CN1264807A - Liquid gas storage tank - Google Patents

Abstract

A large, box-like polygonal tank for storing liquefied gas on land or on ground based structures and a method of constructing the tank. The tank is comprised of an internal, truss-braced, rigid frame, having a cover on the frame for containing the stored liquid within the tank. The internal, truss-braced frame allows the interior of the tank to be contiguous throughout while compensating for the dynamic loads caused by the 'sloshing' of stored liquid which, in turn, is due to the short excitation periods caused by seismic activity.

Description

Liquefied gas storage

The present invention relates to the liquid gas holding vessel, and aspect some, relate to a kind of storage tank that is suitable for storing with the low-temperature atmosphere-pressure condition low-temperature liquid gas (for example LNG Liquefied natural gas LNG) emphatically in the earthquake hotspot.

LNG Liquefied natural gas (LNG) is stored in the storage tank or container of double-wall structure usually.The internal layer tank body is contained as the first order of LNG Liquefied natural gas (LNG) and is held body, and outer casing then is used for thermoinsulation material is fixed on correct position, and protects internal layer tank body and thermal insulating material to avoid the adverse effect of environment.Common outer tank body often also can be used as the second level of LNG and volatilization steam thereof in design and contains the appearance body under the situation that the internal layer tank body lost efficacy.Although at present the storage tank of volume up to 200000 cubic metres built up or is just under construction, at the volume of the shore tank at station, air inlet storehouse and station, gas transmission storehouse generally between 50000 cubic metres to 100000 cubic metres.

At coastal region, the storage tank that is used for storing LNG has generally adopted two kinds of completely different structures.Wherein a kind of structure comprises the upright flat cylindrical tank that makes progress, and this tank body is generally made the internal layer jar with nickeliferous 9% steel, and makes outer casing with carbon steel, 9% nickel steel or reinforcing bar/prestressed concrete.Second kind of tank body is the structure of barrier type, in such structure, is provided with thin (for example 1.2mm is a thick) metal partion (metp) in a columniform concrete structure, and concrete structure is built on the face of land or under the face of land.Between the concrete drum wall of the dividing plate of stainless steel or ferronickel and bearing load and horizontal floor, one deck thermal insulating material is set.

Recently, about station, the LPG storehouse especially construction at station, air inlet storehouse many proposals that basic change is arranged have been proposed.A suggestion wherein relates to builds the station, storehouse on the continental shelf sea area of coastal waters, on such station, storehouse, LNG its be transported to by pipeline sell on the bank or use before, will this carry out from cargo ship unload, storage, pump is got and a series of processing procedures of gasification again.A kind of design that station, such storehouse has prospect to wish may be with the LNG storage tank and again equipment for gasification be installed on the box-shaped barge shape fondational structure (GBS) that a gravity sinks to the bottom, this fondational structure is similar to the fixed concrete gravity formula sea bed that uses as the offshore production platform now structure of taking a seat in the Gulf of Mexico.

But be that the storage tank of drum shape or the storage tank of barrier type are used for storing on station, GBS storehouse and are not had an optimistic view of especially aspect the LNG regrettably.The storage tank of drum shape has occupied space too big on the GBS for its stored LNG volume, and to build this storage tank on GBS be difficult, and cost is also very high.In addition, the size of this gas tank must limit within the specific limits (for example 50000 cubic metres), so that the GBS structure can build out more economically with the manufacturing means of easy acquisition.In order to satisfy a certain specific storage request, just must have many group storage elements like this.But do like this from the angle of cost and operating security and consider it all is undesirable.

And on the other hand,, thereby can provide relatively large storage volumes because the barrier type storage tank system can be built upon the inside of GBS.But the gas tank of building a barrier type but needs the structure flow process of order successively, in this flow process, in the cavity that thermal insulating material and spacer member can be installed in the GBS exterior building before, external structure must be built complete fully.This generally needs a longer construction period, and this will increase cost greatly.In addition, because being the thinking according to a kind of being called as " experience design ", the barrier type storage tank designs, under this Design Mode, to the assurance of the ideal operation performance of a certain storage tank and its Security is to be based upon on the basis of design experiences and laboratory research in the past, rather than is based upon the strictness that is obtained by theory analysis and Quantitative study and proves on the basis.When the storage tank of new shape of needs or size, maybe when having run into different environmental conditions and/or other earthquake loading condition, the functional reliability of barrier type storage tank when stored LNG level change be difficult to guaranteed.

