CN105398547A - Marine cargo tank storage tank - Google Patents

Abstract

The application discloses a marine cargo tank storage tank. The marine cargo tank storage tank comprises a middle tank body, a left tank body and a right tank body, which are arranged in parallel, wherein the left tank body and the right tank body are symmetrically positioned on two sides of the middle tank body; vertical joint surfaces are respectively formed between one side of the middle tank body and the left tank body and between the other side of the middle tank body and the right tank body; longitudinal compartments are arranged on the joint surfaces; and the interiors of the middle tank body, the left tank body and the right tank body are communicated through via holes in the longitudinal compartments. The marine cargo tank storage tank has the advantages that in the same cabin, compared with a two-body tank, a three-body tank has the advantages that the space utilization rate is improved by 7.8%-17.5%; the three-body tank is adopted to improve the single-strip carrying capability of an LNG transport ship greatly, and more values are created; and the three-body tank is provided with the two longitudinal compartment walls, so that the lateral shaking impact on a small liquid tank can be effectively reduced, the fatigue rupture is reduced, the safety of the compartment walls and a ship body structure is ensured, and the service life of the liquid tank is prolonged.

Description

Cargo tank storage tank peculiar to vessel

Technical field

The application relates to a kind of LNG storage tank peculiar to vessel, particularly relates to a kind of cargo tank storage tank peculiar to vessel.

Background technology

Liquefied natural gas (LiquefiedNaturalGas is abbreviated as LNG) enjoys favor as green energy resource, and the mode of conveying LNG has pipeline and carrier two kinds.Along with the widespread use of natural fuels, LNG carrier demand is very vigorous, and its exploitation has become current hot issue with research.Liquid goods tank is as the nucleus equipment of LNG carrier, and the defeated design impact that the form of storage tank is transported LNG is very large.The storage tank form of world today LNG carrier has film-type and self two kinds.

Film-type can be divided into again Technigaz and Gaz-Transport two kinds, and the former cargo hold inwall is ripple type.Be characterized in: can process many preformed parts, shorten the shipbuilding time, because heat-insulation layer is thinner, corresponding charging burden is slightly large, but warm material is more expensive, and insulation adopts bonding mode, can not change after construction, strict to quality control requirement.The latter selects 0.7mm thick, and wide dull and stereotyped INVAR steel (36% nickel steel) the cargo hold inwall of 500mm is plate.Be characterized in: can not process many parts in advance, but easily manufacture, manufacturing time is longer; Because heat-insulation layer is thicker, corresponding charging burden is less a little; Warm material adopts the perlite rock of permeable gas, to add more unreactable gas, reduces warm material expense, and is closed in the interior bolt of thermal case and fixes, and can change after construction.System does not have inner structure, can reach the cargo capacity of 98%, and the chamfering at cargo hold top is owing to reducing the area of LNG free surface simultaneously, while improve Stability of Ship, decreases rocking of goods.

Self has three kinds, A type, Type B and C type, and wherein A type is prismatic or is called IHISPB, arranges complete secondary leakproof interlayer, leaks to protect entire cargo; Type B is spherical, and setting unit secondary leakproof interlayer, to protect a small amount of cargo leakage.The feature of spherical tank type is: independent tank body is not easy to be injured, and can separately manufacture, shipbuilding period is short, and quality inspection is easy; Slosh effect is few, not by loading restriction, fills wide ranges; Warm material (available polyurethane plastics, polystyrene, bakelite resin) consumption is few; Due to storage tank (2kg/cm with pressure ²), flexible operation, increases safety, in emergency circumstances, all can depart from port in any stage of handling, or in the malfunctioning situation of cargo pump, the possibility of unloading is also better, and it is easy to clear the ship when unsnatching goods, but ship is large by windage area.Above two kinds of cargo tanks are mainly used in the construction of Large LNG ship, and current middle-size and small-size LNG carrier adopts C type cargo tank usually, i.e. self-sustaining pressure container.C type independent liquid cargo tank adopts the pressure container of horizontal cylinder, belongs to half-cold, half pressure type pressure container.It can adopt mono-cylindrical or duplex cylindrical, because its bearing capacity is strong, is easy to manufacture, does not need independent setting " secondary screen-wall ", be used widely at present.

