Ship

Abstract

A ship is provided with: a hull; the skirt part is arranged on the ship body and is in a cylindrical shape with an upward opening; a spherical tank serving as a high-pressure tank, the lower half part of the spherical tank being accommodated in the skirt part; a ring-shaped connecting member provided so as to surround the spherical tank from the outer peripheral side above the skirt section; a first welded portion that fixes the inner peripheral portion of the connecting member and the outer surface of the spherical tank to each other; and a second welded portion connecting the lower portion of the connecting member and the upper end of the skirt portion to each other.

Description

Technical Field

[0001] The present invention relates to ships.

[0002] This application claims priority from Japanese Patent Application No. 2022-124764 filed in Japan on August 4, 2022, and the contents are incorporated herein by reference. Background Art

[0003] Patent document 1 discloses a ship having a support structure for supporting an independent spherical tank. The support structure comprises: a cylindrical skirt that surrounds the lower half of the tank and supports the tank; and a joint that constitutes a part of the peripheral wall of the tank, and the upper end of the skirt is fixed to the joint. The joint has a thick wall portion having a plate thickness greater than that of the peripheral wall portion of the tank. The plate thickness of the thick wall portion is at least twice the plate thickness of the peripheral wall portion or the skirt portion of the tank.

[0004] Prior art literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-182878 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The joint is formed by cutting steel to meet strict fatigue strength requirements. There is an upper limit to the thickness of the steel that can be cut, so the joint cannot be made thicker indefinitely. In addition, as mentioned above, the thickness of the peripheral wall of the tank is limited to less than half the thickness of the thick wall. Therefore, the peripheral wall of the tank cannot be made thicker indefinitely.

[0008] However, if the tank is enlarged, the weight of the tank and the weight of the fluid stored in the tank will increase. Therefore, in order to enlarge the tank, it is necessary to design the peripheral wall of the tank to be thicker in order to support the increased weight. However, as described above, in the technology described in Patent Document 1, it is impossible to make the peripheral wall of the tank thicker indefinitely. Thus, there are strict restrictions on the enlargement of the tank, and it becomes difficult to enlarge the tank.

[0009] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a ship capable of alleviating the restriction on the enlargement of a storage tank.

[0010] Means for solving problems

[0011] In order to solve the above-mentioned problems, the ship of the present invention comprises: a hull; a skirt, which is arranged on the above-mentioned hull and is in the shape of a cylinder opening upward; a spherical tank as a high-pressure tank, the lower half of the above-mentioned spherical tank being accommodated in the above-mentioned skirt; a connecting member, which is arranged in a ring shape in a manner of surrounding the above-mentioned spherical tank from the outer peripheral side at a position higher than the above-mentioned skirt; a first welding portion, which fixes the inner peripheral portion of the above-mentioned connecting member and the outer surface of the above-mentioned spherical tank to each other; and a second welding portion, which connects the lower portion of the above-mentioned connecting member and the upper end of the above-mentioned skirt to each other.

[0012] Effects of the Invention

[0013] According to the ship of the present invention, it is possible to alleviate the restriction on the enlargement of the tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a plan view showing the overall structure of a ship according to the first embodiment of the present invention.

[0015] Figure 2 This is a vertical cross-sectional view of the spherical tank according to the first embodiment of the present invention, which is perpendicular to the bow and stern direction and passes through the center point of the spherical tank.

[0016] Figure 3 This is a vertical cross-sectional view showing the upper end of the skirt portion according to the first embodiment of the present invention, taken in the up-down direction perpendicular to the bow and stern direction.

[0017] Figure 4 This is a plan view of the connecting member according to the first embodiment of the present invention as seen from the top and bottom.

[0018] Figure 5 It is a diagram for explaining the process of forming the connecting member according to the first embodiment of the present invention.

[0019] Figure 6 It is a vertical cross-sectional view in the up-down direction orthogonal to the bow and stern direction of a connecting member showing a second embodiment of the present invention. DETAILED DESCRIPTION

[0020] <First embodiment>

[0021] (Ship)

[0022] Below, refer to Figures 1 to 5 A ship 1 according to a first embodiment of the present invention will be described.

[0023] like Figure 1 , Figure 2 As shown, the ship 1 stores and transports liquefied gas such as liquefied natural gas. The ship 1 includes a hull 2, a skirt 10, a spherical tank 20, a connecting member 30, a first weld 40, a second weld 50, and a tank cover 60.

[0024] Hereinafter, the bow and stern direction Da of the ship 1 is referred to as "the bow and stern direction Da", and the ship width direction Dw of the ship 1 is referred to as "the ship width direction Dw". Both the bow and stern direction Da and the ship width direction Dw intersect the up-down direction substantially perpendicularly. The bow and stern direction Da and the ship width direction Dw are orthogonal to each other.

