to the embodiment of the present invention.

  The connecting tank portion 40 is configured by combining a plurality of plate pieces 44, and the vertically connecting portions such as the plate pieces 44 are configured to be located on an arc or a parabola C <b> 3 that forms the connecting tank portion 40.

  This is because a stress concentration phenomenon occurs in the longitudinal connection portion such as a plate piece in the connection tank portion 40 when it deviates on the arc or the parabola (C3).

  Such a connection tank part 40 is coupled to the lower part of the first connection part 41, the second connection part 42 and the second connection part 42 which are separated into the upper and lower parts, and the support skirt 50 is installed on the outer peripheral surface. It consists of.

  The first connecting portion 41 is configured by connecting a plurality of plate pieces 44 and the like so as to have a trapezoidal longitudinal section structure whose base is longer than the upper side, and the upper portion is connected to the bottom surface of the upper tank portion 20. The second connecting portion 42 is configured by combining a plurality of plate pieces 44 and the like so as to have a trapezoidal longitudinal cross-sectional structure that is longer than the upper side, and the upper portion is the lower portion of the first connecting portion 41. The equator portion 45 has a length corresponding to the bottom side of the second connection portion 41 and a bottom side corresponding to the upper side of the lower tank portion 30. The upper stage is coupled to the lower stage of the second connecting part 41 and the lower stage is coupled to the upper stage of the lower tank 30.

  At this time, the plate pieces 44 of the first connecting part 41 and the second connecting part 42 are welded in the lateral direction as plate pieces 44a which are bent plates having a trapezoidal shape with the central part removed, and the longitudinal section is trapezoidal. It has the shape of a truncated cone.

  In the present invention according to the embodiment, the first connecting part 41 and the second connecting part 42 are simply formed by assembling the trapezoidal plate pieces 44a having a two-dimensional curved surface shape when the connecting tank part 40 is manufactured. The first connecting part 41 and the second connecting part 42 have a trapezoidal shape in the longitudinal section, so that the LNG storage capacity is increased from the conventional cylindrical insertion LNG storage tank, and the upper tank part 20 and It is slowly connected to the lower tank part 30 and relieves stress concentration generated in the connection tank part 40.

  FIG. 10 is a perspective view illustrating details of a connection tank unit according to another embodiment of the present invention, and FIG. 11 is a front view illustrating details of the installation state of the connection tank unit according to another embodiment of the present invention. The connection tank unit 40 is configured by a combination of a plurality of plate pieces 44 and the like, and the vertical connection unit of the plate pieces 44 and the like is configured to be positioned on an arc or a parabola (C3) that forms the connection tank unit 40.

  The connecting tank part 40 is installed at the lower part of the first connecting part 41, the second connecting part 42, the third connecting part 43 and the second connecting part 42 which are separated into an upper part, a lower part and a central part, and a support skirt is connected to the outer peripheral surface. And the equator portion 45.

  The first connecting portion 41 is configured by connecting a plurality of plate pieces 44 and the like in the lateral direction so as to have a trapezoidal longitudinal cross-sectional structure whose base is longer than the upper side, and the upper portion is connected to the upper tank portion 20. Connected.

  The third connecting part 43 has a length corresponding to the bottom side of the first connecting part 41 at the upper side, and a plurality of plate pieces 44 having a length corresponding to the upper side of the second connecting part 42. It is configured to be connected and welded to the first connecting part and the second connecting part.

  The second connecting portion 42 is configured by connecting a plurality of plate pieces 44 in the side surface direction so that the upper side has a trapezoidal longitudinal cross-sectional structure whose length is longer than the bottom side, and the upper step portion is the third connecting portion 43. Bound to the bottom of

  The equator portion 45 has a length corresponding to the bottom side of the second connecting portion 42 on the upper side, a length corresponding to the upper side of the lower tank portion 30, and a plurality of plate pieces or the like combined. The upper part is connected to the lower part of the second connecting part 42 and the lower part is connected to the upper part of the lower tank part 30.

  Here, the plate pieces 44 of the first connecting portion 41 and the second connecting portion 42 are bent into a trapezoidal plate piece 44a and the like, and then welded in the lateral direction to form a truncated cone shape. The stress concentration generated in the connecting tank portion 40 is reduced by being slowly connected to the tank portion 30.

  Further, the plate piece 44 of the third connecting portion 43 is welded and joined in the lateral direction by bending a rectangular plate piece 44b and the like.

  FIG. 12 is an exemplary view showing a change in the thickness of the connecting tank part according to the present invention, and the connecting tank part 40 according to the embodiment of the present invention is formed so as to become thicker in the lower direction as shown in FIG. Is done.

  This is due to the fact that the thickness is further increased in the lower direction, taking into account the effects of load due to structural interpretation due to its own weight and cargo loading, rolling and sloshing during cargo transportation, etc. The safety of the tank is ensured.

