Pressure equalization and back flushing co-time sequence control method of pressure swing adsorption oxygen production equipment

Abstract

The application discloses a pressure equalization and back blowing coordination timing control method of a pressure swing adsorption oxygen production equipment and belongs to the technical field of pressure swing adsorption oxygen production control. The application extracts a real-time characteristic parameter set of a desorption process in an extraction tower, matches and solves an optimal gas flow matching coefficient and a regeneration completion verification threshold value suitable for a real-time working condition in combination with desorption kinetics, then dynamically adjusts flow passage cross-sectional areas of a pressure equalization gas path and a back blowing gas path under a pressure equalization gas path conduction state, makes pressure equalization oxygen-enriched gas flow and finished product oxygen back blowing gas flow cooperatively enter a desorption tower to construct a blowing gas flow field matching a desorption process, and completes regeneration completion degree verification in combination with the real-time characteristic parameter set. The application can realize accurate matching of a desorption blowing process and a bed layer kinetic state, improve molecular sieve regeneration uniformity and pressure equalization oxygen-enriched recovery efficiency, simultaneously guarantee working condition stability and control precision of long-period continuous operation of the equipment, and effectively optimize overall operation energy efficiency of the pressure swing adsorption oxygen production system.

Description

Technical Field

[0001] This invention relates to the field of pressure swing adsorption (PSA) oxygen generation control technology, and in particular to a method for coordinated timing control of pressure equalization and backflushing in a PSA oxygen generation device. Background Technology

[0002] In existing pressure swing adsorption (PSA) dual-tower oxygen production processes, the regeneration stage generally employs a mechanism where pressure equalization and depressurization, along with backflushing of finished oxygen, are executed independently in separate steps. This separates the energy recovery process of pressure equalization within the tower from the nitrogen desorption and regeneration process of the molecular sieve bed. Under industrial continuous oxygen production conditions, the nitrogen desorption mass transfer, bed heat transfer evolution, and pipeline gas kinetic energy decay of the molecular sieve bed are all coupled and interconnected physical processes. Different stages of the desorption process naturally adapt to differentiated gas flow coupling and purging states, creating a continuously available range of synergistic operating conditions. The existing traditional step-by-step operation mode completely isolates the flow field coupling between the pressure equalization gas flow and the backflushing gas flow, failing to utilize the dynamic matching relationship of desorption kinetics to achieve synchronous and coordinated operation of the two processes.

[0003] The inherent process mechanism of this sequential division means that the low-energy oxygen-enriched flow at the end of the pressure equalization stage cannot participate in the bed purging operation, and can only simply complete the pressure balance. The finished oxygen backflushing flow also lacks external airflow assistance to construct a uniform purging flow field, resulting in severe differences in the distribution of axial mass transfer driving force in the bed. The nitrogen desorption rate in the upper part of the bed and the local microporous region is lagging behind. Within a single regeneration cycle, there is always an inherent process contradiction of insufficient molecular sieve regeneration uniformity and low effective utilization rate of oxygen enrichment. It is impossible to simultaneously achieve deep regeneration of molecular sieve and efficient recovery of pressure equalization oxygen enrichment. Under long-term operation, there is a significant bottleneck in the overall oxygen production efficiency and operating condition adaptability of the equipment. Summary of the Invention

[0004] This invention provides a method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption (PSA) oxygen generator to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides a method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption (PSA) oxygen generator, comprising:

[0006] Pressure parameters, tail gas concentration parameters, and inlet flow rate parameters of the dual towers of the pressure swing adsorption oxygen generator are collected. Process features are extracted from the collected multi-source parameters to obtain a real-time feature parameter set of the desorption process in the tower.

[0007] The desorption dynamics matching calculation is performed on the real-time feature parameter set to obtain the optimal airflow ratio coefficient and the regeneration completion verification threshold under the current working condition;

[0008] With the equalizing gas path open, the flow cross-sectional area of ​​the equalizing gas path and the backflush gas path are adjusted according to the optimal airflow ratio coefficient, so that the equalizing oxygen-enriched flow and the finished oxygen backflush flow are introduced into the desorption tower in proportion, forming a coordinated purging airflow field that matches the desorption process.

[0009] The real-time feature parameter set is compared with the regeneration completion verification threshold to verify the regeneration completion degree and generate a verification result signal. When the verification result meets the regeneration completion condition, the pressure equalization gas path and the backflush gas path are simultaneously cut off to obtain the dual-tower state of completing pressure equalization recovery and molecular sieve regeneration.

