X-shaped vibration reduction structure of super-large C-shaped fuel tank for ship and assembly process of X-shaped vibration reduction structure
By adding an X-shaped vibration-absorbing structure at the reinforcement ring of the super-large C-type fuel tank for marine use, the resonance problem caused by the low natural frequency of the fuel tank is solved, the natural frequency of lateral vibration is improved, the vibration response and structural failure risk is reduced, and the safer ship operation is achieved.
Patent Information
- Application Number
- CN202510154341.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-12
- Publication Date
- 2025-05-06
AI Technical Summary
The natural frequency of super-large marine C-type fuel tanks is low and can easily coincide with the excitation frequency range of the main engine and propeller, resulting in structural resonance and vibration fatigue damage, affecting the safe operation of the ship.
An X-shaped vibration-absorbing structure is designed to enhance the boundary support stiffness of the tank body in the saddle position by adding cross-set X-shaped webs and T-material webs at the fuel tank reinforcement ring, thereby increasing the natural frequency value of the transverse mode and avoiding the excitation frequency range.
It effectively improves the natural frequency of lateral vibration of the fuel tank, avoids resonance, reduces the level of vibration response, and reduces the risk of structural failure. At the same time, the structure type is simple, the material cost is low, and the processing is convenient.
Smart Images
Figure CN119929062A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an IMO C-type fuel tank, and in particular to an X-shaped vibration reduction structure and an assembly process of an extra-large C-type fuel tank for a ship. Background Art
[0002] The C-type fuel tank for ships is arranged on the hull, close to vibration excitation sources such as the main engine and propeller. The impact of vibration factors on the safety of the tank structure cannot be ignored. At the same time, with the continuous increase in the demand for endurance, the size of the fuel tank has become larger, making the natural frequency value of the super-large fuel tank lower, and it is impossible to completely avoid the excitation frequency range corresponding to the main engine speed range during ship operation.
[0003] If the natural frequency of the tank overlaps with the frequency of the excitation source, it may cause a larger tank vibration response. According to research, when the fuel tank is arranged along the length of the ship, due to the weak rigidity of the upper part of the tank support saddle and the corresponding internal reinforcement ring of the tank, the natural frequency value of the transverse mode of the tank in the ship width direction is usually low, which is very easy to overlap with the external excitation frequency range of the main engine and propeller, and there is a risk of structural resonance. The fuel tank is in a resonant state for a long time, which is very easy to cause vibration fatigue damage, causing the tank structure to fail, and bringing uncontrollable risks to the safe operation of the ship. It is extremely important to design an ultra-large C-type fuel tank vibration reduction structure and a supporting assembly process with a simple structure that can significantly improve the natural frequency of the tank's transverse vibration and avoid the external excitation frequency range, thereby achieving the purpose of vibration reduction. Summary of the invention
[0004] The purpose of the present invention is to provide an X-shaped vibration reduction structure for a super-large C-type fuel tank for a ship, which can increase the lateral vibration natural frequency of the super-large C-type fuel tank to effectively avoid the external excitation frequency range and avoid resonance, thereby reducing the vibration response level of the fuel tank when excited by the ship's main engine and propeller.
[0005] The above technical objectives of the present invention are achieved through the following technical solutions: An X-shaped vibration reduction structure for a super-large C-shaped fuel tank for a ship comprises a fuel tank support saddle, on which a fuel tank is supported, a fuel tank reinforcement ring is arranged inside the fuel tank, the fuel tank reinforcement ring is aligned with the position of the fuel tank support saddle, an X-shaped vibration reduction structure is connected to the inner side of the fuel tank reinforcement ring, and the X-shaped vibration reduction structure comprises a cross-arranged X-shaped web.
[0006] Furthermore, the X-shaped web is cross-shaped, and the intersection point is located at the center of the cross section of the fuel tank.
[0007] Furthermore, the X-shaped web is symmetrically arranged about a vertical line passing through the center of the fuel tank.
[0008] Furthermore, the angle between the cross of the X-shaped web and the horizontal direction is 45 degrees.
[0009] Furthermore, the fuel tank reinforcement ring includes a fuel tank reinforcement ring web and a fuel tank reinforcement ring panel. The fuel tank reinforcement ring web is connected to the inner circumference of the fuel tank and is aligned with the position of the fuel tank support saddle; the fuel tank reinforcement ring panel is connected to the inner circumference of the fuel tank reinforcement ring web, and the X-shaped web is fixed to the inner circumference of the fuel tank reinforcement ring panel and is aligned with the position of the fuel tank reinforcement ring web.
[0010] Furthermore, the two sides of the X-shaped web are respectively connected with a rear T-material web and a front T-material web arranged along the cross-shaped midline thereof, and the rear T-material web and the front T-material web are arranged perpendicular to the plane where the X-shaped web is located.
