A fault early warning diagnosis method, device and program product of a hydrogen liquefaction system

Abstract

The present application relates to the technical field of low temperature, disclose a kind of fault early warning diagnosis method, device and program product of hydrogen liquefaction system, the present application is by obtaining the operating characteristic parameter set of hydrogen liquefaction system, the first parameter set of helium compressor equipment and the second parameter set of helium oil separation and circulating cooling system, realize the comprehensive monitoring of hydrogen liquefaction system and its key subsystem.Further, the representative urgency, sudden accident prediction is combined with the risk causing accident prediction with accumulation effect, both pay attention to the sudden accident scene in system debugging process, also consider the risk accumulation in long-term operation, can more comprehensive, accurate, effectively assess the operating condition of hydrogen liquefaction system, fill the blank of lack of comprehensive fault early warning diagnosis in prior art.

Description

Technical Field

[0001] This invention relates to the field of cryogenic technology, and specifically to a fault early warning and diagnosis method, device, and program product for a hydrogen liquefaction system. Background Technology

[0002] With the development of the hydrogen energy market, the demand for liquid hydrogen in potential civilian applications is expected to gradually expand. Compared to the Claude cycle hydrogen liquefaction process, the helium expansion refrigeration process can produce subcooled liquid hydrogen (subcooled liquid hydrogen means that the temperature at which the liquid hydrogen product is produced is 15~21K), which effectively reduces flash evaporation during the transfer process. Furthermore, because helium is inert, helium compressors do not require complex and sophisticated explosion-proof modifications to meet the high system safety and reliability requirements. Therefore, current hydrogen liquefaction projects awaiting production focus on small to medium-sized hydrogen liquefaction systems with a capacity of ≤5t / d. For these small to medium-sized systems, the helium expansion refrigeration process is primarily used to produce liquid hydrogen.

[0003] Currently, publicly available information on the liquefaction process, equipment risk perception, and even fault early warning diagnosis of helium-refrigerated hydrogen liquefaction systems almost exclusively focuses on real-time data capture of imminent and sudden accidents occurring in a single unit within the hydrogen liquefaction cold box module or helium compressor system, or in a key component that is easy to install monitoring devices. This results in a lack of dynamic early warning capabilities based on risk accumulation in current civilian helium expansion refrigeration hydrogen liquefaction systems. Risk perception and fault early warning diagnosis of relevant main equipment in helium-refrigerated hydrogen liquefaction systems should be carried out by combining the prediction of representative imminent and sudden accidents with the prediction of risk-causing accidents with cumulative effects. Currently, there is no publicly available technology for this.

[0004] Furthermore, the current helium-cooled hydrogen liquefaction system lacks sufficient interaction between risk perception and fault early warning diagnosis, resulting in low accuracy of fault early warning diagnosis. Summary of the Invention

[0005] In view of this, the present invention provides a fault early warning and diagnosis method, device and program product for hydrogen liquefaction systems, in order to solve the problem that there is currently no publicly available technology that combines the prediction of representative urgent and sudden accidents with the prediction of risk-causing accidents with cumulative effects to carry out risk perception and fault early warning diagnosis of relevant main equipment in helium-refrigerated hydrogen liquefaction systems, and that the current degree of interaction between risk perception and fault early warning diagnosis in helium-refrigerated hydrogen liquefaction systems is insufficient, resulting in low accuracy of fault early warning diagnosis.

[0006] In a first aspect, the present invention provides a fault early warning and diagnosis method for a hydrogen liquefaction system, the hydrogen liquefaction system including a helium compressor system, the helium compressor system including helium compressor equipment and a helium-oil separation and circulating cooling system; the method includes:

[0007] The system acquires a set of operational characteristic parameters for the hydrogen liquefaction system, a first set of parameters for the helium compressor equipment, and a second set of parameters for the helium-oil separation and circulating cooling system. The first set of parameters characterizes the performance and structure of the helium compressor equipment, while the second set characterizes the oil separation and cooling performance of the helium-oil separation and circulating cooling system. Based on the operational characteristic parameter set, the first set of parameters, and the second set of parameters, the system provides fault warnings for multiple accident scenarios of the hydrogen liquefaction system and determines whether a fault exists in the system. These multiple accident scenarios are representative, urgent, and sudden accident scenarios encountered during the commissioning of the hydrogen liquefaction system. When no fault exists in the hydrogen liquefaction system, the system evaluates and analyzes multiple risk scenarios with cumulative effects based on the operational characteristic parameter set and the second set of parameters, and determines the fault warning and diagnosis results for the hydrogen liquefaction system.

[0008] The fault early warning and diagnosis method for hydrogen liquefaction systems provided by this invention achieves comprehensive monitoring of the hydrogen liquefaction system and its key subsystems by acquiring a set of operating characteristic parameters of the hydrogen liquefaction system, a first set of parameters for the helium compressor equipment, and a second set of parameters for the helium-oil separation and circulating cooling system. This provides a rich data foundation for fault early warning and diagnosis. Furthermore, for representative urgent and sudden accidents, real-time fault judgment is achieved through parameter analysis, avoiding system downtime or safety accidents caused by sudden faults and overcoming the limitations of existing technologies that only focus on monitoring sudden accidents of individual equipment. When there are no sudden faults in the system, risk scenarios with cumulative effects are further assessed, filling the gap in existing technologies that lack dynamic risk accumulation early warning, and achieving an upgrade from "post-event handling" to "pre-event prevention." Therefore, by implementing this invention, combining the prediction of representative urgent and sudden accidents with the prediction of risk-causing accidents with cumulative effects, it considers both sudden accident scenarios during system commissioning and risk accumulation during long-term operation, enabling a more comprehensive, accurate, and effective assessment of the operating status of the hydrogen liquefaction system, filling the gap in existing technologies that lack comprehensive fault early warning and diagnosis.

[0009] In one optional implementation, based on a set of operating characteristic parameters, a first set of parameters, and a second set of parameters, fault warnings are provided for multiple accident scenarios of the hydrogen liquefaction system, and the presence of a fault in the hydrogen liquefaction system is determined, including:

[0010] Based on the set of operating characteristic parameters and the first set of parameters, it is determined whether the helium compressor equipment has abnormal frequency conversion; when the hydrogen liquefaction system experiences frequent start-stop operations, based on the first set of parameters, it is determined whether the helium compressor equipment generates abnormal vibration; based on the first set of parameters and the second set of parameters, it is determined whether the cooling of each section of the helium compressor equipment meets the requirements; based on the second set of parameters, it is determined whether the oil separation system of the helium compressor equipment is overloaded; based on the first set of parameters, it is determined whether the helium compressor equipment faces a lubrication threat; if the helium compressor equipment does not exhibit any abnormal conditions, does not generate abnormal vibrations, the cooling of each section of the helium compressor equipment meets the requirements, the oil separation system of the helium compressor equipment is not overloaded, and the helium compressor equipment does not face a lubrication threat, it is determined that the hydrogen liquefaction system is not faulty.

[0011] The fault early warning and diagnosis method for hydrogen liquefaction systems provided by this invention judges faults from multiple representative dimensions of urgent and sudden accidents, such as the frequency conversion status of helium compressor equipment, abnormal vibration, cooling of each section, oil separation system, and lubrication status. This avoids system shutdown or safety accidents caused by sudden faults and overcomes the limitations of existing technologies that only focus on monitoring sudden accidents of individual equipment. As a result, it can more accurately identify various problems that may exist in the hydrogen liquefaction system, improve the accuracy and reliability of fault diagnosis, and solve the problem of insufficient interaction between current system risk perception and fault early warning diagnosis, especially for problems such as abnormal frequency conversion of helium compressors and abnormal vibration caused by incompatibility with frequent start-stop conditions in helium compressor systems.

[0012] In one optional implementation, determining whether the helium compressor equipment has experienced abnormal frequency conversion based on the operating characteristic parameter set and the first parameter set includes:

[0013] Based on the set of operating characteristic parameters, determine the allowable power frequency amplitude; based on the set of operating characteristic parameters and the first parameter set, determine the maximum acceptable power frequency amplitude; based on the maximum acceptable power frequency amplitude, determine the target power frequency amplitude; determine whether the target number of occurrences of the helium compressor equipment during actual operation is greater than or equal to the target power frequency amplitude, where the target number represents the number of times the actual power frequency amplitude of the helium compressor equipment during actual operation exceeds the allowable power frequency amplitude; when the target number is greater than or equal to the target power frequency amplitude, it is determined that the helium compressor equipment has an abnormal frequency change.

[0014] The fault early warning and diagnosis method for hydrogen liquefaction systems provided by this invention determines the allowable power frequency amplitude, the maximum acceptable power frequency amplitude, and the target power frequency amplitude, and compares the actual number of target frequency amplitudes with the target power frequency amplitude. This method can accurately monitor whether abnormal frequency changes occur in helium compressor equipment, providing an effective means for timely detection and handling of frequency change-related faults, and helping to ensure the stable operation of helium compressor equipment.

[0015] In one optional implementation, when the hydrogen liquefaction system experiences frequent start-ups and shutdowns, based on a first parameter set, it is determined whether the helium compressor equipment is experiencing abnormal vibration, including:

[0016] When the hydrogen liquefaction system experiences frequent start-stop cycles, the critical axial vibration velocity value of the helium compressor equipment's casing is determined based on the first parameter set; when the real-time axial vibration velocity value of the helium compressor equipment is greater than or equal to the critical axial vibration velocity value of the casing, it is determined that the helium compressor equipment is experiencing abnormal vibration.