[0010] Preferably, the step of extracting process features from the collected multi-source parameters to obtain a real-time feature parameter set of the desorption process within the tower includes:

[0011] Dynamic component decoupling decomposition of the exhaust gas concentration parameters yields a first dynamic component characterizing the desorption rate of residual nitrogen in the molecular sieve bed, and a second dynamic component characterizing the dilution effect of the pressure equalization gas flow.

[0012] The feature ratio between the first dynamic component and the second dynamic component is used as the feature dimension and included in the real-time feature parameter set.

[0013] Preferably, the step of extracting process features from the collected multi-source parameters to obtain a real-time feature parameter set of the desorption process within the tower further includes:

[0014] Irreversible thermodynamic analysis was performed on the real-time fluctuation characteristics of the first dynamic component to obtain the instantaneous entropy generation rate of the nitrogen desorption process.

[0015] The instantaneous entropy generation rate is used as a characteristic parameter to characterize the irreversibility of the molecular sieve desorption process and is included in the real-time characteristic parameter set.

[0016] Preferably, the step of performing desorption dynamic matching calculation on the real-time feature parameter set to obtain the optimal airflow ratio coefficient under the current operating condition includes:

[0017] An evaluation index for the marginal desorption efficiency of backflushing oxygen is constructed based on the first dynamic component. The evaluation index is the ratio of the instantaneous change rate of nitrogen discharge to the backflushing oxygen flow rate.

[0018] With the evaluation index reaching its extreme value as the optimization objective, and combined with the real-time feature parameter set, the optimal airflow ratio coefficient under the current working condition is obtained through optimization.

[0019] Preferably, the step of using the extreme value state of the evaluation index as the optimization objective, and combining real-time feature parameter sets to perform optimization and solve for the optimal airflow ratio coefficient under the current operating conditions includes:

[0020] The optimization objective is to achieve the extreme value of the evaluation index, and a dual-objective collaborative solution domain is constructed by combining the constraint of equal pressure oxygen enrichment recovery efficiency.

[0021] The optimal airflow ratio coefficient, which balances backflushing desorption efficiency and pressure equalization recovery rate, is obtained by optimization and screening within the dual-objective collaborative solution domain.

[0022] Preferably, the step of generating the regeneration completion verification threshold includes:

[0023] Temperature parameters and corresponding tail gas concentration parameters at different axial positions of the molecular sieve bed in the low-pressure desorption tower were collected, and bed temperature change rate sequence and concentration change rate sequence were generated respectively.

[0024] Phase matching analysis was performed on the temperature change rate sequence and the concentration change rate sequence to obtain the phase difference parameter between them;

[0025] When the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold, the regeneration completion verification threshold is generated.

[0026] Preferably, the step of generating a regeneration completion verification threshold when the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold includes:

[0027] When the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold, a joint verification is performed by combining the convergence state of the instantaneous entropy generation rate.

[0028] When the instantaneous entropy generation rate synchronously falls back to the irreversible desorption baseline range, a regeneration completion verification threshold is generated.

[0029] Preferably, the step of introducing the pressure-equalizing oxygen-enriched flow and the finished oxygen backflushing flow into the desorption tower in a specific ratio to form a coordinated purging flow field that matches the desorption process includes:

[0030] The finished oxygen backflush gas is accelerated through a converging channel and then injected into the confluence area between the equalizing gas path and the desorption tower to form a high-speed jet flow field.

[0031] By utilizing the local negative pressure formed in the confluence region by the high-speed jet flow field, the low kinetic energy equalizing airflow at the end of the equalizing gas path is drawn in, and the low kinetic energy equalizing airflow enters the desorption tower together with the backflush airflow, forming a coordinated purging airflow field that matches the desorption process.

[0032] Preferably, after obtaining the dual-tower state where pressure equalization recovery and molecular sieve regeneration are completed, the process further includes:

[0033] Extract the remaining parameters of the dual-tower state at the time of termination of the current collaborative process, and use them as the actual regeneration completion status feedback quantity;

[0034] The actual regeneration completion status feedback quantity is compared with the ideal completion status benchmark calibrated by the process to obtain the working condition correction quantity;

[0035] The optimal airflow ratio coefficient and regeneration completion verification threshold for the next cycle are adaptively corrected using the operating condition correction.

[0036] Preferably, the adaptive correction of the optimal airflow ratio coefficient and regeneration completion verification threshold for the next cycle using the operating condition correction amount further includes:

[0037] By fitting the evolution trend of the actual regeneration completion status feedback quantity over multiple historical cycles, the degradation trend parameter of molecular sieve adsorption performance is obtained.

