CN105526493A - 9Ni steel plate for inner tank wall of large liquefied natural gas storage tank, manufacturing method for 9Ni steel plate and tank wall structure - Google Patents
9Ni steel plate for inner tank wall of large liquefied natural gas storage tank, manufacturing method for 9Ni steel plate and tank wall structure Download PDFInfo
- Publication number
- CN105526493A CN105526493A CN201410514136.4A CN201410514136A CN105526493A CN 105526493 A CN105526493 A CN 105526493A CN 201410514136 A CN201410514136 A CN 201410514136A CN 105526493 A CN105526493 A CN 105526493A
- Authority
- CN
- China
- Prior art keywords
- plate
- thickness
- steel
- steel plate
- tank
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
The invention discloses a 9Ni steel plate for an inner tank wall of a large liquefied natural gas storage tank, a manufacturing method for the 9Ni steel plate and a tank wall structure. The steel plate for the inner tank wall is thick in one end and is thin in the other end in a length direction, the plate thickness of the steel plate is linearly increased or reduced within all or part of a length section, and the plate width and the plate length of the steel plate are constant; the thickness of the steel plate is gradually changed in the length direction, and a gradual-changing gradient is constant in overall length or is constant in sections; a ratio of the plate thickness Tb of the thickest end to the plate thickness Ta of the thinnest end is not greater than 2; L1, L2, and so on are different distances from the thin end part of the steel plate, and the thicknesses of the steel plate are respectively T1, T2, and so on at the corresponding distances; within the length section range of 0-L1, L1-L2, and so on, the inner plate thickness is linearly increased or reduced, and the thickness increase or reduction gradient within the length section is constant. On the premise of not affecting the capacity and the safety of the storage tank, the usage amount of the steel plate for the tank wall of the inner tank is remarkably reduced, the prefabricating processing process of the wall plate is reduced, the welding construction efficiency of the tank wall of the inner tank is improved; and moreover, the matched tank wall steel plate has the characteristics of being great in wide breadth, and trapezoidal and gradually varied in thickness.
Description
Technical field
The present invention relates to Wide and Heavy Plates production technology, in particular to tank skin 9Ni steel plate in large-scale liquefied natural gas (LNG) tank and manufacture method and tank skin structure, this steel plate has good-196 DEG C of low-temperature flexibilities, is applicable to the large-scale liquefied natural gas (LNG) tank of capacity more than 10 ten thousand steres in the energy, chemical industry.
Background technique
Worldwide, rock gas is as one of clean energy resource, and its total demand is in sustainable growth.Particularly after Fukushima, Japan nuclear accident, nuclear energy development and utilization receives very large resistance, and instead rock gas respectively to consume energy the favor of big country by the world more as safety, clean energy resource.Corresponding, domestic natural gas demand is also sharply rising, and to 2013, China's natural gas Apparent con-sumption reached 1650 billion cubic meters, about inlet natural gas reaches 530 billion cubic meters.Expect 2015, China's natural gas supply will reach 2680 billion cubic meters, comprise Domestic Resources 1940 billion cubic meter and import 740 billion cubic meter; The year two thousand twenty deliverability of gas will reach 4310 billion cubic meters, comprise Domestic Resources 2700 billion cubic meter and import 1610 billion cubic meter.By 2015, the proportion that China's natural gas consumption figure accounts for national primary energy total quantity consumed will increase to 9%, be promoted to 12% to the year two thousand twenty by continuing.
As the terminal of the conveying of land natural gas line and marine ships transport, to accept, to store, peak regulation, the size liquefied natural gas station that splits into major function be indispensable important step in whole natural gas supply chain.After natural gas via post liquefaction volume-diminished 600 times, with the form of LNG Liquefied natural gas (hereinafter referred to as LNG) by safety, be stored among LNG storage tank at low cost, one of LNG storage tank key facility just in size liquefied natural gas station.
Along with the quick increase of domestic natural gas demand, the construction of all kinds of Large LNG storage tank is also in rapid rising.Since the first Large LNG storage tank of China in 2003 puts into operation, China only 16 ten thousand stere prestressed concrete LNG storage tank has built or has built up 43, and the LNG storage tank of volume 20 ten thousand stere also completes design, is planning among construction.In the LNG storage tank of above-mentioned different vessels, although tank structure is different, at present modal, particularly in the above LNG storage tank of 10 ten thousand stere, to account for absolute main flow, be cylindrical shape prestressed concrete tank.This LNG storage tank tank body is made up of steel Inner tank and prestressed concrete outer tank, and inner and outer tank tank skin is all cylindrical structure.Wherein, Inner tank tank skin is all by many different-thickness, 9Ni Plate Welding columnar structured with good-196 DEG C of low-temperature flexibilities.
Although amount of capacity is different, traditional steel plate specification designed by cylindrical shape LNG storage tank Inner tank is also different, and generally speaking, the tank skin steel plate of these LNG storage tank Inner tanks has following common feature:
1) Inner tank tank skin structure is columnar structured, and tank skin steel plate divides some layers from top to bottom.In same layer, steel plate is all using the wide floor height as this layer of plate, using plate length as one of tank skin section of arc length, and the thickness of steel plate is all identical.And between different layers, steel plate thickness then from top to bottom stepped increase, that is: the thickness of lower floor's steel plate is always more than or equal to the thickness of last layer, resists in the tank that from top to bottom increases progressively with this static pressure storing LNG liquid and produce.
2) in same layer, the material of steel plate is all identical.According to industry standard, the material of this type of LNG storage tank Inner tank must adopt has good-196 DEG C of low-temperature flexibilities, 9Ni steel plate containing about 9% Ni element, adopt " normalizing+tempering " or " quenching+tempering " explained hereafter, the conventional trade mark has the 06Ni9DR in China's standard GB/T 150, the X7Ni9 in Europe superscript EN10028-4, A553Type1 etc. in American Standard ASTM.
3) Inner tank tank skin steel plate all needs to carry out cans processing, makes its bending radius of curvature equal or be in close proximity to the radius of Inner tank tank skin circumference.The cans processing of tank skin steel plate is one of the prefabricated manufacturing procedure that must have of traditional Inner tank tank shell.
Example is designed to 16 ten thousand stere cylindrical shape prestressed concrete LNG storage tank of certain classics current, its Inner tank tank skin girth is 252 meters, interior tank skin steel plate material is the 9Ni steel in GB150, the trade mark is 06Ni9DR, distinguishes can be divided into " quenching+tempering " type and two kinds, " normalizing+tempering " type by heat treatment process; The tank skin that height overall is 36.12 meters is formed by 12 layers of Plate Welding, the length of every layer of tank skin steel plate and width are all identical, namely be all formed by 22 3.01 meters of wide × 11.45 meter long Plate Weldings, but steel plate thickness is stepped increase from top to bottom then, and namely the thickness of lower floor's steel plate is always more than or equal to the thickness of last layer.
This 16 ten thousand stere LNG storage tank Inner tank tank skin by the specific design of low-temperature flexibility steel plate as following table 1.
Table 1
Accordingly, can extrapolate:
1) this 16 ten thousand stere LNG storage tank Inner tank needs 12 × 22=264 to open 06Ni9DR steel plate altogether, amounts to about (27+25+23+21+19+17+15+13+12+12+12+12) × 2.98 × 11.45 × 22 × 7.85/1000 ≈ 1228 tons;
2) this 16 ten thousand stere LNG storage tank Inner tank need weld circular weld between the long wallboard of total 22 × 252=2771 rice and the longitudinal weld between the long wallboard of 12 × 22 × 2.98=787 rice altogether.
At present, above-mentioned 16 traditional ten thousand stere cylindrical shape prestressed reinforced concrete LNG storage tank have become the mainstay of domestic LNG storage tank, and existing designing technique reaches its maturity, and has started the work including relevant domestic standard and specification in.
For 16 ten thousand stere cylindrical shape prestressed concrete LNG storage tank, analyze prior art, the structural design of its storage tank Inner tank tank skin also exists following deficiency:
Although 1. name is called prestressed concrete storage tank, the true kernel of above-mentioned LNG storage tank or low temperature resistant steel Inner tank, LNG storage tank build technological difficulties and construction cost mainly on Inner tank because its Inner tank is the LNG liquid of direct contact-165 DEG C.