[0017] The fault early warning and diagnosis method for hydrogen liquefaction systems provided by this invention can accurately determine whether the equipment is generating abnormal vibrations when the hydrogen liquefaction system experiences frequent start-stop operations. This is achieved by determining the critical axial vibration velocity value of the helium compressor housing and comparing it with the real-time axial vibration velocity value. This allows for timely detection of equipment vibration problems that may be caused by frequent start-stop operations, providing a basis for equipment maintenance and troubleshooting.

[0018] In one optional implementation, when the hydrogen liquefaction system experiences frequent start-ups and shutdowns, based on a first parameter set, determining whether the helium compressor equipment is experiencing abnormal vibration further includes:

[0019] When the hydrogen liquefaction system experiences frequent start-stop cycles, the critical acceleration value of the axial vibration of the helium compressor housing is determined based on the first parameter set. If the real-time axial vibration acceleration value of the helium compressor housing is greater than or equal to the critical acceleration value of the axial vibration of the housing, it is determined that the helium compressor housing is experiencing abnormal vibration.

[0020] The fault early warning and diagnosis method for hydrogen liquefaction systems provided by this invention determines the critical axial vibration acceleration value of the casing of the helium compressor equipment when the hydrogen liquefaction system experiences frequent start-stop situations, and compares it with the real-time axial vibration acceleration value. This further enriches the basis for judging abnormal vibration of the equipment, improves the accuracy and comprehensiveness of fault judgment, and can more effectively discover potential vibration fault hazards.

[0021] In one optional implementation, based on a first parameter set and a second parameter set, determining whether the cooling of each section of the helium compressor equipment meets the requirements includes:

[0022] The system obtains the first real-time cooling oil atomization particle size in the high-pressure stage, the second real-time cooling oil atomization particle size in the medium-pressure stage, and the third real-time cooling oil atomization particle size in the low-pressure stage of the hydrogen liquefaction system. Based on the maximum oil content in the helium exhaust gas of the helium compressor equipment, the system determines the maximum permissible atomization particle size of the first cooling oil in the high-pressure stage. Based on the first parameter set, the second parameter set, and the maximum permissible atomization particle size of the first cooling oil, the system determines the maximum permissible atomization particle size of the second cooling oil in the medium-pressure stage and the maximum permissible atomization particle size of the third cooling oil in the low-pressure stage. When the first real-time cooling oil atomization particle size is less than or equal to the first maximum permissible atomization particle size, the second real-time cooling oil atomization particle size is less than or equal to the second maximum permissible atomization particle size, and the third real-time cooling oil atomization particle size is less than or equal to the third maximum permissible atomization particle size, the system determines that the cooling of each section of the helium compressor equipment meets the requirements.

[0023] The fault early warning and diagnosis method for hydrogen liquefaction systems provided by this invention fully considers the differences in atomized particle size of cooling oil at different stages when judging whether the cooling of each section of the helium compressor equipment meets the requirements. It determines the maximum allowable atomized particle size of cooling oil at each stage based on the maximum oil content in the helium exhaust gas, and then judges the cooling effect by comparing the real-time particle size with the allowable particle size. This solves the problem in the prior art that the differences in atomized cooling oil particle size are not fully considered when diagnosing cooling effect faults, making the fault diagnosis of the cooling system more in line with the requirements of the segmented cooling process mechanism, which helps to ensure the normal operation of the cooling system and improve the cooling efficiency and stability of the equipment.

[0024] In one optional implementation, based on a first parameter set, a second parameter set, and a first maximum permissible atomized particle size of the cooling oil, the maximum permissible atomized particle size of the second cooling oil in the medium-pressure stage and the maximum permissible atomized particle size of the third cooling oil in the low-pressure stage of the hydrogen liquefaction system are determined, including:

[0025] Based on the first and second parameter sets, a first relationship is determined between the critical pressure at the end of the high-pressure stage and the critical pressure at the end of the medium-pressure stage of the helium compressor equipment, and a second relationship is determined between the critical pressure at the end of the medium-pressure stage and the critical pressure at the end of the low-pressure boosting stage. A third relationship is determined between the high-pressure stage time and the medium-pressure stage time of the helium compressor equipment based on the first relationship. A fourth relationship is determined between the medium-pressure stage time and the low-pressure stage time of the helium compressor equipment based on the second relationship. The maximum permissible atomization particle size of the second cooling oil is determined based on the first and third relationships and the maximum permissible atomization particle size of the first cooling oil. The maximum permissible atomization particle size of the third cooling oil is determined based on the second and fourth relationships and the maximum permissible atomization particle size of the second cooling oil.

[0026] The fault early warning and diagnosis method for hydrogen liquefaction systems provided by this invention, based on a first parameter set and a second parameter set, determines the critical pressure relationship of the helium compressor equipment at different stages, thereby deriving the time relationship of each stage. Based on these relationships and the maximum allowable atomization particle size of the first cooling oil, the maximum allowable atomization particle size of the cooling oil in the medium-pressure stage and the low-pressure stage can be scientifically determined. This provides a reasonable calculation method and basis for accurately judging whether the cooling of each segment meets the requirements, making the fault diagnosis of the entire cooling system more accurate and scientific.

[0027] In one optional implementation, when the hydrogen liquefaction system is fault-free, multiple risk scenarios with cumulative effects on the hydrogen liquefaction system are assessed and analyzed based on a set of operating characteristic parameters and a second set of parameters, and the fault early warning diagnosis results of the hydrogen liquefaction system are determined, including:

[0028] When there is no fault in the hydrogen liquefaction system, the maximum inlet dust particle size at the outlet of the oil filter of the helium compressor is determined based on the first and second parameter sets. The real-time inlet dust particle size at the outlet of the oil filter of the helium compressor is compared with the maximum inlet dust particle size, and it is determined whether the oil filter of the helium compressor meets the dust interception requirements, thus obtaining the first judgment result. The critical displacement of the axial vibration of the shell of the helium compressor is determined based on the operating characteristic parameter set and the second parameter set. The real-time axial vibration displacement of the shell of the helium compressor is compared with the critical displacement of the axial vibration of the shell, and it is determined whether the helium compressor has abnormal vibration, thus obtaining the second judgment result. Based on the first and second judgment results, the fault early warning diagnosis result of the hydrogen liquefaction system is determined.

[0029] The fault early warning and diagnosis method for hydrogen liquefaction systems provided by this invention, when there is no fault in the hydrogen liquefaction system, monitors and compares the particle size of the inlet dust at the outlet of the oil filter of the helium compressor equipment, and judges the critical displacement of the axial vibration of the shell. It focuses on risk scenarios with cumulative effects, such as dust interception problems and potential faults that may be caused by long-term vibration. In this way, it can detect potential safety hazards in the system in advance, provide a guarantee for the long-term stable operation of the system, further improve the fault early warning and diagnosis function, and enable the system to better cope with various potential risks.

[0030] Secondly, the present invention provides a fault early warning and diagnosis device for a hydrogen liquefaction system, the hydrogen liquefaction system including a helium compressor system, the helium compressor system including helium compressor equipment and a helium-oil separation and circulating cooling system; the device includes:

[0031] The acquisition module acquires the operating characteristic parameter set of the hydrogen liquefaction system, the first parameter set of the helium compressor equipment, and the second parameter set of the helium-oil separation and circulating cooling system. The first parameter set characterizes the performance and structure of the helium compressor equipment, and the second parameter set characterizes the oil separation and cooling performance of the helium-oil separation and circulating cooling system. The judgment module, based on the operating characteristic parameter set, the first parameter set, and the second parameter set, provides fault warnings for multiple accident scenarios of the hydrogen liquefaction system and determines whether a fault exists in the hydrogen liquefaction system. The multiple accident scenarios are representative urgent and sudden accident scenarios encountered during the commissioning of the hydrogen liquefaction system. The evaluation and analysis module, when the hydrogen liquefaction system does not have a fault, evaluates and analyzes multiple risk scenarios with cumulative effects of the hydrogen liquefaction system based on the operating characteristic parameter set and the second parameter set, and determines the fault warning and diagnosis results of the hydrogen liquefaction system.

[0032] Fifthly, the present invention provides a computer program product, including computer instructions, which are used to cause a computer to execute the fault early warning and diagnosis method for a hydrogen liquefaction system described in the first aspect or any corresponding embodiment. Attached Figure Description

[0033] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a schematic flowchart of a fault early warning and diagnosis method for a hydrogen liquefaction system according to an embodiment of the present invention.

[0035] Figure 2 This is a flowchart illustrating another fault early warning and diagnosis method for a hydrogen liquefaction system according to an embodiment of the present invention.

[0036] Figure 3 This is a schematic diagram illustrating the relationship between the ratio of the rated liquid hydrogen production rate to the maximum mass flow rate of compressed helium according to an embodiment of the present invention and the theoretical value of the maximum acceptable power frequency amplitude.

[0037] Figure 4 This is a schematic diagram showing the relationship between the continuous statistical period of motor power exceeding the limit and the cumulative running time of a PFPE oil-lubricated helium screw compressor according to an embodiment of the present invention.

[0038] Figure 5This is a schematic diagram showing the relationship between the continuous statistical period of motor power exceeding the limit and the cumulative running time of an ISO VG 32 oil-lubricated helium screw compressor according to an embodiment of the present invention.

[0039] Figure 6 This is a schematic diagram showing the relationship between the continuous statistical period of motor power exceeding the limit and the cumulative running time of a BREOX B 35 oil-lubricated helium screw compressor according to an embodiment of the present invention.

[0040] Figure 7 This is a schematic diagram illustrating the relationship between the over-limit critical ratio and the rated compression ratio of a helium screw compressor according to an embodiment of the present invention;

[0041] Figure 8 This is a schematic diagram illustrating the relationship between the actual value of the motor power over-limit critical number and the maximum acceptable power frequency amplitude according to an embodiment of the present invention.

[0042] Figure 9 This is a schematic diagram showing the relationship between the rated maximum oil content in helium exhaust and the maximum permissible atomized particle size of cooling oil in the high-pressure stage, according to an embodiment of the present invention.