[0038] Based on the attenuation trend parameter, the regeneration completion verification threshold is dynamically compensated by feedforward to obtain an updated verification threshold that adapts to the current performance state of the molecular sieve.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. This invention extracts the desorption process characteristics and performs kinetic matching calculations on the operating parameters of multiple oxygen sources, and outputs the gas flow ratio relationship adapted to the instantaneous desorption state in real time. Relying on the operation mode of coordinated purging of uniform pressure gas flow and backflush gas flow, it can dynamically match the real-time desorption and mass transfer requirements of molecular sieve bed, thereby effectively constructing a uniform and coordinated purging gas flow field adapted to the desorption process, so that uniform pressure enriched oxygen flow fully participates in the bed regeneration purging process, continuously optimizes the mass transfer driving force distribution state in the tower, and stably achieves the simultaneous improvement of molecular sieve regeneration sufficiency and uniform pressure enriched oxygen recovery efficiency.

[0041] 2. This invention combines the phase coupling characteristics of mass and heat transfer with the steady-state characteristics of entropy generation rate to jointly determine the regeneration completion status, and relies on multi-cycle operating condition evolution fitting to achieve feedforward dynamic compensation for molecular sieve performance degradation. This allows the regeneration verification threshold and gas flow ratio control parameters to always adapt to the real-time adsorption performance status of the molecular sieve. Furthermore, the synergistic effect of multi-level adaptive correction and joint verification effectively avoids the process matching deviation caused by single operating condition judgment and fixed control parameters, continuously ensuring the stability and control accuracy of the oxygen production regeneration process under long-cycle continuous operation conditions, and extending the effective service life of the molecular sieve. Attached Figure Description

[0042] Figure 1 This is a schematic flowchart of a pressure swing adsorption oxygen generator's pressure equalization and backflushing coordinated timing control method according to the present invention.

[0043] Figure 2 This is a partial flowchart of the multi-source data acquisition method in this invention;

[0044] Figure 3 This is a flowchart illustrating the method for generating the verification threshold after regeneration in this invention. Detailed Implementation

[0045] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings.

[0046] It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0047] 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0048] Reference Figures 1-3 The diagram shown is a flowchart illustrating a method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption (PSA) oxygen generator according to an embodiment of the present invention. In this embodiment, the method for coordinated timing control of pressure equalization and backflushing in a PSA oxygen generator includes:

[0049] S100. Collect pressure parameters, tail gas concentration parameters, and inlet flow parameters of the dual towers of the pressure swing adsorption oxygen generator. Extract process features from the collected multi-source parameters to obtain a real-time feature parameter set of the desorption process in the tower.

[0050] Among them, process feature extraction is performed on the collected multi-source parameters to obtain a real-time feature parameter set of the desorption process in the tower, including:

[0051] Dynamic component decoupling decomposition of the exhaust gas concentration parameters yields a first dynamic component characterizing the desorption rate of residual nitrogen in the molecular sieve bed, and a second dynamic component characterizing the dilution effect of the pressure equalization gas flow.

[0052] The feature ratio between the first dynamic component and the second dynamic component is used as the feature dimension and included in the real-time feature parameter set.

[0053] This includes extracting process features from the collected multi-source parameters to obtain a real-time feature parameter set of the desorption process within the tower, and also includes:

[0054] S101. Irreversible thermodynamic analysis is performed on the real-time fluctuation characteristics of the first dynamic component to obtain the instantaneous entropy generation rate of the nitrogen desorption process;

[0055] S102. The instantaneous entropy generation rate is used as a characteristic parameter to characterize the irreversibility of the molecular sieve desorption process and is included in the real-time characteristic parameter set.

[0056] In this embodiment, multi-source parameter acquisition is performed first. Specifically, at the moment the single pressure equalization backflushing process of the pressure swing adsorption dual-tower oxygen generator is started, the pressure parameters inside the desorption tower and adsorption tower, the nitrogen concentration parameters of the tail gas at the top of the desorption tower, and the total air inlet flow rate of the equipment are collected respectively.

[0057] In this embodiment, the sampling interval is preferably set to 100 milliseconds. This sampling interval can completely cover the molecular sieve desorption mass transfer change cycle without losing instantaneous operating details. Then, steady-state noise removal processing is performed on all collected parameters, and process feature extraction is carried out. Finally, a complete set of real-time feature parameters of the in-tower desorption process is output.