After inner storage tank fills LNG medium, the static pressure that on Inner tank tank skin, certain any steel plate bears is inversely proportional to its height, therefore, along the pressure-bearing of position under every layer of steel plate is always less than steel plate along the pressure-bearing of position.And the height of every layer is higher, and namely steel plate is wider, the static pressure difference that the upper edge of steel plate and lower edge are born is larger.Obviously, merely from Force Calculation angle, on steel plate, the thickness on edge can be less than the thickness on lower edge completely.But in fact, during existing tank structure design, the thickness of tank skin steel plate is all calculate according to the static pressure of bearing along position under it, that is, for the upper edge of steel plate, always has segment thickness to belong to " unnecessary ".And tank skin floor height is higher, and namely steel plate is wider, the thickness of " unnecessary " is also more, and the steel " waste " of generation are more serious.As everyone knows, the 9Ni steel plate price that in LNG storage tank, tank skin is used is very expensive.From minimizing steel plate use amount angle, the floor height (being also steel plate width) of tank skin is the smaller the better.But the floor height of tank skin is less, the overall length of circumferential weld when causing tank body to build is also longer.The supporting welding consumables price of 9Ni steel is the decades of times of steel plate price, and welding cost is equally also the several times of general steel plate welding cost.Consider from minimizing weld seam total length angle, steel plate width is then more wide better.Obviously conflict is defined between the two.
After overall balance, the interior tank shell width of domestic 16 common at present ten thousand stere LNG storage tank is designed to about 3000mm.
2. but, the theoretically perfect tray of the wide not domestic main flow Wide and Thick Slab producer of this plate of 3000mm is wide.Because current main flow wide and heavy plate mill is all 5 meters of heavy plate mills, and actual maximum finished width is 4600 ~ 4800mm.Therefore for the steel plate width of 3000mm, the manufacturing efficiency of above-mentioned 5 meters of heavy plate mills is unsatisfactory, only has about 75% of 4700mm width steel plate manufacturing efficiency.
3. this plate of 3000mm is wide is unfavorable for welding procedure equally.As mentioned above, a kind of like this design of 16 ten thousand stere LNG storage tank, total weld seam of total about 3560 meters long, wherein, the circular weld between tank skin steel plate is about 2770 meters, and longitudinal weld is about 790 meters, and the length of circular weld is several times as much as the length of longitudinal weld.For LNG storage tank, the circular weld between current wallboard adopts submerged-arc horizontal or stick electrode arc welding usually, and longitudinal weld and fillet weld then adopt stick electrode arc welding usually.Compared with welding with 15 ten thousand stere crude oil storage tanks, the welding efficiency of submerged-arc horizontal, stick electrode arc welding is very low.Obviously, the length reducing circular weld between wallboard just means the welding efficiency that can improve LNG storage tank Inner tank tank skin exponentially.
4. steel plate is all using the wide floor height as tank skin of plate, using plate length as tank skin one section of arc length circumferentially, therefore, traditional tank skin wallboard all needs to carry out cans processing, and its bending radius of curvature is exactly the radius of tank skin circumference.The cans processing of wallboard, as one of the prefabricated manufacturing procedure of traditional Tank wallboard, had both added storage tank manufacture cost, had also extended the manufacturing cycle.
Summary of the invention
The object of the present invention is to provide tank skin 9Ni steel plate and manufacture method and tank skin structure in a kind of large-scale liquefied natural gas (LNG) tank, at tank capacity, when Security is not subject to any loss, the use amount of remarkable minimizing Inner tank tank skin steel plate, reduce the prefabricated manufacturing procedure of wallboard, improve the welding procedure efficiency of Inner tank tank skin, and, supporting tank skin steel plate has large wide cut, thickness is the feature of trapezoidal gradual change, and the steel grade of this tank skin steel plate is have good-196 DEG C of low-temperature flexibilities, 9Ni steel plate containing about 9% Ni element, the trade mark is as the 06Ni9DR in GB GB150, X7Ni9 in Europe superscript EN10028-4, A553Type1 etc. in American Standard ASTM, the Large LNG storage tank of the capacity that is applicable to more than 10 ten thousand steres.
For achieving the above object, technological scheme of the present invention is:
In large-scale liquefied natural gas (LNG) tank, tank skin 9Ni steel plate, is characterized in that, one end is thick in the longitudinal direction, one end is thin for steel plate, and its thickness of slab linearly increases or reduces in all or part of length sections, and the wide W of plate and the long L of plate of steel plate are constant; The thickness of steel plate is gradual change along its length, and the slope of gradual change is the constant or piecewise constant of total length; Wherein, the thickness of slab Tb of the thickest end is not more than 2 with the ratio of the thickness of slab Ta of the thinnest end; L1, L2 ... be respectively the different distance leaving the thin end of steel plate, over this distance, the thickness of steel plate is respectively T1, T2 ..., the rest may be inferred by analogy for it; Within the scope of 0 ~ L1, L1 ~ L2... length of interval, thickness of slab linearly increases or reduces, and the slope of increase or reduction is constant in this length of interval.
The storage tank inner canister of tank skin steel plate in the large-scale liquefied natural gas (LNG) tank of the present invention, this storage tank Inner jar structure is Polygonal barrel structure, adopt at least one deck difference Plate Steel to be welded, difference Plate Steel with its plate length be high, be welded into one deck difference slab layer so that its plate is wide for one of polygonal section length of side; The thickness of difference Plate Steel linearly increases from top to bottom, and namely the geometrical shape of its vertical section is trapezoidal.
Further, when slab layer of being on duty is more than two layers, between difference slab layer and difference slab layer, have uniform thickness flaggy as transition, uniform thickness flaggy with plate wide for high, being polygonal with plate length, limit is welded; The weld seam of each layer tank skin steel plate staggers up and down mutually.
Preferably, adopt upper and lower three-decker, first layer and bottom are the plate face of difference slab layer, and the thickness of difference Plate Steel linearly increases from top to bottom, and namely the geometrical shape of its vertical section is trapezoidal; The second layer, third layer are uniform thickness flaggy.
Preferably, length Deng Plate Steel is the integral multiple of difference Plate Steel width, and carry out bending to differ from Plate Steel width for the length of side, wait the distance between each folding of Plate Steel and folding to be the width of steel plate, after bending, the angle of adjacent two length of sides equals the polygonal interior angle of storage tank Inner tank tank skin.
Preferably, the size of the angle formed after uniform thickness flaggy tank skin steel plate bending equals an interior angle in the Polygonal barrel structure of storage tank Inner tank.
In large-scale liquefied natural gas (LNG) tank of the present invention, the manufacture method of tank skin steel plate, is characterized in that, comprise the steps:
1) the poor Plate Steel of Inner tank tank skin steel plate is identical with existing 9Ni steel plate with the composition of blank used such as Plate Steel such as grade, and sotck thinkness is more than 6 times of the maximum thickness of slab of difference Plate Steel;
2) blank is through wide and heavy plate mill thermo forming;
3) differ from Plate Steel after rolling-forming, must through quenching or normalizing heat treatment, and be on duty Plate Steel maximum ga(u)ge Tb >=16mm time, can only through quenching heat treatment;
During 3.1 quenching heat treatment, time inside furnace, holding time depend on its minimum thickness of slab Ta and maximum thickness of slab Tb, and other parameters of quenching are identical with existing 9Ni steel plate;
Time inside furnace=A*Tb, unit min, wherein, A is time inside furnace thickness coefficient, gets A=1.5 ~ 4.0, unit min/mm;
Holding time=B*Tb, unit min, wherein, B is holding time thickness coefficient, gets B=1.0 ~ 3.0, unit min/mm;
B* (Tb-Ta)≤30, unit min, wherein, Tb, Ta unit is mm;
Time inside furnace during 3.2 normalizing heat treatment, holding time depend on its minimum thickness of slab Ta and maximum thickness of slab Tb: except time inside furnace, holding time, and other normalizing process parameters are identical with the 9Ni steel plate below existing 16mm thickness;
Time inside furnace=A*Tb, unit min, wherein, A is time inside furnace thickness coefficient, gets A=2.0 ~ 5.0, unit min/mm;
Holding time=B*Tb, unit min, wherein, B is holding time thickness coefficient, gets B=1.5 ~ 4.0, unit min/mm; Wherein, Tb, Ta unit is mm;
4) tempering heat treatment
The time inside furnace of difference Plate Steel when temper, holding time depend on its minimum thickness of slab Ta and maximum thickness of slab Tb, and except time inside furnace, holding time, other tempering process are identical with existing 9Ni steel plate;
Time inside furnace=A*Tb, unit min, wherein, A is time inside furnace thickness coefficient, gets A=2.5 ~ 8.0, unit min/mm;
Holding time=B*Tb, unit min, wherein, B is holding time thickness coefficient, gets B=1.5 ~ 7.0, unit min/mm;
B* (Tb-Ta)≤45, unit min, wherein, Tb, Ta unit is mm.
