Patent Publication Number: US-9851051-B2

Title: X-beam structure and pressure tank having X-beam structure

Description:
TECHNICAL FIELD 
     The present invention relates to a pressure tank, and in particular, to a pressure tank having a beam lattice structure capable of withstanding pressure generated by high pressure gas by including an X-beam lattice structure and a reinforcing member thereof in a prismatic-shaped pressure tank and increasing space efficiency and material consumption ratio by being manufactured in a prismatic shape. 
     BACKGROUND ART 
     In order to accommodate a high-pressure fluid, various shapes of pressure tanks have been developed and many patents thereof have been filed. 
       FIG. 1  shows a pressure tank according to the related art, wherein  FIG. 1 a    is a spherical pressure tank.  FIG. 1 b    is a cylindrical pressure tank.  FIG. 1 c    is a lobed pressure tank, and  FIG. 1 d    is a cellular pressure tank. 
     Efficiency of a tank may be determined by volume efficiency and material consumption ratio. 
     
       
         
           
             
               
                 
                   ξ 
                   = 
                   
                     
                       V 
                       tank 
                     
                     
                       V 
                       prism 
                     
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     1 
                   
                   ] 
                 
               
             
           
         
       
     
     ξ V tank  V prism  The above Equation 1 can obtain the volume efficiency. In the above Equation 1, represents the volume efficiency, represents the volume of the tank, and represents the volume of the smallest rectangular parallelepiped box-volume which fully surrounds the tank. 
     ξ The higher the value of, the larger the volume efficiency of the tank, which means better utilization of the practical space consumed by the tank. 
     
       
         
           
             
               
                 
                   η 
                   = 
                   
                     
                       
                         V 
                         material 
                       
                       
                         V 
                         stored 
                       
                     
                     ⁢ 
                     
                       p 
                       
                         σ 
                         a 
                       
                     
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     2 
                   
                   ] 
                 
               
             
           
         
       
     
     η V material  V stored  The above Equation 2 expresses the material consumption ratio. In the above Equation 2, represents the material consumption ratio, the represents the volume of the material utilized to manufacture the tank, and the represents the amount of a fluid that can be filled in the tank. 
     η The lower the value of, the smaller the amount of material configuring the tank of the same volume, which means better increase in the efficiency of the tank. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Type of Pressure Tank 
                 
                   
                     
                       
                         ξ 
                         = 
                         
                           
                             V 
                             tank 
                           
                           
                             V 
                             prism 
                           
                         
                       
                     
                   
                 
                 
                   
                     
                       
                         η 
                         = 
                         
                           
                             
                               V 
                               material 
                             
                             
                               V 
                               stored 
                             
                           
                           ⁢ 
                           
                             p 
                             
                               σ 
                               a 
                             
                           
                         
                       
                     
                   
                 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                   
                 Sherical Type 
                 0.52 
                 1.5 
               
               
                   
                 Cylindrical Type 
                 0.78 
                 1.73-2.0 
               
               
                   
                 Lobe Type 
                 0.85 
                 1.73-2.0 
               
               
                   
                 Cellular Type 
                 &lt;1.0 
                 1.73-2.0 
               
               
                   
                   
               
            
           
         
       
