LNG receiving station risk consequence simulation platform and method based on digital twin

Abstract

The present invention relates to a risk consequence simulation platform and method for an LNG receiving station based on digital twins. The simulation platform includes a DCS data unit, a model building system and a risk consequence evaluation system. The DCS data unit is configured to collect design parameters of a digital twin receiving station system; the model building system is configured to build a three-dimensional geometric model of the LNG receiving station and surrounding buildings; a meteorological condition module is configured to set simulated meteorological conditions; a hazard source identification module is configured to identify potential hazard sources of the LNG receiving station; a leakage scenario selection module is configured to select leakage scenarios; and a simulation analysis module is configured to perform leakage diffusion simulation analysis on the constructed three-dimensional geometric model based on the set meteorological conditions, hazard sources and leakage scenarios. The present invention can be widely used in risk consequence simulation of LNG receiving stations based on digital twins.

Description

Technical Field

[0001] The present invention relates to a risk consequence simulation platform and method for an LNG receiving station based on digital twins, and relates to the technical field of digital twins for LNG receiving stations. Background Art

[0002] The current quantitative evaluation method for LNG receiving stations is mainly based on DNV-Phast's QRA technology, and the generated results are risk consequence envelopes or contour lines. Since the applicable conditions of the leakage, diffusion, and explosion models are not strictly clear, there is a certain degree of uncertainty in the results, and it is difficult to consider vertical conditions such as occlusion in combination with the three-dimensional space in actual projects.

[0003] The three-dimensional consequence evaluation of existing three-dimensional scenes can reflect the three-dimensional space and take into account vertical conditions such as occlusion, and its reliability is improved compared with the above two-dimensional calculation results. However, the construction of existing three-dimensional scenes is relatively simple and is still far from the actual engineering situation. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a risk consequence simulation platform and method for LNG receiving stations based on digital twins, which can obtain accurate failure accident hazard results at the numerical simulation level.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a risk consequence simulation platform for an LNG receiving station based on digital twins, which includes a DCS data unit, a model building system and a risk consequence evaluation system. The risk consequence evaluation system includes a meteorological condition module, a hazard source identification module, a leakage scenario selection module and a simulation analysis module, wherein:

[0007] The DCS data unit is configured to collect design parameters of the digital twin receiving station system;

[0008] The model building system is configured to build a three-dimensional geometric model of the LNG receiving terminal and surrounding buildings;

[0009] The meteorological condition module is configured to set simulated meteorological conditions;

[0010] The hazard source identification module is configured to identify potential hazard sources of the LNG receiving station;

[0011] The leakage scenario selection module is configured to select a leakage scenario;

[0012] The simulation analysis module is configured to perform leakage diffusion simulation analysis on the constructed three-dimensional geometric model based on the set meteorological conditions, hazard sources and leakage scenarios.

[0013] Furthermore, the hazard source includes a continuous leakage mode and an instantaneous leakage mode.

[0014] Furthermore, the leakage scenarios include LNG unloading arm failure leakage scenario, LNG terminal transmission pipeline system failure leakage scenario, LNG storage tank failure leakage scenario, LNG storage tank output pipeline system failure leakage scenario, LNG pressurization and gasification system failure leakage scenario, LNG tank truck loading system failure leakage scenario, LNG system failure leakage scenario and BOG system failure leakage scenario.

[0015] Furthermore, the simulation analysis module uses computer fluid dynamics software to perform leakage and diffusion simulation analysis on the constructed three-dimensional geometric model.

[0016] Furthermore, the LNG receiving station is functionally divided into the wharf area, tank area, process area, public engineering area, tank truck area and surrounding buildings; the surrounding buildings include fire stations, maintenance workshops and warehouses, central control buildings, main transformer buildings, administrative buildings, dormitories and canteens, gate guards, wharf control buildings and seawater substations.

[0017] Furthermore, the three-dimensional scene model of the LNG receiving station and surrounding buildings is constructed based on the three-dimensional model of the LNG receiving station, the general plan layout, the equipment layout, the building plan elevation and related design parameters. The three-dimensional geometric model of the LNG receiving station is constructed. The geometric model of the surrounding buildings outside the LNG receiving station is constructed based on third-party satellite map information and topographic survey maps.

[0018] In a second aspect, the present invention provides a risk consequence simulation method for an LNG receiving station based on digital twins, comprising:

[0019] Construct a 3D geometric model of the LNG terminal and surrounding buildings;

[0020] Set leakage scenarios, meteorological conditions and hazard source identification;

[0021] The three-dimensional geometric model of the LNG receiving station and surrounding buildings is imported into the CFD simulation analysis platform. The flow and heat transfer analysis capabilities of the CFD simulation analysis platform are used to perform leakage and diffusion simulation analysis on the constructed three-dimensional geometric model based on the set meteorological conditions, hazard sources and leakage scenarios.

[0022] Furthermore, meteorological conditions include atmospheric temperature, atmospheric stability, radiant heat, wind speed and wind direction.

[0023] Furthermore, hazard source identification includes continuous leakage mode and instantaneous leakage mode.

[0024] Furthermore, the three-dimensional geometric model of the LNG receiving station and surrounding buildings is constructed based on the three-dimensional model of the LNG receiving station, the general plan layout, the equipment layout, the building plan elevation and related design parameters. The geometric model of the surrounding buildings outside the LNG receiving station is constructed based on third-party satellite map information and topographic survey maps.

[0025] The present invention adopts the above technical solution, which has the following advantages:

[0026] 1. The present invention starts from the perspective of maximizing the use of the digital delivery results obtained in the design stage of the receiving station, directly imports the digital delivery three-dimensional model into the hydraulic analysis simulation analysis platform, realizes digital mirror-level modeling, and restores the real scene on site to the greatest extent. By utilizing the powerful flow and heat transfer analysis capabilities of the hydraulic analysis simulation platform and combining the imported highly refined model, the most accurate failure accident hazard results can be obtained at the numerical simulation level;

[0027] 2. Based on the improvement of conventional two-dimensional risk consequence evaluation and three-dimensional consequence evaluation, the present invention has developed a three-dimensional simulation platform for risk consequences of LNG receiving stations based on digital twins on the basis of commercial risk consequence three-dimensional simulation. Under the three-dimensional scene construction model reaching the digital twin level, the computer fluid dynamics simulation of three-dimensional consequences is carried out with the help of the risk consequence evaluation method of LNG receiving stations based on digital twins, which can reflect the objective influences of leakage, diffusion, explosion, chain disaster consequences (such as explosion waste hitting equipment or storage tanks, fire or explosion shock wave causing damage to equipment and facility performance) of LNG or BOG (boil-off gas) in LNG receiving stations to the greatest extent;

[0028] In summary, the present invention can be widely used in risk consequence simulation of LNG receiving stations based on digital twins. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0030] Figure 1 This is a schematic diagram of the scale and composition structure of an LNG receiving station according to an embodiment of the present invention;

[0031] Figure 2 This is a flow chart of a risk consequence simulation method for an LNG receiving station based on digital twins according to an embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the simulation principle of an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0034] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0035] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0036] For ease of description, spatially relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures, such as "inside", "outside", "inner side", "outside", "below", "above", etc. Such spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figures.

[0037] The digital twin-based LNG receiving station risk consequence simulation platform and method provided by the present invention analyzes the typical process flow and main equipment of the receiving station, and divides the receiving station into five conventional blocks according to function, namely the wharf area, tank area, process area, public engineering area and tank truck area. The most serious potential failure accident leakage scenario is obtained by analyzing the main equipment and pipelines in each block, and combined with the digital results of the design stage, a three-dimensional LNG receiving station model at the digital mirror level is established to accurately restore the real environment of the station, simulate the leakage consequences of the failure accident, and obtain the most realistic and accurate results that can be obtained by using numerical simulation.

[0038] like Figure 1 As shown, the main equipment and facilities of the LNG receiving station based on digital twin include LNG unloading terminal, LNG storage tanks, LNG gasifier, natural gas export (including metering package), LNG tank truck export and buildings. The buildings mainly include fire station, maintenance workshop and warehouse, central control building, main transformer building, administrative building, dormitory and canteen, gate guard, terminal control building, seawater substation, etc.

[0039] The supporting process flow of the LNG receiving station based on digital twin includes the process flow of the LNG receiving station and the operation mode of the LNG receiving station.

[0040] The process flow of LNG receiving station includes the main functional flow of the main processes of typical LNG receiving station.

[0041] The main functional processes of the main processes of a typical LNG receiving station include LNG unloading process, LNG storage process, LNG gasification process, natural gas export process, and LNG tank truck export process.

[0042] The LNG unloading process is that after the LNG carrier arrives at the unloading terminal, the LNG is transported to the LNG storage tank through the delivery pump on the carrier and the unloading arm into the LNG main pipe. The LNG displaced after entering the storage tank is transported back to the LNG storage tank of the carrier through a return gas pipeline to maintain the pressure balance of the system. The LNG storage process is that the LNG receiving station is built with several LNG storage tanks. All the inlet and outlet connections and other instrument interfaces of the storage tank are designed on the top of the storage tank. It can be fed from the top or from the bottom through the internal insertion pipe. The gas phase interfaces of all storage tanks are connected to the BOG main pipe. The evaporation gas main pipe is connected to the inlet of the evaporation gas compressor and the flare system, and is connected to the gas return arm through the unloading gas return pipeline; the LNG gasification process is that the LNG coming out of the condenser directly enters the LNG high-pressure delivery pump, and is transported to the high-pressure gasifier after pressurization. LNG is then gasified into natural gas in the gasifier, and is sent to each user through the gas pipeline after metering. The minimum temperature of the gasified natural gas is 0℃. The natural gas export process, that is, the natural gas export of the LNG receiving station is equipped with a main pipeline for gas supply to various users. The LNG tank truck export process, that is, the car loading station is generally equipped with several tank truck loading positions, which can carry out loading operations at the same time. The car loading system includes a loading arm and a gas phase return arm, metering and loading control. During loading, the displaced gas is returned to the evaporation gas main pipe of the receiving station by pressure difference.

[0043] The operation modes of the LNG receiving station include zero output operation mode, normal output operation mode without ship unloading, and normal output operation mode without ship unloading. The zero output operation mode means that the LNG receiving station is in the no-ship unloading and zero output operation mode. During standby operation, a small amount of LNG is circulated to keep the system cold. The boil-off gas will be used as flare fuel gas, and the excess boil-off gas will be discharged to the flare. The normal output operation mode without ship unloading means that LNG will be transported by the pump according to demand, and then gasified in the vaporizer and transported externally through the recondenser. A small amount of LNG is circulated to keep the unloading main pipe cold. The normal output operation mode without ship unloading means that the LNG circulation will stop, and the feed will be made from the upper or lower part of the LNG storage tank according to the density of the LNG;

[0044] Embodiment 1: Figure 2 As shown, the risk consequence simulation platform for the LNG receiving station based on digital twin provided in this embodiment includes a DCS data unit, a model building system, and a risk consequence assessment system of a three-dimensional simulation model of the receiving station constructed based on the digital twin. The risk consequence assessment system includes a meteorological condition module, a hazard source identification module, a leakage scenario selection module and a simulation analysis module.

[0045] DCS data unit, used to collect design parameters of the digital twin receiving station system.

[0046] Model building system, which builds a 3D geometric model of the LNG terminal and surrounding buildings based on the digital twin level;

[0047] The weather condition module is used to set simulated weather conditions.

[0048] The hazard source identification module is used to identify potential hazard sources in the LNG receiving station. Potential hazard sources include liquefied natural gas, the main storage medium in the LNG receiving station, which is the main hazard source, but there are also other small amounts of media such as diesel. Hazard sources include continuous leakage mode and instantaneous leakage mode.

[0049] The leakage scenario selection module is used to select leakage scenarios. Specifically, the leakage scenarios include LNG unloading arm failure leakage scenario, LNG terminal transmission pipeline system failure leakage scenario, LNG storage tank failure leakage scenario, LNG storage tank output pipeline system failure leakage scenario, LNG boosting and gasification system failure leakage scenario, LNG tank truck loading system failure leakage scenario, LNG system failure leakage scenario and BOG system failure leakage scenario.

[0050] The simulation analysis module is used to select computer fluid dynamics (CFD) software to perform leakage and diffusion simulation analysis on the constructed LNG receiving station three-dimensional geometric model based on the set meteorological conditions, hazard sources and leakage scenarios.

[0051] In some embodiments of the present invention, the simulation analysis module establishes a mathematical simulation model of fluid motion based on the NS equations, establishes a solvable set of equations according to the set boundary conditions, initial conditions, i.e., meteorological conditions, leakage scenarios, etc., and discretizes the partial differential equations to realize numerical calculations, thereby solving the velocity, pressure, temperature and other results at each location in the study area at any time.

[0052] In some embodiments of the present invention, leakage diffusion simulation analysis requires grid division of the area where gas or liquid diffuses, where the liquid diffusion area is the core area, and the gas diffusion area is the extended area. In order to ensure both calculation speed and calculation accuracy, the grid size of the core area is selected based on the simulation system grid selection analysis results to perform simulation area division, and the grids of the buildings that require special attention around the LNG receiving station in the extended area are locally refined and smoothed.

[0053] Embodiment 2: Figure 3 As shown, this embodiment also provides a risk consequence simulation method for an LNG receiving station based on digital twins, including:

[0054] S1. Construct a 3D geometric model of the LNG receiving station and surrounding buildings.

[0055] Specifically, the construction of the three-dimensional geometric model can be modeled using various design software, and the three-dimensional model can be directly imported by directly importing the design results of the design software.

[0056] The three-dimensional geometric model of the LNG receiving station and surrounding buildings is mainly constructed based on the three-dimensional model of the LNG receiving station, the general layout plan, the equipment layout plan, the building plan elevation plan and related technical data. The three-dimensional geometric model of the LNG receiving station is constructed. The geometric model of the surrounding buildings outside the LNG receiving station is constructed based on third-party satellite map information and topographic survey maps.

[0057] S2. Set leakage scenarios, meteorological conditions and hazard source identification

[0058] LNG receiving stations are usually large-scale plants, and there are many areas where leakage accidents may occur. According to the main functions of different areas, they are usually divided into tank areas, process areas, loading areas, etc. The equipment and pipelines in these areas contain liquefied natural gas or cryogenic gaseous natural gas, which may cause leakage hazards. Therefore, it is not possible to analyze leakage accidents in a fixed location, but to consider leakage accidents in all major areas of the LNG receiving station. Even in the same area, the pipelines or equipment that leak are different, and it is usually necessary to select several of the most serious leakage scenarios for simulation analysis. Leakage scenarios include: The settings of the leakage scenarios include tank areas, process areas, loading areas, and the layout and impact criteria of surrounding buildings. For typical LNG leakage accident scenarios (tank areas, process areas, loading areas), the liquid pool module (POOL Version) in the fluid mechanics software is used for numerical calculations.

[0059] Meteorological conditions include: atmospheric temperature (annual average temperature 13.4°C), atmospheric stability (stable), radiant heat (0.5kW / m 2 ), wind speed (2m / s) and wind direction (the wind blows directly towards surrounding buildings), etc.

[0060] Hazard source identification includes: continuous leakage mode and instantaneous leakage mode.

[0061] S3. Determine the time of LNG leakage, perform numerical simulation of the wind field of the LNG station and surrounding buildings, and calculate the gas diffusion scenario

[0062] For typical LNG leakage accident scenarios, the liquid pool module (POOL Version) in the fluid mechanics software is used to perform numerical calculations of the leakage scenario; for fluid mechanics consequence simulation and impact analysis, according to the key input parameters and simulation conditions determined by the leakage scenario, the gas diffusion simulation is completed using the fluid mechanics three-dimensional geometric model. By post-processing the fluid mechanics simulation results, the diffusion range of the combustible concentration gas cloud is determined, and the adverse impact on surrounding buildings is judged. Specifically, the post-processing of the fluid mechanics simulation results is to perform a dynamic simulation of the diffusion after the leakage of key risk scenarios, in which each scenario is simulated for 30 seconds of blank wind field, and then the leakage, liquid pool formation and diffusion begin. The simulation results of each accident scenario determine the diffusion and explosion impact area range.

[0063] S4. Diffusion scenario results analysis

[0064] The diffusion scenario result analysis of this embodiment includes the maximum combustible gas concentration analysis of surrounding buildings in the full-diameter rupture scenario of the ship unloading pipeline, the maximum combustible gas concentration analysis at surrounding buildings during the entire process of leakage diffusion to the disappearance of the gas cloud in the full-diameter rupture scenario of the LNG tank inlet pipeline, the methane concentration range / maximum concentration analysis near surrounding buildings in the large-diameter rupture scenario of the low-pressure external transmission main (maximum external transmission condition), and the maximum combustible gas concentration analysis at surrounding buildings in the large-diameter rupture scenario of the loading main from the beginning of the leakage to the disappearance of the gas cloud.

[0065] S5. Evaluation conclusion

[0066] The gas cloud formed by the evaporation of the LNG liquid pool at the LNG receiving station of this embodiment diffuses, and its gas cloud concentration does not affect the surrounding buildings, that is, in these accident scenarios, the surrounding buildings will not be affected by the flash fire accident; at the same time, under the action of wind flow, the liquid pool continues to expand during the heat and mass transfer with the atmosphere, and is blocked by walls, equipment and buildings, and the surface of the liquid pool presents an irregular shape.

[0067] In summary, the present invention can reflect the objective influences such as leakage, diffusion, explosion, chain disaster consequences (such as explosion waste hitting equipment or storage tanks, fire or explosion shock wave causing damage to equipment and facility performance) of LNG or BOG (boil-off gas) in the LNG receiving station to the greatest extent by adopting the above method.

[0068] Each embodiment in this specification is described in a progressive manner, and the same and similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. In the description of this specification, the description of the reference terms "one embodiment", "some implementations", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of this specification. In this specification, the schematic representation of the above terms does not necessarily target the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A digital twin-based LNG terminal risk consequence simulation platform, It is characterized in that The simulation platform includes a DCS data unit, a model building system and a risk consequence evaluation system. The risk consequence evaluation system includes a meteorological condition module, a hazard source identification module, a leakage scenario selection module and a simulation analysis module, wherein: The DCS data unit is configured to collect design parameters of the digital twin receiving station system; The model building system is configured to build a three-dimensional geometric model of the LNG receiving terminal and surrounding buildings; The meteorological condition module is configured to set simulated meteorological conditions; The hazard source identification module is configured to identify potential hazard sources of the LNG receiving station; The leakage scenario selection module is configured to select a leakage scenario; The simulation analysis module is configured to perform leakage diffusion simulation analysis on the constructed three-dimensional geometric model based on the set meteorological conditions, hazard sources and leakage scenarios; Hazard sources include continuous leakage mode and instantaneous leakage mode; Leakage scenarios include LNG unloading arm failure leakage scenario, LNG terminal transmission pipeline system failure leakage scenario, LNG storage tank failure leakage scenario, LNG storage tank output pipeline system failure leakage scenario, LNG boosting and gasification system failure leakage scenario, LNG tank truck loading system failure leakage scenario, LNG system failure leakage scenario and BOG system failure leakage scenario; The simulation analysis module uses computer fluid dynamics software to perform leakage and diffusion simulation analysis on the constructed three-dimensional geometric model; The LNG receiving station is divided into the wharf area, storage tank area, process area, public engineering area, tank truck area and surrounding buildings according to its functions; the surrounding buildings include the fire station, maintenance workshop and warehouse, central control building, main transformer building, administrative building, dormitory and canteen, guard, wharf control building and seawater substation; The 3D scene model of the LNG receiving station and surrounding buildings is constructed based on the 3D model of the LNG receiving station, the general layout plan, the equipment layout plan, the building plan elevation plan and related design parameters. The 3D geometric model of the LNG receiving station is constructed based on the third-party satellite map information and topographic survey map. The simulation platform performs the following steps: Construct a 3D geometric model of the LNG terminal and surrounding buildings; Set leakage scenarios, meteorological conditions and hazard source identification; The three-dimensional geometric model of the LNG receiving station and surrounding buildings is imported into the CFD simulation analysis platform. The flow and heat transfer analysis capabilities of the CFD simulation analysis platform are used to perform leakage and diffusion simulation analysis on the constructed three-dimensional geometric model based on the set meteorological conditions, hazard sources and leakage scenarios.

2. According to the digital twin-based LNG receiving station risk consequence simulation platform of claim 1, It is characterized in that Meteorological conditions include atmospheric temperature, atmospheric stability, radiant heat, wind speed and direction.

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