  FIG. 13 is an exemplary diagram showing the structural strength interpretation result of the connecting tank portion according to the present invention. The LNG kinetics of the LNG stored in the LNG storage tank, and the structural strength interpretation result for the LNG, the storage tank's own weight and thermal stress. is there.

  At this time, (a) shows the structural strength interpretation result for the cylindrical structure (max 150 MPa) as in the conventional structure of the connecting tank part, and (b) shows the thickness of the connecting tank part that is configured by a cylindrical shape. This shows the structural strength interpretation result for a structure (max 81 MPa) that is thicker toward the bottom. (C) shows the structure interpretation result (max 79 MPa) of the connection tank part 40 by the Example of this invention. As shown in the figure, it can be seen that the stress concentration and the stress distribution applied to the connecting tank portion 40 show the order of (a)> (b)> (c).

  This is because the connecting tank part 40 is coupled with the upper tank part 20 and the lower tank part 30 with a gentle inclination as in the present invention, and the thickness is further increased toward the lower part, thereby relaxing the stress concentration. To be supported safely.

  On the other hand, FIG. 14 is an exemplary view showing the installation structure of the support skirt according to the present invention, and the support skirt 50 is preferably located below the second connecting portion 42 so as to secure a welding work space.

  FIG. 15 is an exemplary view showing a process of processing plate pieces constituting the upper tank portion and the lower tank portion of the present invention. FIG. 16 is an exemplary view showing a cover processing process of the upper tank portion and the lower tank portion of the present invention. FIG. 17 is an exemplary view showing a process of processing the connecting tank portion using the present invention. FIG. 18 is an exemplary view showing a process of processing the connecting tank portion using the present invention.

  The extended spherical LNG storage tank 10 of the present invention combines a plurality of plate pieces 44 to produce an upper tank portion 20 and a lower tank portion 30, and also combines a plurality of plate pieces 44 to form an upper tank portion 20 and a lower tank portion. After manufacturing the connecting tank portion 40 having a larger radius of curvature than 30 and further manufacturing the support skirt 50 installed on the connecting tank portion 40 and fixed to the hull, the connecting tank portion 40 is formed above the lower tank portion 30. The pipe tower 60 is vertically installed at the center of the lower tank part 30, the support skirt 50 is connected around the connection tank part 40, and the upper tank part 20 is connected to the upper part of the connection tank part 40. However, the pipe tower 60 is installed and assembled so that the upper part of the pipe tower 60 is connected to the upper part of the upper tank part 20.

  Here, the upper tank portion 20 is a trapezoidal shape in which a plate piece 48, which is a fan-shaped bent plate from which the central portion is deleted, is bent and joined in the lateral direction so that the bottom is a trapezoid whose length is longer than the upper side. A large number of frustoconical upper tank assemblies 21 having a vertical cross section are formed and connected, and a cover 22 having the same radius of curvature as the upper tank assembly 21 is provided on the upper tank assembly 21 for assembly. It is done.

  Further, the lower tank portion 30 is formed by bending plate pieces 48 and connecting them in the lateral direction to form a plurality of truncated cone-shaped lower tank assembly portions 31 having a trapezoidal longitudinal section whose upper side is longer than the bottom side. Then, the cover 22 having the same curvature as that of the lower tank assembly portion 31 is provided at the lower portion of the lower tank assembly portion 31 for assembly.

  On the other hand, the connecting tank part 40 has a trapezoidal plate piece 44a constituting the second connecting part 42 coupled to the lower part of one trapezoidal plate piece 44a constituting the first connecting part 41 as shown in FIG. One of the plate pieces of the equator portion 45 where the support skirt 50 is installed is vertically connected to the lower part of the trapezoidal plate piece 44a constituting the second connecting portion 42 to form the first connecting tank assembly portion 46. After the plurality of first connection tank assembly parts 46 are assembled by the above-described method, the first connection tank assembly parts 46 are welded and joined in the lateral direction.

  In addition, as shown in FIG. 18, the connection tank portion 40 includes one of the rectangular plate pieces 44 b constituting the third connection portion 43 below the one trapezoidal plate piece 44 a constituting the first connection portion 41. The trapezoidal plate piece 44a of the second connecting portion 42 corresponding to the trapezoidal plate piece 44a of the first connecting portion 41 is connected to the lower portion of the third connecting portion 43, and the second connecting portion 42 is connected. The plate pieces of the equator portion 45 provided with the support skirt 50 at the lower part of the plate piece 44a having the trapezoidal shape are vertically connected to form the second connection tank assembly portion 47, and the plurality of second connection portions are formed by the above-described method. After the tank assembly portion 47 is manufactured, the second connecting tank assembly portion 47 is joined by welding in the side surface direction.