Further, during with wide and heavy plate mill thermo forming, the width W of difference Plate Steel is no more than 4.7 meters.
Again, more than two or two poor Plate Steels are scrabbled up a roller milling large plate to realize multiple length rolling, this roller milling large plate adopts symmetric design, namely thickness in the longitudinal direction can first by thin thickening, again by thick thinning, also can first by thick thinning, again by thin thickening, or the combination of above-mentioned two kinds of modes.
In addition, difference Plate Steel quenching heat treatment adopts the quenching of rolled type quenching unit, and the rolling reduction of each pressure roller is independent controlled; During the quenching of difference Plate Steel, its steel plate speed of travel and the quenching water yield can be that the Plate Steels such as the tradition of Tb are identical with thickness.
The novel tank wall construction of Large LNG storage tank Inner tank of the capacity that the present invention proposes more than 10 ten thousand steres and the design proposal of supporting tank skin steel plate.The outer tank tank skin of this storage tank is still traditional cylindrical shape prestressing force Inner concrete structure, but its inner canister tank skin is polygonal body, caliper portion or whole from top to down of tank skin piecewise linearly increase, and namely the geometrical shape of tank skin vertical section is partly or entirely in trapezoidal shape.Compared with existing storage tank shell, storage tank shell of the present invention, under the prerequisite not affecting tank capacity and Security, significantly reduces the use amount of Inner tank tank skin low-temperature flexibility steel plate, improves the welding procedure efficiency of tank skin.The design proposal of supporting the invention described above tank skin structure, proposes the manufacture method of novel Inner tank tank skin low-temperature flexibility steel plate, make this feature that Inner tank tank skin steel plate has large wide cut, thickness is trapezoidal profile, and the steel grade of this tank skin steel plate is 9Ni steel plate.
Inner tank tank skin steel plate of the present invention is divided into the Plate Steel two kinds such as poor Plate Steel and tradition, and both materials are and have good-196 DEG C of low-temperature flexibilities, 9Ni steel plate containing about 9% Ni element, the trade mark is as the X7Ni9 in the 06Ni9DR in GB GB150, Europe superscript EN10028-4, A553Type1 in American Standard ASTM; Chemical composition, the rolling of the Plate Steels such as this tradition are all identical with existing uniform thickness 9Ni steel plate with heat treatment process, but prefabricated adding must replace brake forming with bending man-hour; The composition of this New Type of Differential Plate Steel blank used is identical with existing uniform thickness 9Ni steel plate, but its rolling and heat treatment process are all different from existing uniform thickness 9Ni steel plate, and does not need bending or brake forming man-hour in prefabricated adding.
Before formation rolling passage, heating, the rolling mill practice of the heating of Plate Steel of the present invention's difference, rolling mill practice and the 9Ni steel plate of common traditional uniform thickness are identical.Formation rolling is the last some passages of rolling, before this, steel plate is uniform thickness distribution along its length, and in this some passage, milling train dynamically adjusts roll gap, and steel plate rolls into that its thickness is gradual change along its length the most at last, the slope of its gradual change is the constant or poor Plate Steel of piecewise constant of total length.
During with wide and heavy plate mill thermo forming, for reducing the fusion length of wallboard, improve the manufacturing efficiency that tank skin builds speed and wallboard, the width of this steel plate should be wide as much as possible, but no more than 4.7 meters; For improving the manufacturing efficiency of wide and heavy plate mill, two or two can also be scrabbled up a roller milling large plate to realize multiple length rolling with upper steel plate.The stacking after finished steel plate is cut into for ease of roller milling large plate, this roller milling large plate adopts symmetric design, that is: thickness in the longitudinal direction can first by thin thickening, again by thick thinning, also can first by thick thinning, again by thin thickening, or the combination of above-mentioned two kinds of modes.
Contrast existing LNG storage tank inner canister tank skin structure, Inner tank tank skin structure involved in the present invention is polygon structure, structure and specially designed steel plate are difference slabs for this reason, namely its thickness is piecewise linearity change along its length, this and above-mentioned two invent in bidrectional cured tank skin structure and its tank skin steel plate that is traditional, uniform thickness have substantial difference, and then make both on steel plate rolling and heat treatment method, on steel plate preprocessing forming method, in the method for construction of Inner tank, also have substantial difference.
Beneficial effect of the present invention:
Adopt the present invention propose for the novel Inner tank tank skin structure of 10 ten thousand stere above Large LNG storage tank and the manufacture method of tank skin 9Ni steel plate, following effect can be reached:
1) the vertical section geometrical shape of large-scale storage tank tank skin of the present invention is based on trapezoidal, contrasts the stepped shape of common big-and-middle-sized storage tank shell vertical section, significantly can reduce the area in cross section, in other words, can reduce the weight of 9Ni steel.
2) width of storage tank Inner tank tank skin difference Plate Steel of the present invention can be increased to the maximum wide cut of current wide and heavy plate mill, to make the number of wallboard reduce as far as possible, the average substance of steel plate is improved as far as possible, and then promotes the manufacturing efficiency of wide and heavy plate mill.
3) described above, the poor Plate Steel number needed for storage tank Inner tank can significantly reduce, and means that the length of steel plate weld seam also can significantly reduce.Particularly, because the number of plies of Inner tank tank skin significantly reduces, between the wallboard making welding efficiency minimum, the length of circular weld reduces at double, and welding efficiency is multiplied.
4) traditional tank skin is all steel plate using the wide floor height as tank skin of plate, is welded as tank skin one section of arc length circumferentially using plate length, and therefore, traditional tank skin steel plate all needs to carry out cans processing, and its bending radius of curvature is exactly the radius of tank skin circumference.And storage tank Inner tank tank skin of the present invention is polygon structure, except the Plate Steel such as tradition of a small amount of blanket layer needs to carry out except bending pretreatment, accounting routine maximum the present invention difference Plate Steel does not need cans to process, and both saves processing cost, the manufacturing cycle shortened again.
Accompanying drawing explanation
Fig. 1 is the vertical cut-away schematic view of storage tank Inner tank tank skin of the present invention.
Fig. 2 is the vertical cut-away schematic view of another Inner tank tank skin of the present invention.
Fig. 3 is the generalized section of the tank skin steel plate of storage tank of the present invention.
Fig. 4 is for the present invention is for realizing the roller milling large plate schematic diagram designed by multiple length rolling.
Fig. 5 is the preprocessing schematic diagram of the Plate Steels such as tradition in the uniform thickness flaggy that proposes of the present invention.
Fig. 6 is the vertical cut-away schematic view of existing 16 ten thousand stere LNG storage tank Inner tank tank skins.
Fig. 7 is the vertical cut-away schematic view of existing 10 ten thousand stere LNG storage tank Inner tank tank skins.
Embodiment
Below in conjunction with embodiment and accompanying drawing, the present invention will be further described.
See Fig. 1, it is depicted as the vertical cut-away schematic view of storage tank Inner tank tank skin of the present invention, in Fig. 1,1 is the plate face of the 1st layer of poor slab layer, 11 is the generalized section of poor Plate Steel in this layer, and its thickness linearly increases from top to bottom, and namely the geometrical shape of its vertical section is trapezoidal, Ta1 is the thickness of its thinnest end, and Tb1 is the thickness of its thickest end; 2 is the plate face of the 2nd layer of poor slab layer, and 21 is the generalized section of New Type of Differential Plate Steel in this layer, and its thickness linearly increases from top to bottom, and namely the geometrical shape of its vertical section is trapezoidal, and Ta2 is the thickness of its thinnest end, and Tb2 is the thickness of its thickest end; 3 is the plate face of traditional blanket layer, it between two layers of poor slab layer as transition, 31 is the generalized section of the Plate Steels such as tradition in this layer; 5 is the longitudinal weld between wallboard, and 6 is the circular weld between wallboard, 7 bending positions when being the Plate Steel preprocessings such as conventional steel plates uniform thickness.
Fig. 2 is the vertical cut-away schematic view of another Inner tank tank skin of the present invention, and this structure is more suitable for the Inner tank tank skin of LNG limit liquid level≤28 meter.In figure, 1 is the plate face of unique one deck difference slab layer in this tank skin structure, and 11 is the generalized section of New Type of Differential Plate Steel in this layer, its thickness linearly increases from top to bottom, namely the geometrical shape of its vertical section is trapezoidal, and Ta is the thickness of its thinnest end, and Tb is the thickness of its thickest end; 3, the 4 plate faces being respectively first layer, second layer uniform thickness flaggy, 31,41 generalized sections being respectively the Plate Steels such as tradition in first layer, second layer uniform thickness flaggy, T3, T4 are respectively the thickness of the Plate Steels 3,4 such as tradition; 5 is the longitudinal weld between wallboard, and 6 is the circular weld between wallboard, 7 bending positions when being traditional uniform thickness tank skin steel plate preprocessing.