[0011] Furthermore, the outer sides of the rear T material web and the front T material web are respectively connected with the rear T material panel and the front T material panel, and the rear T material panel and the front T material panel are respectively combined with the rear T material web and the front T material web to form a T material.
[0012] Furthermore, in the X-shaped web, the free edges at the intersection positions are connected by arc transition.
[0013] Furthermore, a reinforcing bracket is arranged at the outer end of the X-shaped web, and the outer end of the reinforcing bracket is connected to the reinforcement ring of the fuel tank.
[0014] The present application also discloses an assembly process of an X-shaped vibration reduction structure of an extra-large C-shaped fuel tank for a ship, comprising the following steps: First, assemble the X-shaped web, align the rear T-material web with the center line of the X-shaped web, and connect it to the rear side of the X-shaped web to obtain the assembly and turn it over as a whole, then align the front T-material web with the center line of the X-shaped web, and connect it to the front side of the X-shaped web to form an X-shaped vibration reduction structure; finally, fix the obtained X-shaped vibration reduction structure to the fuel tank reinforcement ring.
[0015] In summary, the present invention has the following beneficial effects: Without changing the original structure of the fuel tank, an X-shaped vibration reduction structure is added to the reinforcement ring of the fuel tank to enhance the boundary support stiffness of the tank at the saddle position, thereby effectively increasing the natural frequency value of the tank's lateral mode and avoiding the propeller and main engine excitation frequency range, reducing the risk of structural failure of the tank due to resonance; Compared with the conventional method of increasing the number of vacuum rings of the fuel tank or increasing the size of the vacuum rings of the fuel tank to increase the natural frequency of the tank body, the present invention has a simple structure, significantly improves the natural frequency of the fuel tank, is easy to process, and has low material cost; In addition, the X-shaped vibration-damping structure can slow down the sloshing tendency of the liquid in the tank body and play a certain anti-swaying role; at the same time, the assembly process described in the present invention is adopted to ensure the assembly accuracy and welding quality of the X-shaped vibration-damping structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 It is a side view schematic diagram of a C-type fuel tank and its supporting saddle and a fuel tank reinforcement ring in the present invention; Figure 2 It is a cross-sectional schematic diagram of an X-shaped vibration reduction structure of an extra-large C-shaped fuel tank for a ship of the present invention; Figure 3 yes Figure 2 A cross-sectional view at AA; Figure 4 yes Figure 2 A cross-sectional view at BB; Figure 5 yes Figure 3 Cross-sectional view at CC.
[0017] In the figure, 1, X-shaped web; 2, rear side T-material web; 3, rear side T-material panel; 4, front side T-material web; 5, front side T-material panel; 6, reinforcing ring web; 7, reinforcing ring panel; 8, fuel tank; 9, support saddle; 10, vacuum ring. DETAILED DESCRIPTION
[0018] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings, and this embodiment does not constitute a limitation of the present invention. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.
[0019] An X-shaped vibration reduction structure for a super-large C-shaped fuel tank for a ship, such as Figure 1 and Figure 2 As shown, it includes two parallel fuel tank support saddles 9, and a fuel tank 8 is supported correspondingly above the fuel tank support saddle 9, and the fuel tank 8 also includes a vacuum ring 10; a fuel tank reinforcement ring is fixed in the fuel tank 8 by welding or the like, and the fuel tank reinforcement ring is aligned with the position of the fuel tank support saddle 9; an X-shaped vibration reduction structure is connected to the inner side of the fuel tank reinforcement ring, and the boundary support stiffness of the tank body at the saddle position is enhanced by adding the X-shaped vibration reduction structure at the fuel tank reinforcement ring.
[0020] like Figure 3 and Figure 4 As shown, the X-shaped vibration reduction structure includes an X-shaped web 1, a rear T-material web 2, a rear T-material panel 3, a front T-material web 4, and a front T-material panel 5 which are arranged crosswise; the X-shaped web 1 is a cross-shaped web, and the intersection is located at the center of the cross section of the fuel tank 8; In this embodiment, the X-shaped web 1 is symmetrically arranged about the plumb line axis passing through the center of the fuel tank 8; in other embodiments, the angle between the cross of the X-shaped web 1 and the horizontal direction is set to 45 degrees (the 45-degree setting can most effectively improve the lateral support rigidity at the reinforcement ring of the fuel tank and suppress the lateral vibration of the upper part of the fuel tank 8); in the X-shaped web 1, the free edge at the intersection position (the X-shaped web 1 near the intersection) is connected by an arc transition with a radius of about 0.2 meters to avoid local high stress caused by right-angle transition.