[0025] (Hull)

[0026] The hull 2 ​​has: a pair of sides 3, a bottom 4 and an upper deck 5. The pair of sides 3, the bottom 4 and the upper deck 5 constitute the outer shell of the hull 2. The sides 3 have a pair of side outer plates that form the left and right sides 3, respectively. The bottom 4 has a bottom outer plate that connects these sides 3. Through the pair of sides 3 and the bottom 4, the outer shell of the hull 2 ​​is U-shaped in a cross section orthogonal to the bow and stern direction Da. The upper deck 5 is a full-through deck exposed to the outside. In the hull 2, an upper structure 6 having a living area is formed on the upper deck 5 on the stern 2b side.

[0027] In the hull 2, a plurality of cargo loading sections 7 (cargo holds) are formed on the bow 2a side of the superstructure 6. The plurality of cargo loading sections 7 are arranged in a row in the bow and tail direction Da. The cargo loading area 7 is recessed toward the bottom 4 below the upper deck 5 and is open upward.

[0028] (Skirt)

[0029] One skirt 10 is provided in each cargo loading section 7 on the hull 2 ​​.

[0030] like Figure 2 , Figure 3 As shown in FIG. 1 , the skirt 10 is in the shape of a cylinder that opens upward. Hereinafter, the radial direction Dr of the skirt 10 is sometimes referred to as “radial direction Dr”, and the circumferential direction of the skirt 10 is sometimes referred to as “circumferential direction”. In addition, regarding each structure, the central axis O side of the skirt 10 in the radial direction Dr is referred to as “inner circumferential side”, and the side opposite to the central axis O of the skirt 10 in the radial direction Dr is referred to as “outer circumferential side”.

[0031] The upper part of the skirt 10 is formed of a steel material for low temperature use. The lower part of the skirt 10 is formed of a steel material for normal temperature use, such as a deck. For example, 1 / 3 of the skirt 10 from the upper part is formed of a steel material for low temperature use, and 2 / 3 of the skirt 10 from the lower part is formed of a steel material for normal temperature use. In addition, the material of the skirt 10 is not limited to such a case, and as the material of the skirt 10, steel materials for low temperature use and steel materials for normal temperature use can be appropriately selected. For example, the lower part of the skirt 10 can also be formed of a steel material for low temperature use.

[0032] An upper surface 11 a of the upper end 11 of the skirt portion 10 is gradually inclined so as to be located downward as approaching the outer peripheral side.

[0033] (Spherical tank)

[0034] One spherical tank 20 is supported on each skirt 10. The spherical tank 20 is a high-pressure tank (pressure vessel) for storing high-pressure and low-temperature liquefied gas. For example, liquefied natural gas is stored in the spherical tank 20. The type of the spherical tank 20 is, for example, an independent type IMO Type-C that does not require a secondary wall and is defined as a standard of the IMO (International Marite Organizaition: International Maritime Organization).

[0035] The spherical tank 20 has a tank partition 21. The tank partition 21 is a so-called peripheral wall portion of the spherical tank 20. The tank partition 21 is formed into a spherical shape. In addition, the spherical shape of the tank partition 21 is not limited to a spherical shape having a constant radius of curvature, and includes, for example, a spherical shape other than a spherical shape, such as a flat spherical shape whose dimensions in the up-down direction are different from those in the radial direction Dr. A heat insulating material (not shown) is provided on the outer surface of the tank partition 21 as needed to suppress heat input from the outside.

[0036] Hereinafter, in the present embodiment, a large edge portion where a plane passing through the center point C of the tank bulkhead 21 and extending in the bow and stern direction Da and the ship width direction Dw intersects with the outer surface of the tank bulkhead 21 is referred to as the equator 22 .

[0037] The tank partition 21 has a lower half 23 and an upper half 24 .

[0038] The lower half 23 is accommodated in the skirt 10. The lower half 23 is formed in a hemispherical shape. The dimension of the lower half 23 in the radial direction Dr gradually increases as it approaches from the bottom to the top. The lower half 23 is separated from the skirt 10. A space is ensured between the lower half 23 and the skirt 10 for operations such as grinding and welding.

[0039] The upper half 24 is disposed above the lower half 23. The upper half 24 is formed into a hemispherical shape. The dimension of the upper half 24 in the radial direction Dr gradually decreases as it approaches from the bottom to the top. The upper half 24 and the lower half 23 are integrated into a spherical shape. The boundary between the upper half 24 and the lower half 23 is located near the equator 22.

[0040] (Connecting parts)

[0041] like Figures 2 to 4 As shown, the connecting member 30 is provided above the skirt 10. The connecting member 30 is provided in a ring shape so as to surround the spherical tank 20 from the outer peripheral side. The connecting member 30 surrounds the equator 22 of the tank bulkhead 21. The connecting member 30 is provided so as to extend from the tank bulkhead 21 to the outer peripheral side. The connecting member 30 has a plurality of connecting blocks 31.

[0042] (Connection Block)

[0043] A plurality of connecting blocks 31 are arranged in a circumferential direction on the outer peripheral side of the spherical tank 20. The connecting blocks 31 adjacent to each other in the circumferential direction are connected by welding, and each connecting block 31 is fixed to the tank partition wall 21 of the spherical tank 20. In addition, each connecting block 31 is connected to the skirt 10.