[0043] Figure 10 This is a schematic diagram showing the relationship between the interstage booster oil adaptability coefficient and the rated oil cooling temperature of a PFPE oil-lubricated helium screw compressor according to an embodiment of the present invention.

[0044] Figure 11 This is a schematic diagram showing the relationship between the interstage booster oil adaptability coefficient and the rated oil cooling temperature of an ISO VG 32 oil-lubricated helium screw compressor according to an embodiment of the present invention.

[0045] Figure 12 This is a schematic diagram showing the relationship between the interstage booster oil adaptability coefficient and the rated oil cooling temperature of a helium screw compressor lubricated with BREOX B 35 oil according to an embodiment of the present invention.

[0046] Figure 13 This is a schematic diagram showing the relationship between the rated centrifugal drive strength of oil separation and the maximum mass flow rate of cooling oil required for helium compression according to an embodiment of the present invention.

[0047] Figure 14 This is a schematic diagram showing the relationship between the rated circumferential linear speed of the rotor and the maximum mass flow rate of the cooling oil required for compressing helium, according to an embodiment of the present invention.

[0048] Figure 15 This is a flowchart illustrating another fault early warning and diagnosis method for a hydrogen liquefaction system according to an embodiment of the present invention.

[0049] Figure 16 This is a structural block diagram of a fault early warning and diagnosis device for a hydrogen liquefaction system according to an embodiment of the present invention;

[0050] Figure 17 This is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0052] In a hydrogen liquefaction system employing helium expansion refrigeration, a reverse Brayton cycle refrigerator is required. Helium is used as the circulating working medium to generate the low temperature required for liquefied hydrogen. The helium system uses compressed helium as the refrigerant, and through a helium refrigeration cycle equipped with an expander, the hydrogen condensation temperature is reached. Liquid hydrogen is then obtained through a hydrogen-helium heat exchanger. The equipment used in a helium-refrigerated hydrogen liquefaction system includes main equipment and auxiliary system equipment. The main equipment of the helium-refrigerated hydrogen liquefaction system includes a hydrogen liquefaction cold box module (including the cold box shell, plate-fin heat exchanger, positive and negative hydrogen converter, refrigerant expander, cryogenic adsorber, internal piping, instruments, valves, vacuum system, etc.) and a helium compressor system (including a helium compressor, helium oil injection system, helium-oil separation-circulation cooling system, etc.).

[0053] Suppliers of integrated solutions for helium expansion refrigeration hydrogen liquefaction systems need to map risk perception and subsequent fault early warning and diagnosis to the equipment and even the component level within the hydrogen liquefaction system, in order to detect, dynamically display, and analyze the service status of the equipment within the hydrogen liquefaction system and the relevant working fluid parameters in designated areas within the hydrogen liquefaction system. It should be noted that, in order to build and continuously improve the real-time risk perception and fault early warning and diagnosis functions of the hydrogen liquefaction system, in addition to mature and universal safety detection and analysis functions related to the hydrogen liquefaction cold box, such as pressure detection (e.g., pressure of the refrigerant expander), temperature detection (e.g., temperature of each stage of plate-fin heat exchanger in the hydrogen liquefaction cold box), liquid level detection (e.g., liquid level in the hydrogen cold box container), flow monitoring (e.g., inlet raw material low-temperature hydrogen flow rate of the hydrogen liquefaction cold box), and detection and analysis (e.g., inlet raw material hydrogen impurity composition, intermediate hydrogen impurity composition at the outlet of the low-temperature adsorber, and secondary hydrogen content and impurity composition of the output liquid hydrogen product), it is also necessary to pay more attention to typical risks and fault scenarios related to the helium compressor system, where relevant process experience is relatively scarce during actual commissioning, in order to prevent potential threats to the continuous and stable operation of the helium refrigeration hydrogen liquefaction system due to frequency runaway, mechanical failure, improper heat load management, improper oil separation, and insufficient lubrication.

[0054] During the commissioning of a helium expansion refrigeration hydrogen liquefaction system, helium is prone to leakage and diffusion due to its small molecular weight. Furthermore, the high adiabatic index of helium leads to intense heat generation during compression. Therefore, risk perception and subsequent fault early warning diagnosis of the helium compressor system, helium oil injection system, and helium-oil separation-circulation cooling system—the main equipment of the helium expansion refrigeration hydrogen liquefaction system—are of great significance for the stable and reliable operation of the system.

[0055] Furthermore, the current helium-refrigerated hydrogen liquefaction system suffers from insufficient interaction between risk perception and fault early warning diagnosis, specifically manifested in the following ways:

[0056] I. Lack of fault early warning and diagnosis function for abnormal frequency conversion and abnormal vibration caused by the helium compressor in the helium compressor system due to its inability to adapt to frequent start-stop conditions.

[0057] Second, when diagnosing the cooling effect of the helium oil injection system in the helium compressor system, the influence of the difference in atomized cooling oil particle size on the fault judgment was not fully considered, while this particle size difference needs to meet the requirements of the segmented cooling process mechanism.

[0058] Third, the cooling effect of the helium oil injection system on the helium compressor is not the only fault diagnosis requirement in the helium compressor system. Based on the fault early warning diagnosis of the cooling effect of the helium oil injection system on the helium compressor, the current helium compressor system of the helium expansion refrigeration hydrogen liquefaction system still lacks fault early warning diagnosis functions for the rated centrifugal drive intensity, which can characterize the oil separation load capacity of the helium-oil separation-circulation cooling system, and the rated circumferential linear speed of the rotor, which can characterize the lubrication load capacity of the helium-oil separation-circulation cooling system.

[0059] This invention combines representative urgent and sudden accident scenarios encountered during the commissioning of a helium expansion refrigeration hydrogen liquefaction system to conduct fault early warning and diagnosis. After diagnosing that the helium expansion refrigeration hydrogen liquefaction system is fault-free, the invention then assesses and analyzes risk scenarios with cumulative effects, and based on this, conducts fault early warning and diagnosis for potential risk-causing accident scenarios of the helium expansion refrigeration hydrogen liquefaction system.

[0060] According to an embodiment of the present invention, a fault early warning and diagnosis method for a hydrogen liquefaction system is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0061] This embodiment provides a fault early warning and diagnosis method for a hydrogen liquefaction system. The hydrogen liquefaction system includes a helium compressor system, which further includes a helium compressor unit and a helium-oil separation and circulating cooling system. The hydrogen liquefaction system is a helium expansion refrigeration hydrogen liquefaction system. In this embodiment, a helium screw compressor unit is used as an example for illustration.

[0062] Figure 1 This is a flowchart of a fault early warning and diagnosis method for a hydrogen liquefaction system according to an embodiment of the present invention, such as... Figure 1 As shown, the process includes the following steps:

[0063] Step S101: Obtain the set of operating characteristic parameters of the hydrogen liquefaction system, the first set of parameters of the helium compressor equipment, and the second set of parameters of the helium-oil separation and circulating cooling system.

[0064] The set of operating characteristic parameters may include the rated liquid hydrogen production capacity of the hydrogen liquefaction system. (g / s) and cumulative runtime (s).

[0065] Furthermore, the first parameter set is used to characterize the performance and structure of the helium compressor equipment, and may include the rated motor power of the helium screw compressor. (kW), rated intake pressure (MPa), Rated Compression Ratio (This value is the ratio of exhaust pressure to intake pressure) Minimum mass flow rate of compressed helium (g / s) Maximum mass flow rate of compressed helium (g / s), Rated operating frequency of the frequency converter (Hz), nominal rotor diameter (m), Rotor rated circumferential linear speed (m / s).

[0066] Furthermore, the second parameter set is used to characterize the oil separation performance and cooling performance of the helium-oil separation and circulating cooling system, and may include the rated centrifugal drive intensity of oil separation. (This represents the ratio of the centrifugal driving force generated by the rotating system during helium-oil separation to the gravitational acceleration of the oil), rated maximum oil content in helium exhaust. (ppm), rated oil cooling temperature (K).

[0067] The rated oil cooling temperature can be determined based on the type of oil used in the oil filling system of the helium compressor system. Furthermore, the type of oil used can include PFPE oil (i.e., perfluoropolyether oil), ISO VG 32 oil (such as Chevron Cetus@DE oil), and BREOX B 35 synthetic oil.

[0068] Step S102: Based on the set of operating characteristic parameters, the first set of parameters, and the second set of parameters, perform fault warnings for multiple accident scenarios of the hydrogen liquefaction system and determine whether there is a fault in the hydrogen liquefaction system.

[0069] Among them, several accident scenarios are representative urgent and sudden accident scenarios encountered during the commissioning of hydrogen liquefaction systems, which may include accident scenarios related to the frequency conversion of helium screw compressors, abnormal vibration, cooling of each section, oil separation system, and lubrication.

[0070] Specifically, fault diagnosis is performed from multiple representative dimensions of urgent and sudden accidents, such as the frequency conversion status of helium compressor equipment, abnormal vibration, cooling of each section, oil separation system and lubrication status. This avoids system shutdown or safety accidents caused by sudden failures, overcomes the limitations of existing technologies that only focus on monitoring sudden accidents of individual equipment, and improves the accuracy and reliability of fault diagnosis.

[0071] Step S103: When there is no fault in the hydrogen liquefaction system, based on the set of operating characteristic parameters and the second parameter set, evaluate and analyze multiple risk scenarios with cumulative effects of the hydrogen liquefaction system, and determine the fault early warning diagnosis results of the hydrogen liquefaction system.