For the ship type that height to width ratio (H/B, moldeed depth is than upper molded breadth) is less, the design principal dimensions of cargo tank is subject to cabin limitation in height, and cabin capacity utilization is lower, and single time the economic benefits of transportation efficiency is not high enough.

Along with the development of world economy, to the demand of LNG also in quick growth, this also have stimulated improving constantly of Shipping technology greatly, thus develops the tank vessel of large stowage capacity.Cargo tank width is large, and it is high to load the degree of depth, and while bringing larger delelivered payload capability, also bring certain potential safety hazard, it in navigation process, violent rocking may occur, the shock pressure of generation can serious threat to the safety of bulkhead and hull structure.Therefore, the design requirement of swash bulkhead can additionally be considered in the design process.Like this while increase cargo tank weight, reduce LNG carrying capacity, cause the rising of cost.

Summary of the invention

The object of the present invention is to provide a kind of cargo tank storage tank peculiar to vessel, to overcome deficiency of the prior art.

For achieving the above object, the invention provides following technical scheme:

The embodiment of the present application discloses a kind of cargo tank storage tank peculiar to vessel, comprise the middle tank body be set up in parallel, left tank body and right tank body, described left tank body and right tank body symmetry are positioned at the both sides of described middle tank body, the both sides of described middle tank body form vertical face of joint respectively with between described left tank body and right tank body, this face of joint is provided with vertical diaphragm cabin, described middle tank body, left tank body are communicated with by the through hole on vertical diaphragm cabin with the inside of right tank body.

Preferably, in above-mentioned cargo tank storage tank peculiar to vessel, described middle tank body, left tank body and right tank body comprise cylindrical shell respectively and are sealed in the end socket at cylindrical shell two ends, and the thickness of slab δ of described cylindrical shell meets:

$\mathrm{\δ}=\frac{p_{eq}*D_i}{2*\mathrm{\σ}*e-p_{eq}}+C$

The thickness of slab δ of described end socket meets:

$\mathrm{\δ}=\frac{p_{eq}*D_i*K}{2*\mathrm{\σ}*e}+C$

Wherein, D _i--cylindrical shell radius, σ--permissible stress, e--welding coefficient, C--corrosion allowance and thickness of slab tolerance, p _eq--the maximum pressure that tank body bears, K--end socket shape coefficient.

Preferably, in above-mentioned cargo tank storage tank peculiar to vessel, according to three non-dimensional acceleration component a at the storage tank center of gravity place that motion of ship causes _x, a _y, a _zcalculate the resultant acceleration on arbitrary assigned direction β, then according to the liquid-column height Z of spot pressure in β direction of required calculating _β, calculate this spot pressure by the internal liquid pressure P caused under gravity and acceleration of motion synergy with following formula _gd:

$P_{gd}=a_{\mathrm{\β}}*Z_{\mathrm{\β}}*\left(\frac{\mathrm{\ρ}}{1.02*{10}^5}\right)$

Wherein, ρ is the maximal density of liquid under design temperature.

Preferably, in above-mentioned cargo tank storage tank peculiar to vessel, the component of acceleration at the storage tank center of gravity place that motion of ship causes meets:

Transverse acceleration a _y: $a_y=\±a_0*\sqrt{0.06+A^2-0.25A}$

Longitudinal acceleration a _x: $a_x=\±a_0*\sqrt{0.6+2.5*{\left(\frac{X}{L_0}+0.05\right)}^2+K{\left(1+0.6*K*\frac{Z}{B}\right)}^{1.5}}$

Vertical acceleration a _z: $a_z=\±a_0*\sqrt{1+{\left(5.3-\frac{45}{L_0}\right)}^2*{\left(\frac{X}{L_0}+0.05\right)}^2*{\left(\frac{0.6}{C_b}\right)}^{1.5}}$

Wherein $a_0=0.2*\frac{V}{\sqrt{L_0}}+\frac{34-\frac{600}{L_0}}{L_0}$

In formula:

L ₀--captain defines by recognised standard and determines scantling of structure, m;

C _b--block coefficient

The maximum molded breadth of B--boats and ships, m;

The fore-and-aft distance m between the liquid loadage heart of freighting is arrived in X--ship; Before in ship, X be on the occasion of, after in ship, X is negative value;

Vertical distance between the actual waterline of Z--boats and ships to the liquid loadage heart of freighting, m; More than waterline, Z be on the occasion of, underwater, Z is negative value.

