Method and system for hydrogen quench mixing intensification and temperature field reconstruction in multi-bed hydrogenation reactor

Abstract

The application discloses a kind of multi-bed hydrogenation reactor cold hydrogen mixing reinforcement and temperature field reconstruction method and system, it is related to chemical machinery and chemical process control technical field;For the uneven distribution of cold hydrogen and high temperature reaction stream mixing bed inlet temperature, the problem that the three-dimensional temperature state of bed is difficult to accurately perceive due to the limited distribution of thermocouple, the method obtains the unit area mass flow and cross section temperature in the direction of distribution tray under the condition of cold hydrogen injection in cold hydrogen tank located above distribution tray and parallel to distribution tray;Radial arrangement is carried out along the center of distribution tray to the outer periphery to be the flow distribution and temperature distribution of multiple annular zones;Radial gradient opening structure parameters of distribution tray installed are obtained, and temperature distribution of catalyst bed inlet is determined according to annular zone opening rate, flow distribution and temperature distribution;Read bed thermocouple temperature value, and generate catalyst bed three-dimensional temperature distribution in combination with bed inlet temperature distribution.

Description

Technical Field

[0001] This invention relates to the field of chemical machinery and chemical process control technology, and more specifically, to a method and system for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor. Background Technology

[0002] Multi-bed fixed-bed hydrotreating reactors are widely used in the hydroregeneration of waste lubricating oil, hydrorefining of distillate oil, and related hydrogen-related reactions. These reactors typically have multiple catalyst beds arranged axially, with internal components such as cold hydrogen inlets, cold hydrogen tanks, and distribution plates between adjacent beds. During operation, cold hydrogen enters the cold hydrogen tank through the cold hydrogen inlet, mixes with the high-temperature reactant stream from the previous catalyst bed, and then flows through the distribution plate to the next catalyst bed, thereby achieving bed inlet temperature regulation and reaction heat control. In existing systems, reactor operation status is typically monitored by collecting data such as cold hydrogen flow rate, reactant stream temperature, system pressure, and bed thermocouple temperature via a DCS system. Operators then monitor the cold hydrogen flow rate and bed temperature status based on their process experience.

[0003] However, the current problem is that when cold hydrogen mixes with high-temperature reactant streams in the limited mixing space between the catalyst beds, it is easily affected by the combined influence of the cold hydrogen inlet jet direction, jet velocity, cold hydrogen box space size, and distribution disk structure, resulting in radial differences in the flow rate and temperature state before entering the catalyst bed inlet. This radial difference will cause uneven temperature distribution at the bed inlet, which in turn will induce local hot spots, runaway temperature risk, and accelerated catalyst deactivation. At the same time, the number of thermocouples inside industrial reactors is limited, and they can usually only reflect the temperature at a few locations, making it difficult to accurately obtain the temperature distribution at different axial, radial, and circumferential positions inside the catalyst bed.

[0004] Therefore, there is an urgent need for a temperature field reconstruction scheme that can correlate the cold hydrogen mixing state, the difference in flow rate before the distribution panel, the temperature distribution at the bed inlet, and the temperature measurement data inside the bed. Summary of the Invention

[0005] To overcome the aforementioned deficiencies of the prior art, embodiments of the present invention provide a method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor, thereby addressing the problems mentioned in the background art.

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

[0007] A method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor includes the following steps: Under cold hydrogen injection conditions, obtaining the unit area mass flow rate and cross-sectional temperature of the cross section above the distribution plate and parallel to the distribution plate in the cold hydrogen tank, in the direction of the distribution plate;

[0008] Along the radial direction from the center of the distribution plate to the outer periphery of the distribution plate, the mass flow rate per unit area is organized into a flow distribution of multiple rings, and the ring temperature distribution corresponding to the multiple rings is obtained according to the cross-sectional temperature; the radial gradient opening structure parameters of the installed distribution plate are obtained, including the opening ratio corresponding to the multiple rings.

[0009] The mass distribution ratio after passing through the distribution plate is determined according to the porosity and flow distribution of each annulus, and the inlet temperature distribution of the catalyst bed is generated according to the mass distribution ratio and the temperature distribution of each annulus.

[0010] The temperature readings from the thermocouples in the bed are used to generate a three-dimensional temperature distribution of the catalyst bed, which is then combined with the temperature distribution at the bed inlet.

[0011] In a preferred embodiment, the mass flow rate per unit area is organized into multiple annular flow distributions along the radial direction from the center of the distribution disk to its outer periphery, and the cross-sectional temperature is organized into multiple annular temperature distributions. This includes: dividing a cross-section within the cold hydrogen tank located above and parallel to the distribution disk into multiple concentric annular zones along the radial direction from the center of the distribution disk to its outer periphery; assigning each sampling unit to a corresponding concentric annular zone based on the distance from the center of each sampling unit in the cross-section to the center of the distribution disk; for each sampling unit, reading the velocity component perpendicular to the cross-section and pointing towards the distribution disk; including the mass flow rate of sampling units with a velocity component greater than zero in the mass flow rate of the corresponding concentric annular zone, and excluding the mass flow rate of sampling units with a velocity component less than or equal to zero in the mass flow rate of the corresponding concentric annular zone; dividing the mass flow rate included in each concentric annular zone by the area of ​​the corresponding concentric annular zone to obtain the mass flow rate per unit area of ​​each concentric annular zone; and obtaining the average temperature of the corresponding concentric annular zone based on the temperature of the sampling units with a velocity component greater than zero in each concentric annular zone.

[0012] In a preferred embodiment, obtaining the radial gradient aperture structure parameters of the installed distribution disk includes:

[0013] Read the radial gradient opening structure parameters of the installed distribution plate from the manufacturing records, equipment ledger, maintenance records, or reactor 3D model;

[0014] The radial gradient opening structure parameters include at least the opening ratio of the central region, the opening ratio of the transition region, and the opening ratio of the edge region arranged sequentially along the direction from the center of the distribution disk to the outer periphery of the distribution disk, and may further include the number of through holes in the central region, the number of through holes in the transition region, and the number of through holes in the edge region;

[0015] Among them, the opening ratio of the central region is less than that of the transition region, and the opening ratio of the transition region is less than that of the edge region.

[0016] In a preferred embodiment, the radial gradient aperture structure parameters of the plurality of rings are correlated with those of the installed distribution disc, including:

[0017] Multiple rings are arranged in order from the center of the distribution plate to its outer perimeter;

[0018] Map the first consecutive rings to the central region, the middle consecutive rings to the transition region, and the last consecutive rings to the edge region.

[0019] The aperture ratio of the central region is assigned to the annular zone within the central region, the aperture ratio of the transition region is assigned to the annular zone within the transition region, and the aperture ratio of the edge region is assigned to the annular zone within the edge region.

[0020] In a preferred embodiment, the mass distribution ratio after passing through the distribution plate is determined according to the porosity and flow distribution of each annulus, and the catalyst bed inlet temperature distribution is generated based on the mass distribution ratio and the temperature distribution of each annulus. This includes: summarizing the mass flow rates of each annulus in the central region, transition region, and edge region, and weighting the corresponding annulus temperature according to the mass flow rate of each annulus to obtain the mass flow rate and average temperature of the three regions; under the same installed distribution plate and the same pressure difference condition on both sides, multiplying the mass flow rate of the three regions by the porosity or equivalent porosity of the corresponding region to obtain the relative flow capacity of the three regions; determining the mass distribution ratio of the three regions according to the proportion of the relative flow capacity of the three regions in the sum of the three; mapping the average temperature of the three regions to the central region, transition region, and edge region of the catalyst bed inlet cross section, and generating the catalyst bed inlet temperature distribution based on the mass distribution ratio of the three regions.

[0021] In a preferred embodiment, before obtaining the unit area mass flow rate and cross-sectional temperature of a section above and parallel to the distribution plate within the cold hydrogen tank, facing the distribution plate, under cold hydrogen injection conditions, the method further includes a cold hydrogen injection condition screening step: setting multiple sets of candidate cold hydrogen inlet jet directions and candidate cold hydrogen inlet jet velocities; for each set of candidate cold hydrogen inlet jet directions and candidate cold hydrogen inlet jet velocities, obtaining the unit area mass flow rate of a section above and parallel to the distribution plate within the cold hydrogen tank, facing the distribution plate; and according to the radius direction of the distribution plate, selecting the cross-sections corresponding to each set of candidate cold hydrogen inlet jet directions and candidate cold hydrogen inlet jet velocities. The system is divided into a continuous ring zone near the center of the distribution plate and a continuous ring zone near the outer periphery of the distribution plate. The average mass flow rate per unit area of ​​the continuous ring zone near the center of the distribution plate and the average mass flow rate per unit area of ​​the continuous ring zone near the outer periphery of the distribution plate are calculated respectively. The absolute value of the difference between the average mass flow rate per unit area of ​​the continuous ring zone near the center of the distribution plate and the average mass flow rate per unit area of ​​the continuous ring zone near the outer periphery of the distribution plate is taken as the radial flow rate difference corresponding to the candidate cold hydrogen inlet jet direction and candidate cold hydrogen inlet jet velocity. The candidate cold hydrogen inlet jet direction and candidate cold hydrogen inlet jet velocity with the smallest radial flow rate difference is taken as the cold hydrogen injection condition.

