A combined strut structure for ship LNG tanks

Abstract

This invention provides a combined support structure for a ship's LNG tank compartment. The ship has an inner bottom plate, a second deck, and a third deck. The LNG tank compartment is located between the inner bottom plate and the third deck and is enclosed by the aft bulkhead. The combined support structure includes: an open-structure support body vertically arranged and fixed to the inner side of the aft bulkhead; the upper end of the support body is fixedly connected to a strong structure of the third deck; the lower end of the support body terminates at the height of the second deck, forming a narrowing transition section; the end of the transition section is fixedly connected to a longitudinal profile web fixedly arranged on the aft bulkhead. The load borne by the support body is transferred to the longitudinal profile and the aft bulkhead through the transition section. This invention solves the problems of conventional through-type supports, such as structural complexity, susceptibility to hard points, and obstruction of internal tank compartment layout. It reduces the support length, facilitates the layout of piping and ventilation ducts within the tank compartment, and reduces construction difficulty.

Description

Technical Field

[0001] This invention belongs to the field of shipbuilding technology, and specifically relates to a combined support structure for LNG tanks in ships. Background Technology

[0002] To allow unobstructed vehicle movement within the cabin, passenger roll-on / roll-off ships do not have transverse bulkheads. Instead, a small number of struts are used to support the deck and reduce the span of beams and longitudinal girder. To ensure proper stress transfer and the effective function of the struts, the struts and their corresponding reinforcements are generally connected to strong structures, such as the deck or outer plating.

[0003] A certain passenger ro-ro ship is part of a series of vessels. Originally, decks 1-3, 3-5, and 5-7 were garages, with two pillars supporting each garage level. Subsequent ships switched from diesel-powered to dual-fuel propulsion, eliminating deck 1. An LNG tank was installed between the inner bottom plate and deck 3. The aft wall of the LNG tank was aligned with one of the original pillars between decks 1-3. The conventional design would utilize the aft wall of the LNG tank, extending the original pillar between decks 1-3 to the inner bottom plate, and reinforcing the pillar from the inner bottom plate to the outer plate.

[0004] Conventional design schemes are prone to the following problems:

[0005] The ends of the support column are connected to the strong structure, namely the inner bottom plate and the third deck, spanning two floors with a total height of 8 meters. The support column needs to be equipped with many partitions, which not only increases the amount of welding work, but also makes the support column prone to deformation.

[0006] Hard spots are prone to form at the lower end of the support column, causing stress concentration, structural fatigue failure, and other problems.

[0007] The piping and air ducts inside the tank are mostly arranged on the wall panels, but the dimensions of the support columns are larger than the profiles on the wall panels, which is not conducive to the arrangement of the piping and air ducts.

[0008] Therefore, how to provide a combined support structure for LNG tanks in ships that can solve the problems of structural complexity, easy generation of hard points, and obstruction of internal tank layout of conventional through-support structures has become an urgent technical problem to be solved. Summary of the Invention

[0009] This invention provides a combined support structure for LNG tanks in ships, which can solve the problems of conventional through-type supports, such as complex structure, easy generation of hard points, and obstruction of internal tank layout. While ensuring the structural strength of the hull is met, the length of the support is reduced, which is conducive to the layout of piping and ventilation ducts in the tank and reduces the difficulty of construction.

[0010] In one embodiment of the present invention, a combined strut structure for a ship's LNG tank compartment is provided. The ship has an inner bottom plate, a second deck, and a third deck. The LNG tank compartment is disposed between the inner bottom plate and the third deck and is enclosed by a rear bulkhead. The combined strut structure includes:

[0011] A support column body, which is an open structure, is set vertically and fixedly attached to the inner side of the rear wall panel of the tank compartment;

[0012] The upper end of the support body is fixedly connected to the strong structure of the third deck; the lower end of the support body terminates at the height region of the second deck and forms a narrowing transition section; the end of the transition section is fixedly connected to the web of the longitudinal profile fixedly installed on the rear wall of the tank, so that the load borne by the support body is transferred to the longitudinal profile and the rear wall of the tank through the transition section.

[0013] Furthermore, the cross-sectional dimensions of the support body are the same as those of the support pillars installed in the vehicle cabins between the third and fifth decks of the ship.

[0014] Furthermore, the support body is constructed by welding plates, and the material grade of the plates is not lower than the higher of the material grade of the rear bulkhead of the tank and the material grade of the support pillars in the vehicle compartment between the third and fifth decks.