Thereby LNG accumulator plant in coastal waters needs a kind of storage tank system that has overcome above-mentioned drum shape storage tank and barrier type storage tank shortcoming.This storage tank is polygonal case shape structure, and it can be installed in the inner space of steel or concrete system GBS, and can store jumbo LNG (for example 100000 cubic metres or more volumes) under cryogenic conditions.This tank body should be in the area that may run into face of land pulsation (as earthquake) no matter the liquid level of LNG be that many height can both be worked safely, and wherein said earthquake may cause the rolling of gushing of liquid, and produces corresponding dynamic load in tank body.

Similarly polygonal case shape storage tank has been used in and has stored LNG on the ocean carrier.For example extensively be referred to as " conch " storage tank (No. 2982441, for example visible U. S. Patent) (Conch), this storage tank is built out by 9% nickel steel or aluminum alloy.In the initial design that the above-mentioned patent of mentioning proposes, storage tank is by being (floor, bottom surface of four sides, top board or upper plates and tank body just) that six blocks of plates are built into, and these plates only carry out reinforcement or reinforcing with beam, reinforcing bar or the similar elements of level.According to inventor's design, specially saved the reinforcement of Vertical direction, to eliminate or to reduce thermal stress, wherein thermal stress is because LNG level change and producing in the temperature gradient of Vertical direction appearance in tank body.

" conch " (Conch) in the storage tank, the constraining rod that is provided with level at the angle of cut place of sidewall vertical engagement face to be strengthening the intensity at angle of cut place, and/or with constraining rod as interpleural relatively connection to reduce the distortion of wallboard.However, the embodiment in the as noted above patent is such, wallboard that the level that is still is strengthened and two-dimentional reinforcement floor and top board basic structural strength of tank body and rigidity are provided.The storage tank of building according to such design it is reported that its volume is lower than 10000 cubic metres at first.

Prolonged when using bigger storage tank when the design (as No. 2982441 patents are showed) of Conch type, just presented the such design of similar Fig. 1 (promptly existing known prismatic storage tank) by the development of Tokyo IHI company.In the problem of having considered to change owing to the LNG liquid level temperature gradient that produces, modern material does not limit with design method vertical stiffening rib is set.Thereby the rib shape storage tank shown in the figure comprises the side panel that carries out reinforcement by level and vertical beam/stiffening rib.Even but for 23500 cubic metres small size tank body, in order in engineering-built and job applications, to reach desirable strength and stiffness, Conch storage tank also necessary tabular partition wall and dividing plate with moderate reinforcement, this point can all be provided with a vertical partition wall at each length and width direction from the IHI storage tank and find out.Such design is considered to only be applicable to have relative storage tank than small capacity.

As the bigger capacity storage tank that is applicable to station, modern storehouse according to one of prior art design then the more partition wall of needs support the tank deck building and provide work use in required structural strength and rigidity (for example seeing Fig. 2).Thereby, a typical big capacity stores gas tank and in fact can be counted as comprising a plurality of more small-sized Conch storage tanks that are arranged in together, in such gas tank, the common sidewall between the adjacent tank chamber just becomes the level of total stocking system in whole storage volumes and the partition wall of transverse direction.

For the application on steamer and other cargo ship, partition wall in the storage tank not only provides intensity and rigidity to relatively large holding vessel, also reduced owing to jar in LNG liquid any gush rolling and act on dynamic load on the tank body, wherein the rolling of gushing of LNG is caused by buoyant hulls motion in transit.Because the caused dynamics exciting of the vibration of hull under wind wave action has the relatively long cycle (for example 6-12 second).And in the cabin that causes by the tank body internal partition wall liquid to gush natural period of rolling shorter relatively, thereby avoided the generation of resonance and gushed the enhancing of rolling load.Although curtain wall structure makes such tank body be suitable for the marine transportation of LNG, be applied on the bank or base plate when sinking to the bottom type accumulator plant (as GBS), still there is some shortcoming in it, mainly be because under these environmental conditionss, the dynamics exciting that is caused by earthquake (as earthquake etc.) has the very short cycle (for example 1/2 second to 1 second).

