LNG ship steel plate ordering specification control method

Abstract

According to the LNG ship steel plate ordering specification control method, the total number of the steel plate specifications of the whole ship is optimally controlled in the detailed design stage, the production design stage and the nesting ordering stage of the ship, the steel specification can be standardized, and on the basis that the steel plate utilization rate is guaranteed, the steel plate ordering specification is optimized. The problems of difficulty in material turning on a construction site, high difficulty in assembly and distribution, slow consumption of steel plates and long occupied space period are effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of shipbuilding, and particularly relates to a method for controlling the ordering specifications of LNG ship steel plates. Background Art

[0002] In shipbuilding, it is necessary to purchase structural steel plates of various specifications and sizes according to different design and structural requirements. The steel cost accounts for about 20% of the total shipbuilding cost. The procurement cost of steel plates is closely related to the types and quantities of steel specifications. At present, the types of steel procurement in each shipyard are diverse, which is not conducive to the standardized and large-scale steelmaking of steel mills, and will also cause difficulties in steel plate stacking and turning at the construction site, resulting in an extended construction period, difficult ordering of small-tonnage steel plates, and high additional costs. Summary of the Invention

[0003] In view of this, the present invention provides a method for controlling the ordering specifications of LNG ship steel plates to solve the problem of low overall economic efficiency caused by the diversification of steel plate ordering specifications, long ordering cycle, and difficult turning in the prior art.

[0004] A method for controlling the ordering specifications of LNG ship steel plates specifically includes the following steps:

[0005] S1. Determine the ship design life cycle;

[0006] The ship design life cycle includes the detailed design stage, the production design stage, and the nesting and ordering stage;

[0007] S2. In the detailed design stage, determine the steel plate thickness and arranged plate seams in different stress areas according to the whole-ship section division result, and statistically obtain the preliminary ordering plan for plates;

[0008] S3. In the production design stage, plan the construction processes of each section, optimize the plate seams of special-shaped parts, and re-statistically obtain the preliminary optimized ordering plan for plates according to the optimized results of the plate seams of special-shaped parts;

[0009] S4. According to the preliminary optimized ordering plan for plates, perform pre-nesting on each section, where similar sections are compared for nesting. After the pre-nesting is completed, re-statistically obtain the integrated optimized ordering plan for plates;

[0010] S5. Optimize and integrate similar-specification steel plates in the integrated optimized ordering plan for plates, and statistically obtain the steel plate specifications and the quantity of each specification of steel plates by quota to generate a steel plate ordering list.

[0011] Preferably, in step S2, the specific steps of determining the steel plate thickness and arranged plate seams in different stress areas according to the whole-ship section division result are as follows:

[0012] Perform section division on the whole ship to obtain the size specifications and section compositions of each section;

[0013] Calculate the stress distributions in the bow area, stern area, cargo hold area, and engine room area respectively according to the requirements of the classification society's specifications. Determine the steel plate thickness and steel plate material of each sectional structure based on the calculation results of the stress distributions. Then, arrange the plate seams for each component grillage of each section to minimize the number of sheet specifications, and obtain a preliminary sheet ordering plan, where the same plate gauge is used for similar sections.

[0014] Preferably, in step S3, when planning the construction processes of each section, first divide the sections into sub-assemblies according to their structural characteristics, and then separate the sub-assemblies and component parts of each section into different production lines.

[0015] Preferably, in step S3, when optimizing the plate seams of special-shaped parts, adjust the number and / or position of the plate seams according to the shape of the special-shaped parts so that the length or width of the steel plates required for nesting each part is consistent.

[0016] Preferably, in step S4, when pre-nesting, pre-nesting should be carried out according to the specified nesting requirements. The basic nesting requirements are: parts with regular shapes or the same size specifications are nested first, integral plate parts are nested separately, and small parts are preferably nested in the inner holes of parts with holes.