     
     The above Table 1 represents the volume efficiency and the material consumption ratio of the tank according to the related art. It should be noted that the material ratios for cylindrical, lobe, and cellular tanks do not include the end enclosures such that the real material ratios will be somewhat higher than shown in the table. 
     As can be appreciated from the above Table 1, the cellular tank has the most efficient volume efficiency, and the cylindrical tank, the lobed tank, and the cellular tank have about similar material consumption ratios. 
     It is to be noted that the lobe tanks are made by combining and overlapping two or more cylindrical tanks, have an interior wall spanning between the intersection lines, and are normally capped with doubly curved end shells. Such designs are rather complicated and difficult to manufacture and significant bending occur in the tank walls. The cellular tank has high volume efficiency and is efficient in that it does not require increased plate thickness for large-capacity tanks; one may just increase the number of cells. However, the cellular tank cannot be easily manufactured due to a rather complicated shape; moreover, the end capping problem is a particular challenge. 
     In all tank cases where there are curved shells involved, i.e. spherical, cylindrical, lobe and cell tanks, it is very difficult if not impossible to design for complete double barrier of the exterior walls. 
     CITATION LIST 
     Patent Document 
     Korean Patent Laid-Open Publication No. 2003-0050314 
     DISCLOSURE 
     Technical Problem 
     An objective of the present invention is to provide a prismatic-shaped pressure tank, in particular, a pressure tank capable of extending its size to any dimension thereof and withstanding high pressure and temperature change of an interior fluid. 
     Another objective of the present invention is to provide a pressure tank having high volume efficiency, in particular, a pressure tank capable of preventing a fluid from being leaked from the inside of the pressure tank. 
     Still another objective of the present invention is to provide a pressure tank capable of reducing a sloshing phenomenon due to a fluid and distributing force applied to a tank wall. 
     Technical Solution 
     In one general aspect, an X-beam structure includes: a plurality of beams extending in X-axis, Y-axis, and Z-axis directions and formed in a lattice shape and a plurality of cross intersections  130  at which an X-axis beam, a Y-axis beam, and a Z-axis beam meet one another, wherein a cross section of each beam has a right-angled X shape, and the cross portions  130  are provided with continuous beams  110  in which one beam is continuously formed and attached beams  120  welded to the continuous beam  110 . 
     The X-axis beam may be spaced apart from an X-axis beam positioned on the same plane and adjacent thereto at the same distance, the Y-axis beam may be spaced apart from the Y-axis beam positioned on the same plane and adjacent thereto at the same distance, and the Z-axis beam may be spaced apart from the adjacent Z-axis beam positioned on the same plane and adjacent thereto at the same distance. 
     The attached beams  120  may have protrusions  121  in an angular shape formed at ends thereof and central portions of the protrusions  121  may be provided with cut-outs  122  which are consistent with the cross-sectional shape of the continuous beams  110 . 
     The cross intersection  130  may be formed so that a portion at which the cut-out  122  contacts the continuous beam  110  and a portion at which the protrusion  121  contacts the adjacent protrusion  121  have a smaller cross sectional area toward the outside from the inside. The reason for this is to accommodate beam joining in terms of welding. 
     An end surface of the cross intersections  130  may be welded to intersection brackets  141  and  142 . 
     In another general aspect, a pressure tank having the X-beam structure  100  as described above further includes: a tank body  200  having a high-pressure fluid accommodated therein and manufactured in a prismatic shape, wherein the X-beam structure  100  is disposed in the tank body  200  and reaches the other opposite side wall from one side wall of the tank body  200  and is regularly orthogonally-arranged. 
     Beam structure openings  211  may be provided at a place at which the tank wall  210  of the tank body  200  contacts the X-beam structure  100  in the same shape as the cross section of the X-beam structure  100  and the X-beam structure  100  may be extended to the outside of the wall by being inserted through the beam structure opening  211 . 
     An outer surface of the tank wall  210  may be provided with stiffening members  220  in an orthogonal pattern and the beam structure  100  may be welded to the stiffening members  220  after being inserted through the tank wall  210  the stiffening members  220 . 
     The distance from the tank wall  210  to the most adjacent beam crossing intersections  130  may be different from the distance between the intersection points in the interior of the tank. 
     Advantageous Effects 
     According to the X-beam structure and the pressure tank having the same of the present invention, the pressure tank is formed in a prismatic shape, that is, has a prismatic or box-like shape in appearance, such that the pressure tank can by way of modularity be increased to a size of any dimension thereof and can withstand high pressure and temperature change of a fluid. 
     Further, the tank having the high volume efficiency, that is, the pressure tank is manufactured in a prismatic shape, thereby making it possible to efficiently use the surrounding space thereof. 
     In addition, the X-beam structure having a lattice shape is mounted in the pressure tank thereby making it possible to reduce the internal fluid sloshing phenomenon due to fluid interaction with the X-beam grid which efficiently creates viscous turbulence that slows wave motion at the internal fluid free surface. This in turn efficiently reduces wave impact on the interior tank walls. In addition, the X-beam structure is manufactured to have a cruciform cross section to have good flexural strength, thereby making it possible to prevent the X-beam structure from being easily damaged. 
    
    
     
       DESCRIPTION OF DRAWINGS 
       The above and other objects, features and advantages of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a schematic view of a pressure tank according to the related art; 
         FIG. 2  is a lattice arrangement view of an X-beam structure according to an embodiment of the present invention; 
         FIG. 3  is a perspective view of cross portions according to an embodiment of the present invention; 
         FIG. 4  is an exploded view of cross portions according to an embodiment of the present invention; 
         FIG. 5  is a partial perspective view showing welded zones between beams meeting at a joint according to an embodiment of the present invention; 
         FIG. 6  is a perspective view showing a method of manufacturing an X-beam structure according to an embodiment of the present invention; 
         FIG. 7  is a basic partial perspective view showing an X-beam structure according to another embodiment of the present invention; 
         FIG. 8  is a partial cross-sectional view of a reinforcing bracket contacting an X-beam structure according to another embodiment of the present invention; 
         FIG. 9  is a cross-sectional view of a pressure tank mounted in a ship according to an embodiment of the present invention; 
         FIG. 10  is a partial perspective view showing a method of coupling an X-beam structure to a stiffened tank wall according to an embodiment of the present invention; and 
         FIG. 11  is a partial rear perspective view showing a method of coupling an X-beam structure to a stiffened tank wall according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF MAIN ELEMENTS 
     