[0015] Furthermore, the nominal thickness of the plate constituting the main body of the support column is not less than the nominal thickness of the web of the longitudinal profile on the rear wall of the tank compartment.

[0016] Furthermore, when the thickness of the support plate in the vehicle cabin between the third and fifth decks is greater than the thickness of the web plate of the longitudinal profile, in the area where the upper end of the support body connects to the third deck, within a range extending in each direction by one longitudinal girder height, the thickness of the support body is not less than 0.4 times the thickness of the support plate in the vehicle cabin.

[0017] Furthermore, on the rear wall panel of the tank compartment, the portion corresponding to the connection area of ​​the support body has a wall panel thickness of not less than 0.4 times the thickness of the support panel inside the vehicle compartment.

[0018] Furthermore, the interior of the support body is provided with at least one transverse partition, the thickness of which is the same as the minimum nominal thickness of the sheet metal constituting the support body.

[0019] Furthermore, the two side walls of the transition section converge inward at an angle of no more than 15°, so that the connection dimension at its end matches the web dimension of the longitudinal profile.

[0020] The beneficial effects of this invention are as follows:

[0021] As can be seen from the above scheme, the embodiments of the present invention provide a combined support structure for a ship's LNG tank compartment. The ship has an inner bottom plate, a second deck, and a third deck. The LNG tank compartment is located between the inner bottom plate and the third deck and is enclosed by the tank compartment's aft bulkhead. The combined support structure includes: a support body, which is an open structure, vertically arranged and fixedly attached to the inner side of the tank compartment's aft bulkhead; wherein, the upper end of the support body is fixedly connected to the strong structure of the third deck; the lower end of the support body terminates at the height region of the second deck, forming a narrowing transition section; the end of the transition section is fixedly connected to the web of a longitudinal profile fixedly arranged on the tank compartment's aft bulkhead, so that the load borne by the support body is transferred to the longitudinal profile and the tank compartment's aft bulkhead through the transition section. The technical solution of the present invention can solve the problems of structural complexity, easy generation of hard points, and obstruction of internal tank compartment layout that exist in conventional through-type supports. While ensuring the structural strength of the hull is met, the support length is reduced, which is beneficial for the layout of piping systems and ventilation ducts inside the tank compartment and reduces construction difficulty. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a combined support structure for a ship's LNG tank compartment according to an embodiment of the present invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0024] In this embodiment of the invention, a combined support structure for LNG tanks in ships can solve the problems of conventional through-type supports, such as complex structure, easy generation of hard points, and obstruction of internal tank layout. While ensuring the structural strength of the hull is met, the length of the support is reduced, which is conducive to the layout of piping and ventilation ducts in the tank and reduces the difficulty of construction.

[0025] In one embodiment of the present invention, a combined strut structure for a ship's LNG tank compartment is provided. The ship has an inner bottom plate, a second deck, and a third deck. The LNG tank compartment is disposed between the inner bottom plate and the third deck and is enclosed by a rear bulkhead. The combined strut structure includes:

[0026] A support column body, which is an open structure, is set vertically and fixedly attached to the inner side of the rear wall panel of the tank compartment;

[0027] The upper end of the support body is fixedly connected to the strong structure of the third deck; the lower end of the support body terminates at the height region of the second deck and forms a narrowing transition section; the end of the transition section is fixedly connected to the web of the longitudinal profile fixedly installed on the rear wall of the tank, so that the load borne by the support body is transferred to the longitudinal profile and the rear wall of the tank through the transition section.

[0028] In this embodiment of the invention, the length of the support column is limited to a single deck height (from deck 3 to deck 2), significantly shortening the column length compared to the conventional two-deck design. This simplifies the column structure, reduces the number of internal bulkheads required, significantly reduces welding workload and manufacturing costs, and minimizes the risk of deformation due to excessive welding, thereby improving construction efficiency and quality. By narrowing the lower end of the support column and connecting it to the longitudinal profile of the tank's aft bulkhead, rather than directly connecting it to the highly rigid inner bottom plate, drastic changes in stiffness at the connection point are avoided. This design allows stress to diffuse more evenly through the bulkhead profile and the bulkhead itself, fundamentally eliminating the "hard spot" phenomenon, significantly reducing the risk of stress concentration, and improving the structure's fatigue resistance and service life.