[0072] Specifically, after diagnosing that the hydrogen liquefaction system with helium expansion refrigeration is fault-free, the risk scenarios with cumulative effects are further assessed and analyzed. Based on this, fault early warning diagnosis can be carried out for potential risk-causing accident scenarios of the hydrogen liquefaction system with helium expansion refrigeration, filling the gap in the lack of dynamic risk accumulation early warning in the existing technology and realizing the upgrade from "post-event handling" to "pre-event prevention".

[0073] The fault early warning and diagnosis method for hydrogen liquefaction systems provided in this embodiment achieves comprehensive monitoring of the hydrogen liquefaction system and its key subsystems by acquiring the operating characteristic parameter set of the hydrogen liquefaction system, the first parameter set of the helium compressor equipment, and the second parameter set of the helium-oil separation and circulating cooling system. This provides a rich data foundation for fault early warning and diagnosis. Furthermore, for representative urgent and sudden accidents, real-time fault judgment is achieved through parameter analysis, avoiding system downtime or safety accidents caused by sudden failures and overcoming the limitations of existing technologies that only focus on monitoring sudden accidents of individual equipment. When there are no sudden failures in the system, risk scenarios with cumulative effects are further evaluated, filling the gap in existing technologies that lack dynamic risk accumulation early warning and achieving an upgrade from "post-event handling" to "pre-event prevention." Therefore, by implementing this invention, the prediction of representative urgent and sudden accidents is combined with the prediction of risk-causing accidents with cumulative effects. This approach considers both sudden accident scenarios during system commissioning and risk accumulation during long-term operation, enabling a more comprehensive, accurate, and effective assessment of the operating status of the hydrogen liquefaction system and filling the gap in existing technologies that lack comprehensive fault early warning and diagnosis.

[0074] This embodiment provides a fault early warning and diagnosis method for a hydrogen liquefaction system. The hydrogen liquefaction system includes a helium compressor system, which further includes a helium compressor unit and a helium-oil separation and circulating cooling system. The hydrogen liquefaction system is a helium expansion refrigeration hydrogen liquefaction system. In this embodiment, a helium screw compressor unit is used as an example for illustration.

[0075] Figure 2 This is a flowchart of a fault early warning and diagnosis method for a hydrogen liquefaction system according to an embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps:

[0076] Step S201: Obtain the operating characteristic parameter set of the hydrogen liquefaction system, the first parameter set of the helium compressor equipment, and the second parameter set of the helium-oil separation and circulating cooling system. For details, please refer to [link to relevant documentation]. Figure 1 Step S101 of the illustrated embodiment will not be described again here.

[0077] Step S202: Based on the set of operating characteristic parameters, the first set of parameters, and the second set of parameters, perform fault warnings for multiple accident scenarios of the hydrogen liquefaction system and determine whether there is a fault in the hydrogen liquefaction system.

[0078] Specifically, step S202 includes:

[0079] Step S2021: Based on the set of operating characteristic parameters and the first parameter set, determine whether the helium compressor equipment has experienced abnormal frequency conversion.

[0080] Specifically, a screw compressor is a type of positive displacement compressor. Therefore, helium screw compressors use frequency conversion to adjust the compression chamber volume. Furthermore, under stable operating conditions, the frequency of a helium screw compressor is normally within the rated operating frequency of the frequency converter. The value fluctuates within a certain range (Hz) (this value is generally very small, around 0.2% to 0.5%), but the cumulative operating time of the helium expansion cooling hydrogen liquefaction system... (s) After about 200 hours, the frequency of the helium screw compressor begins to appear. A sudden, relatively large fluctuation (up to about 5%) in the frequency (Hz) over a certain period of time may be caused by occasional forced movement of the rotor. This is detrimental to the compression chamber capacity regulation of the helium screw compressor and will affect the lifespan of the screw compressor's transmission equipment.

[0081] In addition, for hydrogen liquefaction stations and hydrogen-related demonstration parks with new energy power generation grid connection, sudden and large fluctuations in frequency can cause impacts on the power grid. Therefore, it is necessary to monitor the operating frequency of the frequency converter of the helium screw compressor.

[0082] Furthermore, the actual operating frequency of the frequency converter of the helium screw compressor (Hz) is shown in the following relationship (1):

[0083] (1)

[0084] In the formula: This indicates that frequency amplitude variation is permitted.

[0085] Furthermore, for helium expansion refrigeration hydrogen liquefaction systems with larger rated liquid hydrogen production capacity and shorter cumulative operating time, the allowable power frequency amplitude variation is... The smaller.

[0086] Therefore, by allowing power frequency amplitude variation Determine if the helium compressor equipment is experiencing abnormal frequency conversion.

[0087] In some optional implementations, step S2021 above includes:

[0088] Step a1: Determine the allowable power frequency amplitude based on the set of operating characteristic parameters.

[0089] Step a2: Determine the maximum acceptable power frequency amplitude based on the set of operating characteristic parameters and the first parameter set.

[0090] Step a3: Determine the target power frequency amplitude based on the maximum acceptable power frequency amplitude.

[0091] Step a4: Determine whether the target number of times the helium compressor equipment exists during actual operation is greater than or equal to the target power frequency amplitude.

[0092] Step a5: When the target number of cycles is greater than or equal to the target frequency amplitude, it is determined that the helium compressor equipment has an abnormal frequency conversion.

[0093] The target number represents the number of times that the actual power frequency variation of the helium compressor equipment (helium screw compressor) exceeds the allowable power frequency variation during actual operation.

[0094] Specifically, it allows for power frequency amplitude variation. Rated liquid hydrogen production capacity of hydrogen liquefaction system with operating characteristic parameters (g / s) and cumulative runtime (s) is related to the following relation (2):

[0095] (2)

[0096] Furthermore, based on the centralized rated liquid hydrogen production capacity according to the operating characteristic parameters... The first parameter is the maximum mass flow rate of compressed helium. The ratio (g / s), combined with, for example Figure 3 The curve shown can be used to determine the maximum acceptable power frequency amplitude. The theoretical value.

[0097] Furthermore, based on the maximum acceptable power frequency amplitude... The theoretical value, after rounding, can be used to further determine the maximum acceptable power frequency amplitude. The actual value, i.e., the maximum acceptable power frequency amplitude in this embodiment.

[0098] Furthermore, if the helium screw compressor experiences actual frequency fluctuations during the actual commissioning / trial operation... The number of abnormal operating conditions exceeding the allowable power frequency amplitude, i.e., the target number ≥ the target power frequency amplitude (maximum acceptable power frequency amplitude). If +1 is detected, it indicates an abnormal frequency conversion of the helium screw compressor, which can then trigger an emergency stop operation on the helium expansion refrigeration hydrogen liquefaction system.

[0099] Furthermore, by determining the allowable power frequency amplitude, the maximum acceptable power frequency amplitude, and the target power frequency amplitude, and comparing the actual number of target frequency amplitudes with the target power frequency amplitude, it is possible to accurately monitor whether abnormal frequency changes occur in the helium compressor equipment. This provides an effective means for timely detection and handling of frequency change-related faults, and helps to ensure the stable operation of the helium compressor equipment.

[0100] Step S2022: When the hydrogen liquefaction system experiences frequent start-stop cycles, determine whether the helium compressor equipment is generating abnormal vibrations based on the first parameter set.

[0101] Among them, frequent start-stop conditions indicate the actual motor power. (kW) During the period of continuous over-limit statistics for motor power From 0kW to rated motor power (kW) Over-limit critical proportion Or it can be expressed as the rated motor power. (kW) Over-limit critical proportion Number of times it drops to 0kW ≥ (motor power over-limit critical number) The phenomenon of +1).

[0102] Furthermore, the statistical period for continuous motor power exceeding the limit. The value of is related to the cumulative operating time of the helium expansion refrigeration hydrogen liquefaction system. The type of oil used for filling is relevant:

[0103] (1) For PFPE oil-lubricated helium screw compressors, the statistical period of motor power exceeding the limit. (s) Cumulative runtime of the hydrogen liquefaction system with helium expansion refrigeration (Ten thousand s) correspondence as follows Figure 4 As shown.

[0104] (2) For ISO VG 32 oil-lubricated helium screw compressors, the period of continuous over-limit motor power is statistically significant. (s) Cumulative runtime of the hydrogen liquefaction system with helium expansion refrigeration (Ten thousand s) correspondence as follows Figure 5 As shown.

[0105] (3) For BREOX B 35 oil-lubricated helium screw compressors, the period of continuous over-limit motor power is statistically significant. (s) Cumulative runtime of the hydrogen liquefaction system with helium expansion refrigeration (Ten thousand s) correspondence as follows Figure 6 As shown.

[0106] Furthermore, the critical proportion exceeding the limit The value of is related to the rated compression ratio of the helium screw compressor. Related, correspondence such as Figure 7 As shown.

[0107] Furthermore, the motor power exceeds the critical limit. The value of is the same as the maximum acceptable power frequency amplitude when the helium compressor equipment has no abnormal frequency conversion as determined in step S2021 above. The actual value is related, and the corresponding relationship is as follows: Figure 8 As shown.

[0108] In some optional implementations, step S2022 above includes:

[0109] Step b1: When the hydrogen liquefaction system experiences frequent start-stop cycles, determine the critical axial vibration velocity value of the helium compressor housing based on the first parameter set.

[0110] Step b2: When the real-time axial vibration velocity value of the helium compressor equipment is greater than or equal to the critical axial vibration velocity value of the casing, it is determined that the helium compressor equipment is generating abnormal vibration.

[0111] Specifically, suction pressure, as a direct reflection of compressor load, affects the stress on the screw compressor rotor and casing; compression ratio reflects the gas compression intensity, and thus reflects the excitation force fluctuation and surge risk of the screw compressor; the rated circumferential linear speed of the rotor measures the dynamic load of the rotor from a motion perspective, and together with suction pressure and compression ratio, it affects the axial vibration condition.