Because little and the natural period and single order " weak point " Energizing cycle that caused by earthquake that gushing the rolling ripple in the confined space are close, each the less compartment of size that forms by the partition wall in the holding vessel, evoke in storage tank by earthquake just become when liquid gushes rolling very harmful.Thereby, wish continental rise LNG tank body or be installed in the storage area of the tank body on the GBS long and do not cut off, GBS wherein then is landed on the sea bed.This is because such space of opening helps to reduce the caused dynamic load of Energizing cycle short when producing any earthquake.In addition, usually a large amount of compartments that caused in tank body by partition wall will need many cover low temperature refrigeration pumps and be used to fill with and the processing system of the tank body of finding time, and through a plurality of perforation and the connecting tube of top board, and this has correspondingly not only increased common security risk related when storing and handle LNG, also makes investment increase, operating cost raising.

The invention provides a kind of Large Box shape polygonal storage tank of storage liquid gasification and method that is used to make up this storage tank of being used for.This storage tank is particularly suitable for using on land or combines with the marine framework of backplanes support formula that for example gravity sinks to the bottom structure (GBS).Herein " case shape storage tank " speech of Shi Yonging be refer to have two end walls, the polygonal storage tank of sidewall, a top board and a base plate.This storage tank consists essentially of the two-dimentional trusses rigid-framed structure in (a) inside, i.e. the truss of many groups in vertical guide, and they are along longitudinal direction (along its length promptly) and transverse direction (being width direction) cross arrangement setting; And (b) covering, encase rigid-framed structure hermetically, hold the liquid that will store in tank body, to contain.

Said inner trusses rigid frame comprises a series of vertically extending supporting elements and horizontally extending supporting element, these rod members termination separately connected just form the rigid frame of a case shape, and the elements such as beam, pillar, support of having fixed some tubuloses and non-tubular shape in rigid frame further increase the strength and stiffness along length and width direction of rigid frame.With a series of firmization or form the covering of tank body without the outside that the plate (for example 9% nickel steel, aluminium or aluminum alloy etc.) of firmization is fixed on case shape rigid frame.

As on bridge and other civil building, using truss, can make a trusses rigid frame reach required strength and stiffness by different designs to arm beam, pillar, support Rankine-Hugoniot relations.In order to realize storage tank of the present invention, the structure of trusses rigid frame is at longitudinal direction and may be inequality in a lateral direction, or even dissimilar.Required certain strength and the rigidity of total dynamic loading that provides opposing to be caused by earthquake more is provided truss at this both direction in design, and supports huge top board building and bear the requirement that produces load owing to unavoidable base plate injustice.In most preferred embodiment of the present invention, only internal truss frame is set in the horizontal, and the earthquake zone that any pole just can be suitable for moderate strength is not set in the vertical.

More specifically, the Large Box shape polygonal storage tank in the most preferred embodiment of the present invention comprises two essentially identical ends and zero, one or more intermediate portion.All intermediate portions have identical structure basically, each intermediate portion all has a rigid frame, and this rigid frame is made of at least two vertically extending supporting elements and two horizontally extending supporting elements at least, and these supporting elements end separately interconnects.Elements such as other arm beam, pillar, support are fixed on the said rigid frame, with the intensity and the rigidity of further increase rigid frame.When various piece is assembled together, a series of plates are fixed on the outside of said rigid frame, they have formed the covering of said tank body or have contained wall.

Inside trusses rigid frame by using the case shape is as the main support frame of tank body, and the inside of storage tank in fact all is in connected state, and without any the barrier that forms by partition wall or like.This just makes the longer inner chamber of tank body of the present invention be avoided resonating under the dynamic loading in the rolling of gushing that earthquake causes, such dynamic load is different from the dynamic load that the motion owing to the navigation ship takes place substantially, but in contrast.