Fig. 3 is the generalized section of the tank skin steel plate of large-scale storage tank of the present invention, and in Fig. 3,1 is the plate face of new steel plate, and 11 is the side of new steel plate, and W is that the plate of aforementioned new steel plate is wide, and L is that the plate of new steel plate is long, and W and L is constant; The thickness of steel plate is gradual change along its length, and the slope of gradual change can be that total length is constant, also can be piecewise constant.Wherein, the thickness of slab Tb of the thickest end is not more than 2 with the ratio of the thickness of slab Ta of the thinnest end; L1, L2 ... be respectively the different distance leaving the thin end of steel plate, over this distance, the thickness of steel plate is respectively T1, T2 ..., the rest may be inferred by analogy for it; Within the scope of 0 ~ L1, L1 ~ L2... length of interval, thickness of slab linearly increases or reduces, and the slope of increase or reduction is constant in this length of interval.
Fig. 4 is for the present invention is for realizing " roller milling large plate " schematic diagram designed by multiple length rolling, in Fig. 4, W is that the plate of aforementioned new steel plate is wide, L is that the plate of new steel plate is long, W and L is constant, but steel plate thickness is gradual change along its length, wherein, the thickness of slab of " roller milling large plate " thinnest part is Ta, and the thickness of slab in thickness is Tb.Uniform and stable for ensureing plate property, the ratio of Tb and Ta should limit within limits, and generally, the ratio of Tb and Ta should be not more than 2.
Fig. 5 is the preprocessing schematic diagram of the Plate Steels such as the tradition of the uniform thickness flaggy that the present invention proposes, and 3 is the plate face schematic diagram of these Plate Steels, and 31 is the generalized section of these Plate Steels, and L is the length of these Plate Steels, and W is the width of New Type of Differential Plate Steel.For making the weld seam of each layer tank skin steel plate mutually stagger, these Plate Steels should when preprocessing several foldings of bending, the distance between each folding and folding should be the width W of new steel plate just; 〆 is the interior angle that the size of the angle ， 〆 formed after the bending of top layer tank skin steel plate 3 should equal in the polygon structure of Novel storage tank Inner tank just.
Fig. 6 is the vertical cut-away schematic view of existing 16 ten thousand stere LNG storage tank Inner tank tank skins, in figure, the 3 plate face schematic diagram that are the Plate Steels such as tank skin, 312,311,310,39,38,37,36,35,34,33,32 and 31 tank skin the 1st layer, the 2nd layer, the 3rd layer is respectively from bottom to top ... the thickness profile schematic diagram of the 12nd layer of steel plate, 5 is the longitudinal weld between wallboard, 6 be between wallboard circular weld.Can find out in figure, the thickness of 16 traditional ten thousand stere LNG storage tank Inner tank tank skins from top to bottom, increases in stepped shape.
Fig. 7 is the vertical cut-away schematic view of existing 10 ten thousand stere LNG storage tank Inner tank tank skins, in Fig. 7, the 3 plate face schematic diagram that are the Plate Steels such as tank skin, 310,39,38,37,36,35,34,33, the 32 and 31 thickness profile schematic diagram being respectively the Plate Steels such as tank skin the 10th layer, the 9th layer, the 8th layer, the 7th layer, the 6th layer, the 5th layer, the 4th layer, the 3rd layer, the 2nd layer and the 1st layer from bottom to top.5 is the longitudinal weld between wallboard, and 6 is the circular weld between wallboard.Can find out in figure, the thickness of 10 traditional ten thousand stere LNG storage tank Inner tank tank skins from top to bottom, increases in stepped shape.
Embodiment 1
The present embodiment devises the LNG storage tank Inner tank tank skin structure and tank skin steel plate thereof that a theoretical capacity is 16 ten thousand steres.
In prior art designs, such design capacity is that the LNG storage tank Inner tank tank skin structure of 16 ten thousand steres should be as shown in Figure 6.In figure, the 3 plate face schematic diagram that are the Plate Steels such as tank skin, 31,32,33,34,35,36,37,38,39,310, the 311 and 312 thickness profile schematic diagram being respectively tank skin the 1st layer, the 2nd layer, the 3rd layer, the 4th layer, the 5th layer, the 6th layer, the 7th layer, the 8th layer, the 9th layer, the 10th layer, 11th layer and the 12nd layer of steel plate from bottom to top, 5 is the longitudinal weld between wallboard, 6 be between wallboard circular weld.Can find out in figure, the thickness of 16 traditional ten thousand stere LNG storage tank Inner tank tank skins from bottom to top, reduces in stepped shape.The LNG storage tank Inner tank tank skin of these traditional 16 ten thousand steres is circular, and girth is 252 meters, and tank skin is high is 35.76 meters, LNG limit liquid level 34.5 meters; Tank skin is divided into 12 layers, every floor height 2980mm, by 22 2980mm wide × the long steel plate of 11450mm with plate wide for high, with plate length for arc length is welded, steel plate material is selected has good-196 DEG C of low-temperature flexibilities, 9Ni steel plate containing about 9% Ni alloy, and the trade mark is the 06Ni9DR in GB GB150.
Tradition 16 ten thousand stere LNG storage tank Inner tank tank skins are with shown in steel plate tablet menu 2.
Table 2
In the present embodiment, storage tank shell girth, tank skin are high, the material of limit liquid level, tank skin steel plate used is identical with the LNG Inner tank storage tank of 16 ten thousand steres of existing traditional design, that is: tank skin girth is 252 meters, tank skin is high is 35.76 meters, LNG limit liquid level 34.5 meters, and steel plate material selects the 06Ni9DR in GB GB150.
As shown in Figure 1, in the present embodiment, storage tank Inner tank tank skin is 50 quadrilateral structures.Because limit liquid level has exceeded 28 meters, be therefore designed to three-decker.Wherein, the 1st layer adopts the poor Plate Steel 1 of the present invention's design from bottom to top, and with the long 14900mm of its plate for height, one section of length of side using the wide 4665mm of its plate as 50 quadrilaterals is welded into the poor slab layer 11 of one deck 50 quadrilateral.In this layer, the thickness of difference Plate Steel 1 linearly reduces from bottom to top, and its minimum and maximum ga(u)ge is respectively Ta1, Tb1, and Ta1=17, Tb1=27; 3rd layer adopts the New Type of Differential Plate Steel 2 of the present invention's design equally from bottom to top, same with its long 17880mm for height, the poor slab layer 21 of one deck 50 quadrilateral is welded into using its width 4665mm as polygonal one section of length of side, its minimum and maximum ga(u)ge is respectively Ta2, Tb2, and Ta2=12mm, Tb2=17mm; One deck tradition uniform thickness flaggy 31 is have also been devised between these two layers poor slab layer, in this layer, all steel plates still adopt and traditional wait Plate Steel 3, and all with its width for height, with its length (after bending) for the length of side is welded into one deck 50 quadrilateral tank skin.
In Fig. 1,5 represent the longitudinal weld between wallboard, and 6 represent the circular weld between wallboard, and 7 represent the bending position during Plate Steel preprocessings such as tradition.
Shown in Fig. 3, W is that the plate of aforementioned New Type of Differential Plate Steel is wide, and in the present embodiment, New Type of Differential Plate Steel 1 and 2 is all designed to 4665mm.
L is that the plate of difference Plate Steel is long, and in the present embodiment, difference Plate Steel 1 and 2 is designed to 14900mm and 17880mm respectively.
The thickness of the present invention's difference Plate Steel is gradual change along its length, and the slope of gradual change can be that total length is constant, also can be piecewise constant.Wherein Ta is minimum thickness of slab, and Tb is maximum thickness of slab, and T1, T2 etc. are then respectively the steel plate thickness left on the thinnest end distance L1 of steel plate, L2 etc. position.In the present embodiment, the minimum thickness of slab Ta of difference Plate Steel 1 is designed to 17mm, and most thickness of slab Tb is designed to 27mm; Within the scope of total length 14900mm, the slope of gradient thickness of difference Plate Steel 1 is constant, namely 0.67 ‰; The minimum thickness of slab Ta of difference Plate Steel 2 is designed to 12mm; Most thickness of slab Tb is designed to 15mm; Within the scope of total length 17800mm, the slope of gradient thickness of difference Plate Steel 2 be points two sections constant: first paragraph, at the thinnest end to (namely within the scope of 0 ~ 11200mm) within the scope of L1, slope is constant is 0; Second segment, within the scope of L1 to the thickest end (namely within the scope of 11920mm ~ 17880mm), slope is constant is 0.5 ‰.