[0112] Therefore, when the hydrogen liquefaction system experiences frequent start-stop cycles, the rated intake pressure can be determined based on the first parameter. Rated compression ratio Rotor rated circumferential linear speed Determine the critical velocity value of the axial vibration of the casing of the helium compressor equipment. The following relation (3) is shown:

[0113] (3)

[0114] Furthermore, if during the actual operation of a helium expansion refrigeration hydrogen liquefaction system, the real-time axial vibration velocity value measured on the helium screw compressor casing... ≥ If this is the case, it is considered that there is an abnormal vibration caused by the helium screw compressor being unable to adapt to frequent start-stop conditions, and therefore an emergency stop operation can be initiated for the helium expansion refrigeration hydrogen liquefaction system.

[0115] Furthermore, when the hydrogen liquefaction system experiences frequent start-stop cycles, by determining the critical axial vibration velocity value of the helium compressor housing and comparing it with the real-time axial vibration velocity value, it is possible to accurately determine whether the equipment is experiencing abnormal vibration, promptly identify equipment vibration problems that may be caused by frequent start-stop cycles, and provide a basis for equipment maintenance and troubleshooting.

[0116] In some optional implementations, step S2022 above further includes:

[0117] Step b3: When the hydrogen liquefaction system experiences frequent start-stop cycles, determine the critical acceleration value of the axial vibration of the helium compressor housing based on the first parameter set.

[0118] Step b4: If the real-time axial vibration acceleration value of the helium compressor equipment is greater than or equal to the critical axial vibration acceleration value of the casing, it is determined that the helium compressor equipment is generating abnormal vibration.

[0119] Specifically, axial acceleration, along with axial velocity, can identify abnormal impact loads caused by rotor or bearing impacts within a helium screw compressor, thereby determining brittle failures within the screw compressor. In other words, axial acceleration is more sensitive to vibration fault types.

[0120] Furthermore, considering that the nominal rotor diameter affects the moment of inertia, and thus the centrifugal effect, the dynamic changes in force directly act on the shell. Meanwhile, during the actual trial operation of the helium expansion refrigeration hydrogen liquefaction system, no critical acceleration of axial vibration was detected. The given value and the rated circumferential linear speed of the rotor There is a direct correlation.

[0121] Therefore, the critical acceleration value of the axial vibration of the helium compressor housing is related to the first parameter concentrated rated suction pressure. Rated compression ratio Rotor nominal diameter related.

[0122] Furthermore, when the hydrogen liquefaction system experiences frequent start-ups and shutdowns, the critical acceleration value of the axial vibration of the helium compressor housing can be further determined using the following relationship (4):

[0123] (4)

[0124] Furthermore, if during the actual operation of a helium expansion refrigeration hydrogen liquefaction system, the real-time axial vibration acceleration value measured on the helium screw compressor casing... ≥ If this is the case, it is considered that there is an abnormal vibration caused by the helium screw compressor being unable to adapt to frequent start-stop conditions, and therefore an emergency stop operation can be initiated for the helium expansion refrigeration hydrogen liquefaction system.

[0125] Furthermore, in some alternative embodiments, the critical velocity value of the axial vibration of the housing of the constant helium compressor equipment can also be considered. and the critical acceleration value of the axial vibration of the shell To determine whether the helium compressor equipment is producing abnormal vibrations.

[0126] Furthermore, when the hydrogen liquefaction system experiences frequent start-stop cycles, the critical axial vibration acceleration value of the helium compressor housing is determined and compared with the real-time axial vibration acceleration value. This further enriches the basis for judging abnormal vibration of the equipment, improves the accuracy and comprehensiveness of fault diagnosis, and can more effectively detect potential vibration fault hazards.

[0127] Step S2023: Based on the first parameter set and the second parameter set, determine whether the cooling of each section of the helium compressor equipment meets the requirements.

[0128] In some optional implementations, step S2023 above includes:

[0129] Step c1: Obtain the first real-time cooling oil atomization particle size of the hydrogen liquefaction system in the high-pressure stage, the second real-time cooling oil atomization particle size in the medium-pressure stage, and the third real-time cooling oil atomization particle size in the low-pressure stage.

[0130] Specifically, the adiabatic coefficient of a gas, which is the ratio of its isobaric specific heat capacity to its isochoric specific heat capacity, characterizes the degree of temperature rise of a gas at the same compression ratio. The larger the value, the more significant the temperature rise during gas compression. Because helium has a very high adiabatic coefficient, cooling in a helium screw compressor is crucial. To make the helium compression process closer to isothermal compression, the cooling oil needs to be atomized into different particle sizes according to a specific strategy based on the different pressure stages (low pressure, medium pressure, and high pressure) within the helium screw compressor cavity. The atomized particle size is relatively the largest in the low-pressure stage, followed by the medium-pressure stage, and then the high-pressure stage. This approach can control helium cooling energy consumption to a certain extent while ensuring the helium cooling effect.

[0131] Furthermore, segmented cooling specifically refers to cooling compressed helium in three stages: low pressure, medium pressure, and high pressure.

[0132] Furthermore, the real-time cooling oil atomization particle size of the hydrogen liquefaction system at different stages during segmented cooling was obtained.

[0133] Step c2: Determine the maximum permissible atomization particle size of the first cooling oil in the high-pressure stage of the hydrogen liquefaction system based on the maximum oil content in the helium exhaust of the helium compressor equipment.

[0134] Specifically, such as Figure 9 As shown, the maximum oil content in the rated helium exhaust of the helium compressor equipment can be determined based on this. Determine the maximum permissible atomization particle size of the first cooling oil in the high-pressure phase of the hydrogen liquefaction system. (μm).

[0135] Step c3: Based on the first parameter set, the second parameter set, and the maximum permissible atomization particle size of the first cooling oil, determine the maximum permissible atomization particle size of the second cooling oil in the medium-pressure stage of the hydrogen liquefaction system and the maximum permissible atomization particle size of the third cooling oil in the low-pressure stage of the hydrogen liquefaction system.

[0136] In some alternative implementations, step c3 above includes:

[0137] Step c31: Based on the first parameter set and the second parameter set, determine the first relationship between the critical pressure at the end of the high-pressure stage and the critical pressure at the end of the medium-pressure stage of the helium compressor equipment, and the second relationship between the critical pressure at the end of the medium-pressure stage and the critical pressure at the end of the low-pressure boosting stage.

[0138] Step c32: Determine the third relationship between the high-pressure stage time and the medium-pressure stage time of the helium compressor equipment based on the first relationship.

[0139] Step c33: Determine the fourth relationship between the medium-pressure stage time and the low-pressure stage time of the helium compressor equipment based on the second relationship.

[0140] Step c34: Determine the maximum permissible atomization particle size of the second cooling oil based on the first relationship, the third relationship, and the maximum permissible atomization particle size of the first cooling oil.

[0141] Step c35: Determine the maximum permissible atomization particle size of the third cooling oil based on the second relationship, the fourth relationship, and the maximum permissible atomization particle size of the second cooling oil.

[0142] The relevant parameters for the three stages—low pressure, medium pressure, and high pressure—can include:

[0143] (1) Low-pressure stage: The critical pressure at the end of the helium low-pressure pressurization stage (MPa), duration (s).

[0144] (2) Medium-pressure stage: The critical pressure at the end of the helium medium-pressure pressurization stage. (MPa), duration (s).

[0145] (3) High pressure stage: Duration of the helium high pressure boosting stage (s). Furthermore, the critical pressure at the end of the helium high-pressure pressurization. (MPa), which is the rated suction pressure. Compared with the rated compression ratio The product of.

[0146] Specifically, based on the first parameter, the minimum mass flow rate of compressed helium is concentrated. Maximum mass flow rate of compressed helium And the second parameter, the centralized rated oil cooling temperature This allows us to determine the critical pressure at the end of the high-pressure phase of the helium compressor equipment. Critical pressure at the end of the intermediate pressure phase The first relationship between them is shown in the following relation (5):

[0147] (5)

[0148] Furthermore, the critical pressure at the end of the intermediate-pressure phase can also be determined. Critical pressure at the end of the low-pressure boost phase The second relationship between them is shown in the following relation (6):

[0149] (6)

[0150] Furthermore, the high-pressure stage time of the helium compressor equipment can be determined based on the first relationship. Between the medium pressure phase and time The third relation is shown in the following relation (7):

[0151] (7)

[0152] Furthermore, the intermediate pressure stage time of the helium compressor equipment can be determined based on the second relationship. Low-pressure phase time The fourth relationship between them is shown in the following relation (8):

[0153] (8)

[0154] in, The interstage turbocharger adaptability coefficient measures the buffering capacity of the cooling oil for helium turbocharging, which is used to measure the temperature rise between different turbocharging stages. It is related to the type of oil used and the rated cooling temperature of the oil. related:

[0155] (1) For PFPE oil-lubricated helium screw compressors, the interstage booster oil adaptability coefficient With rated oil cooling temperature The correspondence is as follows Figure 10 As shown.

[0156] (2) For helium screw compressors lubricated with ISO VG 32 oil, the interstage booster oil compatibility factor With rated oil cooling temperature The correspondence is as follows Figure 11 As shown.

[0157] (3) For BREOX B 35 oil-lubricated helium screw compressors, the interstage booster oil compatibility factor With rated oil cooling temperature The correspondence is as follows Figure 12 As shown.

[0158] Furthermore, based on the first relationship, the third relationship, and the first maximum permissible atomization particle size of the cooling oil... The maximum permissible atomization particle size of the second cooling oil can be determined. The following relation (9) is shown:

[0159] (9)

[0160] Furthermore, if the maximum atomized particle size of the medium-pressure stage cooling oil obtained according to the above relationship (9) is the maximum allowable atomized particle size of the second cooling oil... ,but .

[0161] Furthermore, if the maximum atomized particle size of the cooling oil in the medium-pressure stage is obtained according to the above relationship (9), ,but The value corresponding to the above relation (9) remains unchanged.

[0162] Furthermore, based on the second relationship, the fourth relationship, and the second maximum permissible atomization particle size of the cooling oil... Determine the maximum permissible atomization particle size of the third cooling oil. The following relation (10) is shown:

[0163] (10)

[0164] Furthermore, if the maximum atomized particle size of the low-pressure stage cooling oil obtained according to the above relationship (9) is the maximum permissible atomized particle size of the third cooling oil... ,but .

[0165] Furthermore, if the maximum atomized particle size of the cooling oil in the medium-pressure stage is obtained according to the above relationship (9), ,but The value corresponding to the above relation (10) remains unchanged.

[0166] Step c4: When the atomized particle size of the first real-time cooling oil is less than or equal to the maximum permissible atomized particle size of the first cooling oil, the atomized particle size of the second real-time cooling oil is less than or equal to the maximum permissible atomized particle size of the second cooling oil, and the atomized particle size of the third real-time cooling oil is less than or equal to the maximum permissible atomized particle size of the third cooling oil, it is determined that the cooling of each section of the helium compressor equipment meets the requirements.

[0167] Specifically, in the high-pressure stage of the actual operation of the helium expansion refrigeration hydrogen liquefaction system, the atomized particle size of the cooling oil, i.e., the first real-time cooling oil atomized particle size... Should ≤ If the requirements are not met, it is considered that the atomized particle size of the cooling oil does not meet the cooling mechanism requirements of the helium screw compressor, and an emergency stop operation can be initiated for the helium expansion refrigeration hydrogen liquefaction system.

[0168] Furthermore, during the medium-pressure stage of the actual operation of the helium expansion refrigeration hydrogen liquefaction system, the atomized particle size of the cooling oil is the second real-time atomized particle size of the cooling oil. Should ≤ If the requirements are not met, it is considered that the atomized particle size of the cooling oil does not meet the cooling mechanism requirements of the helium screw compressor, and an emergency stop operation can be initiated for the helium expansion refrigeration hydrogen liquefaction system.

[0169] Furthermore, during the low-pressure phase of the actual operation of the helium expansion refrigeration hydrogen liquefaction system, the cooling oil atomization particle size, i.e., the third real-time cooling oil atomization particle size... Should ≤ If the requirements are not met, it is considered that the atomized particle size of the cooling oil does not meet the cooling mechanism requirements of the helium screw compressor, and an emergency stop operation can be initiated for the helium expansion refrigeration hydrogen liquefaction system.

[0170] Furthermore, when and and This confirms that the cooling of each section of the helium compressor equipment meets the requirements.

[0171] Step S2024: Based on the second parameter set, determine whether the oil separation system of the helium compressor equipment is overloaded.

[0172] Specifically, as the real-time mass flow rate of the helium screw compressor increases, the mass flow rate of cooling oil required per unit mass of helium compressed also increases. However, the required mass flow rate of cooling oil cannot increase indefinitely. The required mass flow rate of cooling oil is subject to dual limitations, namely, the mass flow rate of cooling oil must meet the oil separation limitation requirements while meeting the cooling requirements.

[0173] Furthermore, for helium-oil separation-circulation cooling systems in small to medium-sized hydrogen liquefaction systems with a capacity of ≤5t / d, when the mass flow rate of the cooling oil is too high, the load on the mechanical centrifugal drive unit of the cyclone separator in the helium-oil separation-circulation cooling system will increase sharply to ensure the specified exhaust performance, resulting in a significant decrease in its service life. Therefore, the increase in the mass flow rate of cooling oil required for helium compression is affected by the rated centrifugal drive intensity of the oil separation specified in the input of the helium-oil separation-circulation cooling system. Restrictions.

[0174] Among them, rated centrifugal drive strength This represents the ratio of the centrifugal driving force generated by the rotating system during helium-oil separation to the gravitational acceleration.

[0175] Furthermore, such as Figure 13 As shown, the rated centrifugal drive strength can be determined based on the second parameter set. Determine the maximum mass flow rate .

[0176] Furthermore, for the rated maximum oil content of helium exhaust gas with specified input... In a helium expansion-cooled hydrogen liquefaction system, if at a certain moment the mass flow rate of cooling oil required to compress helium is greater than or equal to the maximum mass flow rate of cooling oil required to compress helium... If the value is (kg / s), it is considered that the oil separation system of the helium screw compressor is overloaded, and an emergency stop operation can be initiated on the hydrogen liquefaction system of helium expansion refrigeration.

[0177] Step S2025: Based on the first parameter set, determine whether there is a threat of insufficient lubrication in the helium compressor equipment.

[0178] Specifically, the mass flow rate of the cooling oil must meet the cooling requirements as well as the lubrication limitations.

[0179] Furthermore, unlike the screw compressors used for refrigerants in the general air separation industry, the helium screw compressors used in helium expansion refrigeration hydrogen liquefaction systems operate at high speeds while compressing helium at high flow rates, thereby reducing internal leakage losses. However, high speeds may result in poor lubrication of the cooling oil in the transmission system used for helium compression. Therefore, the increase in the mass flow rate of the cooling oil required for helium compression is also affected by the rated circumferential speed of the rotor. The effect of (m / s).

[0180] Furthermore, such as Figure 14 As shown, the rated circumferential linear speed of the rotor can be concentrated based on the first parameter. Determine the maximum mass flow rate .

[0181] Furthermore, for the rated maximum oil content of helium exhaust gas with specified input... In a helium expansion-cooled hydrogen liquefaction system, if at a certain moment the mass flow rate of cooling oil required to compress helium is greater than or equal to the maximum mass flow rate of cooling oil required to compress helium... If this is the case, it is believed that the helium screw compressor is under-lubricated, and therefore an emergency stop operation can be initiated on the helium expansion refrigeration hydrogen liquefaction system.

[0182] Step S2026: If the helium compressor equipment does not exhibit any abnormal conditions, does not generate any abnormal vibrations, the cooling of each section of the helium compressor equipment meets the requirements, the oil separation system of the helium compressor equipment is not overloaded, and the helium compressor equipment is not under-lubricated, it is determined that the hydrogen liquefaction system is not faulty.

[0183] Specifically, if no abnormalities occur in steps S2021 to S2025, it can be further determined that there is no fault in the hydrogen liquefaction system.

[0184] Step S203: When there is no fault in the hydrogen liquefaction system, based on the operating characteristic parameter set and the second parameter set, assess and analyze multiple risk scenarios with cumulative effects on the hydrogen liquefaction system, and determine the fault early warning diagnosis results for the hydrogen liquefaction system. For details, please refer to... Figure 1 Step S103 of the illustrated embodiment will not be described again here.

[0185] The fault early warning and diagnosis method for hydrogen liquefaction systems provided in this embodiment judges faults from multiple representative dimensions of urgent and sudden accidents, such as the frequency conversion status of helium compressor equipment, abnormal vibration, cooling of each section, oil separation system, and lubrication status. This avoids system shutdown or safety accidents caused by sudden faults and overcomes the limitations of existing technologies that only focus on monitoring sudden accidents of individual equipment. As a result, it can more accurately identify various problems that may exist in the hydrogen liquefaction system, improve the accuracy and reliability of fault diagnosis, and solve the problem of insufficient interaction between current system risk perception and fault early warning diagnosis, especially for problems such as abnormal frequency conversion of helium compressors and abnormal vibration caused by incompatibility with frequent start-stop conditions in helium compressor systems.

[0186] This embodiment provides a fault early warning and diagnosis method for a hydrogen liquefaction system. The hydrogen liquefaction system includes a helium compressor system, which further includes a helium compressor unit and a helium-oil separation and circulating cooling system. The hydrogen liquefaction system is a helium expansion refrigeration hydrogen liquefaction system. In this embodiment, a helium screw compressor unit is used as an example for illustration.

[0187] Figure 15 This is a flowchart of a fault early warning and diagnosis method for a hydrogen liquefaction system according to an embodiment of the present invention, such as... Figure 15 As shown, the process includes the following steps:

[0188] Step S301: Obtain the operating characteristic parameter set of the hydrogen liquefaction system, the first parameter set of the helium compressor equipment, and the second parameter set of the helium-oil separation and circulating cooling system. For details, please refer to [link to relevant documentation]. Figure 1 Step S101 of the illustrated embodiment will not be described again here.

[0189] Step S302: Based on the set of operating characteristic parameters, the first parameter set, and the second parameter set, perform fault warnings for multiple accident scenarios of the hydrogen liquefaction system and determine whether a fault exists in the hydrogen liquefaction system. For details, please refer to [link to relevant documentation]. Figure 2 Step S202 of the illustrated embodiment will not be described again here.

[0190] Step S303: When there is no fault in the hydrogen liquefaction system, based on the set of operating characteristic parameters and the second parameter set, evaluate and analyze multiple risk scenarios with cumulative effects of the hydrogen liquefaction system, and determine the fault early warning diagnosis results of the hydrogen liquefaction system.

[0191] Specifically, step S303 includes:

[0192] Step S3031: When there is no fault in the hydrogen liquefaction system, determine the maximum inlet dust particle size at the outlet of the oil filter of the helium compressor equipment based on the first parameter set and the second parameter set.

[0193] Compared to helium screw compressors used in other air separation systems, helium screw compressors used in hydrogen liquefaction systems for helium expansion refrigeration require special attention to the filtration accuracy of the oil filter. If the dust interception level of the helium screw compressor is inadequate, the actual mass flow rate of the helium screw compressor will decrease during long-term operation, leading to a decrease in the actual suction pressure and causing the actual suction pressure to be lower than the rated suction pressure, which will pose a potential negative pressure threat.

[0194] Specifically, the maximum mass flow rate of the helium screw compressor This means that by using an oil filter to limit the maximum load under the allowable operating load, the intake dust particle size can be guaranteed to meet requirements under all load conditions. Furthermore, with the cumulative operating time of the helium expansion refrigeration hydrogen liquefaction system... As the hydrogen liquefaction system gradually increases, the overall requirements for the particle size of the intake dust will decrease.

[0195] Therefore, runtime can be accumulated through the first parameter set. Maximum mass flow rate in the second parameter set The maximum inlet dust particle size of the oil filter outlet of the helium compressor equipment is determined by the following relationship (11):

[0196] (11)

[0197] In the formula: This indicates the maximum intake dust particle size.

[0198] Step S3032: Compare the real-time intake dust particle size at the outlet of the oil filter of the helium compressor equipment with the maximum intake dust particle size, and determine whether the oil filter of the helium compressor equipment meets the dust interception requirements to obtain the first judgment result.

[0199] Specifically, for the rated maximum oil content of helium exhaust gas with specified input. In a helium expansion refrigeration hydrogen liquefaction system, if the particle size of the inlet air at the compressor oil filter outlet is measured at a certain moment, that is, the real-time inlet air particle size... (μm) ≥ Maximum intake dust particle size at the outlet of the compressor oil filter (leading to the oil filling system) If the value is (μm), it is considered that the presence of a helium screw compressor poses a threat of dust interception to the incident helium flow. In other words, the first judgment result is that the oil filter of the helium compressor equipment does not meet the dust interception requirements.

[0200] Furthermore, when the oil filter of the helium compressor equipment fails to meet the dust interception requirements, an emergency stop operation can be initiated for the helium expansion refrigeration hydrogen liquefaction system.

[0201] Step S3033: Determine the critical displacement of the shell axial vibration of the helium compressor equipment based on the set of operating characteristic parameters and the second parameter set.

[0202] Specifically, the helium screw compressor's cumulative operating time increases with the helium-refrigerated hydrogen liquefaction system. (s) gradually increases, which will inevitably lead to increased bearing clearance, deterioration of rotor dynamic balance and decrease in gear meshing accuracy during long-term operation, thus causing changes in the sealing friction state of the helium screw compressor.

[0203] Furthermore, the rated intake pressure The pressure (MPa) directly determines the gas density entering the compression chamber. Higher intake pressure means that, under the same compression ratio, the axial force exerted by the gas in the compression chamber on the rotor helical surface is greater.

[0204] Furthermore, the rated compression ratio It can reflect the peak gas pressure inside the compression chamber of a helium screw compressor, thus reflecting the axial thrust acting on the rotor end face (especially the exhaust end). In addition, changes in the compression ratio also affect the distribution of internal leakage flow and gas force.

[0205] Furthermore, the nominal diameter of the rotor (m) represents the core structural dimensions of the screw compressor, which can reflect the force-bearing area of ​​the compressed helium on the rotor helical surface and end face.

[0206] Therefore, the critical displacement of the axial vibration of the helium compressor casing can be obtained by accumulating the operating time using a set of operating characteristic parameters. And the second parameter, the rated inhalation pressure. Rated compression ratio Rotor nominal diameter The following relation (12) is confirmed:

[0207] (12)

[0208] In the formula: This indicates the critical displacement for axial vibration of the shell; This represents the inherent safety foundation displacement, which is the foundation position obtained through the rotor power test of the new machine. It can be determined based on the inherent safety requirements of the screw compressor, where the inherent safety requirements mainly consider the safety requirements related to the structural stability of the screw compressor. Represents the time-varying cumulative displacement of degradation, which is the cumulative displacement of failure obtained based on accelerated life testing. It is used to characterize the progressive degradation characteristics of a hydrogen liquefaction system with helium expansion cooling in a screw compressor as the operating time increases.

[0209] Step S3034: Compare the real-time axial vibration displacement of the helium compressor equipment with the critical axial vibration displacement of the casing, and determine whether the helium compressor equipment has abnormal vibration, to obtain the second judgment result.

[0210] Specifically, for the rated maximum oil content of helium exhaust gas with specified input. The helium expansion refrigeration hydrogen liquefaction system monitors the axial vibration displacement of the compressor housing in real time. If axial vibration displacement of the compressor housing occurs, it indicates the real-time axial vibration displacement of the housing. (m) ≥ Critical displacement of axial vibration of helium screw compressor casing If (m), then it is considered that the helium screw compressor has experienced abnormal vibration due to continuous operation, that is, the second judgment result is that the helium compressor equipment has abnormal vibration.

[0211] Furthermore, when abnormal vibration occurs in the helium compressor equipment, an emergency stop operation can be initiated for the helium expansion refrigeration hydrogen liquefaction system.

[0212] Step S3035: Based on the first judgment result and the second judgment result, determine the fault early warning diagnosis result of the hydrogen liquefaction system.

[0213] Specifically, by combining the first and second judgment results, fault early warning and diagnosis work can be carried out for potential risk-causing accident scenarios of helium expansion refrigeration hydrogen liquefaction systems, and corresponding fault early warning and diagnosis results can be obtained.

[0214] The fault early warning and diagnosis method for the hydrogen liquefaction system provided in this embodiment, by monitoring and comparing the particle size of the inlet dust at the outlet of the oil filter of the helium compressor equipment and judging the critical displacement of the axial vibration of the casing when there is no fault in the hydrogen liquefaction system, focuses on risk scenarios with cumulative effects, such as dust interception problems and potential faults that may be caused by long-term vibration. In this way, it can detect potential safety hazards in the system in advance, provide a guarantee for the long-term stable operation of the system, further improve the fault early warning and diagnosis function, and enable the system to better cope with various potential risks.

[0215] This embodiment also provides a fault early warning and diagnosis device for a hydrogen liquefaction system. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0216] This embodiment provides a fault early warning and diagnosis device for a hydrogen liquefaction system, wherein the hydrogen liquefaction system includes a helium compressor system, and further, the helium compressor system includes helium compressor equipment and a helium-oil separation and circulating cooling system. Figure 16 As shown, the device includes:

[0217] The acquisition module 401 is used to acquire the operating characteristic parameter set of the hydrogen liquefaction system, the first parameter set of the helium compressor equipment, and the second parameter set of the helium-oil separation and circulating cooling system. The first parameter set is used to characterize the performance and structure of the helium compressor equipment, and the second parameter set is used to characterize the oil separation performance and cooling performance of the helium-oil separation and circulating cooling system.

[0218] The judgment module 402 is used to provide fault warnings for multiple accident scenarios of the hydrogen liquefaction system based on the set of operating characteristic parameters, the first parameter set, and the second parameter set, and to determine whether there is a fault in the hydrogen liquefaction system. Among them, the multiple accident scenarios are representative urgent and sudden accident scenarios encountered by the hydrogen liquefaction system during the commissioning process.

[0219] The assessment and analysis module 403 is used to assess and analyze multiple risk scenarios with cumulative effects of the hydrogen liquefaction system based on the set of operating characteristic parameters and the second parameter set when there is no fault in the hydrogen liquefaction system, and to determine the fault early warning diagnosis results of the hydrogen liquefaction system.

[0220] Further functional descriptions of the above modules are the same as those in the corresponding embodiments described above, and will not be repeated here.

[0221] In this embodiment, the fault early warning and diagnosis device for the hydrogen liquefaction system is presented in the form of a functional unit. Here, a unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0222] This invention also provides a computer device having the above-described features. Figure 16 The device shown is a fault early warning and diagnosis device for a hydrogen liquefaction system.

[0223] Please see Figure 17 , Figure 17 This is a schematic diagram of the structure of a computer device provided in an optional embodiment of the present invention, such as... Figure 17 As shown, the computer device includes one or more processors 10, memory 20, and interfaces for connecting the components, including high-speed interfaces and low-speed interfaces. The components communicate with each other via different buses and can be mounted on a common motherboard or otherwise installed as needed. The processors can process instructions executed within the computer device, including instructions stored in or on memory to display graphical information of a GUI on external input / output devices (such as display devices coupled to the interfaces). In some alternative implementations, multiple processors and / or multiple buses can be used with multiple memories, if desired. Similarly, multiple computer devices can be connected, each providing some of the necessary operations (e.g., as a server array, a group of blade servers, or a multiprocessor system). Figure 17 Take a processor 10 as an example.

[0224] Processor 10 may be a central processing unit, a network processor, or a combination thereof. Processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The programmable logic device may be a complex programmable logic device (CAMP), a field-programmable gate array (FPGA), a general-purpose array logic (GDA), or any combination thereof.

[0225] The memory 20 stores instructions executable by at least one processor 10 to cause at least one processor 10 to perform the method shown in the above embodiments.

[0226] The memory 20 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created based on the use of the computer device. Furthermore, the memory 20 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some alternative embodiments, the memory 20 may optionally include memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0227] The memory 20 may include volatile memory, such as random access memory; the memory may also include non-volatile memory, such as flash memory, hard disk or solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0228] The computer device also includes a communication interface 30 for communicating with other devices or communication networks.

[0229] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code, which, when accessed and executed by the computer, processor, or hardware, implements the methods shown in the above embodiments.