[0044] The connecting block 31 is formed of a material having a higher strength than the spherical tank 20 and the skirt 10. Examples of the high-strength material forming the connecting block 31 include 9% Ni steel and the like. In addition, the connecting block 31 may be formed of the same material as the spherical tank 20 or the skirt 10. All of the connecting blocks 31 are formed in the same shape.

[0045] like Figure 3 As shown, each connection block 31 is formed in an L-shape in a cross-section perpendicular to the circumferential direction. The connection block 31 has a fixing portion 32 fixed to the tank partition wall 21 of the spherical tank 20 and a protrusion 33 protruding downward from the fixing portion 32.

[0046] (Fixed part)

[0047] The fixing portion 32 has an outer peripheral portion 32 d and an inner peripheral portion 34 .

[0048] The outer periphery 32d is in contact with Figure 3 The quadrilateral portion is formed by the upper surface 32a, the outer peripheral surface 32b and the two double-dash lines in the cross-section view perpendicular to the circumference shown. The upper surface 32a of the outer peripheral portion 32d gradually tilts downward as it approaches the outer peripheral side from the inner peripheral side. In addition, the upper surface 32a of the outer peripheral portion 32d may not be tilted. The outer peripheral surface 32b of the outer peripheral portion 32d extends in the up-down direction, specifically, extending downward from the outer peripheral edge of the upper surface 32a. In addition, Figure 3 The boundary between the outer peripheral portion 32d and the protruding portion 33 indicated by the two-dot chain line extends along the bow and stern direction Da and the ship width direction Dw. Figure 3 The boundary between the outer peripheral portion 32d and the inner peripheral portion 34 indicated by the two-dot chain line extends in the up-down direction.

[0049] The inner peripheral portion 34 is provided on the inner peripheral side of the outer peripheral portion 32d. The inner peripheral portion 34 has a shape that tapers from the outer peripheral portion 32d toward the inner peripheral side in a cross-sectional view perpendicular to the circumferential direction. More specifically, the inner peripheral portion 34 includes an upper inclined surface 34a and a lower inclined surface 34b.

[0050] The upper inclined surface 34a extends downward from the upper edge of the inner circumference of the outer circumference 32d and is inclined toward the inner circumference as it approaches downward. The upper inclined surface 34a and the outer surface 20a of the spherical tank 20 form a V-shaped upper groove 36 that opens upward and tapers toward the bottom. The upper groove 36 is formed over the entire circumference of the skirt 10.

[0051] The lower inclined surface 34b extends upward from the lower edge of the inner circumference of the outer circumference 32d and is inclined toward the inner circumference as it approaches upward. A V-shaped lower bevel 37 that opens downward and tapers toward the top is formed by the lower inclined surface 34b and the outer surface 20a of the spherical tank 20. The lower bevel 37 is also formed over the entire circumference of the skirt 10 in the same manner as the upper bevel 36.

[0052] The top 34c of the inner circumference 34 where the upper inclined surface 34a and the lower inclined surface 34b intersect is located at the innermost circumference of the inner circumference 34. In addition, the top 34c of the present embodiment is arranged at a position lower than the middle position between the upper edge of the inner circumference of the outer circumference 32d and the lower edge of the inner circumference of the outer circumference 32d, and is arranged to overlap with the equator 22 in the radial direction. The top 34c is slightly separated from the tank bulkhead 21 in the radial direction Dr. The maximum dimension L1 of the fixing portion 32 in the radial direction Dr (the dimension of the top 34c of the fixing portion 32 in the vertical direction) is larger than the thickness L2 of the tank bulkhead 21. In addition, the upper inclined surface 34a and the lower inclined surface 34b are formed into a straight line with a constant inclination when viewed in a cross section perpendicular to the circumferential direction. However, it is not limited to a straight line with a constant inclination. For example, the inclination may change in stages or be slightly curved.

[0053] (Protrusion)

[0054] The protrusion 33 is formed to protrude downward from the outer peripheral portion 32d of the fixing portion 32. The protrusion 33 has an outer peripheral surface 33b, a lower surface 33c, and an inner peripheral surface 33d. The outer peripheral surface 33b extends in the up-down direction similarly to the outer peripheral surface 32b of the fixing portion 32, and extends in a continuous manner with the outer peripheral surface 32b of the fixing portion 32. The lower surface 33c extends from the lower edge of the outer peripheral surface 33b toward the inner peripheral side and reaches the lower edge of the inner peripheral surface 33d.

[0055] The inner circumferential surface 33d includes a lower inner circumferential surface 33e extending in the vertical direction and an upper inner circumferential surface 33f extending upward from the lower inner circumferential surface 33e and curved in a concave shape so as to be located on the inner circumferential side as it approaches upward. The size of the lower portion of the protrusion 33 in the radial direction Dr is equal to the size of the upper portion of the skirt 10 in the radial direction Dr, and is smaller than the size of the fixing portion 32 in the radial direction Dr. The inner circumferential surface 33d of the protrusion 33 is smoothly connected to the lower surface 32c of the fixing portion 32 via the upper inner circumferential surface 33f.