Shown in the novel 16 ten thousand stere LNG storage tank Inner tank tank skin steel plate tablet menus 3 of the present invention.
Table 3:6 ten thousand stere LNG storage tank Inner tank tank skin steel plate inventory
In the present embodiment, 1st, 3 layer of tank skin adopts the poor Plate Steel of the specially designed gradient thickness of the present invention from bottom to top, 2nd layer of tank skin then adopts conventional thickness steel plate, three-ply plate material all selects the 06Ni9DR in GB GB150, wherein from bottom to top the 1st, 2 layer of tank skin because of thickness >=16mm, therefore all adopt " quenching+tempering " explained hereafter, because of thickness < 16mm, then select " normalizing+tempering " explained hereafter for the 3rd layer.Above-mentioned three layers of poor Plate Steel and tradition wait the composition of Plate Steel blank used all identical with the composition of existing uniform thickness GB15006Ni9DR steel plate blank used.
Above-mentioned poor Plate Steel is by reversible wide and heavy plate mill Rolling Production.The sotck thinkness adopted is the continuous casting billet of 300mm thickness, and sotck thinkness is 11.1 times with the ratio of the maximum ga(u)ge 27mm of difference Plate Steel, >=6 times; Before formation rolling passage, heating, the rolling mill practice of the heating of above-mentioned poor Plate Steel, rolling mill practice and the 9Ni steel plate of common traditional uniform thickness are identical.Formation rolling is last 1 ~ 3 passage of rolling, and before this, steel plate is uniform thickness distribution along its length, and in this 1 ~ 3 passage, milling train dynamically adjusts roll gap, and steel plate rolls into the poor Plate Steel shown in Fig. 3 the most at last.For reducing the fusion length of wallboard, the width W of novel wallboard is designed to 4.665 meters.For improving the manufacturing efficiency of wallboard, shown in Fig. 4, two poor Plate Steels 1 are stitched together, and form one " roller milling large plate " to realize multiple length rolling, enhance productivity.Stack for the ease of the steel plate after cutting, " roller milling large plate " symmetric design should be have employed when piecing together, by the thickest end matching of two blocks of poor Plate Steels together.For ensureing plate property uniform and stable property, the 1st, 3 layer of tank skin maximum ga(u)ge of New Type of Differential Plate Steel used is respectively 1.588 and 1.25 with the ratio of minimum thickness, equal < 2 times; Except shaping passage, the rolling mill practice of the present invention's difference Plate Steel is identical with existing 06Ni9DR steel plate rolling technique.
The maximum ga(u)ge of above-mentioned 1st layer of tank skin New Type of Differential Plate Steel used is from bottom to top 27mm, >=16mm, must through quenching heat treatment by product standard regulation.During quenching, its " time inside furnace ", " holding time " depend on its minimum thickness of slab Ta and maximum thickness of slab Tb:
Time inside furnace=A*Tb (min)
Holding time=B*Tb (min)
And B* (Tb-Ta)≤30 (min)
Wherein, A is time inside furnace thickness coefficient, and B is holding time thickness coefficient.
In the present embodiment, A=2.5 (min/mm), B=1.5 (min/mm).
For the New Type of Differential Plate Steel that the 1st layer of tank skin is used, Tb=27mm, Ta=17mm, therefore, its time inside furnace should be set as 67.5min, and its holding time should be set as 40.5min, and B* (Tb-Ta)=16≤30 (min).
Except " time inside furnace ", " holding time " this binomial process parameter, other quenching process parameters of the present invention's difference Plate Steel are identical with 06Ni9DR steel plate that is existing, uniform thickness.
In the present embodiment, difference Plate Steel adopts the quenching of rolled type quenching unit.During quenching, this difference Plate Steel speed of travel and the quenching water yield identical with the Plate Steel such as the existing 06Ni9DR that thickness is 27mm respectively.
For ensureing still to keep good plate shape after quenching, each pressure roller of this rolled type quenching unit all can realize independently rolling reduction and accurately control, can according to the physical location of difference Plate Steel in quenching unit, and steel plate on relevant position actual (real) thickness, dynamically regulate the rolling reduction of relevant pressure roller, make all pressure rollers in whole quenching process all can push down the plate face of poor Plate Steel, or and difference Plate Steel plate face between only have very little gap.
The maximum ga(u)ge of above-mentioned 3rd layer of tank skin from bottom to top the present invention's difference used Plate Steel is 15mm, < 16mm, must a kind of heat treatment process process in " quenching " or " normalizing " heat treatment by product standard regulation.In the present embodiment, " normalizing " heat treatment is selected.
During normalizing heat treatment, its " time inside furnace ", " holding time " depend on its minimum thickness of slab Ta and maximum thickness of slab Tb:
Time inside furnace=A*Tb (min)
Holding time=B*Tb (min)
Wherein, wherein, A is time inside furnace thickness coefficient, and B is holding time thickness coefficient.
In the present embodiment, A=3 (min/mm), B=2 (min/mm).
For the New Type of Differential Plate Steel of the 3rd layer of tank skin from bottom to top, Tb=15mm, Ta=12mm, therefore, its time inside furnace should be set as 45min, and its holding time should be set as 30min.
All poor Plate Steels, must tempered heat treatment after " quenching " or " normalizing " process.During temper, its " time inside furnace ", " holding time " depend on its minimum thickness of slab Ta and maximum thickness of slab Tb:
Time inside furnace=A*Tb (min)
Holding time=B*Tb (min)
And B* (Tb-Ta)≤45 (min)
Wherein, A is time inside furnace thickness coefficient, and B is holding time thickness coefficient.
In the present embodiment, A=3.0 (min/mm), B=2.0 (min/mm).
For the poor Plate Steel from bottom to top in the 1st layer, Tb=27mm, Ta=17mm, therefore, its time inside furnace should be set as 81min, and its holding time should be set as 54min, and B* (Tb-Ta)=20≤45 (min);
For the New Type of Differential Plate Steel from bottom to top in the 3rd layer, Tb=15mm, Ta=12mm, therefore, its time inside furnace should be set as 45min, and its holding time should be set as 30min, and B* (Tb-Ta)=6≤45 (min).
Except " time inside furnace ", " holding time " this binomial process parameter, other tempering process parameters of the present invention's difference Plate Steel are identical with 06Ni9DR steel plate that is traditional, uniform thickness.
In the present embodiment, between the 1st, the 3rd layer of tank skin, devise one deck tradition uniform thickness flaggy tank skin from bottom to top.Mutually stagger for making the weld seam of above-mentioned three layers of tank skin steel plate, the length of the Plate Steels such as the tradition in these slab layers is configured to 2 multiples of the present invention's difference Plate Steel width, i.e. 9330mm, and be that the length of side carries out bending with 4665mm, after bending, the angle of adjacent two length of sides equals 173.3 °, the 50 quadrilateral interior angle of Novel storage tank tank skin just.Fig. 5 waits the bending schematic diagram of Plate Steel in the uniform thickness flaggy in the present embodiment, and in figure, 3 is the plate face schematic diagram of these Plate Steels, and 31 is the generalized section of these Plate Steels, and L is the length of these Plate Steels, and W is the width of New Type of Differential Plate Steel.For making the weld seam of each layer tank skin steel plate mutually stagger, L is designed to 2 times of W, and namely steel plate must be bent into two foldings, and the distance between each folding and folding should be the width 4665mm of difference Plate Steel just; 〆 is 173.3 °, the interior angle that the size of the angle ， 〆 formed after the bending of top layer tank skin steel plate 2 should equal in 50 quadrilateral structures of storage tank Inner tank just.
Contrast traditional design, in table 2, table 3, such design capacity is the LNG storage tank Inner tank tank skin structure of 16 ten thousand steres need be 1228 tons by tank skin 9Ni steel plate gross weight, 264, average substance 4.64 tons, and LNG storage tank Inner tank tank skin of the present invention only needs 1149 tons, 135 9Ni steel plates, average substance 8.5 tons.Compare the former, both can save the 9Ni steel plate consumption of the costliness of 6.47%, can increase again by the substance of 83%, extremely be conducive to the High-efficient Production of wide and heavy plate mill.