[0017] Preferably, in step S4, when pre-nesting, if some small parts cannot be nested in the inner holes of other parts and their sizes do not meet the minimum specification steel plates determined in the preliminary optimized sheet ordering plan, then merge the plate gauges of the minimum specification steel plates set in the preliminary optimized sheet ordering plan. Set the minimum specification steel plate to a steel plate with a width of not less than 1.5m, and then concentrate the small parts that cannot be nested in the inner holes of other parts on one minimum specification steel plate for nesting.

[0018] Preferably, in step S4, when pre-nesting, if some parts do not meet the basic nesting requirements, first adjust their production lines and use steel plates of the same thickness and the same material in other production lines to nest them.

[0019] If they still do not meet the basic nesting requirements after adjusting the production lines, then adjust the steel plate thickness and use thicker steel plates in this production line or other production lines for nesting.

[0020] If they still do not meet the basic nesting requirements after adjusting the steel plate thickness, then adjust the steel plate grade and use higher strength grade steel plates in this production line or other production lines for nesting.

[0021] Preferably, when adjusting the steel plate thickness for nesting, the thickness adjustment each time does not exceed 2mm.

[0022] Preferably, in step S5, when optimizing and integrating similar-sized plates in the plate order integration and optimization plan, the plates with similar specifications in the plate order integration and optimization plan are screened, and the plates with similar specifications are unified and merged into one plate specification.

[0023] The beneficial effects of the present invention are as follows:

[0024] By optimizing and controlling the total number of steel plate specifications for the entire ship during the detailed ship design stage, production design stage, and nesting and ordering stage, the present invention is conducive to standardizing the steel specifications. On the basis of ensuring the utilization rate of steel plates, it effectively solves the problems of difficult material turning on the construction site, large assembly difficulty, slow steel plate consumption, and long occupation of the site cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1 is a flowchart of the method of the present invention.

[0027] Figure 2 is a schematic diagram of the seam layout on the inner bottom plate of the bottom section.

[0028] Figure 3 is a schematic diagram of the nesting of the inner bottom plate of the bottom section.

[0029] Figure 4 is a schematic diagram of the seam layout in the double-bottom area of the double-bottom section.

[0030] Figure 5 is a schematic diagram of the nesting in the double-bottom area of the double-bottom section.

[0031] The meanings of the reference numerals in the drawings are as follows:

[0032] 1 is the inner bottom plate, 2 is the double bottom, and 3 is the seam. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be described through specific embodiments shown in the drawings. However, it should be understood that these descriptions are exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0034] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms "a", "the", and "said" used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0035] For a better understanding of the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings.

[0036] The present invention provides a method for controlling the ordering specifications of LNG ship steel plates, which specifically includes the following steps:

[0037] S1. Determine the ship design life cycle.

[0038] The ship design life cycle includes the detailed design stage, the production design stage, and the nesting and ordering stage.

[0039] The factors affecting the ordering specifications of steel plates include the selection of plate types and the arrangement of plate seams in the detailed design stage under the condition of meeting the strength requirements, and the arrangement form of part nesting in the pre-nesting stage.

[0040] S2. In the detailed design stage, determine the steel plate thickness and arrange the plate seams in different stress areas according to the sectional division results of the whole ship, and statistically obtain the preliminary ordering plan for the steel plates.

[0041] Specifically, first, divide the whole ship into sections to obtain the size specifications and sectional compositions of each section;

[0042] Calculate the stress distributions in the bow area, stern area, cargo hold area, and engine room area respectively according to the requirements of the classification society's specifications. Determine the steel plate thickness and steel plate material of each section structure according to the calculation results of the stress distribution. Then arrange the plate seams for each component plate frame of each section to minimize the number of steel plate specifications, and obtain the preliminary ordering plan for the steel plates, where the same plate gauge is used for similar sections.

[0043] Each section is composed of multiple parts. When arranging the plate seams for each part of the section, the plate seam positions and the number of plate seams should be determined according to the shape and structural characteristics of the part, so that the lengths or widths of the respective parts of the part after the plate seam division are as consistent or similar as possible to minimize the number of steel plate specifications.