         
           100 : X-beam structure 
           110 : continuous beams 
           120 : attached beams 
           121 : Protrusion 
           122 : cut-out 
           130 : Cross intersection 
           141 , 142 : Bracket 
           200 : Pressure tank 
           210 : Tank wall 
           211 : Beam structure opening 
           220 : stiffening member 
       
    
     BEST MODE 
     Hereinafter, a technical spirit of the present invention will be described in detail with reference to the accompanying drawings. However, the accompanying drawings is only an example shown for describing in more detail the technical spirit of the present invention and therefore, the technical spirit of the present invention is not limited to the accompanying drawings. 
     Overall shape and configuration of an X-beam structure  100  according to an embodiment of the present invention will be described with reference to  FIGS. 2 and 3 . 
     An X-beam structure  100  includes a plurality of beams extending in X-axis, Y-axis, and Z-axis directions and formed in a lattice shape and a plurality of cross intersections  130  at which an X-axis beam, a Y-axis beam, and a Z-axis beam meet one another, wherein a cross section of each beam has a right-angled X shape. 
     The above-mentioned right-angled X shape is manufactured in a cruciform shape, which means that an angle formed when two planes meet each other is at 90°. Herein, everything described below as an X shape has the foregoing shape. In addition, an X axis is orthogonal to a Y axis and a Z axis is orthogonal to an X axis and a Y axis. 
     The X-axis beams are spaced apart from their adjacent neighboring X-axis beams positioned on the same plane at the same distance, the Y-axis beams are spaced apart from their adjacent neighboring Y-axis beams positioned on the same plane at the same distance, and the Z-axis beams are spaced apart from their adjacent neighboring Z-axis s positioned on the same plane at the same distance. 
     In more detail, the X-axis beam is spaced apart from the adjacent X-axis beams, respectively, at the same distance, which are positioned on an X-Y plane or an X-Z plane, the Y-axis beam is spaced apart from the adjacent Y-axis beams, respectively, at the same distance, which are positioned on an X-Y plane or a Y-Z plane, and the Z-axis beam is spaced apart from the adjacent Z-axis beams, respectively, at the same distance, which are positioned on an X-Z plane or a Y-Z plane. 
     The cross intersections  130  according to the present invention will be described in detail with reference to  FIGS. 4 and 5 . 
     The X-beam structure  100  is manufactured to have an X-shaped cross section. Such shape has several advantages, but it also represents a challenge when coupling a continuous beam with two other beams at the cross intersections  130  at which the beams meet each other. In order to solve the above-mentioned problems, in the present invention, ends of attached beams  120  are welded to continuous beams  110  consecutively formed at the cross intersections  130 . 
     In more detail, the attached beams  120  have protrusions  121  in an angular shape formed at axial ends thereof and central portions of the protrusions  121  are provided with cut-outs  122  which are consistent with the cross-sectional shape of the continuous beams  110 . 
     That is, the cross intersections  130  are fixed by welding the cut-outs  122  to the continuous beams  110  and welding the protrusions  121  to the adjacent protrusions  121 , by welding the cut-outs  122  of the attached beams  120  to the continuous beams  110 ; in other words, four attached beams  120  are welded onto a continuous beam  110  at each intersectional joint. 
     In this case, the protrusions  121  and the cut-outs  122  have a smaller cross sectional area from the inside toward the outside and are provided with grooves that can be welded to facilitate butt-welds. 
     The X-beam structure  100  may be manufactured so that when a distance between the adjacent cross intersections  130  is set to be A at the cross intersections  130 , the length of a continuous beam may be  2 A or  3 A and a length of the attached beam  120  may be one of A,  2 A, and  3 A. 
     In addition, both sides of the continuous beam  110  and the attached beams  120  are provided with the protrusions  121 , except for shafts positioned at the outermost sides within the tank walls. 
     A continuous beam  110  may be one of the X-axis beams, the Y-axis beams, and the Z-axis beams in the X-beam lattice structure  100 . That is, when a continuous beam  110  is the X-axis direction, the Y-axis beam and the Z-axis beam are attached beams  120  of which the ends are welded onto the X-axis beam, when the continuous beam  110  is in the Y-axis direction, the X-axis beam and the Z-axis beam are attached beams  120  of which the ends are welded onto the Y-axis beam, and when the continuous beam  110  is the Z-axis beam, the X-axis beam and the Y-axis beam are attached beams  120  of which the ends are welded onto the Z-axis beam. 