[0230] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0231] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A fault early warning and diagnosis method for a hydrogen liquefaction system, characterized in that, The hydrogen liquefaction system includes a helium compressor system, which includes helium compressor equipment and a helium-oil separation and circulating cooling system; the method includes: Obtain the operating characteristic parameter set of the hydrogen liquefaction system, the first parameter set of the helium compressor equipment, and the second parameter set of the helium-oil separation and circulating cooling system. The first parameter set is used to characterize the performance and structure of the helium compressor equipment, and the second parameter set is used to characterize the oil separation performance and cooling performance of the helium-oil separation and circulating cooling system. Based on the set of operating characteristic parameters, the first set of parameters, and the second set of parameters, fault warnings are issued for multiple accident scenarios of the hydrogen liquefaction system, and it is determined whether the hydrogen liquefaction system has a fault. The multiple accident scenarios are representative urgent and sudden accident scenarios encountered by the hydrogen liquefaction system during the commissioning process. When the hydrogen liquefaction system is free from faults, based on the set of operating characteristic parameters and the second set of parameters, multiple risk scenarios with cumulative effects of the hydrogen liquefaction system are evaluated and analyzed, and the fault early warning diagnosis results of the hydrogen liquefaction system are determined. When the hydrogen liquefaction system is free of faults, based on the set of operating characteristic parameters and the second parameter set, multiple risk scenarios with cumulative effects of the hydrogen liquefaction system are evaluated and analyzed, and the fault early warning diagnosis results of the hydrogen liquefaction system are determined, including: When the hydrogen liquefaction system is free from faults, the maximum inlet dust particle size of the oil filter outlet of the helium compressor equipment is determined based on the first parameter set and the second parameter set. The real-time intake dust particle size at the outlet of the oil filter of the helium compressor equipment is compared with the maximum intake dust particle size, and it is determined whether the oil filter of the helium compressor equipment meets the dust interception requirements to obtain the first judgment result. The critical displacement of the casing axial vibration of the helium compressor equipment is determined based on the aforementioned set of operating characteristic parameters and the second set of parameters. The real-time axial vibration displacement of the helium compressor housing is compared with the critical axial vibration displacement of the housing to determine whether the helium compressor housing is experiencing abnormal vibration, thus obtaining a second judgment result. Based on the first judgment result and the second judgment result, the fault early warning diagnosis result of the hydrogen liquefaction system is determined.

2. The method according to claim 1, characterized in that, Based on the aforementioned set of operational characteristic parameters, the first set of parameters, and the second set of parameters, fault warnings are provided for multiple accident scenarios of the hydrogen liquefaction system, and the presence of faults in the hydrogen liquefaction system is determined, including: Based on the set of operating characteristic parameters and the first set of parameters, it is determined whether the helium compressor equipment has experienced abnormal frequency conversion; When the hydrogen liquefaction system experiences frequent start-stop cycles, based on the first parameter set, it is determined whether the helium compressor equipment is generating abnormal vibrations. Based on the first parameter set and the second parameter set, determine whether the cooling of each section of the helium compressor equipment meets the requirements; Based on the second parameter set, determine whether the oil separation system of the helium compressor equipment is overloaded; Based on the first parameter set, determine whether the helium compressor equipment is under-lubricated. If the helium compressor equipment does not exhibit any abnormal conditions, does not generate any abnormal vibrations, the cooling of each section of the helium compressor equipment meets the requirements, the oil separation system of the helium compressor equipment is not overloaded, and the helium compressor equipment is not under-lubricated, then it is determined that the hydrogen liquefaction system is not faulty.

3. The method according to claim 2, characterized in that, Based on the set of operating characteristic parameters and the first set of parameters, determining whether the helium compressor equipment has experienced abnormal frequency conversion includes: Based on the set of operating characteristic parameters, the allowable power frequency amplitude is determined; The maximum acceptable number of power frequency amplitudes is determined based on the set of operating characteristic parameters and the first parameter set; The target power frequency amplitude is determined based on the maximum acceptable power frequency amplitude. Determine whether the target number of times the helium compressor equipment exists during actual operation is greater than or equal to the target power frequency fluctuation number, wherein the target number represents the number of times the actual power frequency fluctuation of the helium compressor equipment exceeds the allowable power frequency fluctuation during actual operation; When the target number of cycles is greater than or equal to the target frequency fluctuation number, it is determined that the helium compressor equipment has experienced abnormal frequency fluctuation.

4. The method according to claim 2, characterized in that, When the hydrogen liquefaction system experiences frequent start-stop cycles, based on the first parameter set, it is determined whether the helium compressor equipment is generating abnormal vibrations, including: When the hydrogen liquefaction system experiences frequent start-stop operations, the critical axial vibration velocity value of the helium compressor equipment casing is determined based on the first parameter set. When the real-time axial vibration velocity value of the helium compressor equipment is greater than or equal to the critical axial vibration velocity value of the housing, it is determined that the helium compressor equipment is generating abnormal vibration.

5. The method according to claim 4, characterized in that, When the hydrogen liquefaction system experiences frequent start-stop cycles, based on the first parameter set, determining whether the helium compressor equipment is generating abnormal vibrations further includes: When the hydrogen liquefaction system experiences frequent start-stop operations, the critical acceleration value of the axial vibration of the helium compressor equipment casing is determined based on the first parameter set. If the real-time axial vibration acceleration value of the helium compressor equipment is greater than or equal to the critical axial vibration acceleration value of the housing, it is determined that the helium compressor equipment is experiencing abnormal vibration.

6. The method according to claim 2, characterized in that, Based on the first parameter set and the second parameter set, determine whether the cooling of each section of the helium compressor equipment meets the requirements, including: The first real-time cooling oil atomization particle size of the hydrogen liquefaction system in the high-pressure stage, the second real-time cooling oil atomization particle size in the medium-pressure stage, and the third real-time cooling oil atomization particle size in the low-pressure stage are obtained. The maximum permissible atomization particle size of the first cooling oil in the high-pressure stage of the hydrogen liquefaction system is determined based on the maximum oil content in the helium exhaust of the helium compressor equipment. Based on the first parameter set, the second parameter set, and the first maximum allowable atomized particle size of the cooling oil, the second maximum allowable atomized particle size of the cooling oil in the medium-pressure stage and the third maximum allowable atomized particle size of the cooling oil in the low-pressure stage of the hydrogen liquefaction system are determined. When the atomized particle size of the first real-time cooling oil is less than or equal to the maximum permissible atomized particle size of the first cooling oil, the atomized particle size of the second real-time cooling oil is less than or equal to the maximum permissible atomized particle size of the second cooling oil, and the atomized particle size of the third real-time cooling oil is less than or equal to the maximum permissible atomized particle size of the third cooling oil, it is determined that the cooling of each section of the helium compressor equipment meets the requirements.

7. The method according to claim 6, characterized in that, Based on the first parameter set, the second parameter set, and the first maximum permissible atomized particle size of the cooling oil, the maximum permissible atomized particle size of the second cooling oil in the medium-pressure stage and the maximum permissible atomized particle size of the third cooling oil in the low-pressure stage of the hydrogen liquefaction system are determined, including: Based on the first parameter set and the second parameter set, a first relationship is determined between the critical pressure at the end of the high-pressure stage and the critical pressure at the end of the medium-pressure stage of the helium compressor equipment, and a second relationship is determined between the critical pressure at the end of the medium-pressure stage and the critical pressure at the end of the low-pressure boosting stage. A third relationship is determined between the high-pressure stage time and the medium-pressure stage time of the helium compressor equipment based on the first relationship; A fourth relationship between the medium-pressure stage time and the low-pressure stage time of the helium compressor equipment is determined based on the second relationship; The maximum allowable atomization particle size of the second cooling oil is determined based on the first relationship, the third relationship, and the maximum allowable atomization particle size of the first cooling oil. The third maximum allowable atomization particle size of the cooling oil is determined based on the second relationship, the fourth relationship, and the second maximum allowable atomization particle size of the cooling oil.

8. A fault early warning and diagnosis device for a hydrogen liquefaction system, characterized in that, The hydrogen liquefaction system includes a helium compressor system, which includes helium compressor equipment and a helium-oil separation and circulating cooling system; the apparatus includes: The acquisition module is used to acquire the operating characteristic parameter set of the hydrogen liquefaction system, the first parameter set of the helium compressor equipment, and the second parameter set of the helium-oil separation and circulating cooling system. The first parameter set is used to characterize the performance and structure of the helium compressor equipment, and the second parameter set is used to characterize the oil separation performance and cooling performance of the helium-oil separation and circulating cooling system. The judgment module is used to provide fault warnings for multiple accident scenarios of the hydrogen liquefaction system based on the set of operating characteristic parameters, the first parameter set, and the second parameter set, and to determine whether there is a fault in the hydrogen liquefaction system. The multiple accident scenarios are representative urgent and sudden accident scenarios encountered by the hydrogen liquefaction system during the commissioning process. The evaluation and analysis module is used to evaluate and analyze multiple risk scenarios with cumulative effects of the hydrogen liquefaction system based on the set of operating characteristic parameters and the second parameter set when there is no fault in the hydrogen liquefaction system, and to determine the fault early warning diagnosis result of the hydrogen liquefaction system. The evaluation and analysis module is specifically used for: when there is no fault in the hydrogen liquefaction system, determining the maximum inlet dust particle size at the outlet of the oil filter of the helium compressor equipment based on the first parameter set and the second parameter set; comparing the real-time inlet dust particle size at the outlet of the oil filter of the helium compressor equipment with the maximum inlet dust particle size, and determining whether the oil filter of the helium compressor equipment meets the dust interception requirements, to obtain a first judgment result; determining the critical displacement of the shell axial vibration of the helium compressor equipment based on the operating characteristic parameter set and the second parameter set; comparing the real-time shell axial vibration displacement of the helium compressor equipment with the critical displacement of the shell axial vibration, and determining whether the helium compressor equipment has abnormal vibration, to obtain a second judgment result; and determining the fault early warning diagnosis result of the hydrogen liquefaction system based on the first judgment result and the second judgment result.

9. A computer program product, characterized in that, It includes computer instructions, which are used to cause a computer to execute the fault early warning and diagnosis method for the hydrogen liquefaction system according to any one of claims 1 to 7.

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