[0056] (First welding part)

[0057] The first welding portion 40 is provided between the connecting member 30 and the spherical tank 20. The connecting member 30 is welded to the spherical tank 20 without gaps over the entire circumference of the spherical tank 20 by the first welding portion 40. The first welding portion 40 fixes the inner circumference 34 of the fixing portion 32 of the connecting member 30 and the outer surface 20a of the spherical tank 20 to each other. The upper and lower exposed surfaces 40a of the first welding portion 40 are curved surfaces that smoothly connect the outer surface 30a of the connecting member 30 and the outer surface 20a of the spherical tank 20. In addition, the exposed surface 40a may also be a flat surface that is linear in cross-section. The first welding portion 40 has an upper welding portion 41 and a lower welding portion 42.

[0058] (Upper side welding part)

[0059] The upper welding portion 41 connects the spherical tank 20 and the upper portion of the inner circumference 34 of the connecting member 30. The upper welding portion 41 is provided in a manner that fills the entire inner side of the upper groove 36. That is, the dimension of the upper welding portion 41 in the radial direction Dr gradually decreases as it approaches downward. The upper surface 41a of the upper welding portion 41 is the upper exposed surface 40a of the upper and lower exposed surfaces 40a of the first welding portion 40, and the upper surface 41a is a concave curved surface that is curved in a manner that is located downward as it approaches the outer circumference. The upper surface 41a smoothly connects the outer surface 20a of the spherical tank 20 and the upper surface 32a of the fixing portion 32. In addition, the upper surface 41a may also be a flat surface that is linear when viewed in section.

[0060] (Bottom welding part)

[0061] The lower welding portion 42 connects the spherical tank 20 and the lower portion of the inner peripheral portion 34 of the connecting member 30. The lower welding portion 42 is provided in a manner that fills the entire inner side of the lower groove 37. That is, the dimension of the lower welding portion 42 in the radial direction Dr gradually decreases as it approaches the upper side. The lower surface 42a of the lower welding portion 42 is the lower exposed surface 40a of the upper and lower exposed surfaces 40a of the first welding portion 40, and the lower surface 42a is a concave curved surface that is curved in a manner that is located at the upper side as it approaches the outer peripheral side. The lower surface 42a smoothly connects the outer surface 20a of the spherical tank 20 and the lower surface 32c of the fixing portion 32. In addition, the lower surface 42a may also be a flat surface that is linear when viewed in section.

[0062] In addition, the lower welded portion 42 and the upper welded portion 41 of the present embodiment are connected between the top portion 34 c and the outer surface 20 a of the spherical tank 20 .

[0063] (Second welding part)

[0064] The second welded portion 50 is provided between the connecting member 30 and the skirt 10. More specifically, the second welded portion 50 is formed so as to fill the groove formed by the lower surface 33c of the protruding portion 33 of the connecting member 30 and the upper surface 11a of the skirt 10. In other words, the size of the second welded portion 50 in the vertical direction gradually decreases as it approaches the inner peripheral side. The connecting member 30 is fixed to the upper end 11 of the skirt 10 over the entire circumference by the second welded portion 50.

[0065] (tank cover)

[0066] One tank cover 60 is provided for each spherical tank 20. The tank cover 60 covers the spherical tank 20 from above. The tank cover 60 is formed in a dome shape extending upward. The lower edge of the tank cover 60 is connected to the upper deck 5.

[0067] Alternatively, the tank cover 60 may be a single connected square cover extending in the bow and stern direction Da when viewed from the top and bottom and covering all the spherical tanks 20 from above.

[0068] (Connection method)

[0069] Next, refer to Figures 3 to 5 A method of connecting the skirt 10 and the spherical tank 20 will be described.

[0070] First, if Figure 5 As shown, the connecting member 30 is cut out from the thick plate-shaped steel material M according to the size of the skirt 10 and the spherical tank 20. At this time, the steel material M is tilted relative to the skirt 10 to minimize the amount of cutting of the steel material M. In this way, a plurality of connecting blocks 31 are formed.

[0071] The processing for forming the connection member 30 is not limited to the cutting processing described above, and the processing for forming the connection member 30 may include other processing methods such as cutting processing for cutting the steel material M. In addition, when processing the steel material M, the steel material M may not be inclined relative to the skirt portion 10 .

[0072] Then, if Figure 3 As shown, a plurality of connecting blocks 31 are welded to the entire area of ​​the equator 22 of the tank partition 21. Specifically, the upper groove 36 and the lower groove 37 between the connecting block 31 and the tank partition 21 are respectively filled with molten metal. At this time, the molten metal filling the upper groove 36 and the molten metal filling the lower groove 37 are connected through the gap between the top 34c of the connecting block 31 and the outer surface 20a of the spherical tank 20. In this way, the entire area of ​​the inner circumference 34 of the connecting block 31 in the up and down direction is welded. In addition, the plurality of connecting blocks 31 welded to the tank partition 21 are further welded and connected to each other to form an annular connecting member 30.

[0073] Next, the upper surface 41a and the lower surface 42a of the welded portion between the connecting member 30 and the tank partition 21 are ground using a grinder or the like to form concave curved surfaces. Thus, the outer surface 20a of the spherical tank 20 and the outer surface 30a of the connecting member 30 are smoothly connected via the upper and lower exposed surfaces 40a (the upper surface 41a and the lower surface 42a) of the first welding portion 40.

[0074] Next, the spherical tank 20 with the connecting member 30 attached is inserted from above into the skirt 10. Then, while the separation distance between the connecting member 30 and the skirt 10 is maintained constant, molten metal is supplied to weld the lower surface 33c of the protrusion 33 of the connecting member 30 to the upper end 11 of the skirt 10. When the molten metal solidifies, the second weld 50 is formed.

[0075] In this way, the skirt 10 and the spherical tank 20 are connected via the connecting member 30 .

[0076] Alternatively, the connecting member 30 may be welded to the upper end 11 of the skirt 10 , and then a portion of the spherical tank 20 (eg, near the equator 22 and the lower half 23 ) may be inserted into the skirt 10 from above and the connecting member 30 and the spherical tank 20 may be welded.

[0077] (Effect)

[0078] According to the ship 1 of this embodiment, the following effects can be achieved.

[0079] In this embodiment, the ship 1 includes: a hull 2, a skirt 10, a spherical tank 20, a connecting member 30, a first weld 40, and a second weld 50. The connecting member 30 is annularly provided above the skirt 10 so as to surround the spherical tank 20 from the outer peripheral side. The first weld 40 fixes the inner peripheral portion 34 of the connecting member 30 and the outer surface 20a of the spherical tank 20 to each other. The second weld 50 connects the lower portion of the connecting member 30 and the upper end 11 of the skirt 10 to each other.

[0080] In this embodiment, a spherical tank 20 (for example, an IMO Type-C tank) is used as a high-pressure tank. In this case, the vapor pressure in the spherical tank 20 becomes high pressure, and the influence of the variable load of the internal fluid becomes small. Therefore, the strength (so-called fatigue strength) against the variable load of the internal fluid is high. As a result, the outer surface 20a of the spherical tank 20 and the connecting member 30 can be welded.

[0081] In the present embodiment, the outer surface 20a of the spherical tank 20 and the connecting member 30 are fixed by the first welding portion 40. Thus, the plate thicknesses of the spherical tank 20, the skirt 10, and the connecting member 30 can be designed independently. Therefore, the plate thickness of the spherical tank 20 can be increased regardless of the plate thicknesses of the skirt 10 and the connecting member 30, so that the restriction on the enlargement of the spherical tank 20 can be alleviated. Thus, the number of spherical tanks 20 mounted on the ship 1 can be reduced. Therefore, the manufacturing cost can be greatly reduced.

[0082] In addition, since the second welding portion 50 connects the lower portion of the connecting member 30 and the upper end 11 of the skirt 10, the connecting portion between the skirt 10 and the connecting member 30 is exposed to the outside. Therefore, the skirt 10 and the connecting member 30 can be welded while confirming the connecting portion between the skirt 10 and the connecting member 30. Therefore, the welding of the skirt 10 and the connecting member 30 becomes easy.

[0083] In the present embodiment, the upper and lower exposed surfaces 40 a of the first welded portion 40 are curved surfaces that smoothly connect the outer surface 30 a of the connecting member 30 and the outer surface 20 a of the spherical tank 20 .

[0084] This can alleviate stress concentration at the fixed portion between the connecting member 30 and the spherical tank 20. Therefore, the fixing strength between the connecting member 30 and the spherical tank 20 can be improved.

[0085] In the present embodiment, the connection member 30 is formed of a material having a higher strength than the spherical tank 20 and the skirt 10 .

[0086] Thus, the strength of the connecting member 30, on which stress is easily concentrated, can be improved compared with the spherical tank 20 and the skirt 10. Therefore, the minimum strength required as the entire structure can be ensured. Thus, the spherical tank 20 can be manufactured from a cheap material having a lower strength than the connecting member 30, so that the cost can be reduced.

[0087] In the present embodiment, the connection member 30 includes a plurality of connection blocks 31 arranged in the circumferential direction, and the connection blocks 31 adjacent to each other in the circumferential direction are joined by welding.

[0088] Thus, the connection member 30 can be fixed to the spherical tank 20 by welding the plurality of connection blocks 31 after the connection blocks 31 are respectively fixed to the spherical tank 20. Thus, even when the diameter of the spherical tank 20 is large, the connection member 30 can be easily manufactured and easily fixed to the spherical tank 20.

[0089] In this embodiment, the connecting member 30 includes a fixing portion 32 fixed to the spherical tank 20 via a first welding portion 40 and a protruding portion 33 protruding downward from the fixing portion 32 and connected to the upper end 11 of the skirt 10 via a second welding portion 50 .

[0090] The fluid stored in the spherical tank 20 is swung by external forces generated by the navigation of the ship 1, etc. Therefore, stress is likely to be concentrated on the fixing portion 32 fixed to the spherical tank 20. According to the present embodiment, the connecting member 30 and the skirt 10 can be welded at a position separated from the fixing portion 32 where stress is likely to be concentrated. Therefore, stress concentration on the second welded portion 50 can be avoided.

[0091] In the present embodiment, the connecting member 30 has an upper inclined surface 34a and a lower inclined surface 34b. The upper inclined surface 34a forms an upper groove 36 that opens upward and tapers toward the bottom between the upper inclined surface 34a and the outer surface 20a of the spherical tank 20. The lower inclined surface 34b opens downward at the lower side of the upper groove 36 and forms a lower groove 37 that tapers toward the top. The first welding portion 40 has an upper welding portion 41 provided at the upper groove 36 and a lower welding portion 42 provided at the lower groove 37. The upper welding portion 41 connects the spherical tank 20 and the upper side of the inner peripheral portion 34 of the connecting member 30. The lower welding portion 42 connects the spherical tank 20 and the lower side of the inner peripheral portion 34 of the connecting member 30, and is connected to the upper welding portion 41.

[0092] According to the present embodiment, the entire region in the vertical direction of the inner peripheral portion 34 of the connecting member 30 is welded to the spherical tank 20. This can suppress the separation of the connecting member 30 and the spherical tank 20. Therefore, the strength of the welding between the connecting member 30 and the spherical tank 20 can be ensured.

[0093] <Second embodiment>

[0094] Below, refer to Figure 6 A ship 201 according to a second embodiment of the present invention will be described. The same configurations as those in the first embodiment are denoted by the same names and reference numerals, and description thereof will be omitted as appropriate.

[0095] In the present embodiment, the ship 201 further includes a baffle 70 provided at the boundary between the protrusion 33 and the skirt 10. The baffle 70 is fixed to the surfaces of the protrusion 33 and the skirt 10 on the spherical tank 20 side by the second weld 50. That is, the baffle 70 is fixed to the inner peripheral surface 33d of the protrusion 33 and the inner peripheral surface 10b of the skirt 10 by the second weld 50. The baffle 70 is separated from the tank bulkhead 21 and is located on the outer peripheral side of the tank bulkhead 21.

[0096] The size of the baffle plate 70 in the radial direction Dr is uniform in the vertical direction. The baffle plate 70 is formed in a rectangular plate shape in a cross-section perpendicular to the circumferential direction. The baffle plate 70 is provided to prevent molten metal from protruding to the inner circumference when the protrusion 33 of the connecting member 30 and the skirt 10 are welded. The inner circumferential surface 10b of the skirt 10 and the inner circumferential surface 33d of the protrusion 33 are connected to each other via the second welding portion 50 so as to be located on substantially the same plane.

[0097] (Effect)

[0098] According to the ship 201 of this embodiment, the following effects can be achieved.

[0099] In the present embodiment, the ship 201 includes a baffle plate 70 provided at a boundary between the protruding portion 33 and the skirt portion 10. The baffle plate 70 is fixed to the surfaces of the protruding portion 33 and the skirt portion 10 on the spherical tank 20 side.

[0100] Thus, the baffle 70 can be brought into contact with the boundary between the protrusion 33 and the skirt 10 from the spherical tank 20 side to weld the connecting member 30 and the skirt 10. Therefore, it is easy to prevent the second welded portion 50 from protruding further to the inner peripheral side than the skirt 10. Therefore, welding of the protrusion 33 and the skirt 10 becomes easy.

[0101] (Other embodiments)

[0102] As mentioned above, although the embodiment of this disclosure is described in detail with reference to drawings, the specific structure is not limited to this embodiment, and design changes etc. which do not deviate from the gist of this disclosure are also included.

[0103] In the above embodiment, each cargo loading section 7 is provided with one skirt 10, but the present invention is not limited thereto. A plurality of skirts 10 may be provided in each cargo loading section 7. In this case, for example, a spherical tank 20 is provided for each skirt 10 in each cargo loading section 7. That is, a plurality of spherical tanks 20 having the same number as the skirt 10 are provided in each cargo loading section 7.

[0104] In the above embodiment, the connecting member 30 surrounds the equator 22 of the tank partition wall 21 , but the present invention is not limited thereto. For example, the connecting member 30 may surround a portion of the tank partition wall 21 below the equator 22 .

[0105] In addition, in the above-mentioned embodiment, after the connecting block 31 is welded to the tank bulkhead 21, a plurality of connecting blocks 31 are welded to each other to form the connecting member 30, but the present invention is not limited thereto. For example, after a plurality of connecting blocks 31 are welded to each other in an annular shape to form the connecting member 30, the connecting member 30 may be welded to the tank bulkhead 21.

[0106] In the above embodiment, the connection member 30 is formed by joining a plurality of connection blocks 31 by welding, but the present invention is not limited thereto. For example, the connection member 30 may be an integrally formed ring.

[0107] In addition, in the above-mentioned embodiment, all the plurality of connection blocks 31 are formed in the same shape, but the present invention is not limited thereto. For example, the lengths of the plurality of connection blocks 31 in the circumferential direction may be different.

[0108] In the above embodiment, the maximum dimension L1 of the fixing portion 32 in the radial direction Dr is larger than the thickness L2 of the tank partition wall 21, but the present invention is not limited thereto. For example, the maximum dimension L1 of the fixing portion 32 in the radial direction Dr may be equal to the thickness L2 of the tank partition wall 21, or may be smaller than the thickness L2 of the tank partition wall 21.

[0109] <Note>

[0110] The ships 1 and 201 described in each embodiment can be understood, for example, as follows.

[0111] (1) The ship 1, 201 of the first embodiment comprises: a hull 2; a skirt 10, which is provided on the hull 2 ​​and is in a cylindrical shape and is open upward; a spherical tank 20 as a high-pressure tank, wherein the lower half 23 of the spherical tank 20 is accommodated in the skirt 10; a connecting member 30, which is provided in an annular shape so as to surround the spherical tank 20 from the outer peripheral side at a position above the skirt 10; a first welding portion 40, which fixes the inner peripheral portion 34 of the connecting member 30 and the outer surface 20a of the spherical tank 20 to each other; and a second welding portion 50, which connects the lower portion of the connecting member 30 and the upper end 11 of the skirt 10 to each other.

[0112] In this embodiment, a spherical tank 20 is used as a high-pressure tank. In this case, the vapor pressure in the spherical tank 20 becomes high pressure, and the influence of the variable load of the internal fluid becomes small. Therefore, the strength (so-called fatigue strength) against the variable load of the internal fluid is high. As a result, the outer surface 20a of the spherical tank 20 and the connecting member 30 can be welded.

[0113] In this embodiment, the outer surface 20a of the spherical tank 20 and the connecting member 30 are fixed by the first welding portion 40. Thus, the plate thicknesses of the spherical tank 20, the skirt 10, and the connecting member 30 can be independently designed. Therefore, the plate thickness of the spherical tank 20 can be increased regardless of the plate thicknesses of the skirt 10 and the connecting member 30.

[0114] In addition, the second welding portion 50 connects the lower portion of the connecting member 30 and the upper end of the skirt 10, so the connection portion between the skirt 10 and the connecting member 30 is exposed to the outside. Therefore, the skirt 10 and the connecting member 30 can be welded while confirming the connection portion between the skirt 10 and the connecting member 30.

[0115] (2) The ship 1, 201 of the second embodiment may be the ship 1, 201 of (1), wherein the upper and lower exposed surfaces 40a of the first weld portion 40 are curved surfaces that smoothly connect the outer surface 30a of the connecting member 30 and the outer surface 20a of the spherical tank 20.

[0116] This can alleviate stress concentration at the fixed portion between the connection member 30 and the spherical tank 20 .

[0117] (3) In the ship 1 or 201 according to the third aspect, in the ship 1 or 201 according to (1) or (2), the connecting member 30 may be formed of a material having a higher strength than the spherical tank 20 and the skirt 10 .

[0118] Thereby, the strength of the connection member 30 on which stress is easily concentrated compared with the spherical tank 20 and the skirt portion 10 can be improved.

[0119] (4) The ship 1, 201 of the fourth scheme may be based on any one of the ships 1, 201 in (1) to (3), wherein the connecting member 30 has a plurality of connecting blocks 31 arranged in the circumferential direction of the skirt 10, and the connecting blocks 31 adjacent to each other in the circumferential direction are joined to each other by welding.

[0120] Thus, the connection member 30 can be fixed to the spherical tank 20 by welding the plurality of connection blocks 31 after the connection blocks 31 are respectively fixed to the spherical tank 20 .

[0121] (5) The ship 1, 201 of the fifth scheme may be based on any one of the ships 1, 201 from (1) to (4), wherein the connecting member 30 comprises: a fixing portion 32 fixed to the spherical tank 20 via the first welding portion 40; and a protruding portion 33 protruding downward from the fixing portion 32 and connected to the upper end of the skirt 10 via the second welding portion 50.

[0122] The fluid stored in the spherical tank 20 is swung by external forces generated by the navigation of the ship 1, etc. Therefore, stress is likely to be concentrated on the fixing portion 32 fixed to the spherical tank 20. According to this embodiment, the connecting member 30 and the skirt 10 can be welded at a position away from the fixing portion 32 where stress is likely to be concentrated.

[0123] (6) The ship 201 of the sixth scheme may be, based on the ship 201 of (5), the ship 201 includes a baffle 70, which is provided at the boundary between the protrusion 33 and the skirt 10 and is fixed to the surfaces of the protrusion 33 and the skirt 10 on the side of the spherical tank 20.

[0124] Thus, the baffle 70 can be brought into contact with the boundary between the protrusion 33 and the skirt 10 from the spherical tank 20 side to weld the connecting member 30 and the skirt 10. Therefore, the second welded portion 50 can be easily prevented from protruding further inward than the skirt 10.

[0125] (7) The ship 1, 201 of the seventh scheme can also be based on any one of the ships 1, 201 in (1) to (6), wherein the above-mentioned connecting member 30 has, between the connecting member 30 and the outer surface 20a of the above-mentioned spherical tank 20: an upper inclined surface 34a, forming an upper groove 36 that opens toward the upper side and tapers toward the lower side; and a lower inclined surface 34b, forming a lower groove 37 that opens toward the lower side and tapers toward the upper side below the above-mentioned upper groove 36, and the above-mentioned first welding part 40 has: an upper welding part 41, which is provided on the above-mentioned upper groove 36 and connects the above-mentioned spherical tank 20 to the upper side of the inner peripheral part 34 of the above-mentioned connecting member 30; and a lower welding part 42, which is provided on the above-mentioned lower groove 37 and connects the above-mentioned spherical tank 20 to the lower side of the inner peripheral part 34 of the above-mentioned connecting member 30 and is connected to the above-mentioned upper welding part 41.

[0126] According to this aspect, the entire region in the up-down direction of the inner peripheral portion 34 of the connection member 30 is welded to the spherical tank 20. Thus, the connection member 30 and the spherical tank 20 can be prevented from being separated.

[0127] Industrial Applicability

[0128] According to the ship of the present invention, it is possible to alleviate the restriction on the enlargement of the tank.

[0129] Description of Reference Numerals

[0130] 1…ship; 2…hull; 2a…bow; 2b…stern; 3…side; 4…bottom; 5…upper deck; 6…superstructure; 7…cargo loading section; 10…skirt; 10a…outer peripheral surface; 10b…inner peripheral surface; 11…upper end; 11a…upper surface; 20…spherical tank; 20a…outer surface; 21…tank bulkhead; 22…equator; 23…lower half; 24…upper half; 30…connecting member; 30a…outer surface; 31…connecting block; 32…fixing part; 32a…upper surface; 32b…outer peripheral surface; 32c…lower surface; 32d…outer peripheral part; 33…protrusion; 33b…outer peripheral surface; 33c…lower surface; 33d…inner circumference; 33e…lower inner circumference; 33f…upper inner circumference; 34…inner circumference; 34a…upper inclined surface; 34b…lower inclined surface; 34c…top; 36…upper bevel; 37…lower bevel; 40…first weld; 40a…exposed surface; 41…upper weld; 41a…upper surface; 42…lower weld; 42a…lower surface; 50…second weld; 60…tank cover; 70…baffle; 201…ship; C…center point; Da…fore and aft direction; Dw…ship width direction; Dr…radial direction; L1…maximum dimension; L2…thickness; M…steel; O…center axis.

Claims

1. A vessel having: hull; A skirt portion, provided on the hull, in a cylindrical shape opening upward; A spherical tank as a high-pressure tank, wherein the lower half of the spherical tank is accommodated in the skirt; A connecting member is provided in an annular shape so as to surround the spherical tank from the outer peripheral side at a position above the skirt portion; a first welding portion for fixing the inner peripheral portion of the connecting member and the outer surface of the spherical tank to each other; and The second welding portion connects the lower portion of the connecting member and the upper end of the skirt portion to each other.

2. The vessel according to claim 1, wherein: The upper and lower exposed surfaces of the first welding portion are curved surfaces that smoothly connect the outer surface of the connecting member and the outer surface of the spherical tank.

3. A vessel according to claim 1 or 2, wherein: The connecting member is formed of a material having a higher strength than that of the spherical tank and the skirt.

4. The vessel according to claim 1 or 2, wherein: The connecting member has a plurality of connecting blocks arranged in a circumferential direction of the skirt portion, The connection blocks adjacent to each other in the circumferential direction are joined by welding.

5. The vessel according to claim 1 or 2, wherein: The connecting member has: a fixing portion fixed to the spherical tank via the first welding portion; and The protruding portion protrudes downward from the fixing portion and is connected to the upper end of the skirt portion via the second welding portion.

6. The vessel according to claim 5, wherein: The ship includes a baffle plate provided at a boundary between the protruding portion and the skirt portion and fixed to surfaces of the protruding portion and the skirt portion on the spherical tank side.

7. The vessel according to claim 1 or 2, wherein: The connecting member has an upper inclined surface between the connecting member and the outer surface of the spherical tank, forming an upper groove opening upward and tapering toward the bottom; and a lower inclined surface formed at the lower side of the upper groove opening downward and tapering toward the top. The first welding portion has: an upper welding portion, provided at the upper groove, connecting the spherical tank to the upper side of the inner peripheral portion of the connecting member; and The lower welding portion is provided at the lower groove, connects the spherical tank to the lower side of the inner peripheral portion of the connecting member, and is connected to the upper welding portion.

Images