Can better understanding be arranged to real work structure of the present invention and obvious advantage with reference to accompanying drawing, accompanying drawing does not need to demarcate in proportion, and identical in the drawings numeral refers to similar parts, among the figure:

Fig. 1 has represented that simply cutting axle open according to the part of the present typical LNG storage tank that uses of prior art design surveys a view;

Fig. 2 surveys view according to a kind of axle that is suitable for being applied in the large-scale storage tank on the station, modern storehouse that designs of expanding of prior art;

Fig. 3 is the perspective view according to a kind of LNG storage tank end portion of best mode for carrying out the invention;

Fig. 4 is that the axle of the intermediate portion in the most preferred embodiment of the present invention is surveyed view;

Fig. 5 is the cross section view of being done along the 5-5 line among Fig. 4;

Fig. 6 is the cross section view of being done along the 6-6 line among Fig. 5; And

Fig. 7 represents that the part of the storage tank that assembles of most preferred embodiment according to the present invention cuts axle open and survey a view.

More specifically with reference to accompanying drawing, Fig. 1 has represented typical polygonal case shape storage tank T in a kind of prior art, and in the transportation process of LNG, the shell H inside that is placed in the sea-freight ship stores LNG to such storage tank at present.This storage tank of 23500 cubic metres is separated into four cabins by a pair of withe LB and across bulkhead TB.Such storage tank is designed by Tokyo IHI company.Fig. 2 has represented a large-scale storage tank 10 (being five times of polygonal storage tank size of the prior art among Fig. 1), and it can carry out design-build with the basic principle that is equal to prior art.

Basically, storage tank 10 comprises sidewall 11,12, end panel 13,14 (plate 14 being removed in order to represent to know), top board or cover plate 15 and base plate 16.Formed laterally vertical partition wall 20 by a series of at the isolated vertical panel of longitudinal direction, the vertical panel of longitudinal extension has then formed withe 21 (only having represented in the design of Fig. 2).These partition walls store the necessary strength and stiffness of LNG for storage tank provides in the sea-freight process.

Side plate 11,12 has been undertaken strengthening or " firmization " by the isolated perpendicular elements of a series of substantially horizontals (for example the T type rigid member of steel or aluminium matter, strengthening rib etc.) 17,18 (having only the minority element that number designation is arranged for clear) respectively, end panel 13,14 usefulness similar elements 18 are carried out reinforcement, and top board 15 carries out reinforcement by element 19.A series of other element (not shown)s can also be set between each reinforcing element 17,18,19, with the orthogonal direction at each element these reinforcing elements are strengthened, for example available a plurality of vertical isolated horizontal cells are strengthened plate between perpendicular elements 18.

Strengthen by the vertical reinforcing element of some horizontal intervals and the horizontal reinforcing element at vertical interval (for clear not shown) equally from the partition wall 20 and 21 that the base plate of storage tank has been crossed over the storage tank entire depth to top board, as those skilled in the art understand, the building course of a tank body 10 generally may be included in the tank body various piece is fitted together before the storage tank 10 that forms the case shape, and supporting member and/or rigidity reinforcing element are fixed to process on their plate shape parts separately with welding or other mode.

The application of continental rise or GBS more needs the to have bigger capacity LNG storage tank of (for example 100000 cubic metres or more).For example in the tank designs of prior art mentioned above, it is necessary to use partition wall to be considered to reach the strength and stiffness of huge tank body like this, especially is used under the condition of sea-freight work when storage tank.In brief, neat jar of high partition wall (for example the plate among Fig. 2 20,21) also provides other benefit in the prior art: promptly storage tank is separated into a plurality of independently compartments 22.Though these compartments 22 may need separately add notes and/or vent line, transfer pump etc., and these equipment have generally increased investment and operating cost significantly, but they have the favourable part that reduces dynamic load really, wherein dynamic load is by the gushing rolling and produce of the LNG in the tank body, and LNG gush the result that rolling is ship motion.

Reducing of dynamic load is because the shock wave natural period of liquid in the limited little space of single compartment 22 do not respond the exciting cycle that is caused by ship motion nearly.And on the other hand, in the storage tank of a continental rise or GBS, any dynamic load that acts in the storage tank all may be caused by earthquake, and earthquake has the short exciting cycle (from about 1/2 second to about 1 second).If partition wall of the prior art is used in such environment, because the rolling of gushing that is caused by partition wall in the compartment has approximate length free period, dynamic load may instead be reinforced.Thereby, when the very big LNG storage tank of capacity is that the partition wall that is provided with is considered to be harmful at interval under continental rise or the condition by the GBS support.

Hereinafter, represented a kind of LNG Liquefied natural gas of the present invention (for example LNG) storage tank 30 among the figure with reference to accompanying drawing 3-7.Basically, storage tank 30 comprises that an inner boom supports rigid frame system 31, and this rigid frame system is coated by plate (being covering), and plate contains the liquid that will be stored in the tank body.The plate that constitutes storage tank 30 sidewalls 32, end wall 33, top board 34 and base plate 35 can be through strengthening or not process reinforcement.Each plate (1) after assembling is finished provides contains the barrier structure that holds LNG in the storage tank, and (2) bear everywhere load and pressure, and load pressure is delivered in the rigidity rigid frame system 31, finally bear all load, comprise the ground dynamic load that causes by earthquake etc. by rigid frame system 31.

More specifically, storage tank 30 is case shape polygonal tank bodies of a free-standing, and it can contain the LNG Liquefied natural gas (LNG) of holding significant volume (for example 100000 cubic metres or more).Although may adopt different build process, Fig. 3-7 has represented a kind of best approach of assembling storage tank 30.Basically, storage tank 30 comprises two end 38 (see figure 3)s and a plurality of intermediate portion 36 (seeing Fig. 5, Fig. 6) between them.Each end 38 is identical structure substantially, they are formed by plate 40, plate 40 connects (for example welding or other connection means) and forms end wall 33 together, and these plates 40 also are used to form each section of top board 34, sidewall 32 and base plate 35 when storage tank is assembled.

Plate 40 can be made by any suitable material (for example 9% nickel steel, aluminium or aluminum alloy etc.), and this material will be ductile, and has qualified fracture characteristics under cryogenic conditions.As shown in the figure, each section end wall 33 and top board 34, sidewall 32, base plate 35 strengthened with element 41 and crossing member 42 (for example T type reinforcing bar, stiffening rib or similar elements etc. only identify subelement for clear).Also can cross over the corner and/or adjacent plate edge is provided with the strength and stiffness of angle brace 43 with further enhancing end 38.

An intersegmental part trusses rigid frame 31 is preferably built in the moulding of intermediate portion 36 earlier, then plate 40 is fixed on their outside.In order to finish such work, form a rigid frame shape member (see figure 5) by the end that connects two perpendicular elements 44 and two horizontal cells 45 (these elements for example are I type beam, H type beam, square or circular pipe etc.), thereby produce one section trusses rigid frame 31.Usually in the frame shape member of outside, fix again other perpendicular elements 44a and horizontal cell 45a to increase its intensity, add sprit bar 46 and finish this section trusses rigid frame 31.Beam, pillar and the support element of forming rigid frame among Fig. 5 have the different arrangement setting of many kinds, in case assembling is finished, use these different arranging methods to provide required strength and stiffness to the inside trusses rigid frame of storage tank.Fig. 5 has only represented a kind of of these Rankine-Hugoniot relationss.

Several less plates 40 can at first fit together, and available supporting element 41,42 strengthens, and this assembled plate is fixed on the outside of rigid frame 31 each sections then.In case end 35 and all intermediate portions 36 have been finished, just they are assembled, be fixed together by welding or other means, form storage tank 30 (see figure 5)s.Strengthen truss at longitudinal direction if desired, other supporting member will be arranged (for example between perpendicular elements 44a and the vertical boom 50 that is fixed thereon, see Fig. 6), they can be installed after the assembling of tank body is finished, or install when building end 35 or intermediate portion 36 before the assembling of tank body is finished.