Contrast traditional design, refer to table 2, table 3, such design capacity is total fusion length that the LNG storage tank Inner tank tank skin structure of 16 ten thousand steres need be welded is 3558 meters, the circular weld that wherein welding efficiency is minimum 2771 meters; And total fusion length of Novel storage tank of the present invention is only 2355 meters, compares the former and reduce 33.8%, wherein circular weld 504 meters, compares the former and is more the reduction of 81.8%;
Contrast traditional design, refer to table 2, table 3, such design capacity is that the LNG storage tank Inner tank tank skin steel plate of 16 ten thousand steres has 264 steel plates, and every block plate all needs to carry out cans processing, and its bending radius of curvature is exactly the radius of tank skin circumference.And Plate Steel totally 27 needs Bending Processing such as Inner tank tank skin of the present invention tradition only in one deck uniform thickness flaggy, both saved processing cost, the manufacturing cycle shortened again.
Embodiment 2
The present embodiment devises the LNG storage tank Inner tank tank skin structure and tank skin steel plate thereof that a theoretical capacity is 10 ten thousand steres.
In existing traditional design, such design capacity is that the LNG storage tank Inner tank tank skin structure of 10 ten thousand steres should be as shown in Figure 7.In figure, the 3 plate face schematic diagram that are the Plate Steels such as tank skin, 31,32,33,34,35,36,37,38, the 39 and 310 thickness profile schematic diagram being respectively tank skin the 1st layer, the 2nd layer, the 3rd layer, the 4th layer, the 5th layer, the 6th layer, the 7th layer, the 8th layer, the 9th layer and the 10th layer steel plate from bottom to top, 5 is the longitudinal weld between wallboard, 6 be between wallboard circular weld.Can find out in figure, the thickness of 10 traditional ten thousand stere LNG storage tank Inner tank tank skins from bottom to top, reduces in stepped shape.The LNG storage tank Inner tank tank skin of these traditional 10 ten thousand steres is circular, and girth is 252 meters, and tank skin is high is 26.76 meters, LNG limit liquid level 25.16 meters; Tank skin is divided into 10 layers, floor height is between 2440 ~ 3000mm, by the long steel plate being 12600mm of 20 plates with plate wide for high, with plate length for arc length is welded, steel plate material is selected has good-196 DEG C of low-temperature flexibilities, 9Ni steel plate containing about 9% Ni element, and the trade mark is the X7Ni9 in Europe superscript EN10028-4.
Tradition 10 ten thousand stere LNG storage tank Inner tank tank skins are with shown in steel plate tablet menu 4.
Table 4
In the present embodiment, storage tank shell girth of the present invention, tank skin are high, the material of limit liquid level, tank skin steel plate used is identical with the LNG storage tank Inner tank of 10 ten thousand steres of existing traditional design, that is: tank skin girth is 252 meters, tank skin is high is 26.76 meters, LNG limit liquid level 25.16 meters, and steel plate material selects the X7Ni9 in Europe superscript EN10028-4.
As shown in Figure 2, in the present embodiment, storage tank Inner tank tank skin is 50 quadrilateral structures.Because limit liquid level has been no more than 28 meters, be therefore designed to the three-decker of individual layer difference slab layer.Wherein, the 1st layer adopts the poor Plate Steel 1 of the present invention's design from bottom to top, and with the long 17360mm of its plate for height, one section of length of side using the wide 4665mm of its plate as 50 quadrilaterals is welded into the poor slab layer 11 of one deck 50 quadrilateral.In this layer, the thickness of New Type of Differential Plate Steel 1 linearly reduces from bottom to top, and its minimum and maximum ga(u)ge is respectively Ta, Tb, and Ta=11.5mm, Tb=22mm; The second layer and third layer still adopt traditional uniform thickness flaggy 31 and 41 from bottom to top.In these two layers, all steel plates still adopt and traditional wait Plate Steel 3,4, and all with its width for height, with its length (after bending) for the length of side is welded into one deck 50 quadrilateral tank skin.
In Fig. 2,5 represent the longitudinal weld between wallboard, and 6 represent the circular weld between wallboard, and 7 represent the bending position during Plate Steel preprocessings such as tradition.
Shown in Fig. 3, W is that the plate of aforementioned poor Plate Steel is wide, L for its plate long.In the present embodiment, W, L of the present invention's difference Plate Steel 1 are designed to 4665mm and 17360mm respectively.
The thickness of difference Plate Steel 1 is gradual change along its length, and the slope of gradual change can be that total length is constant, also can be piecewise constant.Wherein Ta is minimum thickness of slab, and Tb is maximum thickness of slab, and T1, T2 etc. are then respectively the steel plate thickness left on the thinnest end distance L1 of steel plate, L2 etc. position.In the present embodiment, the minimum thickness of slab Ta of the present invention's difference Plate Steel 1 is designed to 11mm; Most thickness of slab Tb is designed to 22mm; Within the scope of total length 17360mm, the thickness of difference Plate Steel 1 is gradual change.And the slope of gradual change be points two sections constant: first paragraph, at the thinnest end to (namely within the scope of 0 ~ 12000mm) within the scope of L1, slope is constant is 0.67 ‰; Second segment, within the scope of L1 to the thickest end (namely within the scope of 12000mm ~ 17360mm), slope is constant is 0.5 ‰.
The present invention 10 ten thousand stere LNG storage tank Inner tank tank skin is with shown in steel plate tablet menu 5.
Table 5: the present invention 10 ten thousand stere LNG storage tank Inner tank tank skin steel plate inventory
In the present embodiment, the 1st layer of tank skin adopts the poor Plate Steel of the specially designed gradient thickness of the present invention from bottom to top, and the steel grade of this steel plate is the X7Ni9 that steel plate material selects in EN10028-4, adopts " quenching+tempering " explained hereafter.The composition of the present invention's difference Plate Steel blank used is identical with the composition of prior art X7Ni9 used blank, by reversible wide and heavy plate mill Rolling Production, the sotck thinkness adopted is the continuous casting billet of 300mm thickness, and the ratio of the maximum ga(u)ge 22mm thick with New Type of Differential is 13.64 times, >=6 times; Before formation rolling passage, heating, the rolling mill practice of the heating of above-mentioned poor Plate Steel, rolling mill practice and the 9Ni steel plate of common traditional uniform thickness are identical.Formation rolling is last 1 ~ 3 passage of rolling, and before this, steel plate is uniform thickness distribution along its length, and in this 1 ~ 3 passage, milling train dynamically adjusts roll gap, and steel plate rolls into the poor Plate Steel shown in Fig. 3 the most at last.For reducing the fusion length of wallboard, the width W of novel wallboard is designed to 4.665 meters.For improving the manufacturing efficiency of wallboard, shown in Fig. 4, two poor Plate Steels 1 are stitched together, and form one " roller milling large plate " to realize multiple length rolling, enhance productivity.Stack for the ease of the steel plate after cutting, " roller milling large plate " symmetric design should be have employed when piecing together, by the thickest end matching of two blocks of poor Plate Steels 1 together.For ensureing plate property uniform and stable property, the 1st layer of tank skin maximum ga(u)ge of poor Plate Steel used is 2 times with the ratio of minimum thickness; Except shaping passage, the rolling mill practice of steel plate of the present invention is identical with existing X7Ni9 steel plate rolling technique.
In the present embodiment, the maximum ga(u)ge of difference Plate Steel is 22mm, >=16mm, therefore after its rolling-forming, and must through quenching heat treatment.During quenching, its " time inside furnace ", " holding time " depend on its minimum thickness of slab Ta and maximum thickness of slab Tb:
Time inside furnace=A*Tb (min)
Holding time=B*Tb (min)
And B* (Tb-Ta)≤30 (min)
Wherein, A is time inside furnace thickness coefficient, and B is holding time thickness coefficient.
In the present embodiment, A=2.8 (min/mm), B=1.8 (min/mm).
For the New Type of Differential Plate Steel of the present embodiment, Tb=22mm, Ta=11mm, therefore, its time inside furnace should be set as 62min, and its holding time should be set as 39min, and B* (Tb-Ta)=20≤30 (min);
Except " time inside furnace ", " holding time " this binomial process parameter, other quenching process parameters of New Type of Differential Plate Steel of the present invention are identical with X7Ni9 steel plate that is traditional, uniform thickness.
In the present embodiment, New Type of Differential Plate Steel adopts the quenching of rolled type quenching unit.During quenching, the steel plate speed of travel and the quenching water yield of New Type of Differential Plate Steel 1 are that the Plate Steels such as traditional X7Ni9 of 22mm are identical respectively with thickness
For ensureing still to keep good plate shape after quenching, each pressure roller of this rolled type quenching unit all can realize independently rolling reduction and accurately control, can according to the physical location of difference Plate Steel in quenching unit, and steel plate on relevant position actual (real) thickness, dynamically regulate the rolling reduction of relevant pressure roller, make all pressure rollers in whole quenching process all can push down the plate face of poor Plate Steel, or and difference Plate Steel plate face between only have very little gap.
