A ship subdivision design method based on concept optimization

Abstract

The present invention relates to a ship subdivision design method based on concept optimization, and belongs to the field of ship design and manufacturing technology. The present invention takes the longitudinal position of each section of transverse bulkhead and the proportion of the cargo hold volume occupied by the cargo hold, ballast tank and empty hold in the cargo hold section as optimization variables, takes the minimum extreme value of the static water bending moment of the hull beam as the objective function, takes the requirements of various specifications and the division principle that is conducive to cargo loading and unloading and reducing the weight of the empty ship as constraints, and adopts an optimization algorithm to perform subdivision optimization. The present invention provides a design method based on concept optimization for ship subdivision design, which can provide more reasonable subdivision according to the ship type characteristics, shipowner requirements and specification requirements of each ship. The static water bending moment of the hull beam is made as small as possible, the ship structure size is effectively controlled, and the economy and green environmental protection of the ship are improved; the present invention reduces the requirements for the professional skills of designers, which can reduce the labor costs of enterprises.

Description

Technical Field

[0001] The invention relates to a ship subdivision design method based on concept optimization, and belongs to the technical field of ship design and manufacturing. Background Art

[0002] In the prior art, the subdivision of ships usually adopts the conventional subdivision form (such as Figure 1 ) or special subdivisions (such as Figure 2 、 3 、4). Figure 1 It is a conventional subdivision form; the equal-width ballast tanks on both sides of the ship are distributed on both sides of the cargo area. Figure 2 The form of setting up the middle ballast tank is to add a ballast tank on each side near the midship towards the cargo area. Figure 3 The form of the first ballast tank being an empty tank is to set the original first ballast tank as an empty tank. Figure 4 The width of the stepped ballast tank decreases from the middle to both sides. (Refer to Chinese patent, patent number CN103129702B; "Ship based on stepped ballast tanks"); Different cabin division forms will have a significant impact on the still water bending moment, thereby affecting the structural dimensions of the ship, affecting the economy and environmental friendliness of the ship. Conventional subdivision forms usually cause large still water bending moments, while special subdivision forms are extremely dependent on the individual ability of the designer and have a limited scope of application. Therefore, this technical field urgently needs to obtain a method that allows ordinary designers to design the theoretically optimal subdivision form for different ships. Summary of the Invention

[0003] The purpose of the present invention is to solve the technical problem of how to obtain a method that can enable ordinary designers to design theoretically optimal subdivision forms for different ships.

[0004] In order to achieve the purpose of solving the above-mentioned problems, the technical solution adopted by the present invention is to provide a ship subdivision design method based on conceptual optimization, taking the longitudinal position of each section of transverse bulkhead and the proportion of the cargo hold volume occupied by the cargo hold, ballast tank and empty hold in the cargo hold section as optimization variables, minimizing the extreme value of the still water bending moment of the hull beam as the objective function, and taking the requirements of various specifications and the division principle that is conducive to cargo loading and unloading and reducing the light ship weight as constraints, an optimization algorithm is used to optimize the subdivision.

[0005] Preferably, the method comprises the following steps,

[0006] Step 1: Determine the number of cargo hold sections N according to the shipowner's requirements and various regulations and criteria. The number of transverse bulkheads is N+1.

[0007] Step 2: Taking the position of each transverse bulkhead as the independent variable, establish the functional relationship between the total volume of each cargo hold section and the position of the transverse bulkhead according to the hull lines;

[0008] Step 3: Take the proportion of cargo hold, ballast tank and void hold in each cargo hold section as the independent variable, and establish the functional relationship between the cargo hold, ballast tank and void hold volumes and the total volume of each cargo hold section;

[0009] Step 4: Based on the different loading conditions required by the specifications, establish the functional relationship between the weight center distribution of each tank under all loading conditions and the proportion of the cargo hold, ballast tank, and void tank occupied by the cargo hold section volume and the position of the transverse bulkhead. On this basis, establish the functional relationship between the still water bending moment of the hull beam under each loading condition and the proportion of the cargo hold, ballast tank, and void tank occupied by the cargo hold section volume and the position of the transverse bulkhead in each cargo hold section;

[0010] Step 5: Taking the shipowner's requirements, the requirements of various rules and regulations, and the division principle that is conducive to cargo loading and unloading and reducing the light ship weight as constraints, and minimizing the extreme value of the still water bending moment under all loading conditions as the optimization goal, the transverse bulkhead position and the proportion of the cargo tank volume occupied by the cargo oil tank, ballast tank, and void tank in each cargo hold section are optimized to obtain the theoretically optimal subdivision design scheme;

[0011] Step 6: Based on step 5, the initial project plan can be obtained, and reasonable adjustments can be made later.

[0012] Preferably, in the above step 3, establishing a functional relationship between the cargo hold, ballast tank, void tank volumes and the total volume of each cargo hold section is establishing a functional relationship between the cargo hold, ballast tank, void tank volumes and the position of the transverse bulkhead.

[0013] Preferably, in step 2 above, the position of each transverse bulkhead is used as an independent variable, and a functional relationship between the total volume of each cargo hold section and the position of the transverse bulkhead is established according to the hull lines. Taking an oil tanker with a single longitudinal bulkhead as an example, assuming that the number of cargo hold sections is N according to the damage requirements, the cargo hold sections are numbered i = 1, 2 ... N; the positions of the front and rear bulkheads of the i-th cargo hold section are X and N respectively. bh (i-1) and X bh (i) According to the hull lines, the functional relationship between the total volume V(i) of the i-th cargo hold section and the bulkhead position is established, V(i) = f(X bh (i-1), X bh (i)).

[0014] Preferably, in step 3 above, the proportion of the cargo hold volume occupied by the cargo hold, ballast tank, and empty tank in each cargo hold section is used as an independent variable, and a functional relationship between the cargo hold, ballast tank, empty tank volume and the total volume of each cargo hold section is established respectively; the proportion of the cargo hold volume to the total volume of the cargo hold section is denoted as k COT (i) The ratio of the ballast tank volume to the total cargo hold volume is k BWT (i) The ratio of the empty hold volume to the total volume of the cargo hold is k emp (i), k COT (i)+kBWT (i)+k emp (i) = 1; we can get the cargo hold volume V COT (i) = k COT (i)*V(i), ballast tank volume V BWT (i) = k BWT (i)*V(i), void volume V emp (i) = k emp (i)*V(i); the total cargo hold volume is ∑V COT (i).

[0015] Preferably, in step 3 above, a functional relationship between the cargo hold, ballast tank, void tank volume and the position of the transverse bulkhead is established; the cargo hold volume V COT (i) = k COT (i)*V(i)=k COT (i)*f(X bh (i-1), X bh (i)), ballast tank volume V BWT (i) = k BWT (i)*V(i)=k BWT (i)*f(X bh (i-1), X bh (i)), the void volume V emp (i) = k emp (i)*f(X bh (i-1), X bh (i)).

[0016] Preferably, the still water bending moment of the hull beam in the above step 4 is calculated based on the still water buoyancy distribution provided by the hull lines, the volume of each compartment, the position of the compartment and the loading conditions specified in the specifications to calculate the still water bending moment M(j) of the hull beam under different working conditions, where j is the number of loading conditions specified in the specifications.

[0017] Preferably, in step 5, the shipowner's requirements, the requirements of various rules and regulations, and the division principle that is conducive to cargo loading and unloading and reducing the light ship weight are used as constraints, and the minimum extreme value of the still water bending moment (max(abs(M(j)))) of all loading conditions is used as the optimization goal. bh (i) The proportion of cargo hold, ballast tank and void tank occupied by the cargo hold volume in each cargo hold section k COT (i), k BWT (i), k emp (i) Optimize and obtain the theoretically optimal compartment design scheme.

[0018] Preferably, the constraint conditions can be determined according to the design requirements of the specific target ship.

[0019] Preferably, the constraint condition includes when the shipowner requires the minimum cargo hold volume to be V COT-targ , then there is a constraint condition ∑V COT (i)≥V COT-targ ; When the anti-pollution regulations require the maximum cargo hold volume to be V COT-lim , then there is a constraint condition ∑V COT (i)≤V COT-lim .

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] This invention provides a conceptual optimization-based design method for ship subdivision design. It can provide more rational subdivision based on the characteristics of each ship, shipowner requirements, and regulatory requirements. This minimizes the still water bending moment of the hull beam, effectively controls the ship's structural dimensions, and improves the ship's economic efficiency and environmental friendliness. Furthermore, this method utilizes optimized calculations to generate subdivision results, reducing the professional expertise required of designers and potentially lowering labor costs for enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of a conventional compartment structure.

[0023] Figure 2 Schematic diagram of the structure of the medium ballast tank set up for special subdivision.

[0024] Figure 3 Schematic diagram of the structure of the first ballast tank set up for special subdivision as an empty tank.

[0025] Figure 4 Schematic diagram of the stepped ballast tank structure designed for special subdivisions.

[0026] Figure 5 This is a schematic diagram of the initial engineering plan for the theoretical optimal solution of subdivision.

[0027] Figure 6 This is a schematic diagram of the second initial engineering solution for the theoretical subdivision optimal solution.

[0028] Reference numerals: 1. Ballast tank; 2. Cargo hold; 3. Transverse bulkhead. DETAILED DESCRIPTION

[0029] In order to make the present invention more clearly understood, preferred embodiments are described in detail below with reference to the accompanying drawings:

[0030] like Figure 1-6As shown, the present invention proposes a ship subdivision design method based on concept optimization, which takes the longitudinal position of each section of transverse bulkhead, the proportional relationship between the cargo hold 2 and the ballast tank 1 in each section of the cargo hold, and the loading rate of the ballast tank 1 in each section as optimizable variables. Through automatic optimization by an optimization algorithm, a theoretically optimal subdivision scheme that minimizes the extreme value of the still water bending moment of the hull beam is given, so that ordinary designers can also design the theoretically optimal subdivision form for different ships.

[0031] The present invention takes the longitudinal position of each section of transverse bulkhead 3 and the proportion of the cargo hold volume occupied by the cargo hold 2, ballast tank 1 and empty hold in the cargo hold section as optimization variables, takes the minimum extreme value of the still water bending moment of the hull beam as the objective function, and takes the requirements of various specifications and the division principle that is conducive to cargo loading and unloading and reducing the light ship weight as constraints, and adopts an optimization algorithm to perform subdivision optimization; the optimization algorithm is a general algorithm and can be implemented.

[0032] The specific steps are as follows:

[0033] (1) According to the shipowner's requirements and various rules and regulations, the number of cargo hold sections N is determined, and the number of transverse bulkheads is N+1.

[0034] (2) Taking the position of each transverse bulkhead 3 as the independent variable, according to the hull lines, establish the functional relationship between the total volume of each cargo hold section and the position of the transverse bulkhead 3;

[0035] (3) Taking the proportion of the cargo hold volume occupied by the cargo hold 2, ballast tank 1, and empty tank in each cargo hold section as independent variables, the functional relationship between the cargo hold 2, ballast tank 1, and empty tank volume and the total volume of each cargo hold section is established, and further, the functional relationship with the position of the transverse bulkhead 3 is established.

[0036] (4) According to the different loading conditions required by the specifications, the functional relationship between the weight center distribution of each tank under all loading conditions and the proportion of the cargo hold volume occupied by the cargo hold 2, ballast tank 1, and empty tank and the position of the transverse bulkhead 3 is established; on this basis, the functional relationship between the still water bending moment of the hull beam under each loading condition and the proportion of the cargo hold volume occupied by the cargo hold 2, ballast tank 1, and empty tank in each cargo hold section and the position of the transverse bulkhead 3 is established.

[0037] (5) Taking the shipowner's requirements, the requirements of various specifications and the division principle that is conducive to cargo loading and unloading and reducing the light ship weight as constraints, the minimum extreme value of the still water bending moment under all loading conditions is taken as the optimization goal. The position of the transverse bulkhead 3 and the proportion of the cargo hold volume occupied by the cargo hold 2, ballast tank 1 and empty tank in each cargo hold section are optimized to obtain the theoretically optimal subdivision design.

[0038] On this basis, the initial project plan can be obtained, and reasonable adjustments can be made later.

[0039] Taking an oil tanker with a single longitudinal bulkhead as an example, assuming that the number of cargo hold sections is determined to be 6 according to the damage requirements, the cargo hold sections are numbered i = 1, 2...6.

[0040] The positions of the front and rear bulkheads of the i-th cargo hold section are X bh (i-1) and X bh (i) According to the hull lines, the functional relationship between the total volume V(i) of the i-th cargo hold section and the bulkhead position is established, V(i) = f(X bh (i-1), X bh (i)).

[0041] The ratio of cargo hold 2 volume to the total volume of cargo hold section is k COT (i) The ratio of the volume of ballast tank 1 to the total volume of the cargo hold is k BWT (i) The ratio of the empty hold volume to the total volume of the cargo hold is k emp (i), k COT (i)+k BWT (i)+k emp (i) = 1. It can be obtained that the volume of cargo hold 2 is V COT (i) = k COT (i)*V(i), ballast tank 1 volume V BWT (i) = k BWT (i)*V(i), void volume V emp (i) = k emp (i)*V(i). The total cargo hold volume is ∑V COT (i).

[0042] Furthermore, a functional relationship between the volume of cargo hold 2, ballast tank 1, void tank and the position of transverse bulkhead 3 is established. COT (i) = k COT (i)*V(i)=k COT (i)*f(X bh (i-1), X bh (i)), ballast tank 1 volume V BWT (i) = k BWT (i)*V(i)=k BWT (i)*f(X bh (i-1), X bh (i)), the void volume V emp (i) = k emp (i)*f(X bh (i-1), X bh (i)).

[0043] Furthermore, the still water buoyancy distribution provided by the hull lines, the volume of each compartment, the position of the compartment and the loading conditions specified in the specifications are used to calculate the still water bending moment M(j) of the hull beam under different working conditions, where j is the number of loading conditions specified in the specifications.

[0044] The shipowner's requirements, the requirements of various rules and regulations, and the division principle that is conducive to cargo loading and unloading and reducing the light ship weight are used as constraints, and the minimum extreme value of the still water bending moment (max(abs(M(j)))) of all loading conditions is taken as the optimization goal. bh (i) The proportion of cargo hold volume occupied by cargo hold 2, ballast tank 1, and empty tank in each cargo hold section k COT (i), k BWT (i), k emp (i) Optimize and obtain the theoretically optimal subdivision design, as shown in Table 1. The constraints can be determined according to the design requirements of the specific target ship. For example, the shipowner requires the minimum cargo hold volume to be V COT-targ , then there is a constraint condition ∑V COT (i)≥V COT-targ For example, the anti-pollution regulations require the maximum cargo hold volume to be V COT-lim , then there is a constraint condition ∑V COT (i)≤V COT-lim .

[0045] On this basis, the initial engineering design can be obtained, such as Figure 5 、 Figure 6 shown.

[0046] Table 1. Subdivision optimization results

[0047] Cargo hold number 1 2 3 4 5 6 Transverse bulkhead (forward) position (m) 50 70 110 170 240 270 Cargo hold ratio (%) 85 75 92 88 70 80 Ballast tank proportion (%) 15 25 8 12 30 20 Empty cabin ratio (%) 0 0 0 0 0 0

[0048] This invention provides a conceptual optimization-based design method for ship subdivision design. It can provide more rational subdivision based on the characteristics of each ship, shipowner requirements, and regulatory requirements. This minimizes the still water bending moment of the hull beam, effectively controls the ship's structural dimensions, and improves the ship's economic efficiency and environmental friendliness. Furthermore, this method utilizes optimized calculations to generate subdivision results, reducing the professional expertise required of designers and potentially lowering labor costs for enterprises.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form or substance. It should be pointed out that ordinary technicians in this technical field can make several improvements and supplements without departing from the present invention, and these improvements and supplements should also be regarded as the scope of protection of the present invention. Any equivalent changes, modifications and evolutions made by technicians familiar with this profession without departing from the spirit and scope of the present invention by using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A ship subdivision design method based on concept optimization, characterized in that: The longitudinal position of each transverse bulkhead section and the proportion of the cargo hold volume occupied by the cargo hold, ballast tank and void tank in the cargo hold section are used as optimization variables. The minimum extreme value of the hull beam bending moment in still water is used as the objective function. The requirements of various codes and the division principle that is conducive to cargo loading and unloading and reduces the light ship weight are used as constraints. The optimization algorithm is used to optimize the subdivision, which includes the following steps: Step 1: Determine the number of cargo hold sections N according to the shipowner's requirements and various regulations and criteria. The number of transverse bulkheads is N+1. Step 2: Taking the position of each transverse bulkhead as the independent variable, establish the functional relationship between the total volume of each cargo hold section and the position of the transverse bulkhead according to the hull lines; Step 3: Take the proportion of cargo hold, ballast tank and void hold in each cargo hold section as the independent variable, and establish the functional relationship between the cargo hold, ballast tank and void hold volumes and the total volume of each cargo hold section; Step 4: Based on the different loading conditions required by the specifications, establish the functional relationship between the weight center distribution of each tank under all loading conditions and the proportion of the cargo hold, ballast tank, and void tank occupied by the cargo hold section volume and the position of the transverse bulkhead. On this basis, establish the functional relationship between the still water bending moment of the hull beam under each loading condition and the proportion of the cargo hold, ballast tank, and void tank occupied by the cargo hold section volume and the position of the transverse bulkhead in each cargo hold section; Step 5: Taking the shipowner's requirements, the requirements of various rules and regulations, and the division principle that is conducive to cargo loading and unloading and reducing the light ship weight as constraints, and minimizing the extreme value of the still water bending moment under all loading conditions as the optimization goal, the transverse bulkhead position and the proportion of the cargo tank volume occupied by the cargo oil tank, ballast tank, and void tank in each cargo hold section are optimized to obtain the theoretically optimal subdivision design scheme; Step 6: Based on step 5, the initial project plan can be obtained, and reasonable adjustments can be made later.

2. A ship subdivision design method based on concept optimization according to claim 1, characterized in that: Establishing the functional relationship between the cargo hold, ballast tank, void tank volumes and the total volume of each cargo hold section in step 3 is to establish the functional relationship between the cargo hold, ballast tank, void tank volumes and the position of the transverse bulkhead.

3. A ship subdivision design method based on concept optimization according to claim 2, characterized in that: In step 2, the position of each transverse bulkhead is used as an independent variable, and a functional relationship between the total volume of each cargo hold section and the position of the transverse bulkhead is established according to the hull line. Taking a tanker with a single longitudinal bulkhead as an example, assuming that the number of cargo hold sections is determined as N according to the damage requirements, the cargo hold sections are numbered i=1, 2...N; the positions of the front and rear bulkheads of the i-th cargo hold section are X bh (i-1) and X bh (i) According to the hull lines, the functional relationship between the total volume V(i) of the i-th cargo hold section and the bulkhead position is established, V(i) = f(X bh (i-1), X bh (i)).

4. A ship subdivision design method based on concept optimization according to claim 3, characterized in that: In step 3, the proportion of cargo hold volume occupied by cargo hold, ballast tank and empty tank in each cargo hold section is used as an independent variable, and the functional relationship between the cargo hold, ballast tank and empty tank volume and the total volume of each cargo hold section is established respectively; the proportion of cargo hold volume to the total volume of the cargo hold section is denoted as k COT (i) The ratio of the ballast tank volume to the total cargo hold volume is k BWT (i) The ratio of the empty hold volume to the total volume of the cargo hold is k emp (i), k COT (i)+k BWT (i)+k emp (i) = 1; we can get the cargo hold volume V COT (i) = k COT (i)*V(i), ballast tank volume V BWT (i) = k BWT (i)*V(i), void volume V emp (i) = k emp (i)*V(i); the total cargo hold volume is ∑V COT (i).

5. A ship subdivision design method based on concept optimization according to claim 4, characterized in that: In step 3, the functional relationship between the cargo hold, ballast tank, void tank volume and transverse bulkhead position is established; the cargo hold volume V COT (i) = k COT (i)*V(i)=k COT (i)*f(X bh (i-1), X bh (i)), ballast tank volume V BWT (i) = k BWT (i)*V(i)=k BWT (i)*f(X bh (i-1), X bh (i)), the void volume V emp (i) = k emp (i)*f(X bh (i-1), X bh (i)).

6. A ship subdivision design method based on concept optimization according to claim 5, characterized in that: In step 4, the hull beam still water bending moment M(j) under different working conditions is calculated based on the still water buoyancy distribution provided by the hull lines, the volume of each tank, the position of the cabin and the loading conditions specified in the specification, where j is the number of loading conditions specified in the specification.

7. A ship subdivision design method based on concept optimization according to claim 6, characterized in that: In step 5, the shipowner's requirements, the requirements of various rules and regulations, and the division principle that is conducive to cargo loading and unloading and reducing the light ship weight are used as constraints, and the minimum extreme value of the still water bending moment (max(abs(M(j)))) of all loading conditions is used as the optimization goal. bh (i) The proportion of cargo tanks, ballast tanks and void tanks in each cargo hold section k COT (i), k BWT (i), k emp (i) Optimize and obtain the theoretically optimal compartment design scheme.

8. A ship subdivision design method based on concept optimization according to claim 7, characterized in that: The constraints can be determined according to the design requirements of the specific target ship.

9. A ship subdivision design method based on concept optimization according to claim 8, characterized in that: The constraints include when the shipowner requires a minimum cargo hold volume of V COT-targ , then there is a constraint condition ∑V COT (i)≥V COT-targ ; When the anti-pollution regulations require the maximum cargo hold volume to be V COT-lim , then there is a constraint condition ∑V COT (i)≤V COT-lim .

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