Vacuum conduit pressure recovery method and apparatus using same

Abstract

The application provides a vacuum pipeline repressing method and a device using the same, and comprises the following steps: determining repressing demand according to pipeline repressing conditions; determining initial repressing time, initial repressing temperature, initial airflow speed and initial pressure rising rate; determining total repressing time and temperature and pressure rising rate in the repressing process; determining a list of maximum repressing valve diameters that can be safely opened under different initial opening pressures; using lumped parameter simulation method and CFD method to analyze the repressing process of the vacuum pipeline by sequentially opening repressing valves with different diameters under different initial opening pressures, and calculating and obtaining valve repressing total time in multiple stages; and determining the diameter and number of repressing valves for final vacuum pipeline repressing according to valve repressing total time in multiple stages and total repressing time of the vacuum pipeline. The technical scheme of the application solves the technical problem that the vacuum repressing process in a small space in the prior art is difficult to be applied to large-size vacuum pipeline repressing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of low vacuum and pipeline transportation, in particular to a vacuum pipeline pressure recovery method and a device using the same. BACKGROUND

[0002] The pipeline train is a new transportation system which uses a train as a carrier, uses superconducting magnetic levitation technology to realize the train and the ground contact to eliminate friction resistance, and uses the internal near-vacuum pipeline environment to greatly reduce air resistance, so as to realize the train theoretical speed of more than 1000 km / h. The low-vacuum pipeline train can greatly shorten the time and space distance between cities, and has many advantages such as not affected by weather conditions, not limited by air traffic flow, and seamless connection with urban rail systems. At present, major economic and technological powers in the world have carried out related technical research and industrial development. A representative is the Hyperloop One company in the United States, which has carried out research on vacuum pipeline trains since 2015 and has obtained a test speed of 387 km / h.

[0003] In addition to establishing and maintaining a vacuum environment in a large-size pipeline space, the vacuum pipeline also has the need to recover from the vacuum environment to normal pressure to meet the requirements of pipeline daily maintenance and emergency escape. The safe and rapid pressure recovery of a large-size vacuum pipeline needs to carry out technical analysis and design for the pressure recovery scheme.

[0004] At present, there are few pressure recovery scheme designs for large-size vacuum pipelines, and similar patents are as follows:

[0005] The patent application "Low-pressure gas pressure recovery device and method" (application number 201410569134.5) discloses a low-pressure gas pressure recovery device and method, which can realize on-site gas high-ratio pressure recovery without external power input.

[0006] The patent application "Vacuum valve device with free opening and closing and high air tightness and manufacturing method" (application number 201410546519.X) gives a vacuum valve device which can realize safe and reliable dynamic sealing effect without oil pollution, which will effectively solve the contradiction between the frequent opening and closing and the high air tightness required by the vacuum chamber of the low-temperature refrigerator in actual application.

[0007] The above-mentioned vacuum valve devices are designed for their respective use scenarios. The large-size vacuum pipeline pressure recovery process has a huge gas flow in a short time, which is quite different from the vacuum pressure recovery process in the small space. Through patent retrieval, it is found that there is no safe and rapid pressure recovery method for large-size vacuum pipelines at present. SUMMARY

[0008] The application provides a vacuum pipeline repressing method and a device using the same, and can solve the technical problem that the vacuum repressing process in a small space is difficult to be applied to repressing of a large-size vacuum pipeline.

[0009] According to an aspect of the application, a vacuum pipeline repressing method is provided, which comprises: determining a repressing requirement of a vacuum pipeline according to a pipeline repressing condition; determining a preliminary repressing time, a preliminary repressing temperature, a preliminary airflow speed and a preliminary pressure rise rate according to the repressing requirement of the vacuum pipeline; based on the preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate, using a lumped parameter simulation method and a CFD method to analyze a repressing process of the vacuum pipeline, and determining a total repressing time of the vacuum pipeline and a temperature and a pressure rise rate in the repressing process; based on the determined total repressing time and the temperature and the pressure rise rate in the repressing process, carrying out CFD analysis on different repressing valve diameters and repressing airflow impact under different initial opening pressures, combining with an allowable maximum wind speed at different positions of the vacuum pipeline, and determining a list of maximum repressing valve diameters that can be safely opened under different initial opening pressures; based on the list of maximum repressing valve diameters, selecting a plurality of different repressing valve diameters, numbers and initial opening pressures for combination, ensuring that airflow impact of any repressing valve opening is within a safe airflow threshold, using the lumped parameter simulation method and the CFD method to sequentially open repressing valves of different repressing valve diameters under a plurality of different initial opening pressures to analyze the repressing process of the vacuum pipeline, combining valve repressing times of different stages to calculate and obtain valve repressing times of different stages, and calculating and obtaining valve repressing total times of a plurality of stages according to the valve repressing times of different stages; determining diameters of repressing valves and numbers of repressing valves for finally repressing the vacuum pipeline according to the valve repressing total times of a plurality of stages and the total repressing time of the vacuum pipeline, and safely and quickly repressing the vacuum pipeline based on the finally determined diameters of repressing valves and numbers of repressing valves.

[0010] Further, the determination of the diameter and the number of the pressure recovery valves for the final vacuum pipeline pressure recovery comprises: comparing the total valve pressure recovery time of the multiple stages with the total pressure recovery time length of the vacuum pipeline; if the total valve pressure recovery time of the multiple stages is greater than the total pressure recovery time length of the vacuum pipeline, adjusting the diameter and the number of the pressure recovery valves, repeating the above process to obtain the adjusted total valve pressure recovery time of the multiple stages until the total valve pressure recovery time of the multiple stages is less than or equal to the total pressure recovery time length of the vacuum pipeline; if the total valve pressure recovery time of the multiple stages is less than or equal to the total pressure recovery time length of the vacuum pipeline, determining whether the pipeline pressure recovery temperature is within a set safe pressure recovery temperature threshold range; if the pipeline pressure recovery temperature exceeds the set safe pressure recovery temperature threshold range, adjusting the diameter and the number of the pressure recovery valves, repeating the above process until the total valve pressure recovery time of the multiple stages is less than or equal to the total pressure recovery time length of the vacuum pipeline and the pipeline pressure recovery temperature is within the set safe pressure recovery temperature threshold range; if the total valve pressure recovery time of the multiple stages is less than or equal to the total pressure recovery time length of the vacuum pipeline and the pipeline pressure recovery temperature is within the set safe pressure recovery temperature threshold range, the determined diameter and the number of the pressure recovery valves are taken as the diameter and the number of the pressure recovery valves for the final vacuum pipeline pressure recovery.

[0011] Further, the lumped parameter simulation method uses AMEsim software for lumped parameter simulation, and the CFD method uses Fluent software for CFD simulation.

[0012] Further, after the diameter and the number of the pressure recovery valves are determined, the vacuum pipeline pressure recovery method further comprises: setting a filtering device before the pressure recovery valve, the filtering device being used for filtering the air inflow.

[0013] Further, after the diameter and the number of the pressure recovery valves are determined, the vacuum pipeline pressure recovery method further comprises: setting a silencer to reduce the noise generated in the pressure recovery process.

[0014] Further, after the diameter and the number of the pressure recovery valves are determined, the vacuum pipeline pressure recovery method further comprises: setting a flow diffuser in the vacuum pipeline, the flow diffuser being in communication with the pressure recovery valve, and the flow diffuser being used for dividing the air outlet direction of the pressure recovery valve into multiple directions.

[0015] Further, after the diameter and the number of the pressure recovery valves are determined, the vacuum pipeline pressure recovery method further comprises: setting a rain and dust proof cover on the upper part of the pressure recovery valve, the rain and dust proof cover being used for preventing the influence of external rain and dust on the pressure recovery valve.

[0016] According to another aspect of the present application, a vacuum pipeline pressure recovery device is provided, which uses the vacuum pipeline pressure recovery method as described above for pipeline pressure recovery.

[0017] The technical scheme of the application provides a vacuum pipeline pressure recovery method, which formulates a pressure recovery scheme according to the pressure recovery working condition requirements, safety index requirements and the like of a large-size vacuum pipeline, considers not only the recovery of pressure from a low vacuum state to normal pressure, but also the suitability and comfort of the vacuum pipeline body, the instruments and equipment in the pipeline and personnel; the lumped parameter simulation method and the CFD simulation method are used in the design of the vacuum pipeline pressure recovery scheme, and the effectiveness and economy of the pressure recovery scheme design are well balanced through comprehensive theoretical analysis and test measurement data; in addition, the pressure recovery scheme of the application starts from the gas flow characteristics of the vacuum container pressure recovery, formulates a scheme, selects a valve diameter and determines an opening time for the supersonic gas flow pressure recovery stage and the subsonic gas flow pressure recovery stage respectively, and through reasonable selection and collocation, the safe and rapid pressure recovery of the large-size vacuum pipeline can be finally realized. Therefore, compared with the prior art, the vacuum pipeline pressure recovery method provided by the application can realize the safe and rapid pressure recovery of the whole large-size vacuum pipeline through the reasonable combination of different diameter valves opened in different conditions. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are included to provide a further understanding of the embodiments of the application and constitute a part of this specification, illustrate embodiments of the application and together with the description help to explain the principles of the application. Obviously, the drawings described below are only some of the embodiments of the application, and other drawings can be obtained by those of ordinary skill in the art without creative effort based on these drawings.

[0019] Figure 1 A flow chart of a vacuum pipeline pressure recovery method provided by a specific embodiment of the application is shown;

[0020] Figure 2 A different diameter pressure recovery valve arrangement scheme provided by a specific embodiment of the application is shown. DETAILED DESCRIPTION

[0021] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The technical solutions in the embodiments of the application will be described clearly and completely below with reference to the drawings of the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, not all. The description of the at least one exemplary embodiment is actually only illustrative, but not as any limitation on the application and its application or use. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the application.

[0022] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting, as the scope of the exemplary embodiments of this application is limited only by the appended claims. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0023] The relative arrangement of parts and steps, numerical expressions, and numerical values set forth in the examples are not intended to limit the scope of the application unless otherwise specifically stated. It is to be understood that the drawings are not necessarily to scale as the dimensions of the parts shown are for the purpose of illustration and description only and not limiting. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered part of the specification as appropriate. In all examples shown and discussed herein, any specific values are to be interpreted as merely illustrative and not limiting. Thus, other examples of the exemplary embodiments can have different values. It is noted that like numbers and letters refer to like elements throughout the several views of the drawings and, as such, no further discussion with regard thereto is deemed necessary.

[0024] As Figure 1 and Figure 2As shown, the specific embodiments according to the present application provide a vacuum pipeline repressing method, which comprises: determining the repressing requirement of the vacuum pipeline according to the pipeline repressing condition; determining the preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate according to the repressing requirement of the vacuum pipeline; based on the preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate, using the lumped parameter simulation method and the CFD method to analyze the repressing process of the vacuum pipeline, and clearly formulating the total repressing time of the vacuum pipeline and the temperature and pressure rise rate in the repressing process; based on the formulated total repressing time and the temperature and pressure rise rate in the repressing process, carrying out CFD analysis on the repressing airflow impact of the repressing valve with different diameters and opened at different initial opening pressures, combining with the allowable maximum wind speed at different positions of the vacuum pipeline, formulating a list of the maximum repressing valve diameters that can be safely opened at different initial opening pressures; based on the list of the maximum repressing valve diameters, selecting multiple different repressing valve diameters, numbers and initial opening pressures for combination, ensuring that the airflow impact of any opened repressing valve is within the safe airflow threshold, using the lumped parameter simulation method and the CFD method to sequentially open the repressing valves with different diameters at multiple different initial opening pressures to analyze the repressing process of the vacuum pipeline, combining the valve repressing time at each stage to calculate and obtain the valve repressing time at each stage, and calculating and obtaining the valve repressing total time at multiple stages according to the valve repressing time at each stage; determining the diameter of the repressing valve and the number of the repressing valves for the final vacuum pipeline repressing according to the valve repressing total time at multiple stages and the total repressing time of the vacuum pipeline, and safely and quickly repressing the vacuum pipeline based on the finally determined diameter of the repressing valve and the number of the repressing valves.

[0025] By using this configuration, a vacuum pipeline repressing method is provided, which formulates a repressing scheme according to the repressing condition requirements, safety index requirements and the like of the large-size vacuum pipeline, not only considers the recovery of pressure from the low vacuum state to the normal pressure, but also considers the suitability and comfort of the vacuum pipeline body, the instruments and equipment in the pipeline and personnel; the lumped parameter simulation method and the CFD simulation method are used in the design of the vacuum pipeline repressing scheme, the theoretical analysis and the test measurement data are combined, and the effectiveness and economy of the repressing scheme design are well balanced; in addition, the repressing scheme of the present application starts from the airflow characteristics of the vacuum container repressing, formulates schemes, selects valve diameters and determines opening times for the supersonic airflow repressing stage and the subsonic airflow repressing stage respectively, and through reasonable selection and collocation, the safe and fast repressing of the large-size vacuum pipeline can be finally realized. Therefore, compared with the prior art, the vacuum pipeline repressing method provided by the present application can realize the safe and fast repressing of the whole large-size vacuum pipeline through the reasonable combination of the opening of the valves with different diameters under different conditions.

[0026] Specifically, the purpose of the present application is to formulate a safe and fast repressing scheme for large-size low-vacuum pipeline to meet the repressing requirements of vacuum pipeline transportation in different scenarios. When repressing a large-size vacuum pipeline, a large amount of gas will be filled in a short time, and because of the large pressure difference between the inside and outside of the pipeline at the initial stage of repressing, the filling gas flow speed exceeds the speed of sound. If no effective measures are taken, the high-speed gas flow will cause serious damage to the vacuum pipeline body, instruments and equipment inside the pipeline, etc. At the same time, the repressing process will cause the overall temperature inside the vacuum pipeline to rise, further threatening the instruments and equipment inside the vacuum pipeline. Therefore, when formulating the repressing scheme for a large-size vacuum pipeline, it is necessary to comprehensively analyze and design the pipeline repressing conditions, repressing safety index requirements and gas flow impact inside the pipeline.

[0027] In order to realize the repressing of a large-size vacuum pipeline, the present application carries out a lumped parameter AMEsim software analysis for the repressing process of a large-size vacuum pipeline, analyzes the relationship between the repressing valve diameter and the repressing time, repressing temperature, repressing gas flow, etc., and accumulates the basis and data for formulating repressing indexes. CFD simulation of repressing gas flow impact of different diameter valves and CFD simulation of repressing gas flow impact of opening valves under different initial pressures are carried out to demonstrate the velocity field distribution at different positions inside the vacuum pipeline under different diameters and opening pressures of the repressing valve, compare with the index requirements at the corresponding positions, and determine the maximum repressing valve diameter that can be safely opened under different initial pressures. According to the simulation calculation, field test measurement results, etc., the repressing scheme for a large-size vacuum pipeline is formulated. The main idea is to use small-diameter valves for throttling repressing at the initial stage of repressing, when the pressure difference between the inside and outside is large and the repressing gas flow is supersonic. After the internal pressure of the vacuum pipeline rises, the repressing gas flow enters the subsonic stage, and large-diameter valves are added for repressing to shorten the total repressing time. Through the reasonable combination of different diameter valves opened in batches under different conditions, safe and fast repressing of a large-size vacuum pipeline can be realized.

[0028] In the present application, in order to realize the repressing of a vacuum pipeline, it is first necessary to determine the repressing requirements of the vacuum pipeline according to the pipeline repressing conditions. As a specific embodiment of the present application, starting from the pipeline repressing conditions, according to different repressing requirements, the repressing process can be divided into slow repressing, fast repressing, emergency repressing, etc. to meet the repressing requirements of daily maintenance, repair and emergency rescue. Among them, the repressing speed of slow repressing is within the first threshold range, the repressing speed of fast repressing is within the second threshold range, and the repressing speed of emergency repressing is within the third threshold range. The values of the first threshold, the second threshold and the third threshold increase in turn. The specific values of the first threshold, the second threshold and the third threshold are determined according to the actual application. As other embodiments of the present application, the repressing process can also be divided in other situations, including but not limited to the above three situations.

[0029] After the repressing demand of the vacuum pipeline is determined, the preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate can be determined according to the repressing demand of the vacuum pipeline. At this time, the preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate are rough numerical ranges determined according to experience, which are determined according to the specific repressing demand. Specifically, if there is no emergency in the pipeline, the repressing time can be lengthened, at this time, the safety indicators in the pipeline can be mainly constrained to ensure the integrity of the vacuum pipeline and the instruments and equipment in the pipeline; if there is an emergency in the pipeline, or someone needs to escape from the vehicle body, the repressing time required for personnel escape should be as short as possible, at this time, the repressing time needs to be considered, and the indicators of repressing can be appropriately relaxed under the premise of not endangering the integrity of the vacuum pipeline.

[0030] Further, after the preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate are determined, the repressing process analysis of the vacuum pipeline can be carried out based on the preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate using the lumped parameter simulation method and the CFD method, and the repressing total time of the vacuum pipeline and the temperature and pressure rise rate in the repressing process are determined.

[0031] After the repressing total time of the vacuum pipeline and the temperature and pressure rise rate in the repressing process are determined, the CFD analysis can be carried out for different repressing valve diameters and repressing airflow impact under different initial opening pressures based on the repressing total time and the temperature and pressure rise rate in the repressing process, and the list of maximum repressing valve diameters that can be safely opened under different initial opening pressures is determined in combination with the allowable maximum wind speed at different positions of the vacuum pipeline.

[0032] After the list of maximum repressing valve diameters that can be safely opened under different initial opening pressures is determined, multiple different repressing valve diameters, numbers and initial opening pressures can be combined based on the list of maximum repressing valve diameters to ensure that the airflow impact of any repressing valve opening is within the safe airflow threshold, and the repressing process analysis of the vacuum pipeline can be carried out by sequentially opening repressing valves of different repressing valve diameters under multiple different initial opening pressures using the lumped parameter simulation method and the CFD method. The valve repressing time of each stage is combined to calculate the valve repressing time of each stage, and the valve repressing total time of multiple stages is calculated according to the valve repressing time of each stage.

[0033] Further, after the total valve repressing time of the multiple stages is obtained, the diameter and the number of the repressing valves for the final vacuum pipeline repressing can be determined according to the total valve repressing time of the multiple stages and the total repressing time length of the vacuum pipeline, and the vacuum pipeline is safely and quickly repressed based on the diameter and the number of the repressing valves finally determined. In the present application, the diameter and the number of the repressing valves for the final vacuum pipeline repressing are determined according to the total valve repressing time of the multiple stages and the total repressing time length of the vacuum pipeline, which specifically includes: comparing the total valve repressing time of the multiple stages with the total repressing time length of the vacuum pipeline, if the total valve repressing time of the multiple stages is greater than the total repressing time length of the vacuum pipeline, adjusting the diameter and the number of the repressing valves, repeating the above process to obtain the adjusted total valve repressing time of the multiple stages until the total valve repressing time of the multiple stages is less than or equal to the total repressing time length of the vacuum pipeline; if the total valve repressing time of the multiple stages is less than or equal to the total repressing time length of the vacuum pipeline, determining whether the pipeline repressing temperature is within the set safe repressing temperature threshold range, if the pipeline repressing temperature exceeds the set safe repressing temperature threshold range, adjusting the diameter and the number of the repressing valves, repeating the above process until the total valve repressing time of the multiple stages is less than or equal to the total repressing time length of the vacuum pipeline and the pipeline repressing temperature is within the set safe repressing temperature threshold range; if the total valve repressing time of the multiple stages is less than or equal to the total repressing time length of the vacuum pipeline and the pipeline repressing temperature is within the set safe repressing temperature threshold range, the determined diameter and number of the repressing valves are taken as the diameter and the number of the repressing valves for the final vacuum pipeline repressing.

[0034] As a specific embodiment of the present application, the lumped parameter simulation method adopts AMEsim software for lumped parameter simulation, and the CFD method adopts Fluent software for CFD simulation. As other embodiments of the present application, the lumped parameter simulation method can also adopt other one-dimensional thermal fluid calculation software for lumped parameter simulation.

[0035] Further, in the present application, after the diameter and the number of the repressing valves are determined, the vacuum pipeline repressing method further includes: setting a filtering device before the repressing valve, and the filtering device is used for filtering the air inflow. In this configuration, by setting the filtering device, impurities in the air inflow can be effectively removed, and the cleanliness of the repressing inflow is improved.

[0036] In addition, in the present application, after the diameter and the number of the repressing valves are determined, the vacuum pipeline repressing method further includes: setting a silencer to reduce the noise generated in the repressing process. The silencer can be arranged outside, inside or both inside and outside the vacuum pipeline according to the demand, and a soundproof shielding cover can be additionally arranged outside when the repressing noise is large.

[0037] Further, in the present application, after the diameter of the pressure recovery valve and the number of the pressure recovery valves are determined, the vacuum pipeline pressure recovery method further comprises: arranging a flow diffuser in the vacuum pipeline, the flow diffuser being in communication with the pressure recovery valve, and the flow diffuser being used to divide the air outlet direction of the pressure recovery valve into multiple directions.

[0038] By using the arrangement, the direction and dispersion degree of the incident air flow can be controlled to avoid the air flow from impacting the key instruments and equipment in the pipeline.

[0039] Further, in the present application, after the diameter of the pressure recovery valve and the number of the pressure recovery valves are determined, the vacuum pipeline pressure recovery method further comprises: arranging a flow diffuser in the vacuum pipeline, the flow diffuser being in communication with the pressure recovery valve, and the flow diffuser being used to divide the air outlet direction of the pressure recovery valve into multiple directions.

[0040] According to another aspect of the present application, a vacuum pipeline pressure recovery device is provided, which uses the vacuum pipeline pressure recovery method as described above to recover the pipeline. Since the pressure recovery method of the present application formulates the pressure recovery scheme according to the pressure recovery working condition requirements, safety index requirements and the like of the large-size vacuum pipeline, not only the pressure recovery from the low vacuum state to the normal pressure is considered, but also the suitability and comfort of the vacuum pipeline body, the instruments and equipment in the pipeline and the personnel are considered; the lumped parameter simulation method and the CFD simulation method are used in the vacuum pipeline pressure recovery scheme design, the theoretical analysis and the test measurement data are comprehensively analyzed, and the effectiveness and economy of the pressure recovery scheme design are well balanced; in addition, the pressure recovery scheme of the present application starts from the air flow characteristics of the vacuum container pressure recovery, formulates the scheme, selects the valve diameter and determines the opening time for the supersonic air flow pressure recovery stage and the subsonic air flow pressure recovery stage, and through the reasonable selection and collocation, the safe and rapid pressure recovery of the large-size vacuum pipeline can be finally realized, so that the method is used in the pressure recovery device to recover the pipeline, and the working performance of the pressure recovery device can be greatly improved.

[0041] In order to further understand the present application, the following Figure 1 and Figure 2 The vacuum pipeline pressure recovery method provided by the present application is described in detail.

[0042] As shown in Figure 1 and Figure 2 , the vacuum pipeline pressure recovery method according to the specific embodiment of the present application comprises the following steps.

[0043] The repressing demand of the vacuum pipeline is determined according to the repressing condition of the pipeline. In the embodiment, the repressing process is divided into slow repressing, fast repressing, emergency repressing and the like according to different repressing demands to meet the repressing demands of daily maintenance, repair and emergency rescue.

[0044] The preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate are determined according to the repressing demand of the vacuum pipeline. In the embodiment, different safety index setting requirements are corresponded to different repressing demands, including the temperature, the airflow speed, the pressure rise rate and the like. If there is no emergency in the pipeline, the repressing time can be lengthened, at this time, the safety indexes in the pipeline can be mainly restricted to ensure the integrity of the vacuum pipeline and the instruments and equipment in the pipeline; if there is an emergency in the pipeline or a person needs to escape from the vehicle body, the repressing time is required to be as short as possible, at this time, the repressing time is mainly considered, and the indexes of the repressing can be appropriately relaxed without endangering the integrity of the vacuum pipeline.

[0045] Based on the preliminary repressing time, the preliminary repressing temperature, the preliminary airflow speed and the preliminary pressure rise rate, the repressing process analysis of the vacuum pipeline is carried out by using the lumped parameter simulation method and the CFD method to determine the total repressing time t of the vacuum pipeline and the temperature and the pressure rise rate in the repressing process. In the embodiment, the repressing process analysis is carried out by using the AMEsim (lumped parameter simulation method) and the CFD method to determine the total repressing time of the vacuum pipeline and the specific temperature, the pressure rise rate and the like in the repressing process.

[0046] Based on the determined total repressing time and the temperature and the pressure rise rate in the repressing process, the CFD analysis is carried out for different repressing valve diameters and the repressing airflow impact under different initial opening pressures, and the list of the maximum repressing valve diameters that can be safely opened under different initial opening pressures is determined in combination with the maximum allowable wind speed of the equipment and instruments at different positions of the vacuum pipeline.

[0047] Based on the list of the maximum repressing valve diameters, a plurality of different repressing valve diameters, numbers and initial opening pressures are selected for combination to ensure that the airflow impact of any opened repressing valve is within the safety airflow threshold, the repressing process analysis of the vacuum pipeline is carried out by using the lumped parameter simulation method and the CFD method to sequentially open the repressing valves of different repressing valve diameters under a plurality of different initial opening pressures, the valve repressing time of each stage is combined to calculate the valve repressing time of each stage, and the valve repressing total time t of a plurality of stages is calculated according to the valve repressing time of each stage. sum .

[0048] The valve repressing total time t of a plurality of stages is calculated according to the valve repressing time of each stage. sumThe total re-pressurization time t of the vacuum pipeline is used to determine the diameter and number of the re-pressurization valves for the final re-pressurization of the vacuum pipeline, and the vacuum pipeline is re-pressurized safely and quickly based on the diameter and number of the re-pressurization valves finally determined. In this embodiment, the total re-pressurization time t of the valves in multiple stages is used to determine the diameter and number of the re-pressurization valves for the final re-pressurization of the vacuum pipeline. sum The total re-pressurization time t of the vacuum pipeline determines the diameter of the re-pressurization valve and the number of re-pressurization valves for the final re-pressurization of the vacuum pipeline. Specifically, the total re-pressurization time t of the valves in multiple stages is sum Compare with the total re-pressurization time t of the vacuum pipeline. If the total re-pressurization time t of the valves in the multiple stages is sum If the total re-pressurization time of the vacuum pipeline is greater than t, adjust the diameter and number of the re-pressurization valves, and repeat the above process to obtain the total re-pressurization time of the valves in multiple stages after adjustment, until the total re-pressurization time of the valves in multiple stages is t sum Less than or equal to the total re-pressurization time t of the vacuum pipeline; if the total re-pressurization time t of the valves in multiple stages sum If the pressure is less than or equal to the total re-pressurization time t of the vacuum pipeline, determine whether the pipeline re-pressurization temperature is within the set safety re-pressurization temperature threshold range. If the pipeline re-pressurization temperature exceeds the set safety re-pressurization temperature threshold range, adjust the diameter and number of the re-pressurization valves, and repeat the above process until the total re-pressurization time t of the valves in the multiple stages is sum Less than or equal to the total re-pressurization time t of the vacuum pipeline and the pipeline re-pressurization temperature is within the set safe re-pressurization temperature threshold range; if the total re-pressurization time t of the valves in the multiple stages sum If the total re-pressurization time t of the vacuum pipeline is less than or equal to the total re-pressurization time t and the pipeline re-pressurization temperature is within the set safe re-pressurization temperature threshold range, the determined caliber and number of re-pressurization valves will be used as the caliber and number of re-pressurization valves for the final re-pressurization of the vacuum pipeline.

[0049] In summary, the present invention provides a vacuum pipeline re-pressurization method, which formulates a re-pressurization scheme based on the re-pressurization working condition requirements, safety index requirements, etc. of large-scale vacuum pipelines, not only considering the pressure recovery from a low vacuum state to normal pressure, but also considering the suitability and comfort of the vacuum pipeline body, the instruments and equipment in the pipeline, and the personnel; in the design of the vacuum pipeline re-pressurization scheme, the lumped parameter simulation method and the CFD simulation method are used, and the effectiveness and economy of the re-pressurization scheme design are well balanced by comprehensive theoretical analysis and experimental measurement data; in addition, the re-pressurization scheme of the present invention starts from the airflow characteristics of the vacuum container re-pressurization, and formulates schemes, selects valve calibers, and determines the opening time for the supersonic airflow re-pressurization stage and the subsonic airflow re-pressurization stage respectively. Through reasonable selection and matching, the safe and rapid re-pressurization of large-scale vacuum pipelines can be finally achieved. Therefore, compared with the prior art, the vacuum pipeline re-pressurization method provided by the present invention can achieve safe and rapid re-pressurization of the entire large-scale vacuum pipeline through a reasonable combination of valves of different calibers opened in batches under different conditions.

[0050] In the description of the application, it needs to be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicated orientation or positional relationship is generally based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, without making the opposite statement, these orientation words do not indicate and imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the scope of protection of the application; the orientation words "inner, outer" refer to the inner and outer relative to the contour of each component.

[0051] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper" and the like can be used herein to describe the spatial positional relationship of one device or feature with other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device described in the drawings. For example, if the device in the drawing is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0052] In addition, it should be noted that the use of "first", "second" and the like words to define parts, only for the convenience of corresponding parts, such as no further declaration, the above words have no special meaning, therefore, it cannot be understood as a limitation on the scope of protection of the application.

[0053] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

Claims

1. A vacuum pipeline re-pressurization method, characterized in that: The vacuum pipeline re-pressurization method comprises: Determine the re-pressurization requirements of the vacuum pipeline according to the pipeline re-pressurization working conditions; Determining a preliminary repressurization time, preliminary repressurization temperature, preliminary air flow velocity, and preliminary pressure rise rate according to the repressurization requirement of the vacuum pipeline; Based on the initial repressurization time, initial repressurization temperature, initial airflow velocity, and initial pressure rise rate, the repressurization process of the vacuum pipeline is analyzed using the lumped parameter simulation method and CFD method. The total repressurization time of the vacuum pipeline, as well as the temperature and pressure rise rate during the repressurization process, are clearly determined. Based on the established total re-pressurization time, temperature, and pressure rise rate during the re-pressurization process, CFD analysis was conducted on the re-pressurization airflow impact of different re-pressurization valve calibers and at different initial opening pressures. Combined with the maximum allowable wind speed at different locations in the vacuum pipeline, a list of maximum re-pressurization valve calibers that can be safely opened at different initial opening pressures was developed; Based on the maximum re-pressure valve caliber list, multiple different re-pressure valve calibers, numbers, and initial opening pressures are selected for combination to ensure that the airflow impact caused by the opening of any of the re-pressure valves is within the safe airflow threshold. The re-pressure valves of different re-pressure valve calibers are opened in sequence under multiple different initial opening pressures using the lumped parameter simulation method and the CFD method to analyze the re-pressure process of the vacuum pipeline. The valve re-pressure time of each stage is combined to calculate the valve re-pressure time of each stage. The total valve re-pressure time of multiple stages is calculated based on the valve re-pressure time of each stage. The caliber and number of the re-pressurization valves for the final re-pressurization of the vacuum pipeline are determined based on the total re-pressurization time of the valves in multiple stages and the total re-pressurization time of the vacuum pipeline. The vacuum pipeline is re-pressurized safely and quickly based on the finally determined caliber and number of the re-pressurization valves.

2. The vacuum pipeline re-pressurization method according to claim 1, characterized in that: The method of determining the caliber and number of the pressure-recovering valves for finally re-pressurizing the vacuum pipeline according to the total pressure-recovering time of the valves in multiple stages and the total pressure-recovering time of the vacuum pipeline specifically includes: comparing the total pressure-recovering time of the valves in multiple stages with the total pressure-recovering time of the vacuum pipeline; if the total pressure-recovering time of the valves in multiple stages is greater than the total pressure-recovering time of the vacuum pipeline, adjusting the caliber and number of the pressure-recovering valves; repeating the above process to obtain the adjusted total pressure-recovering time of the valves in multiple stages, until the total pressure-recovering time of the valves in multiple stages is less than or equal to the total pressure-recovering time of the vacuum pipeline; if the total pressure-recovering time of the valves in multiple stages is less than or equal to the total pressure-recovering time of the vacuum pipeline, judging the pipeline Whether the re-pressurization temperature is within the set safety re-pressurization temperature threshold range; if the pipeline re-pressurization temperature exceeds the set safety re-pressurization temperature threshold range, adjust the caliber and number of the re-pressurization valves, and repeat the above process until the total valve re-pressurization time of the multiple stages is less than or equal to the total re-pressurization time of the vacuum pipeline and the pipeline re-pressurization temperature is within the set safety re-pressurization temperature threshold range; if the total valve re-pressurization time of the multiple stages is less than or equal to the total re-pressurization time of the vacuum pipeline and the pipeline re-pressurization temperature is within the set safety re-pressurization temperature threshold range, the determined caliber and number of the re-pressurization valves will be used as the caliber and number of the re-pressurization valves for the final vacuum pipeline re-pressurization.

3. The vacuum pipeline re-pressurization method according to claim 2, characterized in that: The lumped parameter simulation method uses AMEsim software to perform lumped parameter simulation, and the CFD method uses Fluent software to perform CFD simulation.

4. The vacuum pipeline re-pressurization method according to claim 1, characterized in that: After the caliber and number of the pressure-regenerating valves are determined, the vacuum pipeline pressure-regenerating method further includes: arranging a filter device before the pressure-regenerating valve, wherein the filter device is used to filter the incoming air flow.

5. The vacuum pipeline re-pressurization method according to claim 4, characterized in that: After the caliber of the pressure-replenishing valve and the number of the pressure-replenishing valves are determined, the vacuum pipeline pressure-replenishing method further includes: providing a muffler to reduce noise generated during the pressure-replenishing process.

6. The vacuum pipeline re-pressurization method according to claim 5, characterized in that: After determining the caliber of the re-pressure valve and the number of the re-pressure valves, the vacuum pipeline re-pressure method further includes: arranging a diffuser in the vacuum pipeline, the diffuser being connected to the re-pressure valve, and the diffuser being used to divide the air outlet direction of the re-pressure valve into multi-directional flow.

7. The vacuum pipeline re-pressurization method according to claim 6, characterized in that: After determining the caliber and number of the pressure-resetting valves, the vacuum pipeline pressure-resetting method further includes: providing a rainproof and dustproof cover on the upper part of the pressure-resetting valve, wherein the rainproof and dustproof cover is used to prevent external rain and dust from affecting the pressure-resetting valve.

8. A vacuum pipeline re-pressurization device, characterized in that: The vacuum pipeline re-pressurization device uses the vacuum pipeline re-pressurization method according to any one of claims 1 to 7 to perform pipeline re-pressurization.

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