The present invention's difference Plate Steel is after Quenching Treatment, and all steel plates must tempered heat treatment.During temper, its " time inside furnace ", " holding time " depend on its minimum thickness of slab Ta and maximum thickness of slab Tb:
Time inside furnace=A*Tb (min)
Holding time=B*Tb (min)
And B* (Tb-Ta)≤45 (min)
Wherein, A is time inside furnace thickness coefficient, and B is holding time thickness coefficient.
In the present embodiment, A=3.5 (min/mm), B=2.5 (min/mm).
For the New Type of Differential Plate Steel of the present embodiment, Tb=22mm, Ta=11mm, therefore, its time inside furnace should be set as 77min, and its holding time should be set as 38min, and B* (Tb-Ta)=27.5≤45 (min);
Except " time inside furnace ", " holding time " this binomial process parameter, other tempering process parameters of New Type of Differential Plate Steel are identical with X7Ni9 steel plate that is traditional, uniform thickness.
In the present embodiment, except one deck difference slab layer, for strengthening the height of Inner tank tank skin, have also been devised two layers of traditional uniform thickness flaggy tank skin.Mutually stagger for making the weld seam of above-mentioned three layers of tank skin steel plate, the length of the Plate Steels such as tradition is configured to 2 multiples of the present invention's difference Plate Steel width, i.e. 9330mm, and with the width of the latter for the length of side carries out bending, after bending, the angle of adjacent two length of sides equals 173.3 °, the 50 quadrilateral interior angle of storage tank Inner tank tank skin of the present invention just.Fig. 5 waits the bending schematic diagram of Plate Steel in the uniform thickness flaggy in the present embodiment, and in figure, 3 be the plate face schematic diagram of these Plate Steels, and 31 is the generalized section of these Plate Steels, and L is the length of these Plate Steels, and W is the width 4665mm differing from Plate Steel.For making the weld seam of each layer tank skin steel plate mutually stagger, L is designed to 2 times of W, and namely steel plate must be bent into two foldings, and the distance between each folding and folding should be the width 4665mm of steel plate just; 〆 is 173.3 °, the interior angle that the size of the angle ， 〆 formed after the bending of top layer tank skin steel plate 2 should equal in 50 quadrilateral structures of Novel storage tank Inner tank just.
Contrast traditional design, in table 4, such design capacity is the LNG storage tank Inner tank tank skin structure of 10 ten thousand steres need be 788.08 tons by tank skin 9Ni steel plate gross weight, 200, average substance 3.94 tons, and LNG storage tank Inner tank tank skin of the present invention only needs 755.68 tons, 108 9Ni steel plates, average substance 7.0 tons.Compare the former, both can save the 9Ni steel plate consumption of the costliness of 4.11%, can increase again by the substance of 77.5%, extremely be conducive to the High-efficient Production of wide and heavy plate mill.
Contrast traditional design, refer to table 4, table 5, such design capacity is total fusion length that the LNG storage tank Inner tank tank skin structure of 10 ten thousand steres need be welded is 2868 meters, the circular weld that wherein welding efficiency is minimum 2268 meters; And total fusion length of storage tank of the present invention is only 1695 meters, compares the former and reduce 40.9%, the circular weld that wherein welding efficiency is minimum 504 meters, compares the former and is more the reduction of 77.8%.
Contrast traditional design, refer to table 4, table 5, such design capacity is that the LNG storage tank Inner tank tank skin steel plate of 10 ten thousand steres has 200 steel plates, and every block plate all needs to carry out cans processing, and its bending radius of curvature is exactly the radius of tank skin circumference.And Plate Steel totally 54 needs Bending Processing such as Inner tank tank skin of the present invention tradition only in two layers of uniform thickness flaggy, both saved processing cost, the manufacturing cycle shortened again.
Claims (9)
1. tank skin 9Ni steel plate in large-scale liquefied natural gas (LNG) tank, is characterized in that, one end is thick in the longitudinal direction, one end is thin for steel plate, and its thickness of slab linearly increases or reduces in all or part of length sections, and the wide W of plate and the long L of plate of steel plate are constant; The thickness of steel plate is gradual change along its length, and the slope of gradual change is the constant or piecewise constant of total length; Wherein, the thickness of slab Tb of the thickest end is not more than 2 with the ratio of the thickness of slab Ta of the thinnest end; L1, L2 ... be respectively the different distance leaving the thin end of steel plate, over this distance, the thickness of steel plate is respectively T1, T2 ..., the rest may be inferred by analogy for it; Within the scope of 0 ~ L1, L1 ~ L2... length of interval, thickness of slab linearly increases or reduces, and the increase of thickness or the slope of reduction are constant in this length of interval.
2. by the storage tank inner canister of tank skin steel plate in large-scale liquefied natural gas (LNG) tank according to claim 1, it is characterized in that, this storage tank Inner jar structure is Polygonal barrel structure, adopt at least one deck difference Plate Steel to be welded, difference Plate Steel with its plate length be high, be welded into one deck difference slab layer so that its plate is wide for one of polygonal section length of side; The thickness of difference Plate Steel linearly increases from top to bottom, and namely the geometrical shape of its vertical section is trapezoidal.
3. storage tank inner canister as claimed in claim 2, is characterized in that, when slab layer of being on duty is more than two layers, has uniform thickness flaggy as transition between difference slab layer and difference slab layer, uniform thickness flaggy with plate wide for high, being polygonal with plate length, limit is welded; The weld seam of each layer tank skin steel plate staggers up and down mutually.
4. storage tank inner canister as claimed in claim 2, is characterized in that, adopt upper and lower three-decker, and first layer and bottom are the plate face of difference slab layer, and the thickness of difference Plate Steel linearly increases from top to bottom, and namely the geometrical shape of its vertical section is trapezoidal; The second layer, third layer are uniform thickness flaggy.
5. the storage tank inner canister as described in claim 3 or 4, it is characterized in that, Deng Plate Steel several foldings of bending when preprocessing, the distance between each folding and folding is the width W of difference Plate Steel, and after uniform thickness steel plate bending, the angle of adjacent two length of sides equals the polygonal interior angle of storage tank Inner tank tank skin.
6. the manufacture method of tank skin steel plate in large-scale liquefied natural gas (LNG) tank as claimed in claim 1, is characterized in that, comprise the steps:
1) the poor Plate Steel of Inner tank tank skin steel plate is identical with existing 9Ni steel plate with the composition of blank used such as Plate Steel such as grade, and sotck thinkness is more than 6 times of the maximum thickness of slab of difference Plate Steel;
2) blank is through wide and heavy plate mill thermo forming;
3) differ from Plate Steel after rolling-forming, must through quenching or normalizing heat treatment, and be on duty Plate Steel maximum ga(u)ge Tb >=16mm time, can only through quenching heat treatment;
Time inside furnace during 3.1 quenching heat treatment, holding time depend on its minimum thickness of slab Ta and maximum
Thickness of slab Tb, other parameters of quenching are identical with existing 9Ni steel plate;
Time inside furnace=A*Tb, unit min, wherein, A is time inside furnace thickness coefficient, gets A=1.5 ~ 4.0, unit min/mm;
Holding time=B*Tb, unit min, wherein, B is holding time thickness coefficient, gets B=1.0 ~ 3.0, unit min/mm;
B* (Tb-Ta)≤30, unit min, wherein, Tb, Ta unit is mm;
Time inside furnace during 3.2 normalizing heat treatment, holding time depend on its minimum thickness of slab Ta and maximum thickness of slab Tb: except time inside furnace, holding time, and other normalizing process parameters are identical with the 9Ni steel plate below existing 16mm thickness;
Time inside furnace=A*Tb, unit min, wherein, A is time inside furnace thickness coefficient, gets A=2.0 ~ 5.0, unit min/mm;
Holding time=B*Tb, unit min, wherein, B is holding time thickness coefficient, gets B=1.5 ~ 4.0, unit min/mm; Wherein, Tb, Ta unit is mm;
4) tempering heat treatment
The time inside furnace of difference Plate Steel when temper, holding time depend on its minimum thickness of slab Ta and maximum thickness of slab Tb, and except time inside furnace, holding time, other tempering process are identical with existing 9Ni steel plate;
Time inside furnace=A*Tb, unit min, wherein, A is time inside furnace thickness coefficient, gets A=2.5 ~ 8.0, unit min/mm;
Holding time=B*Tb, unit min, wherein, B is holding time thickness coefficient, gets B=1.5 ~ 7.0, unit min/mm;
B* (Tb-Ta)≤45, unit min, wherein, Tb, Ta unit is mm.