V--operational speed, kn;

K--is 1.

Preferably, in above-mentioned cargo tank storage tank peculiar to vessel, resultant acceleration calculates and meets:

I) to cargo tank Transverse plane (y-z)

$a_{y\left(z\right)}=a_y\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}$

${\mathrm{tan\β}}_{(y-z)}=\frac{a_y\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}}{1+z}$

Horizontal resultant acceleration a can be calculated _{β (y-z)}for:

$a_{\mathrm{\β}(y-z)}=\sqrt{{(1+z)}^2+{a_y}^2*\left(1-{\left(\frac{z}{a_z}\right)}^2\right)}$

$a_{\mathrm{\β}(y-z)}=(1+z)*\sqrt{1+{\tan }^2{\mathrm{\β}}_{y-z}}$

Ii) in like manner, to the longitudinal plane (x-z) of cargo tank

$a_{x\left(z\right)}==a_x\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}$

${\mathrm{tan\β}}_{(x-z)}=\frac{a_x\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}}{1+z}$

Longitudinal resultant acceleration a can be calculated _{β (x-z)}for:

$a_{\mathrm{\β}(x-z)}=\sqrt{{(1+z)}^2+{a_x}^2*\left(1-{\left(\frac{z}{a_z}\right)}^2\right)}$

$a_{\mathrm{\β}(y-z)}=(1+z)*\sqrt{1+{\tan }^2{\mathrm{\β}}_{x-z}}$

When time, inclination maximum β can be drawn _maxwith relevant abscissa value Z ₀;

For y-z plane: ${\mathrm{tan\β}}_{max}=\frac{a_y}{\sqrt{1-{a_z}^2}};$

For x-z plane: ${\mathrm{tan\β}}_{max}=\frac{a_x}{\sqrt{1-{a_z}^2}}$

By above-mentioned formula, can by a _βbecome the function of β.

Preferably, in above-mentioned cargo tank storage tank peculiar to vessel, the liquid-column height Z of storage tank horizontal section upward pressure point _βmeet:

To flow container the first half (-a ₀≤ a≤90 °):

To flow container the latter half (0≤a ₁≤ 90 ° of+a ₀):

The liquid-column height Z of storage tank longitudinal profile upward pressure point _βmeet:

Spot pressure 1:Z _β=L*sin β+R* (1-cos β)+D*cos β

Spot pressure 2: $Z_{\mathrm{\β}}=L*sin\mathrm{\β}+R*(1-cos\mathrm{\β})+\frac{D}{2}*cos\mathrm{\β}$

Spot pressure 3:Z _β=L*sin β+R* (1-cos β)

Spot pressure 4: $Z_{\mathrm{\β}}=(L+R)*sin\mathrm{\β}+R*(1-cos\mathrm{\β})+\frac{D}{2}*cos\mathrm{\β}$

Wherein, a--flow container first half spot pressure inclination angle, a ₀--flow container indulges summit, diaphragm cabin and flow container circle centre position angle, a ₁--flow container lower part spot pressure inclination angle;

Spot pressure 1, spot pressure 2 and spot pressure 3 are respectively the end socket base point crossing with flow container cylindrical shell, middle part point and top point, spot pressure 4 is the sphere summit of end socket, the head of liquid of four spot pressures can be obtained by above-mentioned formula respectively, and then calculate the thickness of slab at flow container diverse location place;

β--cargo tank inclination angle;

The internal diameter of D--cylindrical shell, m;

The radius of R--cylindrical shell, m;

The longitudinal length of L--cylindrical shell, m.

Preferably, in above-mentioned cargo tank storage tank peculiar to vessel, the membrane stress acted on vertical diaphragm bulkhead meets:

$P_v=2*P_m*sin\mathrm{\θ}=2*P_m*\frac{e/2}{R}=2*P_m*\frac{e}{D}$

In formula:

P _v--the tension and compression membrane stress (per unit length) produced on line of centers next door, Mpa;

P _m--act on the tension and compression membrane stress (per unit length) on cylindrical shell cylinder plate, Mpa;

Line between the point of connection of θ--middle tank body and left tank body and left tank body center and the angle of vertical direction;

The radius of R--cylindrical shell;

Distance in the middle of e--between the tank body center of circle and the left tank body center of circle;

The diameter of D--cylindrical shell.

Preferably, in above-mentioned cargo tank storage tank peculiar to vessel, vertical diaphragm cabin thickness of slab meets:

$t_L=\frac{P_V}{\mathrm{\σ}}=\frac{2*P_m*\frac{e}{D}}{\mathrm{\σ}}=2*\frac{P_m}{\mathrm{\σ}}*\frac{e}{D}=\frac{2*t_s*e}{D}$

In formula:

σ--flow container material membrane stress allowable

T _s--cylindrical shell thickness of slab.

Compared with prior art, the invention has the advantages that:

1, in same cabin, three body tanks are relative to binary tank, and space availability ratio promotes 7.8%, three body tanks relative to binary tank, and space availability ratio promotes 17.5%.

2, adopt three body tanks, greatly can promote LNG carrier list and plow carrying capacity, create and be more worth.

3, three body tanks self are with two vertical diaphragm bulkheads, can effectively reduce liquid tank and laterally rock impact, reduce endurance failure, ensure the safety of bulkhead and hull structure, increase flow container service life.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present application or technical scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or description of the prior art below, apparently, the accompanying drawing that the following describes is only some embodiments recorded in the application, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Figure 1 shows that the structural representation of cargo tank storage tank peculiar to vessel in the specific embodiment of the invention;

Figure 2 shows that three-dimensional acceleration ellipse schematic diagram (x);

Figure 3 shows that three-dimensional acceleration ellipse schematic diagram (y);

Figure 4 shows that storage tank bench section liquid-column height Z _βschematic diagram (flow container upper part);

Figure 5 shows that storage tank bench section liquid-column height Z _βschematic diagram (flow container lower part);

Figure 6 shows that storage tank elevation profile liquid-column height Z _βschematic diagram;

Figure 7 shows that vertical diaphragm bulkhead force analysis schematic diagram.

Detailed description of the invention

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be described in detail the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, the every other embodiment that those of ordinary skill in the art obtain under the prerequisite not making creative work, all belongs to the scope of protection of the invention.

Shown in ginseng Fig. 1, cargo tank storage tank peculiar to vessel, comprise the middle tank body 1, left tank body 2 and the right tank body 3 that are set up in parallel, left tank body 2 and right tank body 3 symmetry are positioned at the both sides of middle tank body 1, the both sides of middle tank body 1 form vertical face of joint respectively with between left tank body 2 and right tank body 3, this face of joint is provided with vertical diaphragm cabin 4, middle tank body, left tank body 2 are communicated with by the through hole on vertical diaphragm cabin with the inside of right tank body 3.

Determine the calculating of flow container internal liquid pressure dependence to flow container diverse location thickness of slab, thickness of slab computing formula is:

Cylindrical shell thickness of slab: $\mathrm{\δ}=\frac{p_{eq}*D_i}{2*\mathrm{\σ}*e-p_{eq}}+C$ End socket thickness of slab: $\mathrm{\δ}=\frac{p_{eq}*D_i*K}{2*\mathrm{\σ}*e}+C$

In formula:

δ--calculate thickness of slab, mm;

D _i--flow container radius, m;

σ--permissible stress, Mpa;

E--welding coefficient;

K--end socket shape coefficient.

C--corrosion allowance and thickness of slab tolerance, mm;

P _eq--design pressure, Mpa;

Wherein, design pressure p _eq(maximum pressure that flow container bears) is by design steam pressure p ₀with internal liquid pressure (p _gd) _maxthe result of synthesis, but do not comprise the impact of liquid sloshing.Flow container internal liquid pressure comprises the kinetic pressure that hydrostatic pressure and motion of ship cause.According to three non-dimensional acceleration component a at the flow container center of gravity place that motion of ship causes _x, a _y, a _zcalculate the resultant acceleration on arbitrary assigned direction β.Again according to the liquid-column height Z of spot pressure in β direction of required calculating _β, calculate this spot pressure by the internal liquid pressure P caused under gravity and acceleration of motion synergy with following formula _gd:

$P_{gd}=a_{\mathrm{\β}}*Z_{\mathrm{\β}}*\left(\frac{\mathrm{\ρ}}{1.02*{10}^5}\right)Mpa$

In formula, ρ is the maximal density (kg/m of liquid under design temperature ³).Then the internal liquid Pressure maximum value (P of each spot pressure in each possible β direction is found out _gd) _max, calculation process is as follows:

1), the component of acceleration at flow container center of gravity place that causes of motion of ship:

Transverse acceleration a _y: $a_y=\±a_0*\sqrt{0.06+A^2-0.25A}$

Longitudinal acceleration a _x: $a_x=\±a_0*\sqrt{0.6+2.5*{\left(\frac{X}{L_0}+0.05\right)}^2+K{\left(1+0.6*K*\frac{Z}{B}\right)}^{1.5}}$

Vertical acceleration a _z: $a_z=\±a_0*\sqrt{1+{\left(5.3-\frac{45}{L_0}\right)}^2*{\left(\frac{X}{L_0}+0.05\right)}^2*{\left(\frac{0.6}{C_b}\right)}^{1.5}}$

Wherein $a_0=0.2*\frac{V}{\sqrt{L_0}}+\frac{34-\frac{600}{L_0}}{L_0}$

In formula:

L ₀--captain defines by recognised standard and determines scantling of structure, m;

C _b--block coefficient

The maximum molded breadth of B--boats and ships, m;

The fore-and-aft distance m between the liquid loadage heart of freighting is arrived in X--ship; Before in ship, X be on the occasion of, after in ship, X is negative value;

Vertical distance between the actual waterline of Z--boats and ships to the liquid loadage heart of freighting, m; More than waterline, Z be on the occasion of, underwater, Z is negative value.

V--operational speed, kn;

K--is generally 1.

A _x, a _y, a _zfor the maximum non-dimensional acceleration (namely relative to acceleration due to gravity) in respective direction, can think during calculating that they act on respectively, a _zdo not comprise net gravitational force component, a _ycomprise rolling and cause net gravitational force component in the horizontal, a _xcomprise the net gravitational force component that pitching causes in the vertical.

2), by Fig. 2 and Fig. 3 three-dimensional acceleration ellipse schematic diagram, resultant acceleration is calculated.

I) to cargo tank Transverse plane (y-z)

$a_{y\left(z\right)}=a_y\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}$

${\mathrm{tan\β}}_{(y-z)}=\frac{a_y\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}}{1+z}$

Horizontal resultant acceleration a can be calculated _{β (y-z)}for:

$a_{\mathrm{\β}(y-z)}=\sqrt{{(1+z)}^2+{a_y}^2*\left(1-{\left(\frac{z}{a_z}\right)}^2\right)}$

$a_{\mathrm{\β}(y-z)}=(1+z)*\sqrt{1+{\tan }^2{\mathrm{\β}}_{y-z}}$

Ii) in like manner, to the longitudinal plane (x-z) of boats and ships

$a_{x\left(z\right)}==a_x\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}$

${\mathrm{tan\β}}_{(x-z)}=\frac{a_x\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}}{1+z}$

Longitudinal resultant acceleration a can be calculated _{β (x-z)}for:

$a_{\mathrm{\β}(x-z)}=\sqrt{{(1+z)}^2+{a_x}^2*\left(1-{\left(\frac{z}{a_z}\right)}^2\right)}$

$a_{\mathrm{\β}(y-z)}=(1+z)*\sqrt{1+{\tan }^2{\mathrm{\β}}_{x-z}}$

When time, just can draw inclination maximum β _maxwith relevant abscissa value Z ₀.

For y-z plane: ${\mathrm{tan\β}}_{max}=\frac{a_y}{\sqrt{1-{a_z}^2}};$

For x-z plane: ${\mathrm{tan\β}}_{max}=\frac{a_x}{\sqrt{1-{a_z}^2}}$

By above-mentioned formula, can by a _βbecome the function of β.

3), three body tank different pressures point head of liquid Z are derived in calculating _β.

According to liquid tank structure shape, pressure point locations and angle of acceleration β, be deduced liquid-column height Z under arbitrary spot pressure _βcomputing formula, as follows:

I) to cargo tank horizontal section

The liquid-column height Z of horizontal section upward pressure point _βcan be represented by Fig. 4 and Fig. 5.If there is perforate in vertical diaphragm cabin, i.e. three Ti Guanshi UNICOMs, then can be obtained by geometric relationship in figure:

To flow container the first half (-a ₀≤ a≤90 °):

To flow container the latter half (0≤a ₁≤ 90 ° of+a ₀):

If vertical diaphragm cabin is liquid-tight, then liquid pipe in both sides can be considered separately, as long as now get e=0 in formula.

Ii) flow container longitudinal profile

At longitudinal profile, the computing formula of the corresponding liquid-column height of each point can be derived by geometric relationship in Fig. 6, as follows:

Spot pressure 1:Z _β=L*sin β+R* (1-cos β)+D*cos β

Spot pressure 2: $Z_{\mathrm{\β}}=L*sin\mathrm{\β}+R*(1-cos\mathrm{\β})+\frac{D}{2}*cos\mathrm{\β}$

Spot pressure 3:Z _β=L*sin β+R* (1-cos β)

Spot pressure 4: $Z_{\mathrm{\β}}=(L+R)*sin\mathrm{\β}+R*(1-cos\mathrm{\β})+\frac{D}{2}*cos\mathrm{\β}$

In formula:

A--flow container first half spot pressure inclination angle, a ₀--flow container indulges summit, diaphragm cabin and flow container circle centre position angle, a ₁--flow container lower part spot pressure inclination angle;

Spot pressure 1, spot pressure 2 and spot pressure 3 are respectively the end socket base point crossing with flow container cylindrical shell, middle part point and top point, spot pressure 4 is the sphere summit of end socket, the head of liquid of four spot pressures can be obtained by above-mentioned formula respectively, and then calculate the thickness of slab at flow container diverse location place;

β--cargo tank inclination angle;

The internal diameter of D--cylindrical shell, m;

The radius of R--cylindrical shell, m;

The longitudinal length of L--cylindrical shell, m;

Calculate horizontal and vertical section acceleration/accel a respectively _βand head of liquid Z _β, elevation profile and bench section internal liquid pressure P can be obtained respectively _gd, get maxim and bring thickness of slab computing formula into and just can obtain end socket and cylindrical shell diverse location place thickness of slab.

By Fig. 7 geometric relationship, diaphragm bulkhead is indulged to three body tanks and carry out mechanical analysis.

The membrane stress acted on vertical diaphragm bulkhead is tried to achieve by following formula:

$P_v=2*P_m*sin\mathrm{\θ}=2*P_m*\frac{e/2}{R}=2*P_m*\frac{e}{D}$

In formula:

P _v--the tension and compression membrane stress (per unit length) produced on line of centers next door, Mpa;

P _m--act on the tension and compression membrane stress (per unit length) on cylinder cylinder plate, Mpa;

Above formula reflect act on tension and compression membrane stress on a plate due to be added in crossover sites press act on equably film flexible in condition under the result of gained, but do not consider the problem of corrosion thinning here.

Vertical diaphragm cabin calculates thickness of slab:

$t_L=\frac{P_V}{\mathrm{\σ}}=\frac{2*P_m*\frac{e}{D}}{\mathrm{\σ}}=2*\frac{P_m}{\mathrm{\σ}}*\frac{e}{D}=\frac{2*t_s*e}{D}$

In formula:

σ--the flow container material membrane stress allowable drawn by specification;

T _s--the cylindrical shell thickness of slab calculated by interior pressure.

When considering the moment of flexure support reaction that crossover sites produces when designing, the thickness of plate should get the slightly thicker value of the thickness that draws than this formula.Meanwhile, phase analysis in the early stage considers the tank weights of acceleration/accel and moment of flexure that support reaction applies or shearing, can with reference to the way process identical with monomer cylindrical tank.That is, consider the unstability caused by moment of flexure, axle power and external pressure, also can analyze by same manner.Decide the configuration of reinforcing pad according to the standard of pressure container, the local enhancement methods at the place such as vault, support portion is also identical.By way as above, in preliminary design, the shape of three body cylindrical tanks and scantling of structure can be decided.

It should be noted that, in this article, the such as relational terms of first and second grades and so on is only used for an entity or operation to separate with another entity or operational zone, and not necessarily requires or imply the relation that there is any this reality between these entities or operation or sequentially.And, term " comprises ", " comprising " or its any other variant are intended to contain comprising of nonexcludability, thus make to comprise the process of a series of key element, method, article or equipment and not only comprise those key elements, but also comprise other key elements clearly do not listed, or also comprise by the intrinsic key element of this process, method, article or equipment.When not more restrictions, the key element limited by statement " comprising ... ", and be not precluded within process, method, article or the equipment comprising described key element and also there is other identical element.