[0021] like Figure 3 and Figure 4 As shown, the two sides of the X-shaped web 1 are respectively connected with the rear side T-material web 2 and the front side T-material web 4 arranged along the cross fork thereof, and the rear side T-material web 2 and the front side T-material web 4 are arranged perpendicular to the plane where the X-shaped web 1 is located (aligned with the midline of the width of the cross fork of the X-shaped web 1); the outer sides of the rear side T-material web 2 and the front side T-material web 4 are respectively connected with the rear side T-material panel 3 and the front side T-material panel 5, and the rear side T-material panel 3 and the front side T-material panel 5 are respectively combined with the rear side T-material web 2 and the front side T-material web 4 to form a T-material; The width of a single cross fork of the X-shaped web 1 is D, which is determined according to the tank vibration calculation requirements, and the width D should not be too large, generally 0.8 to 1.2 meters (because as the width increases, the mass of the attached water will also increase accordingly, causing the natural frequency value of the local mode of the X-shaped vibration reduction structure along the length direction of the fuel tank to be low, which is easy to overlap with the excitation frequency range and produce local resonance of the X-shaped vibration reduction structure); The depth of the rear T-material web 2 and the front T-material web 4 is H, which is determined according to the tank vibration calculation requirements, and the depth H should not be too large, generally 0.4 to 0.6 meters (because when the depth increases, the T-material is easy to tip over, and a local vibration mode of lateral local torsion is generated, and the natural frequency of this mode is low, which is easy to overlap with the excitation frequency range to produce local resonance of the X-type vibration reduction structure); The width of the rear T-material panel 3 and the front T-material panel 5 is d, which is determined according to the tank vibration calculation requirements and should not be too large, generally 0.4 to 0.6 meters, to avoid the need for additional panel anti-tilt structure due to excessive width.
[0022] like Figure 2As shown, the X-shaped web 1 includes a middle cross-shaped plate, four rectangular plates and four end fan-shaped plates, the four rectangular plates and the cross-shaped plate are fixed by welding, the outer ends of the end fan-shaped plates gradually widen, and a number of reinforcing brackets can be connected on both sides thereof, and the outer ends of the reinforcing brackets are connected to the reinforcement rings of the fuel tank; in this embodiment, the reinforcing brackets are integrally connected to the X-shaped web 1, the width of the reinforcing brackets is about 0.4~0.6D, the free edge of the reinforcing brackets is in the shape of an arc, and the radius of the arc is about 0.5D. The reinforcing brackets at the ends can increase the end constraints of the X-shaped vibration reduction structure and improve its vibration resistance. The free edge of the bracket is in the shape of an arc, which can alleviate the stress concentration at the ends of the brackets.
[0023] The rear T-material panel 3 and the front T-material panel 5 are connected by an arc transition at the cross position, and the arc radius is about 0.15 meters to avoid local high stress caused by right-angle transition; the rear T-material panel 3 includes a central cross-shaped plate and four rectangular segment plates, the four rectangular segment plates and the cross-shaped plate are fixed by welding, and the joints are polished until the weld surface is smooth, the front T-material panel 5 also adopts the same structure and similar joint treatment, thereby alleviating stress concentration at the panel joint weld.
[0024] like Figure 3 As shown, the fuel tank reinforcement ring includes a fuel tank reinforcement ring web 6 and a fuel tank reinforcement ring panel 7. The fuel tank reinforcement ring web 6 is vertically welded to the inner periphery of the fuel tank 8 and is aligned with the position of the fuel tank support saddle 9; the fuel tank reinforcement ring panel 7 is vertically welded to the inner periphery of the fuel tank reinforcement ring web 8; the X-shaped web 1 is fixed to the inner periphery of the fuel tank reinforcement ring panel 7 and is aligned with the position of the fuel tank reinforcement ring web 6 (aligned with the fuel tank reinforcement ring web 6 according to the center line of the plate thickness).
[0025] like Figure 3 and Figure 5 As shown, the ends of the rear T-material web 2 and the front T-material web 4 are beveled at 30 degrees and terminate near the fuel tank reinforcement ring panel 7; the ends of the rear T-material panel 3 and the front T-material panel 5 are beveled at 15 degrees on both sides and terminate at the bevel starting positions of the rear T-material web 2 and the front T-material web 4, respectively. The bevel design can avoid structural mutations at the structural termination position, thereby alleviating stress concentration; In this embodiment, the X-shaped web 1, the rear T-material web 2, the rear T-material panel 3, the front T-material web 4, and the front T-material panel 5 are immersed in LNG fuel with a temperature as low as -163°C. Considering the low-temperature performance of the material, their material is set to be consistent with the material of the fuel tank 8, specifically nine-nickel steel in this embodiment.