As can be seen, because inner trusses rigid frame 31 is open, the inside of storage tank 30 in fact all is intercommunication on the whole, thereby the LNG or other liquid that are stored in wherein can freely spring up from one end to the other side, and betwixt without any effectively shielding parting.This must make storage tank and have bigger effective storage volumes with respect to the same size tank body that partition wall is set, and such storage tank also only needs a cover connecting tube road and is used to inject pump group with the emptying tank body.The more important thing is that because the relatively long connection spans of storage tank of the present invention 30, stored liquid is anyly gushed rolling all can only evoke very little dynamic load relatively on tank body by what earthquake caused.This load is significantly smaller than as not and adopts prior art to form the situation of the tank body of a plurality of compartments with partition wall.

Claims (10)

1. Large Box shape polygonal storage tank that is used for storaging liquid, this storage tank has sidewall, end wall, a top board and a base plate, said storage tank comprises: many groups are arranged the internal vertical truss that is provided with along the length direction longitudinal separation of said storage tank, these internal truss frames all comprise: a series of vertically extending supporting elements and horizontally extending supporting element, these supporting elements termination separately couple together and form a framework; At the said framework internal fixation boom element that couples together by vertical extent supporting element and horizontal-extending supporting element with its intensity of further enhancing; And a covering is fixed on the said vertical truss group hermetically, said covering has formed and has been used for containing said sidewall, end wall, top board and the base plate that holds said liquid.

2. storage tank according to claim 1 is characterized in that: said storage tank comprises the vertical truss of at least one longitudinal extension, and it and is fixed in therebetween between the truss group of said longitudinal separation.

3. storage tank according to claim 1 is characterized in that: said covering comprises the polylith plate, and these plates are strengthened in vertical and/or substantially horizontal by a series of reinforcing elements, and is fixed on the outside of said trusses rigid frame.

4. storage tank according to claim 3 is characterized in that: said plate is to be made of 9% nickel steel.

5. storage tank according to claim 3 is characterized in that: said plate is made of aluminium.

6. Large Box shape polygonal storage tank that is used for storaging liquid, this storage tank has sidewall, end wall, a top board and a base plate, and said storage tank comprises two ends, and each end comprises again: in said two end walls one; One section of the said sidewall that each links to each other with said end wall; One section of the said base plate that links to each other with said end wall; And a section of the said top board that links to each other with said end wall; Storage tank also comprises an intermediate portion of locating and being fixed between said two ends at least, said intermediate portion comprises: at least one rigid frame, this rigid frame is made up of at least two vertically extending supporting elements and two horizontally extending supporting elements, and these supporting elements termination separately is interconnected to form a vertical framework; And further strengthen its intensity at said framework internal fixation boom; And a series of plates that are fixed on said framework periphery, thereby the intermediate section of formation sidewall, base plate and top board; Wherein saidly be fixed on polylith plate on the said rigid frame when storage tank is assembled, form said sidewall, base plate, top board by being connected with corresponding plate on said two ends respectively.

7. storage tank according to claim 6 is characterized in that: storage tank comprises the said intermediate portion with rigid frame that at least one is other; And the vertical truss of at least one longitudinal extension, it is positioned between the said rigid frame of said at least one intermediate portion and that other intermediate portion, and is fixed in therebetween.

8. storage tank according to claim 6 is characterized in that: said plate is to be made of 9% nickel steel.

9. storage tank according to claim 6 is characterized in that: said plate is made of aluminium.

10. a construction is used for the method for the Large Box shape polygonal storage tank of storaging liquid, this storage tank has two end walls, sidewall, a top board and a base plate, said method comprises: build two ends, and each end wherein is built into like this: form in said two end walls; One section of each said sidewall is linked to each other with said end wall; Respectively one section of said top board with said base plate one section is linked to each other with the bottom with the top of said end wall, and said each section of top board, negative and said sidewall linked to each other on said end wall, each jar section adjoins each other on end wall; And build at least one intermediate portion, wherein said at least one intermediate portion is to build like this: form a rigid frame; Further strengthen its intensity at this rigid frame internal fixation boom; And by the plate of said intermediate portion and each plate of said end are connected, thereby said intermediate portion is fixed between said two ends, when said end and said at least one intermediate portion are joined together, the said plate that couples together has just formed the Sheng of said storage tank and has held wall, thereby has formed said polygonal storage tank.

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