     A method of manufacturing the X-beam structure  100  according to the present invention will be described with reference to  FIG. 6 . In addition, the X-beam structure  100  may be manufactured by building a structure of a single plane, welding the attached beams  120  to the cross intersections  130  and thereafter stacking and welding together plane upon plane. 
     Therefore, the X-beam structure  100  is not manufactured all at once, but is manufactured by building a unit structure and placing it and attaching it in its appropriate position. Note also that the X-beam structure has an extreme degree of repetitiveness, most of this structure will consist of similar beam sections of one, two or three unit lengths. The X-beam structure  100  may further include brackets  141  and will be described with reference to  FIG. 7 . 
     The cross intersections  130  are coupled with each other by welding and therefore, has more degraded strength than that of other portions. Therefore, the brackets  141  are welded to the cross intersections  130  so as to reinforce the cross intersections  130 , thereby increasing the strength of the cross intersections  130 . 
     The brackets  141  are formed at a portion at which an end surface parallel with the X axis of the X-axis beam of the cross intersection  130  is orthogonal to an end surface parallel with the Y axis of the Y-axis beam thereof, a portion at which an end surface parallel with the Y axis of the Y-axis beam thereof is orthogonal to an end surface parallel with the Z axis of the Z-axis beam thereof, and a portion at which an end surface parallel with the X axis of the X-axis beam thereof is orthogonal to an end surface parallel with the Z axis of the Z-axis beam thereof. 
     As shown in  FIG. 8 , when the length of the bracket  141  is extended for reinforcement, the bracket  141  is manufactured in a rectangular plate shape of having a hole formed at a center thereof like a bracket  142  and may be welded to ends of each shaft (see  FIG. 8 ). 
     A pressure tank including an X-beam structure  100  according to the embodiment of the present invention will be described in detail with reference to  FIGS. 7 and 11 . 
     The pressure tank is manufactured in a prismatic shape and the X-beam structure  100  is disposed in the pressure tank and is connected with each of the tank walls  210 . 
     The above-mentioned prismatic shape is not limited to a hexahedron, but if so desired an angled pressure tank having various shapes can be provided. 
     The X-beam structure  100  is disposed in a tank body  200  and reaches the other opposite side wall from one side wall of the tank body  200  and is regularly and orthogonally arranged. 
     Beam structure openings  211  are provided at a place at which the tank wall  210  of the tank body  200  intersects with the X-beam structure  100  in the same shape as the cross section of the X-beam structure  100 . In addition, a portion of the beam structure is protruded into the outside wall by inserting the beam structure  100  into the beam structure openings  211  and welding together the X-beams with the wall structure. 
     In addition, in order to increase the strength of the tank wall  210 , stiffening members  220  in an orthogonal shape are disposed at an outer surface of the tank wall  210 . 
     In this configuration, a portion in which the X-beam structure  100  is protruded to the outside is welded to the stiffening members  220  as well as to the tank wall itself. 
     The distance from the tank wall  210  to the most adjacent beam intersections  130  may be different from the distance between internal beam intersections themselves. Therefore, according to the X-beam structure  100  and the pressure tank having the same of the exemplary embodiment of the present invention, the pressure tank is formed in a prismatic shape, that is, has a prismatic shape in appearance, and has repetitive modular structure, such that the pressure tank can be increased to a size of any dimension thereof and can withstand the high pressure and temperature change of a fluid. 
     Further, the pressure tank having the high volume efficiency, that is, the pressure tank is manufactured in a prismatic shape, thereby making it possible to efficiently use the surrounding space thereof. This property is particularly important when placing a tank inside tank carrying body such as a ship or an offshore structure. 
     In addition, the X-beam structure  100  having a lattice shape is mounted in the pressure tank, thereby making it possible to reduce the sloshing phenomenon due to a tank fluid and reducing dynamic impact forces applied to the inner side of the tank wall  210 . 
     In addition, the X-beam structure  100  is manufactured to have a cruciform cross section to have good bending stiffness and strength, thereby making it possible to prevent the X-beam structure  100  from being easily damaged.