[0044] Taking the deck section as an example, the area of the hull deck is very large. Usually, the deck is welded by multiple steel plates. Therefore, in the design stage, it is necessary to design the position of the splicing welds of the deck, that is, the plate seams. When arranging the plate seams on the deck, try to divide it into multiple plates with equal lengths and widths as equal or similar as possible to minimize the types of plate specifications. At the same time, when arranging the plate seams, consider the position of the allowance addition.

[0045] If there is a position with a change in plate thickness on the section, give priority to arranging the plate seam at this position to reduce the generation of surplus materials during subsequent nesting.

[0046] At the same time, under the condition of meeting the strength requirements, the types of plate materials should also be minimized as much as possible.

[0047] S3. In the production design stage, plan the construction processes of each section and optimize the plate seams of special-shaped parts. According to the optimization results of the plate seams of special-shaped parts, re-statistics the plate specifications to obtain a preliminary optimized plan for plate ordering.

[0048] Specifically, when planning the construction processes of each section, first divide the sections into assemblies according to their structural characteristics, and then divide the assemblies and component parts of each section into different processes.

[0049] After the division of assemblies and parts into different processes, adjust the number and / or position of the plate seams according to the shape of the special-shaped parts so that the lengths or widths of the steel plates required for nesting each part are the same, or the combined lengths or widths of some parts are the same as those of other parts.

[0050] For non-flat special-shaped parts, the plate seams are preferably arranged at the bending places of the plate surface.

[0051] For flat special-shaped parts, taking Figure 2 the inner bottom plate of the bilge section shown as an example, due to the special structure of the inner bottom plate of the bilge section, a large amount of surplus materials will be generated during nesting, and the utilization rate of the steel plate is not high. Therefore, starting from the purpose of reducing the number of steel plate specifications and improving the utilization rate of the steel plate, the inner bottom plate is divided into three parts: the left partial plate, the middle partial plate, and the right partial plate, so that the sum of the lengths of the left partial plate and the right partial plate is approximately equal to the length of the middle partial plate, so as to ensure the main body length, and thus ensure the consistency of the steel plate specifications after nesting, as Figure 3 shown, Figure 3 which is a schematic diagram of nesting the inner bottom plate of the bilge section.

[0052] Taking Figure 4Taking the double-bottom segment shown in the figure as an example, since there is a pipe area in the double-bottom area, there is a large opening in the pipe area. When opening the hole, the large opening leads to a decrease in the utilization rate of the steel plate. At the same time, the length of the plate rack does not meet the minimum plate gauge length, and the assembling of different segments will increase the additional plate gauge, which is time-consuming. Therefore, two plate seams are added on the basis of the original plate seam arrangement ( Figure 4 The red line shown in the figure is the plate seam, and the two horizontal red lines in the middle are the newly added plate seams). In this way, when nesting, the length of the steel plate meets the minimum plate gauge requirement, and the plate gauge (plate specification) used in similar sections is also the same, such as Figure 5 As shown, Figure 5 Schematic diagram of the double bottom area structure nesting.

[0053] When optimizing plate seams, the following principles should be followed:

[0054] 1. The thicker area can only be expanded, and it is strictly forbidden to shrink it;

[0055] 2. After the plate seam is optimized, it should not affect the assembly and installation of various parts;

[0056] 3. After the plate joints are optimized, the convenience of construction cannot be affected.

[0057] S4, according to the preliminary optimization plan for plate ordering, pre-nesting is performed on each segment, wherein similar segments are compared and nested. After the pre-nesting is completed, the plate specifications are re-counted to obtain the integrated optimization plan for plate ordering.

[0058] During pre-nesting, parts with regular shapes or the same size specifications are nested first, whole-plate parts are nested separately, and small parts are nested in the inner holes of parts with holes first.

[0059] The width of the plate should be as close to the width of the whole plate as possible. If there are holes in the whole plate, put the small parts into the holes of the whole plate.