  FIG. 19 is an exemplary view showing an assembly process of the LNG storage tank of the present invention. A connecting tank portion 40 is installed on the upper part of the lower tank portion 30 that is assembled in advance and placed in the dock, and a pipe tower 60 is installed vertically in the center of the lower tank portion 30, and a support skirt according to the periphery of the connecting tank portion 40. 50 is installed and the upper tank part 20 is coupled to the upper part of the connecting tank part 40, but the assembly is completed by installing the upper part of the pipe tower 60 to be connected to the upper part of the upper tank part 20.

  The present invention is not limited to the specific preferred embodiments described above, and various modifications can be made by anyone having ordinary knowledge in the technical field to which the invention belongs without departing from the spirit of the present invention claimed in the claims. Of course, such modifications are within the scope of the claims.

DESCRIPTION OF SYMBOLS 10 Extended spherical LNG storage tank 11 Cylindrical insertion LNG storage tank 20 Upper tank part 21 Upper tank assembly part 22 Cover 30 Lower tank part 31 Lower tank assembly part 40 Connection tank part 40a Cylindrical connection tank part 41 1st connection part 42 1st 2 connection part 43 3rd connection part 44, 48 plate piece 44a trapezoidal plate piece 44b square plate piece 45 equatorial part 46 first connection tank assembly part 47 second connection tank assembly part 50 support skirt 60 pipe tower 70 dock 80 Tangential slope 100 LNG carrier 101 Vessel cockpit 102 Visible distance 103 Control line of sight

Claims (5)

In an LNG storage tank comprising an upper tank part and a lower tank part having a radius of curvature R, and a connecting tank part provided between the upper tank part and the lower tank part to expand the LNG storage capacity.
The connecting tank part has two circles (C1, C2) forming an upper tank part and a lower tank part.
Formed by an arc or a parabola (C3) circumscribing
The connection tank portion is configured by combining a plurality of plate pieces and equator portions having different thicknesses, and the plate pieces are combined so as to increase in thickness from the upper tank portion side to the lower tank portion side,
Of the plurality of plate pieces having different thicknesses, the plate piece coupled closest to the lower tank part is thicker than the lower tank part,
The connection tank portion includes a first connection portion and a second connection portion which are separated into upper and lower portions, and an equatorial portion which is coupled to a lower portion of the second connection portion and is provided with a support skirt. Spherical LNG storage tank. In an LNG storage tank comprising an upper tank part and a lower tank part having a radius of curvature R, and a connecting tank part provided between the upper tank part and the lower tank part to expand the LNG storage capacity.
The connecting tank part has two circles (C1, C2) forming an upper tank part and a lower tank part.
Formed by an arc or a parabola (C3) circumscribing
The connection tank portion is configured by combining a plurality of plate pieces and equator portions having different thicknesses, and the plate pieces are combined so as to increase in thickness from the upper tank portion side to the lower tank portion side,
Of the plurality of plate pieces having different thicknesses, the plate piece coupled closest to the lower tank part is thicker than the lower tank part,
The connection tank part includes an upper part, a first connection part separated into a central part and a lower part, a third connection part and a second connection part, and an equator part connected to a lower part of the second connection part and having a support skirt. An extended spherical LNG storage tank characterized by comprising: In the first connecting portion, a plurality of plate pieces having a trapezoidal vertical cross-sectional structure whose base is longer than the top are combined in the side surface direction,
3. The extension according to claim 1, wherein the second connecting portion includes a plurality of plate pieces having a trapezoidal longitudinal cross-sectional structure whose upper side is longer than the bottom side and coupled in the side surface direction. Spherical LNG storage tank. Combining a plurality of plate pieces to produce a hemispherical upper tank portion and lower tank portion;
Combining a plurality of plate pieces having different thicknesses and an equator portion to produce a connecting tank portion having a larger radius of curvature than the upper tank portion and the lower tank portion;
Producing a support skirt for supporting the tank by being installed at the equator of the connecting tank and being fixed to the hull;
A connecting tank part is connected to the upper part of the lower tank part, a pipe tower is installed vertically in the center of the lower tank part, a support skirt is connected around the connecting tank part, and an upper part of the connecting tank part An assembly step of connecting an upper tank part to the upper tank part and connecting the pipe tower to an upper stage part of the upper tank part,
The step of manufacturing the connecting tank part includes:
Coupling the plate piece constituting the second connecting part to the lower part of the plate piece constituting the first connecting part;
Look including a coupling a plate piece of the equatorial portion of the support skirt is installed at the bottom of the plate pieces constituting the second connecting portion,
A method of manufacturing an extended spherical LNG storage tank , wherein a plurality of plate pieces having different thicknesses forming the connection tank portion are joined so as to increase in thickness from the upper tank portion side toward the lower tank portion side . The plate piece constituting the first connecting portion has a trapezoidal longitudinal cross-sectional structure whose base is longer than the top.
5. The method for manufacturing an extended spherical LNG storage tank according to claim 4, wherein the plate piece constituting the second connecting portion has a trapezoidal longitudinal cross-sectional structure having a longer top side than a bottom side.