The above is only the detailed description of the invention of the application; it should be pointed out that for those skilled in the art, under the prerequisite not departing from the application's principle; can also make some improvements and modifications, these improvements and modifications also should be considered as the protection domain of the application.

Claims (8)

1. a cargo tank storage tank peculiar to vessel, it is characterized in that, comprise the middle tank body be set up in parallel, left tank body and right tank body, described left tank body and right tank body symmetry are positioned at the both sides of described middle tank body, the both sides of described middle tank body form vertical face of joint respectively with between described left tank body and right tank body, this face of joint is provided with vertical diaphragm cabin, described middle tank body, left tank body are communicated with by the through hole on vertical diaphragm cabin with the inside of right tank body.

2. cargo tank storage tank peculiar to vessel according to claim 1, is characterized in that: described middle tank body, left tank body and right tank body comprise cylindrical shell respectively and be sealed in the end socket at cylindrical shell two ends, and the thickness of slab δ of described cylindrical shell meets:

$\mathrm{\δ}=\frac{p_{eq}*D_i}{2*\mathrm{\σ}*e-p_{eq}}+C$

The thickness of slab δ of described end socket meets:

$\mathrm{\δ}=\frac{p_{eq}*D_i*K}{2*\mathrm{\σ}*e}+C$

Wherein, D _i--cylindrical shell radius, σ--permissible stress, e--welding coefficient, C--corrosion allowance and thickness of slab tolerance, p _eq--the maximum pressure that tank body bears, K--end socket shape coefficient.

3. cargo tank storage tank peculiar to vessel according to claim 2, is characterized in that: according to three non-dimensional acceleration component a at the storage tank center of gravity place that motion of ship causes _x, a _y, a _zcalculate the resultant acceleration on arbitrary assigned direction β, then according to the liquid-column height Z of spot pressure in β direction of required calculating _β, calculate this spot pressure by the internal liquid pressure P caused under gravity and acceleration of motion synergy with following formula _gd:

$P_{gd}=a_{\mathrm{\β}}*Z_{\mathrm{\β}}*\left(\frac{\mathrm{\ρ}}{1.02*{10}^5}\right)$

Wherein, ρ is the maximal density of liquid under design temperature.

4. cargo tank storage tank peculiar to vessel according to claim 3, is characterized in that: the component of acceleration at the storage tank center of gravity place that motion of ship causes meets:

Transverse acceleration a _y: $a_y=\±a_0*\sqrt{0.06+A^2-0.25A}$

Longitudinal acceleration a _x: $a_x=\±a_0*\sqrt{0.6+2.5*{(\frac{X}{L_0}+0.05)}^2+K{(1+0.6*K*\frac{Z}{B})}^{1.5}}$

Vertical acceleration a _z: $a_z=\±a_0*\sqrt{1+{(5.3-\frac{45}{L_0})}^2*{(\frac{X}{L_0}+0.05)}^2*{\left(\frac{0.6}{C_b}\right)}^{1.5}}$

Wherein $a_0=0.2*\frac{V}{\sqrt{L_0}}+\frac{34-\frac{600}{L_0}}{L_0}$

In formula:

L ₀--captain defines by recognised standard and determines scantling of structure, m;

C _b--block coefficient

The maximum molded breadth of B--boats and ships, m;

The fore-and-aft distance m between the liquid loadage heart of freighting is arrived in X--ship; Before in ship, X be on the occasion of, after in ship, X is negative value;

Vertical distance between the actual waterline of Z--boats and ships to the liquid loadage heart of freighting, m; More than waterline, Z be on the occasion of, underwater, Z is negative value.

V--operational speed, kn;

K--is 1.

5. cargo tank storage tank peculiar to vessel according to claim 4, is characterized in that: resultant acceleration calculates and meets:

I) to cargo tank Transverse plane (y-z)

$a_{y\left(z\right)}=a_y\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}$

${\mathrm{tan\β}}_{(y-z)}=\frac{a_y\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}}{1+z}$

Horizontal resultant acceleration a can be calculated _{β (y-z)}for:

$a_{\mathrm{\β}(y-z)}=\sqrt{{(1+z)}^2+{a_y}^2*(1-{\left(\frac{z}{a_z}\right)}^2)}$

$a_{\mathrm{\β}(y-z)}=(1+z)*\sqrt{1+{\tan }^2{\mathrm{\β}}_{y-z}}$

Ii) in like manner, to the longitudinal plane (x-z) of cargo tank

$a_{x\left(z\right)}==a_x\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}$

${\mathrm{tan\β}}_{(x-z)}=\frac{a_x\sqrt{1-{\left(\frac{z}{a_z}\right)}^2}}{1+z}$

Longitudinal resultant acceleration a can be calculated _{β (x-z)}for:

$a_{\mathrm{\β}(x-z)}=\sqrt{{(1+z)}^2+{a_x}^2*(1-{\left(\frac{z}{a_z}\right)}^2)}$

$a_{\mathrm{\β}(y-z)}=(1+z)*\sqrt{1+{\tan }^2{\mathrm{\β}}_{x-z}}$

When time, inclination maximum β can be drawn _maxwith relevant abscissa value Z ₀;

For y-z plane: ${\mathrm{tan\β}}_{max}=\frac{a_y}{\sqrt{1-{a_z}^2}};$

For x-z plane: ${\mathrm{tan\β}}_{max}=\frac{a_x}{\sqrt{1-{a_z}^2}}$

By above-mentioned formula, can by a _βbecome the function of β.

6. cargo tank storage tank peculiar to vessel according to claim 5, is characterized in that: the liquid-column height Z of storage tank horizontal section upward pressure point _βmeet:

To flow container the first half (-a ₀≤ a≤90 °): $Z_{\mathrm{\β}}=\frac{D}{2}\[1+\frac{e}{D/2}sin\mathrm{\β}-cos(a+\mathrm{\β})\]$

To flow container the latter half (0≤a ₁≤ 90 ° of+a ₀): $Z_{\mathrm{\β}}=\frac{D}{2}\[1+\frac{e}{D/2}sin\mathrm{\β}-cos(a_1+\mathrm{\β})\]$

The liquid-column height Z of storage tank longitudinal profile upward pressure point _βmeet:

Spot pressure 1:Z _β=L*sin β+R* (1-cos β)+D*cos β

Spot pressure 2: $Z_{\mathrm{\β}}=L*sin\mathrm{\β}+R*(1-cos\mathrm{\β})+\frac{D}{2}*cos\mathrm{\β}$

Spot pressure 3:Z _β=L*sin β+R* (1-cos β)

Spot pressure 4: $Z_{\mathrm{\β}}=(L+R)*sin\mathrm{\β}+R*(1-cos\mathrm{\β})+\frac{D}{2}*cos\mathrm{\β}$

Wherein, a--flow container first half spot pressure inclination angle, a ₀--flow container indulges summit, diaphragm cabin and flow container circle centre position angle, a ₁--flow container lower part spot pressure inclination angle;

Spot pressure 1, spot pressure 2 and spot pressure 3 are respectively the end socket base point crossing with flow container cylindrical shell, middle part point and top point, and spot pressure 4 is the sphere summit of end socket;

β--cargo tank inclination angle;

The internal diameter of D--cylindrical shell, m;

The radius of R--cylindrical shell, m;

The longitudinal length of L--cylindrical shell, m.

7. cargo tank storage tank peculiar to vessel according to claim 2, is characterized in that: the membrane stress acted on vertical diaphragm bulkhead meets:

$P_v=2*P_m*sin\mathrm{\θ}=2*P_m*\frac{e/2}{R}=2*P_m*\frac{e}{D}$

In formula:

P _v--the tension and compression membrane stress (per unit length) produced on line of centers next door, Mpa;

P _m--act on the tension and compression membrane stress (per unit length) on cylindrical shell cylinder plate, Mpa;

Line between the point of connection of θ--middle tank body and left tank body and left tank body center and the angle of vertical direction;

The radius of R--cylindrical shell;

Distance in the middle of e--between the tank body center of circle and the left tank body center of circle;

The diameter of D--cylindrical shell.

8. cargo tank storage tank peculiar to vessel according to claim 7, is characterized in that: vertical diaphragm cabin thickness of slab meets:

$t_L=\frac{P_V}{\mathrm{\σ}}=\frac{2*P_m*\frac{e}{D}}{\mathrm{\σ}}=2*\frac{P_m}{\mathrm{\σ}}*\frac{e}{D}=\frac{2*t_s*e}{D}$

In formula:

σ--flow container material membrane stress allowable

T _s--cylindrical shell thickness of slab.