[0029] By shortening the support columns and using smaller connections at their lower ends, more valuable space is freed up inside the LNG tank compartment. Piping, ventilation ducts, and other equipment can be arranged more flexibly along the wall panels, bypassing the obstruction of the support columns, thus improving the utilization of the internal space and the convenience of equipment placement, facilitating subsequent installation and maintenance. By requiring the support column cross-section to be consistent with that of the upper garage support columns and specifying the selection principles for materials and plate thickness, this design is easily integrated into existing ship design systems, which is beneficial for standardized production and cost control of a series of vessels.

[0030] In one embodiment of the present invention, the cross-sectional dimensions of the support body are the same as those of the support pillars installed in the vehicle cabin between the third and fifth decks of a ship, which facilitates standardized design and manufacturing.

[0031] In one embodiment of the present invention, the support body is constructed by welding plates, and the material grade of the plates is not lower than the higher of the material grade of the rear bulkhead of the tank and the material grade of the support in the vehicle compartment between the third and fifth decks, to ensure the material performance of critical stress areas.

[0032] In one embodiment of the present invention, the nominal thickness of the plate constituting the support body is not less than the nominal thickness of the web of the longitudinal profile on the rear wall of the tank, which is conducive to smooth stress transition while ensuring the strength of the rear wall of the tank.

[0033] In one embodiment of the present invention, when the thickness of the support plate of the vehicle cabin interior pillar between the third deck and the fifth deck is greater than the thickness of the web plate of the longitudinal profile, in the area where the upper end of the support plate connects to the third deck, within a range extending in each direction by a longitudinal girder height, the thickness of the support plate of the support body is not less than 0.4 times the thickness of the support plate of the vehicle cabin interior pillar, so as to locally strengthen the critical connection area.

[0034] In one embodiment of the present invention, on the rear wall panel of the tank compartment, the portion corresponding to the connection area of ​​the support body has a wall panel thickness of not less than 0.4 times the thickness of the support panel inside the vehicle compartment, thereby further enhancing the local load-bearing capacity of the wall panel.

[0035] In one embodiment of the present invention, at least one transverse partition is provided inside the support body, and the thickness of the transverse partition is the same as the minimum nominal thickness of the plate constituting the support body, so as to ensure the stability of the support itself.

[0036] In one embodiment of the present invention, the two side walls of the transition section converge inward at an angle of no more than 15°, so that the connection dimension at its end matches the web dimension of the longitudinal profile. This gentle transition angle can effectively avoid stress concentration and ensure smooth load transfer.

[0037] Through the above design, this invention successfully achieves three major objectives: structural simplification, elimination of hard points, and optimization of space. This solution has been successfully applied to actual ship projects and has gained recognition from shipowners and classification societies, demonstrating its technical feasibility and significant advantages.

[0038] like Figure 1 As shown, Figure 1 This is a schematic diagram of a combined support structure for a ship's LNG tank compartment according to an embodiment of the present invention.

[0039] Figure 1 Among them, a combined strut structure for LNG tanks in ships includes: a strut body.

[0040] The support column is an open support column, attached to the rear wall of the LNG tank. The tank is located on the inner bottom plate to the third deck. The upper end of the support column is connected to the third deck, and the lower end narrows at the height of the second deck and connects to the profile on the wall panel.

[0041] The dimensions of the combined support column should be consistent with those of the 3-5A garage support columns, and the material should be the superior of the material of the tank tank rear wall panel and the 3-5A garage support column. The thickness of the combined support column plate should be consistent with the thickness of the web plate of the profile on the LNG tank tank rear wall. When multiple specifications of profiles exist, the profile connected to the end of the support column shall prevail. When the thickness of the 3-5A garage support column is greater than the thickness of the web plate of the profile on the tank tank rear wall, the thickness of the combined support column at the upper end in at least one longitudinal girder height range in each direction should not be less than 0.4 times the thickness of the corresponding 3-5A garage support column plate, and the thickness of the plate within the support column range on the wall panel should not be less than 0.4 times the thickness of the corresponding 3-5A garage support column plate. A partition plate should be installed inside the combined support column, and the thickness of the partition plate should be the minimum thickness of the support column plate. The lower end of the combined support column should gradually narrow to match the profile dimensions, with a transition angle not exceeding 15°.

[0042] By adopting this method, stress can still be transferred well, satisfying the structural strength of the hull while reducing the length of the support pillars and increasing the effective layout space inside the LNG tank.

[0043] In this embodiment of the invention, the upper end of the combined support structure is fixedly connected to the longitudinal girder or other strong structure of the third deck by welding to withstand the load from the upper deck. The cross-sectional dimensions of the support body are consistent with the dimensions of the garage supports between the upper third and fifth decks, for example, using the same box-shaped cross-section.

[0044] Regarding material selection, the plate material of the support column body shall be no less superior than the material of the rear wall panel of the tank compartment and the material of the upper garage support column. Its thickness shall be no less than the web thickness of the longitudinal profile connected to it. If the upper garage support column is thicker, it shall be locally thickened in the upper connection area of ​​the support column (within one longitudinal girder height), and the thickened plate thickness shall be no less than 0.4 times the thickness of the upper garage support column plate. Simultaneously, the thickness of the plate on the rear wall panel of the tank compartment corresponding to the support column connection area shall also be increased accordingly to no less than 0.4 times this value. A transverse partition shall be installed inside the support column, with its thickness being the minimum value of the support column plate thickness.

[0045] In this embodiment of the invention, a combined strut structure for a ship's LNG tank is provided. The ship has an inner bottom plate, a second deck, and a third deck. The LNG tank is located between the inner bottom plate and the third deck and is enclosed by a rear bulkhead. The combined strut structure includes: a strut body, which is an open structure, vertically arranged and fixedly attached to the inner side of the rear bulkhead; wherein, the upper end of the strut body is fixedly connected to the rigid structure of the third deck; the lower end of the strut body terminates at the height region of the second deck, forming a narrowing transition section; the end of the transition section is fixedly connected to the web of a longitudinal profile fixedly arranged on the rear bulkhead, so that the load borne by the strut body is transferred to the longitudinal profile and the rear bulkhead through the transition section.

[0046] The technical solution of this invention can solve the problems of conventional through-type support columns, such as complex structure, easy generation of hard points, and obstruction of internal tank layout. While ensuring the structural strength of the ship, the length of the support column is reduced, which is conducive to the layout of piping and ventilation ducts in the tank and reduces the construction difficulty.

[0047] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A combined strut structure for a ship's LNG tank compartment, the ship having an inner bottom plate, a second deck, and a third deck, the LNG tank compartment being disposed between the inner bottom plate and the third deck and enclosed by a rear bulkhead, characterized in that, The combined support structure includes: A support column body, which is an open structure, is set vertically and fixedly attached to the inner side of the rear wall panel of the tank compartment; The upper end of the support body is fixedly connected to the strong structure of the third deck; the lower end of the support body terminates at the height region of the second deck and forms a narrowing transition section; the end of the transition section is fixedly connected to the web of the longitudinal profile fixedly installed on the rear wall of the tank, so that the load borne by the support body is transferred to the longitudinal profile and the rear wall of the tank through the transition section. The cross-sectional dimensions of the support body are the same as those of the support columns installed in the vehicle cabin between the third and fifth decks of the ship. When the thickness of the support plate in the vehicle cabin between the third and fifth decks is greater than the thickness of the web plate of the longitudinal profile, the thickness of the support body is not less than 0.4 times the thickness of the support plate in the vehicle cabin within the area where the upper end of the support body connects to the third deck and extends along each direction by one longitudinal girder height.

2. A combined support structure for a ship's LNG tank as described in claim 1, characterized in that, The support body is constructed by welding plates, and the material grade of the plates is not lower than the higher of the material grade of the rear wall panel of the tank and the material grade of the support pillars in the vehicle compartment between the third and fifth decks.

3. A combined support structure for a ship's LNG tank as described in claim 1, characterized in that, The nominal thickness of the plate constituting the main body of the support column is not less than the nominal thickness of the web of the longitudinal profile on the rear wall of the tank.

4. A combined support structure for a ship's LNG tank as described in claim 1, characterized in that, On the rear wall panel of the tank compartment, the portion corresponding to the connection area of ​​the support body has a wall panel thickness of not less than 0.4 times the thickness of the support panel inside the vehicle compartment.

5. A combined support structure for a ship's LNG tank as described in claim 1, characterized in that, The interior of the support body is provided with at least one transverse partition, the thickness of which is the same as the minimum nominal thickness of the plate material constituting the support body.

6. A combined support structure for a ship's LNG tank as described in claim 1, characterized in that, The two side walls of the transition section converge inward at an angle of no more than 15°, so that the connection dimension at its end matches the web dimension of the longitudinal profile.

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