7. the manufacture method of tank skin steel plate in large-scale liquefied natural gas (LNG) tank as claimed in claim 6, is characterized in that, during with wide and heavy plate mill thermo forming, the width of difference Plate Steel is no more than 4.7 meters.
8. the manufacture method of tank skin steel plate in large-scale liquefied natural gas (LNG) tank as claimed in claim 6, it is characterized in that, more than two or two poor Plate Steels are scrabbled up a roller milling large plate to realize multiple length rolling, this roller milling large plate adopts symmetric design, namely thickness in the longitudinal direction can first by thin thickening, again by thick thinning, also can first by thick thinning, again by thin thickening, or the combination of above-mentioned two kinds of modes.
9. the manufacture method of tank skin steel plate in large-scale liquefied natural gas (LNG) tank as claimed in claim 6, it is characterized in that, difference Plate Steel quenching heat treatment adopts the quenching of rolled type quenching unit, the rolling reduction of each pressure roller is independent controlled, during quenching, differ from the Plate Steel speed of travel, the water yield equals the speed of travel of the Plate Steels such as the tradition of this difference Plate Steel maximum ga(u)ge Tb with thickness, the water yield of quenching is identical in quenching.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410514136.4A CN105526493B (en) | 2014-09-29 | 2014-09-29 | Tank skin 9Ni steel plates and manufacturing method and tank skin structure in large-scale LNG tank |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410514136.4A CN105526493B (en) | 2014-09-29 | 2014-09-29 | Tank skin 9Ni steel plates and manufacturing method and tank skin structure in large-scale LNG tank |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105526493A true CN105526493A (en) | 2016-04-27 |
| CN105526493B CN105526493B (en) | 2018-06-01 |
Family
ID=55768894
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410514136.4A Active CN105526493B (en) | 2014-09-29 | 2014-09-29 | Tank skin 9Ni steel plates and manufacturing method and tank skin structure in large-scale LNG tank |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105526493B (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107414347A (en) * | 2017-06-05 | 2017-12-01 | 中石化宁波工程有限公司 | A kind of large-scale low-temperature storage tank inner canister spiral assembly welding technique |
| CN109854050A (en) * | 2019-03-18 | 2019-06-07 | 海洋石油工程股份有限公司 | The connection method of LNG tank primary tank bottom ring wall plate and annular slab |
| CN113462879A (en) * | 2020-03-31 | 2021-10-01 | 上海梯杰易气体工程技术有限公司 | On-site post-welding heat treatment process for inner tank installation of ultra-large low-temperature liquefied hydrocarbon storage tank |
| CN114406624A (en) * | 2022-02-28 | 2022-04-29 | 山西四建集团有限公司 | Thick steel plate steel structure column square-to-round joint forming process |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3471053A (en) * | 1968-03-04 | 1969-10-07 | Chicago Bridge & Iron Co | Liquid storage tank using metal ring band instead of thicker lower courses |
| US3880315A (en) * | 1972-09-11 | 1975-04-29 | Exxon Research Engineering Co | Large volume tanks |
| JP2001009512A (en) * | 1999-06-25 | 2001-01-16 | Sumitomo Metal Ind Ltd | Manufacture of tapered steel plate |
| CN103498100A (en) * | 2013-10-21 | 2014-01-08 | 武汉钢铁(集团)公司 | Low-Ni high-Mn economical low-temperature steel capable of being used at minus 196 DEG C and preparing method thereof |
| CN103540838A (en) * | 2013-09-29 | 2014-01-29 | 舞阳钢铁有限责任公司 | Steel plate for low-temperature vessel and production method thereof |
| CN103898418A (en) * | 2014-03-07 | 2014-07-02 | 舞阳钢铁有限责任公司 | High-thickness Ni series steel plate for low-temperature vessels and production method for steel plate |
-
2014
- 2014-09-29 CN CN201410514136.4A patent/CN105526493B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3471053A (en) * | 1968-03-04 | 1969-10-07 | Chicago Bridge & Iron Co | Liquid storage tank using metal ring band instead of thicker lower courses |
| US3880315A (en) * | 1972-09-11 | 1975-04-29 | Exxon Research Engineering Co | Large volume tanks |
| JP2001009512A (en) * | 1999-06-25 | 2001-01-16 | Sumitomo Metal Ind Ltd | Manufacture of tapered steel plate |
| CN103540838A (en) * | 2013-09-29 | 2014-01-29 | 舞阳钢铁有限责任公司 | Steel plate for low-temperature vessel and production method thereof |
| CN103498100A (en) * | 2013-10-21 | 2014-01-08 | 武汉钢铁(集团)公司 | Low-Ni high-Mn economical low-temperature steel capable of being used at minus 196 DEG C and preparing method thereof |
| CN103898418A (en) * | 2014-03-07 | 2014-07-02 | 舞阳钢铁有限责任公司 | High-thickness Ni series steel plate for low-temperature vessels and production method for steel plate |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107414347A (en) * | 2017-06-05 | 2017-12-01 | 中石化宁波工程有限公司 | A kind of large-scale low-temperature storage tank inner canister spiral assembly welding technique |
| CN107414347B (en) * | 2017-06-05 | 2019-04-05 | 中石化宁波工程有限公司 | A kind of large-scale low-temperature storage tank inner canister spiral assembly welding technique |
| CN109854050A (en) * | 2019-03-18 | 2019-06-07 | 海洋石油工程股份有限公司 | The connection method of LNG tank primary tank bottom ring wall plate and annular slab |
| CN113462879A (en) * | 2020-03-31 | 2021-10-01 | 上海梯杰易气体工程技术有限公司 | On-site post-welding heat treatment process for inner tank installation of ultra-large low-temperature liquefied hydrocarbon storage tank |
| CN114406624A (en) * | 2022-02-28 | 2022-04-29 | 山西四建集团有限公司 | Thick steel plate steel structure column square-to-round joint forming process |
| CN114406624B (en) * | 2022-02-28 | 2023-10-24 | 山西四建集团有限公司 | Square-to-round joint forming process for thick steel plate steel structure column |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105526493B (en) | 2018-06-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104028556B (en) | A kind of milling method of Multi-layer metal alloy clad steel plate | |
| CN105526493A (en) | 9Ni steel plate for inner tank wall of large liquefied natural gas storage tank, manufacturing method for 9Ni steel plate and tank wall structure | |
| CN103624410B (en) | The welding method of special-shaped Multicarity steel megastructure | |
| CN101417387A (en) | Short stage preparation method of multi-layer metal composite plate | |
| CN106238646A (en) | Pressure vessel large-scale changeover portion entirety abnormity forging method | |
| CN102926320B (en) | The U-shaped ribs of bridge variable cross-section hot rolling and production technology thereof | |
| CN204018703U (en) | A kind of Novel welding cinder ladle being applicable to copper ashes retarded cooling process | |
| CN104120278A (en) | Novel welding slag ladle for copper slag slow cooling process | |
| CN105598163A (en) | Process for rolling metal composite rod with corrugated bonding surface | |
| CN102172627B (en) | Composite insulator hardware helical groove skew rolling roll groove design method | |
| CN105886861B (en) | A kind of aluminium alloy is continuously managed and its manufacture method | |
| CN202368981U (en) | Large-scale recovered oil gas storage tank | |
| CN104110576B (en) | Spherical tank supporting structure | |
| CN205926599U (en) | Edger roll with nested hole groove structure | |
| CN103286137B (en) | Supporting roller of rolling mill for wide and thick plates | |
| CN105484945A (en) | Polygonal wind power tower and manufacturing method thereof | |
| CN103789471B (en) | A kind of multi-angular convex polygon structure metallurgical slag tank and manufacture method thereof | |
| CN104504169A (en) | Structural design of M-shaped novel hole pattern for implementing multidirectional large plastic strain bar rolling | |
| CN201574612U (en) | Pole for transmission tower | |
| CN105523308A (en) | TMCP high strength steel plate for large storage tank wall and production method of steel plate as well as tank wall structure | |
| CN203753354U (en) | Vessel pressure tank type solid floor | |
| CN105438677A (en) | Steel plate for tank wall of large-medium-sized storage tank, manufacturing method of steel plate and tank wall structure | |
| CN207762389U (en) | Boiler and pressure container cylinder emplacement type heavy caliber thick wall are taken over | |
| CN103496206B (en) | A kind of Super-strong high-tenacity sandwich plate with orthotropic structure and preparation technology thereof | |
| CN110657342B (en) | Transverse thickness-variable wide common carbon-manganese steel plate and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |