Explosion damage modes and comprehensive identification methods for key components of shipborne steam turbines

Abstract

This invention relates to the field of shipborne steam turbine battle damage detection and damage assessment technology. It discloses a method for identifying explosion damage modes and a comprehensive discrimination method for key components of shipborne steam turbines. By constructing a basic database of explosion damage including cylinders, high and low pressure steam connecting pipes, and blades, and combining on-site multi-equipment detection with LS-DYNA simulation to collect and preprocess damage physical parameters, a damage mode classification system corresponding to fragments and shock wave loads is established. A three-level damage quantification discrimination model is constructed, ultimately outputting the damage mode, level, and targeted treatment strategy. This invention solves the problems in existing technologies such as inaccurate identification of explosion damage modes for key components of shipborne steam turbines, lack of unified quantitative standards for damage severity determination, poor adaptability of discrimination methods to component characteristics, and disconnect between damage discrimination and treatment strategies.

Description

Technical Field

[0001] This invention relates to the field of war damage detection and damage assessment technology for shipborne steam turbines, and particularly to explosion damage modes and comprehensive discrimination methods for key components of shipborne steam turbines. Background Technology

[0002] Shipborne steam turbines are the core of a ship's propulsion system, often referred to as the "heart" of the vessel. Their operational reliability directly determines the ship's propulsion, maneuverability, and overall survivability. Cylinders, high- and low-pressure steam connecting pipes, and blades, as key components of shipborne steam turbines, respectively undertake crucial functions such as constructing a confined space, transporting high-temperature and high-pressure steam, and converting steam energy. The structural integrity and functional stability of these components directly affect the steam turbine's power output efficiency and operational safety, forming the foundation for ensuring the ship's normal mission execution.

[0003] In complex combat environments, critical components of shipborne steam turbines are susceptible to the combined effects of fragment impacts, shock waves, and other explosive loads, resulting in various damage modes such as perforation, plastic deformation, fracture, and vibration impact. This can lead to component failure and, in severe cases, paralyze the entire ship's propulsion, directly threatening the ship's survivability and operational continuity. With the continuous improvement of the power of anti-ship weapons in modern naval warfare, the risk of explosive damage to shipborne steam turbines has increased significantly, placing higher demands on rapid detection, accurate assessment, and efficient handling of explosive damage.

[0004] Currently, the technology for assessing explosion damage to key components of shipborne steam turbines still has many shortcomings and cannot meet the needs of actual combat. First, damage assessment relies heavily on manual experience, lacking a unified quantitative standard based on physical parameters. The criteria for assessment vary depending on the inspector, component, and load type, making it difficult to generate objective and accurate results and prone to misjudgments or omissions. Second, existing assessment methods are poorly adapted to the structural characteristics of key shipborne steam turbine components. They lack specific models designed for characteristics such as thick-walled cylinder structures, high-speed blade rotation, and the pressure-bearing characteristics of high- and low-pressure steam connecting pipes, leading to significant discrepancies between assessment results and actual damage. Third, damage assessment and treatment strategies are severely disconnected. Most methods only output damage results and cannot provide targeted repair or replacement suggestions based on damage mode, damage level, and component importance, significantly prolonging the recovery time after shipborne steam turbine explosions. Finally, existing technologies cannot fully cover the combined effects of multiple explosive loads such as fragments and shock waves, failing to effectively identify hidden damage and hindering the rapid repair of shipwrecked vessels and the improvement of their sustained combat capabilities. Therefore, developing a method that can systematically classify the explosion damage modes of key components of shipborne steam turbines, quantitatively determine the damage level, and rapidly match the response strategies has become a critical issue that urgently needs to be addressed in the field of war damage assessment of ship propulsion systems. It has significant engineering application value and military significance. Summary of the Invention

[0005] The present invention aims to provide a method for identifying explosion damage modes and a comprehensive method for identifying key components of shipborne steam turbines, in order to solve the problems in the prior art such as inaccurate identification of explosion damage modes of key components of shipborne steam turbines, lack of unified quantitative standards for determining the degree of damage, poor adaptability of the identification method to the characteristics of the components, and disconnect between damage identification and treatment strategies.

[0006] To achieve the above objectives, the present invention provides the following method:

[0007] The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines provided by this invention are as follows:

[0008] S1: Construct a basic database of explosion damage to key components of shipborne steam turbines, sort out the basic parameters of various key components of shipborne steam turbines and their mechanical response characteristics under explosion loads, collect the core physical parameters of explosion loads, and establish the mapping relationship between functional damage and structural damage to key components of shipborne steam turbines.

[0009] S2: Collect physical parameters of the explosion damage of the key components of the shipborne steam turbine, and obtain the damage physical parameters of the key components of the shipborne steam turbine through a combination of on-site detection and simulation.

[0010] S3: Establish a classification system for the explosion damage modes of the key components of the shipborne steam turbine, classify the damage modes according to the explosion load type and the structural failure characteristics of the key components of the shipborne steam turbine, and extract the core physical criteria indicators of each damage mode.

[0011] S4: Construct a quantitative discrimination model for the explosion damage of the key components of the shipborne steam turbine, using the standardized damage physical parameters as input, and establish quantitative discrimination formulas and damage level judgment standards for each damage mode;

[0012] S5: Input the standardized damage physical parameters of the key components of the shipborne steam turbine to be identified into the quantitative discrimination model to complete the damage mode identification and damage level determination, and output the discrimination result.

[0013] Furthermore, in step S1, the key components of the shipborne steam turbine are cylinders, high and low pressure steam connecting pipes, and blades; the explosion loads include shock wave loads, fragment impact loads, and detonation gas impulse loads; the basic parameters of the key components of the shipborne steam turbine include structural parameters and material properties; the damage characterization features of the key components of the shipborne steam turbine include appearance morphology features, structural dimensional deviation features, mechanical performance attenuation features, and motion fit accuracy features; the basic database reserves a data update interface to support continuous improvement of the basic database through the addition of new engineering cases.

[0014] Furthermore, the on-site inspection in step S2 is completed using a drone, a 3D laser scanner, a stress-strain tester, and an acceleration sensor to acquire the explosion process and macroscopic damage scene, 3D morphology data, stress distribution data, and peak acceleration data of the key components of the shipborne steam turbine, respectively. The simulation is performed using LS-DYNA explosion simulation analysis software to simulate the mechanical response of the key components of the shipborne steam turbine under different explosion conditions. All the acquired physical parameters are preprocessed by outlier removal, missing value completion, data normalization, and feature dimensionality reduction to form a standardized dataset.

[0015] Furthermore, the damage modes described in step S3 are divided into fragment load-induced damage mode and shock wave load-induced damage mode; the fragment load-induced damage mode is a perforation damage mode, and the core physical criterion is the number of fragment perforations per unit area; the shock wave load-induced damage mode includes plastic deformation damage mode and tensile fracture damage mode; the core physical criterion includes the deformation amount, number of cracks, and crack propagation length of the key components of the shipborne steam turbine.

[0016] Furthermore, the damage levels mentioned in step S4 are uniformly divided into three levels: minor damage, moderate damage, and severe damage. The determination of each level of damage level is based on the degree of functional failure, structural damage status, and repair feasibility of the key components of the shipborne steam turbine.

[0017] Furthermore, in step S4, regarding the fragment load-induced damage mode of the high- and low-pressure steam connecting pipe, the reduction in steam turbine efficiency caused by steam leakage is calculated using the following formula, and the damage level is determined by combining the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe: Leakage rate calculation formula:

[0018] ;

[0019] In the formula, Leakage rate, in kg / s; The leakage coefficient depends on the shape and size of the leak. The cross-sectional area of ​​the leak is given in units of... ; It is the acceleration due to gravity; The pressure difference across the leak is expressed in Pa. This refers to the density of steam, in units of... Heat loss calculation formula:

[0020] ;

[0021] In the formula, Heat loss, expressed in J; Specific enthalpy of steam, expressed in J / kg; power loss calculation formula:

[0022] ;

[0023] In the formula, Power loss, measured in watts (W). The actual efficiency of the steam turbine; the formula for calculating efficiency reduction:

[0024] ;

[0025] In the formula, This represents the reduction in steam turbine efficiency. The actual output power of the steam turbine is expressed in W. When the number of perforations per unit area of ​​the high-low pressure steam connecting pipe is 1, it is judged as minor damage; when the number of perforations per unit area of ​​the high-low pressure steam connecting pipe is 2 to 5, it is judged as moderate damage; when the number of perforations per unit area of ​​the high-low pressure steam connecting pipe is greater than or equal to 6, it is judged as severe damage.

[0026] Furthermore, in step S4, for the shock wave load-induced damage mode of the cylinder, the damage level is determined based on the relationship between the deformation of the cylinder and the radial clearance between the blade and the cylinder: when the deformation of the cylinder is less than the radial clearance between the blade and the cylinder, it is determined to be minor damage; when the deformation of the cylinder is greater than the radial clearance between the blade and the cylinder, it is determined to be severe damage.

[0027] Furthermore, in step S4, regarding the shock wave load-induced damage mode of the high-low pressure steam connecting pipe, the damage level is determined based on the ratio of the deformation amount of the high-low pressure steam connecting pipe to its diameter: when the ratio of the deformation amount of the high-low pressure steam connecting pipe to its diameter is less than or equal to 10%, it is determined to be minor damage; when the ratio of the deformation amount of the high-low pressure steam connecting pipe to its diameter is greater than 10% and less than or equal to 30%, it is determined to be moderate damage; when the ratio of the deformation amount of the high-low pressure steam connecting pipe to its diameter is greater than 30% or the high-low pressure steam connecting pipe undergoes tensile fracture, it is determined to be severe damage.

[0028] Furthermore, the judgment result in step S5 includes the explosion damage mode, damage level, and corresponding handling strategy of the key component of the shipborne steam turbine to be judged; the handling strategy is formulated based on the damage mode, damage level, and importance of the key component of the shipborne steam turbine to be judged in the shipborne steam turbine system. The importance of the key component of the shipborne steam turbine to be judged is determined using the Failure Mode and Effects Analysis (FMEA) method; the handling strategy corresponding to minor damage is to carry out simple on-site repair of the key component of the shipborne steam turbine to be judged and strengthen subsequent operation monitoring; the handling strategy corresponding to moderate damage is to carry out professional repair of the key component of the shipborne steam turbine to be judged and then reuse it after passing performance testing; the handling strategy corresponding to severe damage is to determine the repair or replacement plan after comprehensive structural performance testing and evaluation of the key component of the shipborne steam turbine to be judged.

[0029] The beneficial effects of this invention are as follows: Addressing the core problems of existing shipborne steam turbine key component explosion damage identification technologies, such as low identification accuracy, lack of quantitative standards, poor adaptability, and disconnect between treatment and assessment, this invention achieves accurate identification and efficient treatment of explosion damage by constructing a dedicated basic database, a multi-dimensional data acquisition system, an adaptable damage classification model, and an integrated treatment mechanism. This invention abandons generalized damage classification methods and establishes a dedicated classification system for the structural characteristics of cylinders, high- and low-pressure steam connecting pipes, and blades, clearly defining core damage patterns and judgment indicators, significantly improving the accuracy of damage pattern identification. Furthermore, it integrates engineering-based identification methods to formulate a unified three-level damage quantification standard. All judgments are based on measurable physical parameters and accompanied by quantitative calculation formulas, completely eliminating the subjective bias of human experience and realizing a transformation from qualitative to quantitative assessment of damage severity. Meanwhile, this invention employs a combination of on-site multi-device collaborative detection and numerical simulation to comprehensively cover both apparent and latent internal damage, providing all-round data support for assessment. It deeply binds damage assessment results with the importance of the component system, establishing three-dimensional treatment strategy matching rules to directly output targeted repair, replacement, and protection recommendations, significantly improving the efficiency of battle damage repair. Furthermore, the basic database constructed by this invention reserves standardized update interfaces, and the quantitative assessment model adopts a modular design, allowing for flexible adjustment based on new component parameters. It is not only applicable to various types of currently in-service shipborne steam turbines but can also be extended to damage assessment scenarios for similar equipment such as land-based power plants, demonstrating broad engineering application value. Attached Figure Description

[0030] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0031] Figure 1 A flowchart illustrating the steps of the explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines provided in an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of a visualization model of the damage mode and comprehensive discrimination method for key components of shipborne steam turbines based on explosion damage characteristics provided in an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram showing the undamaged key components of a shipborne steam turbine provided in an embodiment of the present invention;

[0034] Figure 4 A schematic diagram of minor damage to a key component of a shipborne steam turbine provided in an embodiment of the present invention;

[0035] Figure 5 This is a schematic diagram of moderate damage to a key component of a shipborne steam turbine provided in an embodiment of the present invention.

[0036] Figure 6 This is a schematic diagram of severe damage to a key component of a shipborne steam turbine, provided as an embodiment of the present invention. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present invention, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or end that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or ends.

[0039] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0040] Currently, the technology for assessing explosion damage to key components of shipborne steam turbines still has many shortcomings and cannot meet the needs of actual combat. First, damage assessment relies heavily on manual experience, lacking a unified quantitative standard based on physical parameters. The criteria for assessment vary depending on the inspector, component, and load type, making it difficult to generate objective and accurate results and prone to misjudgments or omissions. Second, existing assessment methods are poorly adapted to the structural characteristics of key shipborne steam turbine components. They lack specific models designed for characteristics such as thick-walled cylinder structures, high-speed blade rotation, and the pressure-bearing characteristics of high- and low-pressure steam connecting pipes, leading to significant discrepancies between assessment results and actual damage. Third, damage assessment and treatment strategies are severely disconnected. Most methods only output damage results and cannot provide targeted repair or replacement suggestions based on damage mode, damage level, and component importance, significantly prolonging the recovery time after shipborne steam turbine explosions. Finally, existing technologies cannot fully cover the combined effects of multiple explosive loads such as fragments and shock waves, failing to effectively identify hidden damage and hindering the rapid repair of shipwrecked vessels and the improvement of their sustained combat capabilities. Therefore, developing a method that can systematically classify the explosion damage modes of key components of shipborne steam turbines, quantitatively determine the damage level, and rapidly match the response strategies has become a critical issue that urgently needs to be addressed in the field of war damage assessment of ship propulsion systems. It has significant engineering application value and military significance.

[0041] The present invention aims to provide a method for identifying explosion damage modes and a comprehensive method for identifying key components of shipborne steam turbines, in order to solve the problems in the prior art such as inaccurate identification of explosion damage modes of key components of shipborne steam turbines, lack of unified quantitative standards for determining the degree of damage, poor adaptability of the identification method to the characteristics of the components, and disconnect between damage identification and treatment strategies.

[0042] like Figure 1 and Figure 2 As shown, the specific embodiments of the present invention provide a method for determining the explosion damage mode and comprehensive discrimination of key components of shipborne steam turbines, including the following steps:

[0043] S1: Construct a basic database of explosion damage to key components of shipborne steam turbines, sort out the basic parameters of various key components of shipborne steam turbines and their mechanical response characteristics under explosion loads, collect the core physical parameters of explosion loads, and establish the mapping relationship between functional damage and structural damage to key components of shipborne steam turbines.

[0044] In this embodiment of the invention, the core components of the shipborne steam turbine are the cylinder, high- and low-pressure steam connecting pipe, and blades. The structural parameters, material properties, and mechanical response characteristics under explosive loads of various key components of the shipborne steam turbine are analyzed. Typical structural parameters of the cylinder include wall thickness, flange diameter, and radial clearance between the blade and the cylinder; the commonly used material is chromium-molybdenum steel ZG15Cr1Mo. Typical structural parameters of the high- and low-pressure steam connecting pipe include pipe diameter, wall thickness, and design pressure; the commonly used material is heat-resistant alloy steel. Typical structural parameters of the blade include blade profile dimensions and root structure; the commonly used material is high-temperature alloy.

[0045] Core physical parameters of three types of explosive loads—fragmentation, shock wave, and detonation gas impulse—are collected, including fragment perforation density, fragment impact velocity, shock wave overpressure peak value, impulse, structural deformation, and peak ground acceleration at measuring points. Through engineering case analysis and simulation test data accumulation, a quantitative mapping relationship between functional damage and structural damage to key components of shipborne steam turbines is established, clarifying the functional failure states corresponding to different degrees of structural damage. The basic database reserves a data update interface, supporting continuous improvement of the basic database through the addition of new engineering cases and experimental data, thereby enhancing the accuracy and applicability of the discrimination model.

[0046] S2: Conduct physical parameter collection of explosion damage to key components of shipborne steam turbines, and obtain the damage physical parameters of key components of shipborne steam turbines through a combination of on-site testing and simulation.

[0047] In this embodiment of the invention, a combination of on-site inspection and simulation is used to obtain the damage physical parameters of key components of the shipborne steam turbine. On-site inspection employs a multi-device collaborative mode: an unmanned aerial vehicle (UAV) records the explosion process and the macroscopic damage scene of the key components of the shipborne steam turbine; a 3D laser scanner acquires the 3D morphological data of the damaged key components, extracting apparent physical criteria such as structural plastic deformation and tear length; a stress-strain tester collects stress distribution data of the key components; and an accelerometer collects peak acceleration data at measurement points, ultimately forming an on-site inspection dataset.

[0048] The simulation is based on the LS-DYNA explosion simulation analysis software. A three-dimensional finite element model of the key components of the shipborne steam turbine is established. Different explosion conditions are input, including TNT equivalent, explosion distance, and explosion source location. The damage evolution process of the key components of the shipborne steam turbine under fragment impact and shock wave action is simulated. The mechanical response physical criteria such as shock wave overpressure peak value, impulse, maximum structural deformation, and crack propagation law are obtained to form a simulation dataset.

[0049] The field detection dataset and the simulation dataset are preprocessed, including outlier removal, missing value completion, data normalization and feature dimensionality reduction, to form a standardized dataset, providing a unified data input for subsequent damage identification.

[0050] S3: As Figure 3-6 As shown, various degrees of damage to key components of shipborne steam turbines are presented. A classification system for explosion damage modes of key components of shipborne steam turbines is established. Damage modes are divided according to the type of explosion load and the structural failure characteristics of key components of shipborne steam turbines, and the core physical criteria indicators of each damage mode are extracted.

[0051] In this embodiment of the invention, a multi-dimensional damage mode classification system is established based on the type of explosion load and the structural failure characteristics of key components of shipborne steam turbines, dividing the damage modes into two major categories: fragment load-induced damage mode and shock wave load-induced damage mode.

[0052] The main damage mode caused by fragment load is the perforation damage mode, which refers to the damage caused by fragments impacting the surface of key components of shipborne steam turbines under the action of explosive kinetic energy, resulting in penetrating damage or surface depression damage. Its core characteristics are clear perforations and pits on the surface of the components, which may be accompanied by microcracks in the surrounding materials. The core physical criterion is the number of fragment perforations per unit area.

[0053] The damage modes caused by shock wave loads include plastic deformation damage mode and tensile fracture damage mode. It refers to the irreversible permanent plastic deformation or fracture of the materials of key components of shipborne steam turbines caused by the instantaneous action of shock wave overpressure. The core physical criteria include the deformation amount, number of cracks and crack propagation length of key components of shipborne steam turbines.

[0054] S4: Construct a quantitative discrimination model for explosion damage to key components of shipborne steam turbines. Using standardized damage physical parameters as input, establish quantitative discrimination formulas and damage level judgment standards for each damage mode.

[0055] In this embodiment of the invention, standardized damage physical parameters are used as input to establish quantitative discrimination formulas and damage level judgment standards corresponding to each damage mode. The damage level is uniformly divided into three levels: minor damage, moderate damage, and severe damage. The judgment criteria for each level of damage level are the degree of functional failure, structural damage status, and repair feasibility of key components of the shipborne steam turbine.

[0056] For the fragment load-induced damage mode of the high- and low-pressure steam connecting pipe, the reduction in steam turbine efficiency caused by steam leakage is calculated using the following formula, and the damage level is determined by combining the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe: Leakage rate calculation formula:

[0057] ;

[0058] In the formula, Leakage rate, in kg / s; The leakage coefficient depends on the shape and size of the leak. The cross-sectional area of ​​the leak is given in units of... ; It is the acceleration due to gravity; The pressure difference across the leak is expressed in Pa. This refers to the density of steam, in units of... Heat loss calculation formula:

[0059] ;

[0060] In the formula, Heat loss, expressed in J; Specific enthalpy of steam, expressed in J / kg; power loss calculation formula:

[0061] ;

[0062] In the formula, Power loss, measured in watts (W). The actual efficiency of the steam turbine; the formula for calculating efficiency reduction:

[0063] ;

[0064] In the formula, This represents the reduction in steam turbine efficiency. This represents the actual output power of the steam turbine, expressed in watts (W).

[0065] When the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe is 1, it is judged as minor damage; when the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe is 2 to 5, it is judged as moderate damage; when the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe is greater than or equal to 6, it is judged as severe damage.

[0066] For the damage mode caused by shock wave load on the cylinder, the damage level is determined based on the relationship between the cylinder deformation and the radial clearance between the blade and the cylinder: when the cylinder deformation is less than the radial clearance between the blade and the cylinder, it is judged as minor damage; when the cylinder deformation is greater than the radial clearance between the blade and the cylinder, it is judged as severe damage.

[0067] For the shock wave load-induced damage mode of the high- and low-pressure steam connecting pipe, the damage level is determined based on the ratio of the deformation of the high- and low-pressure steam connecting pipe to its diameter: when the ratio is less than or equal to 10%, it is considered minor damage; when the ratio is greater than 10% and less than or equal to 30%, it is considered moderate damage; and when the ratio is greater than 30% or the high- and low-pressure steam connecting pipe experiences tensile fracture, it is considered severe damage.

[0068] S5: Input the standardized physical parameters of damage to the key components of the shipborne steam turbine to be identified into the quantitative discrimination model, complete the damage mode identification and damage level determination, and output the discrimination result.

[0069] In this embodiment of the invention, the standardized physical parameters of the damage to the key components of the shipborne steam turbine to be identified are input into the quantitative discrimination model. First, the explosion damage mode of the key components of the shipborne steam turbine to be identified is determined by matching the core physical criteria indicators with the features of the damage mode classification system. Second, based on the calculation results of the quantitative discrimination model and combined with the damage level judgment criteria, the damage level of the key components of the shipborne steam turbine to be identified is determined. Finally, the importance of the key components of the shipborne steam turbine to be identified in the shipborne steam turbine system is determined by the failure mode impact and hazard analysis method. According to the three-dimensional matching rule of "damage mode + damage level + component importance", a targeted handling strategy is output.

[0070] The handling strategy for minor damage is to carry out simple on-site repairs on the key components of the identified shipborne steam turbine and strengthen subsequent operational monitoring; the handling strategy for moderate damage is to carry out professional repairs on the key components of the identified shipborne steam turbine and then reuse them after passing performance testing; the handling strategy for severe damage is to determine the repair or replacement plan after a comprehensive structural performance test and evaluation of the key components of the identified shipborne steam turbine.

[0071] Example 1: Damage Assessment of Shipborne Steam Turbine Cylinder Explosion (Shock Wave Load)

[0072] Taking the explosion damage assessment of a ship's onboard steam turbine cylinder as an example, the specific implementation steps are as follows:

[0073] Basic database retrieval: Retrieve basic cylinder information from the basic database, including material ZG15Cr1Mo chromium-molybdenum steel, wall thickness 80mm, radial clearance between blade and cylinder 5mm, flange diameter 1500mm; retrieve explosion load parameters of the explosion accident, including explosion source 2.6m to the left of the center, TNT equivalent 175kg, explosion distance 1.35m; retrieve relevant judgment thresholds.

[0074] Damage Data Acquisition and Preprocessing: On-site inspection used a drone to record the macroscopic damage scene of the cylinder, and a 3D laser scanner was used to acquire the 3D morphology of the cylinder, measuring a maximum deformation of 6mm. An ultrasonic flaw detector detected no internal cracks. An accelerometer measured a peak acceleration of 8×10³g at the measuring point. Simulation: A finite element model of the cylinder was established based on LS-DYNA to simulate the above explosion conditions, obtaining a shock wave overpressure peak of 98.49MPa, an impulse of 12.76MPa·ms, and a structural stiffness attenuation rate of 12%. All data were normalized, and the core physical parameters were extracted: deformation 6mm, peak overpressure 98.49MPa, impulse 12.76MPa·ms, peak acceleration 8×10³g, and hardness change rate 10%.

[0075] Damage mode matching: Based on the core physical parameters and the damage mode classification system, it is determined that the damage to the cylinder is caused by the shock wave load, which manifests as large plastic deformation without perforation or fracture, and belongs to the shock wave load-induced plastic deformation damage mode.

[0076] Damage level determination: The core physical parameters are input into the overpressure-impulse quantization discrimination model, and the model calculation satisfies...

[0077] ;

[0078] in =91.74MPa =3.86 MPa·ms; Based on the damage level standard, the cylinder deformation of 6 mm is greater than the radial clearance of 5 mm between the blade and the cylinder, and the peak acceleration of 8 × 10³g falls within the range of 6 × 10³ to 1.5 × 10. 4 In the g-interval, the damage level is determined to be moderate.

[0079] Judgment results and disposal strategy output: The model outputs that the explosion damage mode of the cylinder is shock wave-induced plastic deformation damage, and the damage level is moderate damage. Considering the importance of the cylinder in the shipborne steam turbine system, the disposal strategy is matched as follows: immediately shut down the machine, reshape and heat-treat the cylinder for repair, and after repair, use a 3D laser scanner to detect the deformation, an ultrasonic flaw detector to detect the internal structure, and a hardness tester to detect the material hardness. After ensuring that the deformation is ≤2mm, there is no hidden damage, and the hardness has returned to the standard range, the steam turbine can be resumed to run. At the same time, protection recommendations are output: add shock wave protection armor to the outside of the cylinder, optimize the structural layout around the cylinder to improve its shock resistance, and regularly conduct wall thickness detection and vibration monitoring of the cylinder.

[0080] Example 2: Damage assessment of high and low pressure steam connecting pipes in shipborne steam turbines (fragment load)

[0081] Taking the explosion damage assessment of the high- and low-pressure steam connection pipes of a ship's onboard steam turbine as an example, the specific implementation steps are as follows:

[0082] Basic database retrieval: Retrieve basic information about the high and low pressure steam connecting pipe from the basic database, including pipe diameter of 300mm, wall thickness of 12mm, design pressure of 16MPa, and material of 12Cr1MoV heat-resistant alloy steel; retrieve explosion load parameters of the explosion accident, including fragment impact velocity of 1200m / s and number of fragments puncturing per unit area of ​​3.

[0083] Damage data acquisition and preprocessing: On-site inspection used a 3D laser scanner to acquire the 3D morphology of the high- and low-pressure steam connecting pipe, measuring the cross-sectional area of ​​a single fragment perforation as 0.0008 m². A pressure sensor measured the pressure difference across the leak as 15.5 MPa. A steam parameter monitoring system measured the steam density as 5.2 kg / m³, the steam specific enthalpy as 3200 kJ / kg, the actual output power of the steam turbine as 25 MW, and the actual efficiency as 38%. All data were normalized, and core physical parameters were extracted.

[0084] Damage mode matching: Based on the core physical parameters and the damage mode classification system, it was determined that the damage to the high and low pressure steam connecting pipe was caused by fragment load, manifested as perforation damage, and belonged to the fragment load-induced perforation damage mode.

[0085] Damage severity assessment: Substituting core physical parameters into the quantitative assessment formula, the leakage rate is calculated. =2.3kg / s, heat loss =7.36× J / s, power loss =19.37MW, efficiency reduction value =77.5%; Based on the damage level standard, the number of perforations per unit area of ​​the high and low pressure steam connecting pipe is 3, which is in the range of 2 to 5, and the damage level is judged to be moderate damage.

[0086] Judgment results and response strategy output: The model outputs that the explosion damage mode of the high- and low-pressure steam connecting pipe is fragmentation-induced perforation damage, with a damage level of moderate. Considering the importance of the high- and low-pressure steam connecting pipe in the shipborne steam turbine system, the response strategy is as follows: Immediately shut down the turbine, weld the perforated part of the high- and low-pressure steam connecting pipe, conduct hydrostatic and airtightness tests after repair, and resume steam turbine operation after ensuring no leakage. At the same time, the model outputs protection recommendations: Install a fragmentation protection net on the outside of the high- and low-pressure steam connecting pipe and conduct non-destructive testing on the welds regularly.

[0087] Example 3: Damage Assessment of Shipborne Steam Turbine Blades Due to Explosion (Shock Wave Load)

[0088] Taking the explosion damage assessment of the turbine blades of a ship's steam turbine as an example, the specific implementation steps are as follows:

[0089] Basic database retrieval: Retrieve basic information of the moving blade from the basic database, including blade length of 120mm, root width of 25mm, and material of GH4169 high-temperature alloy; retrieve explosion load parameters of the explosion accident, including shock wave overpressure peak of 65MPa and impulse of 8.2MPa・ms.

[0090] Damage data acquisition and preprocessing: On-site inspection using an ultrasonic flaw detector revealed a 4mm long microcrack on the blade body; the peak acceleration at the measuring point was measured to be 1.1×10⁻⁶ using an accelerometer. 4 g; The material hardness change rate was 12% as measured by a hardness tester. All data were normalized, and core physical parameters were extracted.

[0091] Damage mode matching: Based on the core physical parameters and the damage mode classification system, it was determined that the damage to the moving blade was caused by the shock wave load, manifested as crack propagation, and belonged to the shock wave load-induced crack propagation damage mode.

[0092] Damage severity assessment: Based on the damage severity standards, the crack length of the moving blade is 4mm ≤ 5mm, and the peak acceleration is 1.1 × 10⁻⁶ mm. g is at 6× ~1.5× In the g-interval, the damage level is determined to be moderate.

[0093] Judgment results and disposal strategy output: The model outputs that the explosion damage mode of the moving blade is shock wave-induced crack propagation damage, and the damage level is moderate damage; combined with the importance of the moving blade in the shipborne steam turbine system, the disposal strategy is matched as follows: immediately shut down the machine, grind and polish the microcracks of the moving blade, and after repair, perform magnetic particle inspection and dynamic balancing tests to ensure that there are no residual cracks and the rotor dynamic balance meets the standards before resuming steam turbine operation; at the same time, the protection recommendations are output: optimize the structural design of the blade, improve the impact resistance of the blade, and regularly inspect the blade for cracks.

[0094] The beneficial effects of this invention are as follows: Addressing the core problems of existing shipborne steam turbine key component explosion damage identification technologies, such as low identification accuracy, lack of quantitative standards, poor adaptability, and disconnect between treatment and assessment, this invention achieves accurate identification and efficient treatment of explosion damage by constructing a dedicated basic database, a multi-dimensional data acquisition system, an adaptable damage classification model, and an integrated treatment mechanism. This invention abandons generalized damage classification methods and establishes a dedicated classification system for the structural characteristics of cylinders, high- and low-pressure steam connecting pipes, and blades, clearly defining core damage patterns and judgment indicators, significantly improving the accuracy of damage pattern identification. Furthermore, it integrates engineering-based identification methods to formulate a unified three-level damage quantification standard. All judgments are based on measurable physical parameters and accompanied by quantitative calculation formulas, completely eliminating the subjective bias of human experience and realizing a transformation from qualitative to quantitative assessment of damage severity. Meanwhile, this invention employs a combination of on-site multi-device collaborative detection and numerical simulation to comprehensively cover both apparent and latent internal damage, providing all-round data support for assessment. It deeply binds damage assessment results with the importance of the component system, establishing three-dimensional treatment strategy matching rules to directly output targeted repair, replacement, and protection recommendations, significantly improving the efficiency of battle damage repair. Furthermore, the basic database constructed by this invention reserves standardized update interfaces, and the quantitative assessment model adopts a modular design, allowing for flexible adjustment based on new component parameters. It is not only applicable to various types of currently in-service shipborne steam turbines but can also be extended to damage assessment scenarios for similar equipment such as land-based power plants, demonstrating broad engineering application value.

[0095] The above descriptions are merely embodiments of the present invention. Commonly known technical solutions or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for determining the explosion damage modes and comprehensive identification of key components of shipborne steam turbines, characterized in that... The method includes: S1: Construct a basic database of explosion damage to key components of shipborne steam turbines, sort out the basic parameters of various key components of shipborne steam turbines and their mechanical response characteristics under explosion loads, collect the core physical parameters of explosion loads, and establish the mapping relationship between functional damage and structural damage to key components of shipborne steam turbines. S2: Collect physical parameters of the explosion damage of the key components of the shipborne steam turbine, and obtain the damage physical parameters of the key components of the shipborne steam turbine through a combination of on-site detection and simulation. S3: Establish a classification system for the explosion damage modes of the key components of the shipborne steam turbine, classify the damage modes according to the explosion load type and the structural failure characteristics of the key components of the shipborne steam turbine, and extract the core physical criteria indicators of each damage mode. S4: Construct a quantitative discrimination model for the explosion damage of the key components of the shipborne steam turbine, using the standardized damage physical parameters as input, and establish quantitative discrimination formulas and damage level judgment standards for each damage mode; S5: Input the standardized damage physical parameters of the key components of the shipborne steam turbine to be identified into the quantitative discrimination model to complete the damage mode identification and damage level determination, and output the discrimination result.

2. The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines according to claim 1, characterized in that: In step S1, the key components of the shipborne steam turbine are cylinders, high and low pressure steam connecting pipes, and blades; The explosive loads include shock wave loads, fragment impact loads, and detonation gas impulse loads. The basic parameters of the key components of the shipborne steam turbine include structural parameters and material properties. The damage characterization features of the key components of the shipborne steam turbine include appearance morphology features, structural dimensional deviation features, mechanical performance attenuation features, and motion fit accuracy features. The basic database has a reserved data update interface, which supports continuous improvement of the basic database by adding new project cases.

3. The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines according to claim 1, characterized in that: The on-site inspection described in step S2 is completed using a drone, a 3D laser scanner, a stress-strain tester, and an acceleration sensor to acquire the explosion process and macroscopic damage scene, 3D morphology data, stress distribution data, and peak acceleration data of the key components of the shipborne steam turbine, respectively. The simulation was conducted using LS-DYNA explosion simulation analysis software to simulate the mechanical response of the key components of the shipborne steam turbine under different explosion conditions. All collected physical parameters undergo preprocessing, including outlier removal, missing value completion, data normalization, and feature dimensionality reduction, to form a standardized dataset.

4. The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines according to claim 1, characterized in that: The damage modes described in step S3 are divided into fragment load-induced damage mode and shock wave load-induced damage mode; The fragment load-induced damage mode is the perforation damage mode, and the core physical criterion is the number of fragment perforations per unit area. The damage modes caused by the shock wave load include plastic deformation damage mode and tensile fracture damage mode. The core physical criteria include the deformation, number of cracks, and crack propagation length of the key components of the shipborne steam turbine.

5. The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines according to claim 2, characterized in that: The damage levels mentioned in step S4 are uniformly divided into three levels: minor damage, moderate damage, and severe damage. The determination of each level of damage level is based on the degree of functional failure, structural damage status, and repair feasibility of the key components of the shipborne steam turbine.

6. The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines according to claim 5, characterized in that: In step S4, for the fragment load-induced damage mode of the high- and low-pressure steam connecting pipe, the reduction in steam turbine efficiency caused by steam leakage is calculated using the following formula, and the damage level is determined by combining the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe: Leakage rate calculation formula: ； In the formula, Leakage rate, in kg / s; The leakage coefficient depends on the shape and size of the leak. The cross-sectional area of ​​the leak is given in units of 1. ; It is the acceleration due to gravity; The pressure difference across the leak is expressed in Pa. This refers to the density of steam, in units of... Heat loss calculation formula: ； In the formula, Heat loss, expressed in J; Specific enthalpy of steam, expressed in J / kg; power loss calculation formula: ； In the formula, Power loss, measured in watts (W). This refers to the actual efficiency of the steam turbine; Efficiency reduction calculation formula: ； In the formula, This represents the reduction in steam turbine efficiency. This represents the actual output power of the steam turbine, expressed in watts (W). When the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe is 1, it is judged as minor damage; when the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe is 2 to 5, it is judged as moderate damage; when the number of perforations per unit area of ​​the high- and low-pressure steam connecting pipe is greater than or equal to 6, it is judged as severe damage.

7. The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines according to claim 5, characterized in that: In step S4, for the shock wave load-induced damage mode of the cylinder, the damage level is determined based on the relationship between the deformation of the cylinder and the radial clearance between the blade and the cylinder: When the deformation of the cylinder is less than the radial clearance between the blade and the cylinder, it is determined to be minor damage; When the deformation of the cylinder is greater than the radial clearance between the blade and the cylinder, it is determined to be severely damaged.

8. The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines according to claim 5, characterized in that: In step S4, regarding the shock wave load-induced damage mode of the high-low pressure steam connecting pipe, the damage level is determined based on the ratio of the deformation of the high-low pressure steam connecting pipe to its diameter: when the ratio is less than or equal to 10%, it is determined to be minor damage; when the ratio is greater than 10% and less than or equal to 30%, it is determined to be moderate damage; when the ratio is greater than 30% or more, or when the high-low pressure steam connecting pipe undergoes tensile fracture, it is determined to be severe damage.

9. The explosion damage mode and comprehensive discrimination method for key components of shipborne steam turbines according to claim 1, characterized in that: The judgment result in step S5 includes the explosion damage mode, damage level, and corresponding handling strategy of the key component of the shipborne steam turbine to be judged. The handling strategy is formulated based on the damage mode, damage level, and importance of the key component in the shipborne steam turbine system. The importance of the key component is determined using the Failure Mode and Effects Analysis (FMEA) method. The handling strategy for minor damage is to perform simple on-site repairs on the key component and strengthen subsequent operational monitoring. The handling strategy for moderate damage is to perform professional repairs on the key component and allow it to be reused only after passing performance testing. The corresponding handling strategy for severe damage is to determine the repair or replacement plan after a comprehensive structural performance test and evaluation of the key components of the shipborne steam turbine to be identified.

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