[0022] In a preferred embodiment, after obtaining the catalyst bed inlet temperature distribution, the method further includes an inlet temperature evaluation step: selecting the maximum value from the temperatures at different radial positions in the catalyst bed inlet cross section as the highest inlet temperature, and selecting the minimum value as the lowest inlet temperature;

[0023] The difference between the highest and lowest inlet temperatures is taken as the radial temperature difference at the catalyst bed inlet.

[0024] The temperature difference between different radial positions and the average temperature of the catalyst bed inlet section was calculated to obtain the catalyst bed inlet temperature deviation result.

[0025] In a preferred embodiment, the temperatures at different axial, radial, and circumferential positions in the catalyst bed are generated based on the temperatures at each radial position in the catalyst bed inlet section and the temperatures at the locations of the bed thermocouples. This includes: dividing the catalyst bed into a three-dimensional grid consisting of an axial layer, a radial ring, and a circumferential sector; using the temperatures at each radial position in the catalyst bed inlet section as inlet temperature points and the temperatures at the locations of the bed thermocouples as internal temperature measurement points; for any three-dimensional grid point with a temperature to be determined, selecting multiple known temperature points closest to that three-dimensional grid point, including at least two inlet temperature points and at least one internal temperature measurement point; determining the influence weights based on the spatial distances between the three-dimensional grid point with the temperature to be determined and each known temperature point, and obtaining the temperature of the three-dimensional grid point based on the temperatures of each known temperature point and the corresponding influence weights.

[0026] In a preferred embodiment, after generating the three-dimensional temperature distribution of the catalyst bed, the step further includes an operation information generation step: based on the three-dimensional temperature distribution of the catalyst bed, determining the difference between the highest and lowest temperatures at the same axial position, and selecting the maximum value from the differences corresponding to different axial positions as the maximum radial temperature difference of the bed.

[0027] When the maximum radial temperature difference of the bed layer is not greater than the first temperature difference threshold, output normal operation information;

[0028] When the maximum radial temperature difference of the bed is greater than the first temperature difference threshold but not greater than the second temperature difference threshold, cold hydrogen regulation information is output.

[0029] When the maximum radial temperature difference of the bed exceeds the second temperature difference threshold, an early warning message is output.

[0030] The second temperature difference threshold is greater than the first temperature difference threshold.

[0031] The multi-bed hydrogenation reactor cold hydrogen mixing enhancement and temperature field reconstruction system includes the following modules: a cross-sectional data acquisition module, used to acquire the unit area mass flow rate and cross-sectional temperature of a cross-section above and parallel to the distribution plate in the cold hydrogen tank under cold hydrogen injection conditions, oriented towards the distribution plate; a ring-shaped arrangement module, used to arrange the unit area mass flow rate into multiple ring-shaped flow distributions along the radial direction from the center of the distribution plate to its outer periphery, and to arrange the cross-sectional temperature into multiple ring-shaped temperature distributions; and an orifice structure parameter acquisition module, used to acquire the radial gradient orifice structure parameters of the installed distribution plate, the radial gradient orifice structure parameters including multiple... The module defines the open area ratio corresponding to the rings, with the open area ratio of the central ring being smaller than that of the outer ring; the bed inlet temperature generation module is used to determine the temperature distribution entering the catalyst bed inlet after passing through the installed distribution plate, based on the open area ratio, flow distribution, and temperature distribution of multiple rings; the bed temperature generation module is used to read the bed temperature measurement value from the catalyst bed thermocouple and combine it with the catalyst bed inlet temperature distribution to generate a three-dimensional temperature distribution of the catalyst bed; and the operation information generation module is used to generate normal operation information, cold hydrogen regulation information, or disposal early warning information based on the three-dimensional temperature distribution of the catalyst bed.

[0032] The technical effects and advantages of the present invention regarding the method and system for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor are as follows: The present invention obtains the unit area mass flow rate and cross-sectional temperature of the section above the distribution plate in the cold hydrogen tank, and arranges it radially into multiple annular flow distributions and annular temperature distributions, so that the radial flow rate difference and radial temperature difference of the mixture flow in front of the distribution plate can be quantitatively expressed; by reading the radial gradient opening structure parameters of the installed distribution plate, and using the annular opening ratio, flow distribution, and annular temperature distribution together to generate the catalyst bed inlet temperature distribution, the flow restriction effect on the center side and the compensation effect on the outer periphery side of the distribution plate can be reflected in the bed inlet temperature boundary. Furthermore, this invention combines the bed inlet temperature distribution with the bed thermocouple temperature measurement values ​​to generate a three-dimensional temperature distribution of the catalyst bed. This reduces the limitation of relying on only a small number of thermocouples to judge the bed temperature state, improves the completeness of bed temperature sensing under limited thermocouple placement conditions, and can output early warning information for normal operation, cold hydrogen regulation, or disposal based on the maximum radial temperature difference of the bed. This provides data basis for hot spot risk identification, cold hydrogen regulation, and catalyst operation and maintenance, and reduces the risk of local hot spots and runaway temperatures. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the process for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to the present invention.

[0034] Figure 2 This is a schematic diagram of the cold hydrogen mixing structure of the reactor of the present invention;

[0035] Figure 3 This is a schematic diagram of the opening structure of the distribution disk used in this invention;

[0036] Figure 4 This is a schematic diagram illustrating the generation of the three-dimensional temperature distribution of the bed in this invention;

[0037] Figure 5 This is a comparative schematic diagram of the bed inlet temperature distribution of the present invention;

[0038] Figure 6 This is a schematic diagram of the structure of the multi-bed hydrogenation reactor cold hydrogen mixing enhancement and temperature field reconstruction system of the present invention. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Example

[0041] To enable those skilled in the art to clearly understand the technical solution of the present invention, the embodiments of the present invention will be described below in conjunction with the cold hydrogen injection of the multi-bed hydrogenation reactor, the acquisition of radial gradient opening structure parameters of the installed distribution plate, the generation of bed inlet temperature, and the generation process of three-dimensional temperature distribution of the bed. The specific values ​​in the following embodiments are used to illustrate an implementable operating condition, initial value, or calibration method, and are not intended to limit the scope of protection of the present invention.

[0042] Please see Figure 1 This invention provides a method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor. This method can be applied to fixed-bed hydrogenation reactors, and is particularly suitable for scenarios where a protection reactor, a dechlorination / modification reactor, and a supplementary refining reactor operate in series in a waste lubricating oil hydrorefining unit. Cold hydrogen enters the cold hydrogen tank through the cold hydrogen inlet and mixes with the high-temperature reaction stream flowing out of the previous catalyst bed above the distribution plate before entering the next catalyst bed. In the operating scenario of a waste lubricating oil hydrorefining unit, the reactor is under high pressure, high temperature, and hydrogen-rich conditions. The cold hydrogen temperature can be 50°C to 70°C, and the reaction stream temperature can be 250°C to 385°C. When the radial gradient opening structure parameters of the installed distribution plate are not read in a ring-like manner as described in this embodiment and are not used to generate the bed inlet temperature distribution, the radial temperature difference at the bed inlet can reach 15°C to 20°C. This temperature difference can easily lead to local hot spots and runaway temperatures in the catalyst bed.

[0043] like Figure 1As shown, the method provided in this embodiment of the invention may include the following steps:

[0044] S101, under cold hydrogen injection conditions, obtain the unit area mass flow rate and cross-sectional temperature of the cross-section located above and parallel to the distribution plate in the cold hydrogen tank, facing the distribution plate.

[0045] S102, along the radial direction from the center of the distribution plate to the outer periphery of the distribution plate, the mass flow rate per unit area is organized into a flow distribution of multiple rings, and the cross-sectional temperature is organized into a temperature distribution corresponding to multiple rings;

[0046] S103, obtain the radial gradient opening structure parameters of the installed distribution plate. The radial gradient opening structure parameters include the opening ratio corresponding to multiple rings, and the opening ratio corresponding to the central ring is less than the opening ratio corresponding to the outer ring.

[0047] S104. Based on the porosity, flow rate distribution, and temperature distribution corresponding to multiple annular zones, determine the temperature distribution entering the catalyst bed inlet after passing through the installed distribution plate, and obtain the catalyst bed inlet temperature distribution.

[0048] S105: Read the temperature measurement value of the catalyst bed from the thermocouple and generate a three-dimensional temperature distribution of the catalyst bed by combining the inlet temperature distribution of the catalyst bed.

[0049] Based on the above method, this invention does not simply adjust the cold hydrogen flow rate empirically, but first obtains the radial flow rate and temperature status of the cold hydrogen and reactant streams before they enter the distribution plate, and then obtains the radial gradient opening structure parameters of the installed distribution plate. The radial gradient opening structure parameters of the installed distribution plate are then used to participate in the generation of the bed inlet temperature distribution, and the bed thermocouple temperature measurement values ​​are used to generate the three-dimensional temperature distribution of the bed. Through this process, a continuous data processing link is formed between the cold hydrogen injection status, the radial gradient opening structure parameters of the installed distribution plate, the catalyst bed inlet temperature distribution, and the catalyst bed three-dimensional temperature distribution.

[0050] In S101, the cold hydrogen injection condition refers to the operating status when cold hydrogen enters the cold hydrogen tank, including at least one of the following: cold hydrogen flow rate, cold hydrogen inlet jet direction, cold hydrogen inlet jet velocity, cold hydrogen temperature, reactant stream inlet temperature, system pressure, and hydrogen-to-oil ratio; the cold hydrogen tank is the mixing space located between the cold hydrogen inlet and the distribution plate. The distribution plate is a porous plate-shaped internal component located below the cold hydrogen tank and used to distribute the mixture flow to the catalyst bed inlet.

[0051] The section inside the cold hydrogen tank, located above and parallel to the distribution plate, between the cold hydrogen inlet and the distribution plate, is used to indicate the flow rate and temperature of the cold hydrogen and reactant streams before they enter the distribution plate; for example... Figure 2As shown, the cold hydrogen inlet is located on the side of the reactor shell. After entering the cold hydrogen tank, the cold hydrogen mixes with the high-temperature reaction stream. The sampling section is located inside the cold hydrogen tank and above the distribution plate. Bed thermocouples are arranged at different positions within the catalyst bed to provide internal temperature values. The mass flow rate per unit area refers to the mass of material passing through a unit area of ​​the cross section per unit time, with the flow direction pointing towards the distribution plate. The cross section temperature refers to the temperature of each sampling point within the cross section. If the flow direction at a certain sampling point is away from the distribution plate, the mass flow rate corresponding to that sampling point is not included in the mass flow rate per unit area towards the distribution plate.

[0052] In some embodiments, the data processing device can read the aforementioned cross-sectional data from the three-dimensional flow heat transfer calculation results. It should be noted that obtaining the cross-sectional data in this embodiment does not require directly arranging a flow sensor array covering the entire cross-section within the high-temperature, high-pressure hydrogen reactor. The cross-sectional data can be obtained from the three-dimensional flow heat transfer calculation results, from a condition database verified by cold model experiments or historical operating data, or from calculations by an online soft sensor model based on cold hydrogen flow rate, cold hydrogen temperature, reaction stream temperature, system pressure, hydrogen-to-oil ratio, and bed thermocouple temperature collected by the DCS system. When using an online soft sensor model to obtain the cross-sectional data, the training samples of the online soft sensor model consist of the three-dimensional flow heat transfer calculation results, cold model experiment verification results, and historical stable operating condition data. Each training sample includes cold hydrogen flow rate, cold hydrogen temperature, reactant inlet temperature, system pressure, hydrogen-to-oil ratio, cold hydrogen inlet jet velocity, cold hydrogen inlet jet direction, radial gradient orifice structure parameters of the installed distribution plate, and bed thermocouple temperature readings. The output of each training sample includes the mass flow rate per unit area and cross-sectional temperature of each sampling unit in the cross-section above and parallel to the distribution plate in the cold hydrogen tank, oriented towards the distribution plate.

[0053] When used online, the data processing device reads the DCS operating data within the current sampling period and matches the current operating data with the operating parameters in the training samples. When the current operating data falls within the operating range covered by the training samples, the online soft measurement model outputs the unit area mass flow rate and cross-sectional temperature of the corresponding data sampling section. When the current operating data exceeds the operating range covered by the training samples, the data processing device outputs a cross-sectional data verification flag or calls the three-dimensional flow heat transfer calculation results to update the operating sample library.

[0054] To verify the output results of the online soft measurement model, the data processing equipment compares the bed inlet temperature distribution output by the soft measurement model with the temperature change trend corresponding to the bed thermocouple temperature measurement value. When the temperature deviation between the two exceeds the preset model verification threshold, the cross-sectional data of that sampling period is marked as data to be verified and is not used to update the three-dimensional temperature distribution of the bed.

[0055] For example, the initial value of the reactor inner diameter can be 1920 mm, the initial value of the working pressure can be 15.7 MPa to 17.1 MPa, the initial value of the design temperature can be 400 °C, the initial value of the cold hydrogen temperature can be 50 °C to 70 °C, and the initial value of the number of bed thermocouples can be 6. The above initial values ​​can be calibrated based on the reactor construction drawings, the basic data of the equipment design, and the historical operating data of the DCS. Among them, the reactor inner diameter and the cold hydrogen inlet pipe diameter are determined by the equipment drawings, the number of bed thermocouples is determined by the number of thermocouple openings, and the cold hydrogen temperature and the reaction stream temperature are obtained by statistical analysis of instrument data during normal operation cycles. The DCS is a distributed control system used to collect reactor operating data and output control commands to the cold hydrogen regulating valve.

[0056] For example, when establishing the three-dimensional computational space, the initial mesh size for the cold hydrogen inlet jet region can be 2mm to 5mm, the initial mesh size for the main body of the cold hydrogen tank can be around 8mm, the initial mesh size for the catalyst bed region can be around 10mm, and the initial total number of meshes can be 8 million to 12 million. These initial mesh values ​​can be calibrated through mesh independence verification. During calibration, the mesh is progressively refined, and the changes in the unit area mass flow rate and catalyst bed inlet temperature distribution in the cross-section above and parallel to the distribution disk within the cold hydrogen tank are compared. When the changes in the results after two adjacent mesh refinements are within the engineering allowable range, the current mesh settings are used as the conditions for subsequent calculations.

[0057] In S102, the cross-sectional data is organized into annular flow distribution and annular temperature distribution, including: organizing the mass flow rate per unit area into multiple annular flow distributions along the radial direction from the center of the distribution disk to the outer periphery of the distribution disk, and organizing the cross-sectional temperature into multiple annular temperature distributions; in this embodiment, the radial direction from the center of the distribution disk to the outer periphery of the distribution disk refers to the direction from the center of the distribution disk as the starting point to the outer edge of the distribution disk; dividing multiple annular zones according to this direction means that the sampling point is assigned to the corresponding concentric annular zone according to the distance from the sampling point to the center of the distribution disk; the innermost region can be a circular region, and the remaining regions are concentric annular regions; each sampling point is assigned to the corresponding annular zone according to its distance from the center of the distribution disk.

[0058] In some embodiments, for a cross-section located above and parallel to the distribution disk within the cold hydrogen tank, the data processing device divides the cross-section into multiple concentric rings along the direction from the center of the distribution disk to its outer periphery, with the center of the distribution disk as the center. For each sampling unit in the cross-section, the data processing device assigns each sampling unit to its corresponding concentric ring based on the distance from the center of the sampling unit to the center of the distribution disk. The data processing device reads the velocity component perpendicular to the cross-section and pointing towards the distribution disk in each sampling unit. When the velocity component is greater than zero, the sampling unit is identified as a forward sampling unit, and the mass flow rate of the sampling unit is determined based on its density, velocity component, and sampling unit area. When the velocity component is less than or equal to zero, the sampling unit is identified as a recirculation sampling unit or a non-forward sampling unit, and the mass flow rate of the corresponding sampling unit is not included in the mass flow rate of its corresponding concentric ring.

[0059] The data processing device sums the mass flow rates of the forward sampling units within each concentric ring to obtain the ring mass flow rate of the corresponding concentric ring; and divides the ring mass flow rate by the area of ​​the corresponding concentric ring to obtain the mass flow rate per unit area of ​​each concentric ring. The area of ​​the corresponding concentric ring can be the sum of the areas of all sampling units within that concentric ring, used to characterize the forward flow intensity on the overall cross-section of the concentric ring.

[0060] The data processing equipment obtains the average temperature of the corresponding concentric ring based on the temperature of the forward sampling unit within each concentric ring. Specifically, when the mass flow rate corresponding to the forward sampling unit is not zero, the temperature is weighted and averaged according to the mass flow rate of the forward sampling unit to obtain the average temperature of the corresponding concentric ring; when the difference between the density and velocity components of each forward sampling unit is less than a preset difference threshold, the temperature can be averaged according to the area of ​​the forward sampling unit; when the areas of each forward sampling unit are the same, the arithmetic mean of the temperatures of the forward sampling units can be calculated. Sampling units with velocity components less than or equal to zero are used to identify local backflow conditions and do not participate in the calculation of the ring mass flow rate and average temperature of the corresponding concentric ring.

[0061] If there is no forward sampling unit within a certain concentric ring, the data processing device determines the ring mass flow rate and unit area mass flow rate of that concentric ring as zero, and marks that concentric ring as a reflux ring; the temperature of the reflux ring is only used as a reflux status display value and is not included in the mass flow rate weighted calculation of the catalyst bed inlet temperature distribution.

[0062] Based on the above processing, the discrete sampling point data in the cross section above and parallel to the distribution plate in the cold hydrogen tank are converted into annular flow distribution and annular temperature distribution arranged along the radial direction. The annular flow distribution is used to correspond with the radial gradient opening structure parameters of the installed distribution plate, and the effective temperature in the annular temperature distribution is used to generate the inlet temperature distribution of the catalyst bed. This ensures that the flow processing and temperature processing use the same radial partitioning basis and avoids inconsistencies between the data objects before and after.

[0063] In some embodiments, multiple rings can be arranged in order from the center of the dispensing disk to the outer periphery of the dispensing disk, and divided into a central region, a transition region, and an edge region; the central region is composed of the rings arranged first and continuously, the transition region is composed of the rings arranged in the middle and continuously, and the edge region is composed of the rings arranged last and continuously.

[0064] For example, the initial value of the central region boundary can be a radius ratio of no more than 0.5, the initial value of the transition region boundary can be a radius ratio of more than 0.5 and no more than 0.8, and the initial value of the edge region boundary can be a radius ratio of more than 0.8. The radius ratio refers to the ratio between the distance from the sampling point to the center of the distribution disk and the radius of the distribution disk. The above-mentioned initial boundary values ​​can be calibrated by the variation curve of the mass flow rate per unit area of ​​each ring along the radial direction. During calibration, the mass flow rate per unit area of ​​each ring is read from the center of the distribution disk outward. When the mass flow rate per unit area of ​​the continuous ring on the central side is higher than that of the transition position, and the mass flow rate per unit area of ​​the continuous ring on the outer periphery side is lower than that of the transition position, the corresponding boundary is adjusted into a continuous circular boundary that is easy to process by the distribution disk.

[0065] In S103, the radial gradient aperture structure parameters of the installed distribution disk are obtained. The installed distribution disk refers to the distribution disk that has been manufactured, selected, or modified and is installed below the cold hydrogen tank; the radial gradient aperture structure parameters include at least the aperture ratio of the central region, the aperture ratio of the transition region, and the aperture ratio of the edge region, and may further include the number of through holes in the central region, the number of through holes in the transition region, and the number of through holes in the edge region.

[0066] It should be noted that the radial gradient opening structure parameters of the distribution disk are fixed structural parameters of the installed distribution disk. In this embodiment, reading or calling these structural parameters during operation does not mean that the through-hole structure of the installed distribution disk is changed in real time during the operation of the hydrogenation reactor. The opening ratio refers to the proportion of the sum of the areas of all through holes in a certain area to the plate area of ​​that area. A through hole is a hole that penetrates the distribution disk and allows the mixture to flow through.

[0067] In some embodiments, the mass flow rate per unit area of ​​the central region, transition region, and edge region is first determined separately; the mass flow rate per unit area of ​​the central region is the sum of the mass flows of all annular zones within the central region divided by the total area of ​​the central region; the transition region and edge region are obtained in the same way; when the mass flow rate per unit area of ​​the central region is greater than that of the transition region, and the mass flow rate per unit area of ​​the transition region is greater than that of the edge region, it indicates that there is a decreasing flow rate difference in the mixed flow before entering the distribution plate from the central side to the outer periphery.

[0068] In one embodiment, the installed distribution plate can employ a radial gradient perforation structure, which can be determined based on cold model experiments and three-dimensional flow heat transfer calculations during the manufacturing, selection, or modification phase of the distribution plate. Specifically, the perforation ratio of the transition region can be used as a benchmark, reducing the perforation ratio of the central region relative to the transition region and increasing the perforation ratio of the edge region relative to the transition region, thereby obtaining radial gradient perforation structure parameters where the perforation ratio of the central region is less than that of the transition region, and the perforation ratio of the transition region is less than that of the edge region.

[0069] In this embodiment, the aforementioned aperture ratio is not re-determined during operation, nor does it imply real-time changes to the through-hole structure of the installed distribution plate during the operation of the hydrogenation reactor; the radial gradient aperture structure parameters are fixed structural parameters determined during the manufacturing, selection, or overhaul / modification phases of the distribution plate. The data processing equipment reads these fixed structural parameters during operation and uses the aperture ratio distribution—smaller at the center and larger at the periphery—as the boundary correction parameter for generating the bed inlet temperature distribution. This restricts the higher flow tendency at the center in front of the distribution plate and compensates for the lower flow tendency at the periphery. Figure 3 As shown, the distribution disk can be divided into a central region, a transition region, and an edge region along the radial direction. The opening ratio of the central region is relatively small, the opening ratio of the transition region is moderate, and the opening ratio of the edge region is relatively large, thus forming an opening structure with central side flow restriction and peripheral side compensation.

[0070] For example, the installed distribution plate can adopt a radial gradient opening structure with a central region opening ratio of 3%, a transition region opening ratio of 5%, and an edge region opening ratio of 7%. This opening structure can be calibrated through cold model experiments and three-dimensional flow heat transfer calculations during the manufacturing or overhaul of the distribution plate. During operation, the data processing equipment reads the above-mentioned radial gradient opening structure parameters and uses them as calculation parameters for generating the inlet temperature distribution of the catalyst bed.

[0071] As a verification example, under the conditions of momentum flux ratio J=12 and cold hydrogen inlet jet direction of 60°, the temperature variation coefficient of the bed inlet section corresponding to the uniformly perforated distribution disk is 0.148. After adopting a radial gradient perforation structure with a central region perforation rate of 3%, a transition region perforation rate of 5%, and an edge region perforation rate of 7%, the temperature variation coefficient of the bed inlet section is reduced to 0.072, and the corresponding radial temperature difference is reduced from about 18℃ to about 8℃.

[0072] In some embodiments, the radial gradient opening structure parameters of the installed distribution disk may further include the number of through holes in each region. The number of through holes in each region can be calculated from the opening ratio of each region during the manufacturing, selection, or overhaul and modification stages of the distribution disk; specifically, the opening area of ​​the central region is obtained by multiplying the plate area of ​​the central region by the opening ratio of the central region; the opening area of ​​the transition region is obtained by multiplying the plate area of ​​the transition region by the opening ratio of the transition region; the opening area of ​​the edge region is obtained by multiplying the plate area of ​​the edge region by the opening ratio of the edge region; then, the opening area of ​​each region is divided by the area of ​​a single through hole to obtain the number of through holes in each region.

[0073] During operation, the data processing equipment reads the number of through holes or the corresponding opening ratio, without changing the number of through holes on the installed distribution plate.

[0074] For example, the initial value of the through-hole diameter can be 8mm to 15mm. This initial value can be jointly calibrated by the existing processing specifications, anti-clogging requirements, and plate strength requirements of the distribution plate. During calibration, a range of hole diameters that are not easily clogged in industrial operation and will not weaken the load-bearing strength of the distribution plate is selected, and it is verified whether the total open area corresponding to the number of through holes in each region meets the bed pressure drop requirements. If there is a deviation between the total open area after rounding up the number of through holes and the target open area, the number of through holes in the transition area can be adjusted first to avoid weakening the effect of limiting the flow in the central area and compensating the flow in the edge area.

[0075] In some embodiments, before executing S101, the cold hydrogen inlet jet direction and cold hydrogen inlet jet velocity can be screened first; the cold hydrogen inlet jet direction is the angle between the centerline of the cold hydrogen inlet and the mainstream direction of the reaction stream, and the cold hydrogen inlet jet velocity is the average velocity of cold hydrogen at the cold hydrogen inlet cross section; the screening of the cold hydrogen inlet jet direction and cold hydrogen inlet jet velocity can be used in the design stage of new reactors, the renovation stage of distribution plates or cold hydrogen inlets, or for cold hydrogen inlets with adjustable injection structures; for reactors already in operation where the cold hydrogen inlet direction is fixed, the data processing equipment reads the actual jet direction of the installed cold hydrogen inlet as the cold hydrogen injection condition parameter, which does not mean that the cold hydrogen inlet pipe direction will necessarily be changed during operation.

[0076] For example, candidate initial values ​​for the cold hydrogen inlet jet direction may include 30°, 45°, 60° and 90°, and candidate initial values ​​for the cold hydrogen inlet jet velocity may include 10 m / s, 20 m / s, 30 m / s, 40 m / s and 50 m / s. The aforementioned candidate initial values ​​can be determined based on the cold hydrogen inlet nozzle arrangement space, the cold hydrogen design flow rate, and the cold model experimental condition matrix. For each set of cold hydrogen inlet jet direction and cold hydrogen inlet jet velocity, the data processing equipment obtains the unit area mass flow rate in the cross section above and parallel to the distribution plate in the cold hydrogen tank, oriented towards the distribution plate. The cross section is then divided into a continuous ring zone near the center of the distribution plate and a continuous ring zone near the outer periphery of the distribution plate according to the radial direction of the distribution plate. The data processing equipment calculates the average unit area mass flow rate of the continuous ring zone near the center of the distribution plate and the average unit area mass flow rate of the continuous ring zone near the outer periphery of the distribution plate. The absolute value of the difference between the two average values ​​is then used as the radial flow rate difference under the corresponding cold hydrogen inlet jet direction and cold hydrogen inlet jet velocity. The set of cold hydrogen inlet jet direction and cold hydrogen inlet jet velocity with the smallest radial flow rate difference is selected as the cold hydrogen injection condition.

[0077] In some embodiments, a cold model experiment can be used to calibrate the initial values ​​of the cold hydrogen inlet jet direction and velocity. The cold model experiment can be based on an industrial R-1101 protected reactor, and a scaled-down model can be established according to geometric similarity. For example, the initial inner diameter of the industrial reactor is 1920 mm, and the initial inner diameter of the cold model is 384 mm. The industrial cold hydrogen inlet pipe diameter can be DN80, where DN represents the nominal diameter and DN80 represents a pipe specification with a nominal diameter of 80 mm. The cold hydrogen inlet pipe diameter of the cold model can be DN16. The initial value of the cold hydrogen tank height can be scaled down from the industrial estimated value of about 400 mm to about 80 mm. In the cold model experiment, compressed air can be used as the main stream, and carbon dioxide gas can be used as the jet to make the density ratio close to the density ratio of industrial high-pressure hydrogen and oil gas.

[0078] For example, in a cold model experiment, when the momentum flux ratio is 12 and the cold hydrogen inlet jet direction is 60°, the mixing completion distance is 5.1d, where d is the cold hydrogen inlet pipe diameter. The mixing completion distance of 5.1d means that the distance from the mixing completion position to the cold hydrogen inlet is 5.1 times the cold hydrogen inlet pipe diameter, the distribution disk cross-section concentration variation coefficient is 0.062, and the dead zone volume fraction is 9.8%. When the cold hydrogen inlet jet direction is 30°, the mixing completion distance is 8.7d, and the distribution disk cross-section concentration variation coefficient is 0.142. When the cold hydrogen inlet jet direction is 90°, the mixing completion distance is 7.8d, and the distribution disk cross-section concentration variation coefficient is 0.115. Thus, 60° can be used as the initial value for the cold hydrogen inlet jet direction in this example. For the momentum flux ratio, 12 to 18 can be used as an initial range that balances mixing effect and hydrogen consumption economy, and 16 can be used as a compromise initial value.

[0079] In S104, the catalyst bed inlet temperature distribution is generated, including: determining the temperature distribution entering the catalyst bed inlet after passing through the installed distribution plate according to the porosity, flow rate distribution and temperature distribution corresponding to multiple annular zones, thus obtaining the catalyst bed inlet temperature distribution; the catalyst bed inlet temperature distribution is the set of temperatures formed at different radial positions of the catalyst bed inlet cross section after the mixture flows through the installed distribution plate.

[0080] In some embodiments, the mass flow rate and average temperature of multiple annular zones are first divided into a central region, a transition region, and an edge region. The mass flow rate of the central region is the sum of the mass flow rates of all annular zones within the central region, and the mass flow rates of the transition region and the edge region are determined in the same way. The average temperature of each region can be averaged based on the average temperature of each annular zone within that region and the corresponding annular zone mass flow rate, so that the annular zone with a larger mass flow rate has a greater influence on the average temperature of the region.

[0081] In this embodiment, the central region, transition region, and edge region are located on the same installed distribution plate. The orifice types of the three regions are identical, and all three regions are under the same pressure difference condition on both sides of the distribution plate. In this embodiment, the product of the mass flow rate of each region and the corresponding orifice ratio is used as the relative flow capacity. When determining the relative flow capacity, the data processing device first determines whether the central region, transition region, and edge region are located on the same installed distribution plate and whether each region is under the same pressure difference condition on both sides of the distribution plate. When the orifice types and orifice diameters of the three regions are identical, the orifice ratio of each region is directly used in the relative flow capacity calculation. When the orifice diameter, orifice type, or bubble cap structure of different regions are different, the orifice structure of the corresponding region is first converted into an equivalent orifice ratio based on the single-hole area, orifice resistance coefficient, or equivalent flow area. Then, the relative flow capacity of the corresponding region is determined by the product of the region's mass flow rate and the equivalent orifice ratio. The relative flow capacity is used to represent the relative mass distribution trend of the mixed flow after passing through the installed distribution plate, and does not mean that the actual flow rate is determined solely by the orifice ratio. Relative flow capacity is used to characterize the relative mass distribution trend of different radial regions after passing through the installed distribution plate, and does not mean that the actual flow rate after passing through the distribution plate is determined solely by the orifice ratio.

[0082] Therefore, the data processing equipment calculates the product of the mass flow rate and the opening ratio of the central region, the transition region, and the edge region, respectively, and uses each product as the relative flow capacity of the corresponding region. The data processing equipment determines the inlet mass distribution ratio of the central region, transition region, and edge region after passing through the installed distribution plate, based on the proportion of the relative flow capacity of the central region, transition region, and edge region to the sum of the three. The average temperature of the central region, transition region, and edge region corresponds to the central region, transition region, and edge region of the catalyst bed inlet cross-section, respectively, and generates the catalyst bed inlet temperature distribution by combining the inlet mass distribution ratio. When generating the catalyst bed inlet temperature distribution, the data processing equipment uses the inlet mass distribution ratio of the central region, transition region, and edge region as the mass distribution correction amount for the inlet temperature boundary of the corresponding region. For any of the central, transition, and edge regions, the data processing device uses the average temperature of that region as the initial value of the inlet temperature for that region, and performs boundary correction on the initial value of the inlet temperature for that region based on the proportion of inlet mass distribution in that region. The higher the proportion of inlet mass distribution, the greater the flow contribution of that region after passing through the installed distribution panel, and the greater the influence of the average temperature of that region on the distribution of bed inlet temperature.

[0083] When it is necessary to refine the regional inlet temperature distribution to the annular inlet temperature distribution, the data processing equipment allocates the regional inlet mass distribution ratio to the corresponding annular zone according to the proportion of the mass flow rate of each annular zone to the mass flow rate of the region, and generates the annular inlet temperature distribution based on the average temperature of the annular zone.

[0084] If different orifice types or diameters are used in different areas, the corresponding orifice type or diameter is first converted into the area of ​​a single through hole, and then the relative flow capacity of the corresponding area is determined based on the area of ​​the opening and the mass flow rate of the area.

[0085] In some embodiments, the radial temperature difference at the catalyst bed inlet and the temperature deviation at the catalyst bed inlet can be calculated based on the catalyst bed inlet temperature distribution; wherein, the radial temperature difference at the catalyst bed inlet is the difference between the maximum and minimum values ​​of the temperature at different radial positions of the catalyst bed inlet cross section; and the temperature deviation at the catalyst bed inlet is the difference between the temperature at different radial positions and the average temperature of the bed inlet cross section.

[0086] For example, the initial threshold for monitoring the radial temperature difference at the inlet can be set to 8°C, and the initial warning threshold can be set to 12°C. These initial values ​​can be calibrated using catalyst lifetime testing data from the microreactor and industrial operation data. During calibration, the relative activity decay of the protective agent under different radial temperature differences is compared, and the temperature range where deactivation acceleration significantly increases is used as the basis for threshold setting. In a microreactor catalyst lifetime test, catalyst deactivation accelerates by approximately 32% when the radial temperature difference is 10°C, by approximately 57% when the radial temperature difference is 15°C, and by approximately 96% when the radial temperature difference is 20°C. Therefore, the initial threshold for monitoring the radial temperature difference at the inlet can be set to 8°C, and the initial warning threshold can be set to 12°C. These initial values ​​are used to distinguish between normal operation, operating states requiring adjustment of the cold hydrogen quantity, and operating states requiring intervention.

[0087] In step S105, generating the three-dimensional temperature distribution of the catalyst bed includes: reading the bed temperature values ​​from the catalyst bed thermocouples and combining them with the catalyst bed inlet temperature distribution to generate the three-dimensional temperature distribution of the catalyst bed. The bed thermocouple temperature is the measured temperature at the spatial location of the thermocouple; the thermocouple location includes axial, radial, and circumferential positions; the three-dimensional temperature distribution of the catalyst bed is the set of temperatures corresponding to different axial, radial, and circumferential positions within the catalyst bed.

[0088] In some embodiments, the data processing device uses the catalyst bed inlet temperature distribution as the temperature at each radial position in the catalyst bed inlet cross section and the bed thermocouple temperature as the temperature at the location of the bed thermocouple; then, the catalyst bed is divided into a three-dimensional grid consisting of an axial layer, a radial ring, and a circumferential sector, and the temperature at each position in the three-dimensional grid is generated based on the temperature at each radial position in the catalyst bed inlet cross section and the temperature at the location of the bed thermocouple.

[0089] In a directly implementable method, the catalyst bed can be divided into a three-dimensional grid consisting of axial layers, radial rings, and circumferential sectors. For example, the initial resolution of the three-dimensional grid can be set to 50 axial layers and 20 radial rings; preferably, it can be set to 100 axial layers and 30 radial rings. This initial value can be calibrated based on the bed height, the number of thermocouples, the calculation response time, and the temperature field display accuracy. During calibration, a lower resolution is first used to generate the three-dimensional temperature distribution, and then the resolution is gradually increased while comparing the maximum radial temperature difference and hot spot position changes. When the changes in the above results are within the engineering allowable range after the resolution is increased, the current resolution is used as the initial value for the embodiment. After the three-dimensional grid is determined, the temperature of each three-dimensional grid point can be determined as follows: When generating the three-dimensional temperature distribution of the catalyst bed using a three-dimensional grid, the data processing device first uses the temperature of each radial position in the catalyst bed inlet section as the inlet temperature point, and the bed thermocouple temperature as the internal temperature measurement point of the bed.

[0090] For any 3D grid point with a temperature to be determined, the data processing device selects multiple known temperature points closest to that grid point. These known temperature points include at least two inlet temperature points and at least one temperature measurement point inside the catalyst bed. The inlet temperature points provide radial temperature constraints at the catalyst bed inlet boundary, while the temperature measurement points inside the bed provide measured temperature constraints within the catalyst bed. The data processing device determines the corresponding influence weights based on the spatial distance between the 3D grid point and each known temperature point, assigning greater influence weights to closer known temperature points and smaller influence weights to farther known temperature points.

[0091] When the number of internal temperature measurement points near a certain 3D grid point is insufficient, the data processing equipment selects all internal temperature measurement points in the bed to participate in the influence weight calculation, while maintaining the inlet temperature point in the calculation. This ensures that the bed inlet temperature distribution always serves as the inlet boundary constraint for 3D temperature reconstruction. Therefore, it avoids relying solely on a single thermocouple temperature measurement value to extrapolate a large area of ​​the bed, improving the stability of the 3D temperature distribution generation results under limited thermocouple placement conditions.

[0092] Specifically, the data processing equipment calculates the spatial distance between each known temperature point and the three-dimensional grid point whose temperature is to be determined. The spatial distance is then added to a preset zero-distance constant, and the reciprocal is taken to obtain the initial weight of the known temperature point. The initial weights of each known temperature point are then normalized to obtain the corresponding influence weights. Subsequently, the temperature of each known temperature point is multiplied by its corresponding influence weight and summed to obtain the temperature of the three-dimensional grid point. The known temperature points include at least the inlet temperature point in the catalyst bed inlet temperature distribution and the internal temperature measurement point where the thermocouple is located. The temperature is calculated point-by-point for each three-dimensional grid point within the catalyst bed in the above manner to obtain the temperature at different axial, radial, and circumferential positions within the catalyst bed, thereby generating the three-dimensional temperature distribution of the catalyst bed; for example... Figure 4 As shown, the inlet temperature distribution of the catalyst bed and the temperature measurement value of the thermocouple in the bed are used as known temperature data input into the temperature point correlation calculation process. The temperature is generated point by point through the spatial correlation between the known temperature points and the grid points to be determined, so as to obtain the three-dimensional temperature distribution of the catalyst bed and further calculate the maximum radial temperature difference of the bed.

[0093] In some embodiments, multiple sets of operating condition samples can be used to establish the bed temperature calculation relationship. When a machine learning surrogate model is used to generate the three-dimensional temperature distribution of the catalyst bed, the training samples are generated by a three-dimensional flow and heat transfer calculation model or an operating condition database verified by cold model experiments. Each set of training samples includes cold hydrogen flow rate, cold hydrogen temperature, reactant inlet temperature, system pressure, hydrogen-to-oil ratio, radial gradient opening structure parameters of the distribution plate, and bed thermocouple position temperature. The output target is the three-dimensional temperature distribution of the catalyst bed under the corresponding operating condition. In online applications, the data processing equipment reads the current operating parameters and bed thermocouple temperature measurements from the DCS system, inputs them into the trained surrogate model, and outputs the current three-dimensional temperature distribution of the catalyst bed. The proxy model implementation is an alternative implementation of the distance weight reconstruction method; wherein, the operating condition samples include inlet temperature, cold hydrogen flow rate, system pressure, hydrogen-to-oil ratio, distribution disk opening structure, bed thermocouple temperature and corresponding bed temperature distribution; the initial value of the number of samples can be set to 500 to 1000 sets, which is obtained by combining the inlet temperature level, cold hydrogen flow rate level, hydrogen-to-oil ratio level, distribution disk opening structure type and catalyst activity state.

[0094] In some optional embodiments, the bed temperature calculation relationship can be used as an auxiliary calculation method for the aforementioned spatial distance weighted reconstruction method. When establishing the bed temperature calculation relationship, the operating condition sample includes the catalyst bed inlet temperature distribution, cold hydrogen flow rate, system pressure, hydrogen-to-oil ratio, radial gradient opening structure parameters of the distribution plate, bed thermocouple temperature, and corresponding bed temperature distribution; wherein, the corresponding bed temperature distribution can be obtained from the three-dimensional flow heat transfer calculation results verified by industrial operating data. After training, the data processing equipment uses operating condition samples that have not participated in the training for verification, and calculates the reconstruction residual of the thermocouple positions in the verification sample; when the verification residual is not greater than the residual allowable threshold, the bed temperature calculation relationship is used for online auxiliary reconstruction; when the verification residual is greater than the residual allowable threshold, the three-dimensional temperature distribution is not output using the bed temperature calculation relationship, and the spatial distance weighted reconstruction method of the inlet temperature point and the temperature measurement point inside the bed is reverted to; in online application, the DCS system reads the bed thermocouple temperature in real time and inputs the trained bed temperature calculation relationship, and outputs the three-dimensional temperature distribution of the catalyst bed.

[0095] For example, the initial value of the online reconstruction response time of the bed temperature field can be set to no more than 30 seconds, preferably no more than 10 seconds, and ideally no more than 5 seconds. This initial value is jointly determined by the DCS sampling cycle, the operator's need to view the bed temperature status, and the performance of the computing equipment. If the DCS system reads the bed thermocouple temperature at a cycle of 1 minute, the temperature field reconstruction response time should be less than this sampling cycle to complete the update of the current three-dimensional temperature distribution of the bed before the next sampling.

[0096] As a complete example of the present invention, a waste lubricating oil hydrogenation protection reactor is used as the object. The reactor has an inner diameter of 1920 mm, a cold hydrogen inlet of DN80, 6 thermocouples in the bed, a cold hydrogen temperature of 50°C to 70°C, and a working pressure of 15.7 MPa to 17.1 MPa. First, a three-dimensional computational space is established for the reactor shell, cold hydrogen inlet, cold hydrogen tank, distribution plate, and catalyst bed. A grid size of 2 mm to 5 mm is used in the cold hydrogen inlet jet zone, a grid size of about 8 mm is used in the main body area of ​​the cold hydrogen tank, and a grid size of about 10 mm is used in the catalyst bed area.

[0097] Among the candidate values ​​of 30°, 45°, 60°, and 90° for the cold hydrogen inlet jet direction, the data processing device calculates the average mass flow rate per unit area for the continuous ring zone near the center of the distribution disk and the average mass flow rate per unit area for the continuous ring zone near the outer periphery of the distribution disk for each candidate jet direction. The absolute value of the difference between the two average values ​​is taken as the radial flow rate difference. The jet direction with the smallest radial flow rate difference is selected. Based on the cold model experimental results, 60° can be used as the initial value for the example, and the momentum flux ratio of 12 to 18 can be used as the initial range. Subsequently, the mass flow rate per unit area and the cross-sectional temperature are read at a section located above and parallel to the distribution disk in the cold hydrogen tank, and the section is divided into multiple ring zones according to the radial direction of the distribution disk.

[0098] Based on the ring zone division, continuous ring zones with a radius ratio not greater than 0.5 are designated as the central region, continuous ring zones with a radius ratio greater than 0.5 but not greater than 0.8 are designated as the transition region, and continuous ring zones with a radius ratio greater than 0.8 are designated as the edge region. The installed distribution plate adopts a radial gradient opening structure with an opening ratio of 3% in the central region, 5% in the transition region, and 7% in the edge region. The data processing equipment reads the above radial gradient opening structure parameters from the equipment ledger, maintenance records, or reactor 3D model, and assigns the opening ratios of the central region, transition region, and edge region to the corresponding ring zones.

[0099] After obtaining the radial gradient opening structure parameters of the installed distribution plate, the mass flow rate after passing through the distribution plate is distributed according to the product of the mass flow rate of each region and the corresponding opening ratio. The average temperature of each region is then mapped to the catalyst bed inlet section to obtain the catalyst bed inlet temperature distribution. Verification shows that this embodiment can reduce the coefficient of variation of the bed inlet temperature from approximately 0.148 to approximately 0.072, and reduce the radial temperature difference from approximately 18℃ to approximately 8℃. Figure 5As shown, compared to the bed inlet temperature distribution corresponding to a uniform perforated structure, the temperature difference between the central side and the outer periphery is reduced in the bed inlet temperature distribution corresponding to the perforated structure in this embodiment. The radial temperature difference at the inlet and the coefficient of temperature variation are both decreased, indicating that the bed inlet temperature distribution tends to be more uniform. Subsequently, the temperatures of six bed thermocouples were read. The bed inlet temperature distribution was used as the inlet cross-sectional temperature, and the bed thermocouple temperatures were used as the internal temperature constraints of the bed to generate a three-dimensional temperature distribution of the catalyst bed.

[0100] In some embodiments, after step S105, the method further includes: generating normal operation information, cold hydrogen regulation information, or disposal warning information based on the three-dimensional temperature distribution of the catalyst bed; the normal operation information is used to indicate that the current temperature distribution of the catalyst bed is within the allowable range; the cold hydrogen regulation information is used to indicate the adjustment direction and adjustment range of the cold hydrogen flow rate; the disposal warning information is used to indicate that there is a hot spot risk, runaway temperature risk, or protective agent tipping risk in the catalyst bed.

[0101] In some embodiments, the data processing device reads temperature values ​​layer by layer according to the axial position in the three-dimensional temperature distribution of the catalyst bed; for the same axial position, the data processing device selects the highest and lowest temperatures from the temperatures at different radial and circumferential positions corresponding to that axial position, and uses the difference between the highest and lowest temperatures as the radial temperature difference at that axial position; the data processing device selects the maximum value from the radial temperature differences corresponding to multiple axial positions as the maximum radial temperature difference of the bed; the maximum radial temperature difference of the bed is used to indicate the degree of non-uniformity of temperature distribution within the catalyst bed.

[0102] For example, the initial value of the first temperature difference threshold can be set to 8°C, and the initial value of the second temperature difference threshold can be set to 12°C. The first temperature difference threshold is used to distinguish between normal operation and operation requiring cold hydrogen regulation, and the second temperature difference threshold is used to distinguish between operation requiring cold hydrogen regulation and operation requiring intervention. The above initial values ​​can be calibrated through catalyst lifetime testing and industrial operation data; during calibration, the relative activity decay rate of the catalyst under different radial temperature difference conditions is compared, and the temperature difference range where the catalyst deactivation rate increases significantly is used as the basis for threshold setting.

[0103] In some embodiments, when the maximum radial temperature difference of the bed is not greater than the first temperature difference threshold, the data processing device outputs normal operation information; the normal operation information is used to indicate that the current cold hydrogen mixing state and the catalyst bed temperature uniformity are within the allowable range, and the cold hydrogen flow rate remains at the current set value.

[0104] When the maximum radial temperature difference of the bed is greater than the first temperature difference threshold and not greater than the second temperature difference threshold, the data processing device outputs cold hydrogen regulation information. The cold hydrogen regulation information includes the cold hydrogen flow rate adjustment direction and the cold hydrogen flow rate adjustment step size. The cold hydrogen flow rate adjustment direction is used to indicate whether to increase the cold hydrogen flow rate, decrease the cold hydrogen flow rate, or maintain the cold hydrogen flow rate. The cold hydrogen flow rate adjustment step size is used to indicate the amount of cold hydrogen flow rate change corresponding to each adjustment.

[0105] For example, the initial value of the cold hydrogen flow rate adjustment step can be determined based on the minimum opening change that the cold hydrogen regulating valve in the DCS control system can stably execute, and obtained based on the cold hydrogen flow rate change corresponding to the minimum opening change; during calibration, the opening change record of the cold hydrogen regulating valve and the cold hydrogen flow rate response record within the stable operating cycle are read, and the flow rate change that will not cause a sudden change in the bed inlet temperature and can be stably executed by the regulating valve is used as the initial value of the cold hydrogen flow rate adjustment step.

[0106] When the maximum radial temperature difference of the catalyst bed exceeds the first temperature difference threshold but does not exceed the second temperature difference threshold, the data processing equipment determines the direction of cold hydrogen flow adjustment based on the hot spot location, the average temperature of the catalyst bed inlet cross-section, and the proportion of the low-temperature region area. The hot spot location is the spatial location with the highest temperature in the three-dimensional temperature distribution of the catalyst bed. The proportion of the low-temperature region area refers to the ratio of the area of ​​the catalyst bed inlet cross-section with a temperature lower than the target inlet temperature to the total area of ​​the catalyst bed inlet cross-section. The target inlet temperature can be determined based on the current reactor bed inlet temperature setpoint.

[0107] When the hot spot is located in the central region of the catalyst bed and the average temperature of the catalyst bed inlet section is not lower than the target inlet temperature, the data processing equipment generates information to increase the cold hydrogen flow rate and sends the hot spot location, the maximum radial temperature difference of the bed, and the cold hydrogen flow rate adjustment step size to the DCS control system. The DCS control system adjusts the opening of the cold hydrogen regulating valve according to the cold hydrogen regulation information, so that the cold hydrogen flow rate increases according to the cold hydrogen flow rate adjustment step size.

[0108] When the average temperature of the catalyst bed inlet cross section is lower than the target inlet temperature, and the area ratio of the low-temperature region is greater than the preset area ratio, the data processing equipment generates information to reduce the cold hydrogen flow rate. The preset area ratio is used to determine whether the cold hydrogen flow rate has caused an excessively low-temperature region to appear at the inlet cross section. Its initial value can be determined based on the statistical value of the area ratio of the low-temperature region at the inlet of the bed during the stable operation cycle.

[0109] When the maximum radial temperature difference of the bed is mainly caused by the high temperature in the edge region, the data processing equipment generates information to check the opening status of the distribution plate edge region or the cold hydrogen inlet jet status; the high temperature in the edge region means that the temperature in the edge region is higher than the average temperature at the same axial position; after completing the cold hydrogen flow adjustment or check prompt output, the data processing equipment rereads the catalyst bed thermocouple temperature in the next sampling cycle and regenerates the three-dimensional temperature distribution of the catalyst bed to determine whether the maximum radial temperature difference of the bed has decreased.

[0110] When the maximum radial temperature difference of the catalyst bed exceeds the second temperature difference threshold, the data processing equipment outputs a warning message. This warning message includes the hotspot location, the maximum radial temperature difference of the bed, the hotspot temperature, and suggested actions. The hotspot location is the spatial location with the highest temperature in the three-dimensional temperature distribution of the catalyst bed, represented by its axial, radial, and circumferential positions. Suggested actions include at least one of the following: increasing the cold hydrogen flow rate, reducing the feed rate, checking the cold hydrogen inlet, and checking the operating status of the distribution plate.

[0111] In some embodiments, the data processing device can also read the bed pressure drop and generate a protective agent tipping warning based on the bed pressure drop and the maximum radial temperature difference of the bed; the bed pressure drop is the pressure difference between the catalyst bed inlet and the catalyst bed outlet. The initial value of the bed pressure drop can be taken as the average value of the bed pressure drop when the unit enters the stable operation stage after startup; the pressure drop increase ratio is the increase ratio of the current bed pressure drop relative to the initial value of the bed pressure drop.

[0112] For example, when the pressure drop increases by more than 40% and the maximum radial temperature difference of the bed reaches more than 10°C, the data processing equipment outputs a protective agent tipping warning message. The protective agent tipping warning message indicates that the catalyst bed may have formed a cycle of deactivation leading to increased pressure drop, increased pressure drop leading to flow deviation, flow deviation leading to hot spots, and hot spots accelerating deactivation, requiring protective agent tipping or maintenance inspection.

[0113] It should be noted that step S106 can be executed after step S105, or it can be executed periodically after each update of the three-dimensional temperature distribution of the catalyst bed; the cold hydrogen regulation information and disposal warning information output by step S106 can be sent to the DCS control system or to the operator's monitoring terminal; as long as the cold hydrogen regulation information or warning information can be output according to the three-dimensional temperature distribution of the catalyst bed, it is an implementation method of this embodiment.

[0114] Please see Figure 6The present invention also provides a cold hydrogen mixing enhancement and temperature field reconstruction system for a multi-bed hydrogenation reactor; the system can be deployed in the control room server, digital twin server or data processing equipment communicating with DCS of the hydrogenation unit; the system includes a cross-sectional data acquisition module, a ring sorting module, an opening structure parameter acquisition module, a bed inlet temperature generation module, a bed temperature generation module and an operation information generation module;

[0115] The cross-sectional data acquisition module is used to obtain the unit area mass flow rate and cross-sectional temperature of the cross-section located above and parallel to the distribution plate in the cold hydrogen tank, facing the distribution plate.

[0116] The ring-belt sorting module is used to form multiple ring-belt flow and temperature distributions according to the radius direction of the distribution plate;

[0117] The aperture structure parameter acquisition module is used to acquire the radial gradient aperture structure parameters of the installed distribution plate. The radial gradient aperture structure parameters include the aperture ratio corresponding to multiple rings, and the aperture ratio corresponding to the central ring is less than the aperture ratio corresponding to the outer ring.

[0118] The bed inlet temperature generation module is used to determine the temperature distribution entering the catalyst bed inlet after passing through the installed distribution plate, based on the porosity, flow rate distribution, and temperature distribution of multiple annular zones, and thus obtain the catalyst bed inlet temperature distribution.

[0119] The bed temperature generation module is used to read the bed temperature measurement value from the catalyst bed thermocouple and generate a three-dimensional temperature distribution of the catalyst bed by combining the inlet temperature distribution of the catalyst bed.

[0120] The operation information generation module is used to determine the maximum radial temperature difference of the catalyst bed based on the three-dimensional temperature distribution of the bed, and to generate normal operation information, cold hydrogen regulation information or disposal warning information based on the comparison results between the maximum radial temperature difference of the bed and the first temperature difference threshold and the second temperature difference threshold.

[0121] In some embodiments, the operation information generation module is also used to read the bed pressure drop and generate a protective agent tipping warning based on the increase ratio of the bed pressure drop relative to the initial value of the bed pressure drop and the maximum radial temperature difference of the bed. The operation information generation module can send the cold hydrogen regulation information to the DCS control system, so that the DCS control system can adjust the opening of the cold hydrogen regulating valve according to the cold hydrogen flow adjustment direction and the cold hydrogen flow adjustment step size.

[0122] In some embodiments, the system further includes a DCS data interface, a model data interface, a structural parameter storage unit, a temperature field calculation unit, and an operation information output interface. The DCS data interface is used to read cold hydrogen flow rate, cold hydrogen temperature, reaction stream temperature, system pressure, bed thermocouple temperature, and cold hydrogen regulating valve opening; the model data interface is used to read three-dimensional flow heat transfer calculation results or data section data from the verified operating condition database; the structural parameter storage unit is used to store the opening ratio of the central region, the opening ratio of the transition region, the opening ratio of the edge region, the number of through holes, the hole diameter, and the hole type information of the installed distribution plate; the temperature field calculation unit is used to perform annular sizing, relative flow capacity calculation, inlet temperature distribution generation, and three-dimensional temperature distribution generation; the operation information output interface is used to send normal operation information, cold hydrogen regulation information, or emergency warning information to the DCS control system or the operator's monitoring terminal.

[0123] Those skilled in the art will understand that the above module division is a logical functional division. In actual implementation, multiple modules can be integrated into the same processing device, or different modules can be deployed in different devices. The above system embodiments and method embodiments belong to the same concept. The specific way in which each module in the system performs operations can be referred to the corresponding process in the aforementioned method embodiments.

[0124] Those skilled in the art will recognize that the modules and algorithm modules of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and inventive conditions of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0125] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0126] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0127] In conclusion, the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor, characterized in that, Includes the following steps: Under cold hydrogen injection conditions, obtain the unit area mass flow rate and cross-sectional temperature of the cross section above the distribution plate and parallel to the distribution plate in the cold hydrogen tank, in the direction of the distribution plate; Along the radial direction from the center of the distribution plate to the outer periphery of the distribution plate, the mass flow rate per unit area is organized into multiple annular flow distributions, and the annular temperature distributions corresponding to the multiple annular zones are obtained based on the cross-sectional temperature. Obtain the radial gradient aperture structure parameters of the installed distribution plate, including the aperture ratio corresponding to multiple rings; The mass distribution ratio after passing through the distribution plate is determined according to the porosity and flow distribution of each annulus, and the inlet temperature distribution of the catalyst bed is generated according to the mass distribution ratio and the temperature distribution of each annulus. The temperature readings from the thermocouples in the bed are used to generate a three-dimensional temperature distribution of the catalyst bed, which is then combined with the temperature distribution at the bed inlet.

2. The method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to claim 1, characterized in that, Along the radial direction from the center of the distribution plate to its outer periphery, the mass flow rate per unit area is organized into multiple annular flow distributions, and the cross-sectional temperature is organized into multiple annular temperature distributions, including: The cross section inside the cold hydrogen tank, located above and parallel to the distribution plate, is divided into multiple concentric rings along the radial direction from the center of the distribution plate to its outer periphery. Based on the distance from the center of each sampling unit in the cross section to the center of the distribution disk, each sampling unit is assigned to the corresponding concentric ring. For each sampling unit, read the velocity component perpendicular to the cross section and pointing towards the distribution disk; The mass flow rate of sampling units with a velocity component greater than zero is included in the mass flow rate of the corresponding concentric ring, while the mass flow rate of sampling units with a velocity component less than or equal to zero is not included in the mass flow rate of the corresponding concentric ring. Divide the mass flow rate counted in each concentric ring by the area of ​​the corresponding concentric ring to obtain the mass flow rate per unit area of ​​each concentric ring. The average temperature of the corresponding concentric ring is obtained based on the temperature of the sampling unit where the velocity component is greater than zero within each concentric ring.

3. The method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to claim 2, characterized in that, Obtain the radial gradient aperture structure parameters of the installed distribution disk, including: Read the radial gradient opening structure parameters of the installed distribution plate from the manufacturing records, equipment ledger, maintenance records, or reactor 3D model; The radial gradient opening structure parameters include at least the opening ratio of the central region, the opening ratio of the transition region, and the opening ratio of the edge region, which are arranged sequentially along the direction from the center of the distribution disk to the outer periphery of the distribution disk, and include the number of through holes in the central region, the number of through holes in the transition region, and the number of through holes in the edge region. Among them, the opening ratio of the central region is less than that of the transition region, and the opening ratio of the transition region is less than that of the edge region.

4. The method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to claim 3, characterized in that, The parameters of the radial gradient opening structure of multiple rings are mapped to those of the installed distribution disc, including: Multiple rings are arranged in order from the center of the distribution plate to its outer perimeter; Map the first consecutive rings to the central region, the middle consecutive rings to the transition region, and the last consecutive rings to the edge region. The aperture ratio of the central region is assigned to the annular zone within the central region, the aperture ratio of the transition region is assigned to the annular zone within the transition region, and the aperture ratio of the edge region is assigned to the annular zone within the edge region.

5. The method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to claim 4, characterized in that, The mass distribution ratio after passing through the distribution plate is determined according to the porosity and flow distribution of each annulus, and the inlet temperature distribution of the catalyst bed is generated according to the mass distribution ratio and the temperature distribution of each annulus. This includes summarizing the mass flow rate of each annulus in the central region, transition region and edge region respectively, and weighting the corresponding annulus temperature according to the mass flow rate of each annulus to obtain the mass flow rate of the three regions and the average temperature of the three regions. Under the same installed distribution panel and the same pressure difference on both sides, the mass flow rate of the three zones is multiplied by the corresponding zone opening ratio or equivalent opening ratio to obtain the relative flow capacity of the three zones. The quality allocation ratio of the three regions is determined according to the proportion of their relative flow capacity in the sum of the three regions. The average temperature of the three regions is mapped to the central region, transition region, and edge region of the catalyst bed inlet section, and the catalyst bed inlet temperature distribution is generated by combining the mass distribution ratio of the three regions.

6. The method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to claim 1, characterized in that, Before obtaining the unit area mass flow rate and cross-sectional temperature of the cross section located above and parallel to the distribution plate in the cold hydrogen tank under cold hydrogen injection conditions, the method further includes a cold hydrogen injection condition screening step: setting multiple sets of candidate cold hydrogen inlet jet directions and candidate cold hydrogen inlet jet velocities respectively. For each group of candidate cold hydrogen inlet jet direction and candidate cold hydrogen inlet jet velocity, obtain the unit area mass flow rate towards the distribution disk in the cross section located above and parallel to the distribution disk in the cold hydrogen tank. According to the radius direction of the distribution disk, the cross section corresponding to the direction of the candidate cold hydrogen inlet jet and the velocity of the candidate cold hydrogen inlet jet is divided into a continuous ring zone near the center of the distribution disk and a continuous ring zone near the outer periphery of the distribution disk. Calculate the average mass flow rate per unit area of ​​the continuous ring zone near the center of the distribution plate, and the average mass flow rate per unit area of ​​the continuous ring zone near the outer perimeter of the distribution plate, respectively. The absolute value of the difference between the average mass flow rate per unit area of ​​the continuous ring zone near the center of the distribution disk and the average mass flow rate per unit area of ​​the continuous ring zone near the outer periphery of the distribution disk is used as the radial flow rate difference corresponding to the jet direction and velocity of each group of candidate cold hydrogen inlet. The candidate cold hydrogen inlet jet direction and candidate cold hydrogen inlet jet velocity with the smallest radial flow difference are taken as the cold hydrogen injection conditions.

7. The method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to claim 6, characterized in that, After obtaining the catalyst bed inlet temperature distribution, the method further includes an inlet temperature evaluation step: selecting the maximum value from the temperatures at different radial positions in the catalyst bed inlet cross section as the highest inlet temperature, and selecting the minimum value as the lowest inlet temperature; The difference between the highest and lowest inlet temperatures is taken as the radial temperature difference at the catalyst bed inlet. The temperature difference between different radial positions and the average temperature of the catalyst bed inlet section was calculated to obtain the catalyst bed inlet temperature deviation result.

8. The method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to claim 7, characterized in that, Based on the temperature at each radial position in the catalyst bed inlet section and the temperature at the location of the bed thermocouple, the temperatures at different axial, radial, and circumferential positions in the catalyst bed are generated, including: The catalyst bed is divided into a three-dimensional grid consisting of axial layers, radial rings, and circumferential sectors; The temperature at each radial position in the inlet section of the catalyst bed is taken as the inlet temperature point, and the temperature at the location of the thermocouple in the bed is taken as the temperature measurement point inside the bed. For any three-dimensional grid point whose temperature is to be determined, select multiple known temperature points that are closest to the three-dimensional grid point. The multiple known temperature points include at least two inlet temperature points and at least one temperature measurement point inside the bed. The influence weights are determined based on the spatial distance between the three-dimensional grid point of the temperature to be determined and each known temperature point, and the temperature of the three-dimensional grid point is obtained based on the temperature of each known temperature point and the corresponding influence weight.

9. The method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor according to claim 8, characterized in that, After generating the three-dimensional temperature distribution of the catalyst bed, the process also includes an operation information generation step: based on the three-dimensional temperature distribution of the catalyst bed, the difference between the highest and lowest temperatures at the same axial position is determined, and the maximum value is selected from the differences corresponding to different axial positions as the maximum radial temperature difference of the bed. When the maximum radial temperature difference of the bed layer is not greater than the first temperature difference threshold, output normal operation information; When the maximum radial temperature difference of the bed is greater than the first temperature difference threshold but not greater than the second temperature difference threshold, cold hydrogen regulation information is output. When the maximum radial temperature difference of the bed exceeds the second temperature difference threshold, an early warning message is output. The second temperature difference threshold is greater than the first temperature difference threshold.

10. A system for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor, used to implement the method for enhancing cold hydrogen mixing and reconstructing the temperature field in a multi-bed hydrogenation reactor as described in any one of claims 1-9, characterized in that, Includes the following modules: a cross-sectional data acquisition module, used to acquire the unit area mass flow rate and cross-sectional temperature of a cross section located above and parallel to the distribution plate in the cold hydrogen tank under cold hydrogen injection conditions, facing the distribution plate direction; The ring-zone sorting module is used to sort the mass flow rate per unit area into multiple ring-zone flow distributions along the radial direction from the center of the distribution plate to the outer periphery of the distribution plate, and to sort the cross-sectional temperature into multiple ring-zone temperature distributions. The aperture structure parameter acquisition module is used to acquire the radial gradient aperture structure parameters of the installed distribution plate. The radial gradient aperture structure parameters include the aperture ratio corresponding to multiple rings, and the aperture ratio corresponding to the central ring is less than the aperture ratio corresponding to the outer ring. The bed inlet temperature generation module is used to determine the temperature distribution entering the catalyst bed inlet after passing through the installed distribution plate, based on the porosity, flow rate distribution, and temperature distribution of multiple annular zones, and thus obtain the catalyst bed inlet temperature distribution. The bed temperature generation module is used to read the bed temperature measurement value from the catalyst bed thermocouple and generate a three-dimensional temperature distribution of the catalyst bed by combining the inlet temperature distribution of the catalyst bed. The operation information generation module is used to generate normal operation information, cold hydrogen regulation information, or disposal early warning information based on the three-dimensional temperature distribution of the catalyst bed.

Images