[0060] If some small parts cannot be inserted into the inner holes of other parts and their sizes do not meet the minimum specification of the steel plate, which is 1.5m * 6.0m as determined in the preliminary optimized plan for steel plate ordering, then the steel plates with the minimum specification set in the preliminary optimized plan for steel plate ordering will be combined in terms of plate specifications. The minimum specification steel plate is set as a steel plate with a width of not less than 1.5m. Then, the small parts that cannot be inserted into the inner holes of other parts are concentrated on one minimum specification steel plate for nesting, and combined with other segments in the length or width direction. For example, after pre-nesting, the required steel plate specification for segment A is 1.5m * 2.0m, and the required steel plate specification for segment B after pre-nesting is 1.5m * 3.0m. Since the plate specifications of 1.5m * 2.0m and 1.5m * 3.0m do not meet the minimum specification of the steel plate, these two plate specifications are combined in the length direction and ordered as the minimum specification steel plate of 1.5m * 6.0m (that is, the parts of segment A and segment B are nested on the same 1.5m * 6.0m steel plate); another example, after pre-nesting, the required steel plate specification for segment C is 0.6m * 8.2m, and the required steel plate specification for segment D after nesting is 0.8 * 8.2m. Since the plate specifications of 0.6m * 8.2m and 0.8 * 8.2m do not meet the minimum specification of the steel plate, these two plate specifications are combined in the width direction and ordered as the minimum specification steel plate of 1.5m * 8.2m.

[0061] For the nesting of a single segment, only the quota plate of this segment can be used, and the quota plates of other segments cannot be used. For example, when nesting the deck segment, only the quota plate corresponding to the deck segment can be used, and the quota plate of the bilge segment cannot be used.

[0062] The quota plate refers to the steel plate specification and the required quantity of each specification of steel plate determined after nesting a certain segment in the above-mentioned integrated and optimized plan for steel plate ordering.

[0063] During pre-nesting, if some parts do not meet the above nesting requirements (that is, the whole-plate parts are nested separately, and the small parts are preferentially nested in the inner holes of the parts with holes), then their lanes are preferentially adjusted, and the steel plates with the same thickness and the same material in other lanes of this segment are used for nesting them;

[0064] If the nesting requirements are still not met after adjusting the lanes, then the thickness of the steel plate is adjusted, and thicker steel plates in this lane or other lanes are used for nesting. Each adjustment of the steel plate thickness does not exceed 2mm;

[0065] If the nesting requirements are still not met after adjusting the thickness of the steel plate, then the grade of the steel plate is adjusted, and higher-strength grade steel plates in this lane or other lanes are used for nesting.

[0066] During the process of nesting by adjusting the thickness or grade of the steel plate, the thickness or grade of the steel plate can only be increased, and it is prohibited to decrease.

[0067] The sheet material specifications adopted for similar segments are the same, and their nesting methods and techniques are also the same.

[0068] Similar segments refer to segments with similar structural forms.

[0069] In this embodiment, the nesting software adopted is CADWIN.

[0070] S5. Optimize and integrate the similar-specification sheet materials in the sheet material ordering integration and optimization plan, conduct quota statistics on the steel plate specifications and the quantity of each specification of steel plate, and generate a steel plate ordering list.

[0071] When optimizing and integrating the similar-specification sheet materials in the sheet material ordering integration and optimization plan, screen the sheet materials with similar specifications in the sheet material ordering integration and optimization plan, unify and combine the sheet materials with similar specifications into one sheet material specification, and conduct sheet gauge combination according to the principle of a width step of 50 mm and a length step of 100 mm. Sheet gauges in batches (number of sheets ≥ 5) or with a thickness of ≥ 30 mm can be ordered according to the actual nesting sheet gauge. (Note during sheet gauge combination: If the sheet gauge during pre-nesting is 12*1920*10000 and the adjacent sheet is 12*2000*10000, the actual order will still be based on 12*1920*10000; if the adjacent sheet is 12*1950*10000, then it will be combined into 12*1950*10000 for ordering).

[0072] It should be clear that the described embodiments are only part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

Claims

1. A method for controlling the ordering specifications of LNG ship steel plates, characterized in that: The specific steps include: S1, determine the ship design life cycle; The ship design life cycle includes the detailed design stage, the production design stage and the kitting ordering stage; S2, detailed design stage, according to the block division results of the whole ship, the thickness of steel plates in different stress areas and the arrangement of plate seams are determined, and the preliminary ordering plan of plates is obtained by statistics; S3, production design stage, planning the construction process of each segment, and optimizing the plate seams of special-shaped parts. According to the optimization results of the plate seams of special-shaped parts, recalculate the plate specifications and obtain the preliminary optimization plan for plate ordering; S4, according to the preliminary optimization plan for plate ordering, pre-nesting is performed on each segment, wherein similar segments are compared and nested. After the pre-nesting is completed, the plate specifications are re-counted to obtain the plate ordering integration optimization plan; S5, optimize and integrate the plates of similar specifications in the plate ordering integration optimization plan, calculate the steel plate specifications and the quantity of each specification of steel plates, and generate a steel plate ordering list.

2. The LNG ship steel plate ordering specification control method according to claim 1 is characterized in that: In step S2, the specific steps of determining the steel plate thickness in different stress areas and arranging the plate seams according to the whole ship segmentation result are as follows: Divide the entire ship into sections to obtain the size specifications and composition of each section; According to the requirements of classification society rules, the stress distribution of the bow area, stern area, cargo hold area and engine room area is calculated respectively. The steel plate thickness and material of each segment structure are determined according to the stress distribution calculation results. Then, the plate seams of each component plate frame of each segment are arranged to minimize the number of plate specifications, and a preliminary ordering plan for plates is obtained, in which similar segments use the same plate specifications.

3. The LNG ship steel plate ordering specification control method according to claim 1 is characterized in that: In step S3, when planning the construction process of each segment, each segment is first assembled and divided according to its structural characteristics, and then the assembly and component parts of each segment are divided into different paths.

4. The LNG ship steel plate ordering specification control method according to claim 1 is characterized in that: In step S3, when optimizing the plate seams of the special-shaped parts, the number of plate seams and / or the position of plate seams are adjusted according to the shape of the special-shaped parts so that the length or width of the steel plates required for nesting of each part is kept consistent.

5. The LNG ship steel plate ordering specification control method according to claim 1, characterized in that: In step S4, during pre-nesting, the pre-nesting should be carried out in accordance with the prescribed nesting requirements. The basic requirements for nesting are: parts with regular shapes or the same size specifications are nested first, whole-plate parts are nested separately, and small parts are nested in the inner holes of parts with holes first.

6. The LNG ship steel plate ordering specification control method according to claim 5 is characterized in that: In step S4, during pre-nesting, if some small parts cannot be nested in the inner holes of other parts, and their sizes do not meet the minimum specification plates determined in the preliminary optimization plan for plate ordering, the minimum specification plates set in the preliminary optimization plan for plate ordering are merged, and the minimum specification plates are set to steel plates with a width of not less than 1.5m. Then, the small parts that cannot be nested in the inner holes of other parts are concentrated on a minimum specification plate for nesting.

7. The method for controlling ordering specifications of LNG ship steel plates according to claim 5, characterized in that: In step S4, during pre-nesting, if some parts do not meet the basic nesting requirements, their lanes are adjusted first and the steel plates of the same thickness and material in other lanes are used to nest them; If the basic requirements for nesting are still not met after adjusting the lanes, adjust the thickness of the steel plate and use thicker steel plates in this lane or other lanes for nesting; If the basic requirements for nesting are still not met after adjusting the steel plate thickness, the steel plate grade should be adjusted and steel plates with higher strength grades in this lane or other lanes should be used for nesting.

8. The method for controlling ordering specifications of LNG ship steel plates according to claim 7, characterized in that: When adjusting the thickness of the steel plate for nesting, the thickness adjustment should not exceed 2mm each time.

9. The LNG carrier steel plate ordering specification control method according to claim 1, characterized in that: In step S5, when optimizing and integrating the plates of similar specifications in the plate ordering integration optimization plan, the plates of similar specifications in the plate ordering integration optimization plan are screened and the plates of similar specifications are unified into one plate specification.

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