[0026] This embodiment also discloses an assembly process of an X-shaped vibration reduction structure of an extra-large C-shaped fuel tank for a ship, comprising the following main steps: S10, placing four rectangular plates, end sector plates and a cross-shaped plate horizontally on a special welding frame, and assembling them into an X-shaped web 1 by butt welding; S20, assembling the four rectangular sections of the rear T-material panel 3 and the cross-shaped panel into a rear T-material panel group by butt welding, and assembling the front T-material panel 5 into a front T-material panel group by the same assembly method; grinding the joints of all T-material panel groups until the weld surface is smooth; S30, assembling the rear T-material web 2 along the center line of the rectangular section of the rear T-material panel 3 vertically to the rear T-material panel group in a T-shaped assembly manner by fillet welding to form a rear assembled material as a whole; assembling the front T-material web 4 to the front T-material panel group in the same assembly manner to form a front assembled material as a whole; S40, aligning the width center line of the cross fork of the rear T-material web 2 with the X-shaped web 1, and integrally assembling the rear side composite material to the rear side of the X-shaped web 1 by fillet welding, and keeping it perpendicular to the plane where the X-shaped web 1 is located; S50, then turning over the assembly obtained in step S40 as a whole, and assembling the front side assembly material as a whole to the front side of the X-shaped web 1 by the alignment and assembly method in S40, thereby forming an X-shaped vibration reduction structure; S60, then align the X-shaped web 1 and the fuel tank reinforcement ring web 6 according to the center line of the plate thickness, and use fillet welding to fix the X-shaped vibration reduction structure to the fuel tank reinforcement ring panel 7 to form a fuel tank reinforcement ring assembly (note that the angle between the cross line of the X-shaped web 1 and the horizontal direction is 45 degrees); S70, finally, the fuel tank reinforcement ring assembly is turned over as a whole and placed on a welding frame, and the corner welding of the connection between the X-shaped vibration reduction structure on the other side and the fuel tank reinforcement ring panel 7 is completed.
[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art may make various modifications or equivalent substitutions to the present invention within the essence and protection scope of the present invention, and such modifications or equivalent substitutions should also be deemed to fall within the protection scope of the technical solution of the present invention.
Claims
1. An X-shaped vibration reduction structure for a super-large C-shaped fuel tank for a ship, characterized in that: It includes a fuel tank support saddle, on which a fuel tank is supported, a fuel tank reinforcement ring is arranged inside the fuel tank, the fuel tank reinforcement ring is aligned with the position of the fuel tank support saddle, an X-shaped vibration reduction structure is connected to the inner side of the fuel tank reinforcement ring, and the X-shaped vibration reduction structure includes a cross-arranged X-shaped web.
2. The X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship according to claim 1 is characterized in that: The X-shaped web is a cross-shaped web, and the intersection point is located at the center of the cross section of the fuel tank.
3. The X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship according to claim 2 is characterized in that: The X-shaped web is symmetrically arranged about a vertical line passing through the center of the fuel tank.
4. The X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship according to claim 2 or 3, characterized in that: The angle between the cross of the X-shaped web and the horizontal direction is 45 degrees.
5. The X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship according to claim 1 is characterized in that: The fuel tank reinforcement ring includes a fuel tank reinforcement ring web and a fuel tank reinforcement ring panel. The fuel tank reinforcement ring web is connected to the inner circumference of the fuel tank and is aligned with the position of the fuel tank support saddle; the fuel tank reinforcement ring panel is connected to the inner circumference of the fuel tank reinforcement ring web, and the X-shaped web is fixed to the inner circumference of the fuel tank reinforcement ring panel and is aligned with the position of the fuel tank reinforcement ring web.
6. The X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship according to claim 1 or 5, characterized in that: The two sides of the X-shaped web are respectively connected with a rear T-material web and a front T-material web arranged along the cross-shaped midline thereof, and the rear T-material web and the front T-material web are arranged perpendicular to the plane where the X-shaped web is located.
7. The X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship according to claim 6 is characterized in that: The outer sides of the rear T material web and the front T material web are respectively connected with the rear T material panel and the front T material panel, and the rear T material panel and the front T material panel are respectively combined with the rear T material web and the front T material web to form a T material.
8. The X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship according to claim 1 is characterized in that: In the X-shaped web, the free edges at the intersection positions are connected by arc transition.
9. The X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship according to claim 1 or 8, characterized in that: A reinforcing bracket is arranged at the outer end of the X-shaped web, and the outer end of the reinforcing bracket is connected to the reinforcement ring of the fuel tank.
10. An assembly process for the X-shaped vibration reduction structure of a super-large C-shaped fuel tank for a ship as claimed in claim 6 or 7, characterized in that: The following steps are involved: First, assemble the X-shaped web, align the rear T-material web with the center line of the X-shaped web, and connect it to the rear side of the X-shaped web to obtain the assembly and turn it over as a whole, then align the front T-material web with the center line of the X-shaped web, and connect it to the front side of the X-shaped web to form an X-shaped vibration reduction structure; finally, fix the obtained X-shaped vibration reduction structure to the fuel tank reinforcement ring.