[0058] Then, the dynamic component decoupling and decomposition of the tail gas concentration parameter is performed. The first dynamic component refers to the real-time change in tail gas concentration caused by the nitrogen desorption behavior of the molecular sieve bed itself, which changes only with the change in the nitrogen desorption rate of the bed and is not affected by external air intake. The second dynamic component refers to the concentration change caused by the dilution disturbance of the tail gas in the tower after the equalizing gas flow enters the desorption tower, which changes only with the change in the flow rate of the equalizing gas flow. The two types of changes can be separated independently by time-series separation to achieve dynamic component decoupling and decomposition.

[0059] Then, the real-time numerical ratio of the first dynamic component to the second dynamic component is calculated. This characteristic ratio can quantify the relative relationship between the actual desorption progress and the pressure equalization dilution interference. This characteristic ratio is directly incorporated into the real-time characteristic parameter set to complete the construction of the first type of characteristic dimension.

[0060] Then, irreversible thermodynamic analysis is carried out on the rise, fall, amplitude and frequency of the first dynamic component throughout the entire process. Specifically, the energy loss and the degree of disorder of matter in the nitrogen desorption mass transfer process are continuously counted in each sampling period. If the desorption fluctuation is violent, the degree of disorder of matter increases, and the corresponding entropy value increases. If the desorption tends to be stable, the entropy value continues to fall. The instantaneous entropy generation rate of the nitrogen desorption process can be directly obtained through this real-time statistical method.

[0061] It is important to emphasize that the instantaneous entropy generation rate is used to characterize the irreversibility of the molecular sieve desorption process. The larger the entropy generation rate, the higher the disorder of the current desorption mass transfer process and the less complete the regeneration. When the entropy generation rate tends to stabilize and return to zero, it means that the desorption process is about to be completed. This instantaneous entropy generation rate is used as the second type of core feature parameter and is simultaneously included in the real-time feature parameter set to finally form a complete real-time feature parameter set that can be used for kinetic calculation.

[0062] S200. Perform desorption dynamic matching calculation on the real-time feature parameter set to obtain the optimal airflow ratio coefficient and regeneration completion verification threshold under the current working condition;

[0063] Among them, the desorption dynamics matching solution is performed on the real-time feature parameter set to obtain the optimal airflow ratio coefficient under the current operating conditions, including:

[0064] An evaluation index for the marginal desorption efficiency of backflushing oxygen is constructed based on the first dynamic component. The evaluation index is the ratio of the instantaneous change rate of nitrogen discharge to the backflushing oxygen flow rate.

[0065] With the evaluation index reaching its extreme value as the optimization objective, and combined with the real-time feature parameter set, the optimal airflow ratio coefficient under the current working condition is obtained through optimization.

[0066] Among them, taking the extreme value state of the evaluation index as the optimization objective, and combining the real-time feature parameter set for optimization, the optimal airflow ratio coefficient under the current operating condition is obtained, including:

[0067] The optimization objective is to achieve the extreme value of the evaluation index, and a dual-objective collaborative solution domain is constructed by combining the constraint of equal pressure oxygen enrichment recovery efficiency.

[0068] The optimal airflow ratio coefficient, which balances backflushing desorption efficiency and pressure equalization recovery rate, is obtained by optimization and screening within the dual-objective collaborative solution domain.

[0069] The steps for generating the verification threshold after regeneration include:

[0070] Temperature parameters and corresponding tail gas concentration parameters at different axial positions of the molecular sieve bed in the low-pressure desorption tower were collected, and bed temperature change rate sequence and concentration change rate sequence were generated respectively.

[0071] Phase matching analysis was performed on the temperature change rate sequence and the concentration change rate sequence to obtain the phase difference parameter between them;

[0072] When the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold, the regeneration completion verification threshold is generated.

[0073] Among them, when the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold, a regeneration completion verification threshold is generated, including:

[0074] S301. When the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold, a joint verification is performed by combining the convergence state of the instantaneous entropy generation rate.

[0075] S302. When the instantaneous entropy generation rate synchronously falls back to the irreversible desorption baseline range, a regeneration completion verification threshold is generated.

[0076] In this embodiment, the desorption kinetics matching calculation is first performed on the real-time feature parameter set that includes the feature ratio and the instantaneous entropy generation rate. Specifically, the real-time change trend of each feature parameter in the parameter set is used to match the change law of molecular sieve desorption kinetics. The optimal airflow ratio coefficient and regeneration completion verification threshold corresponding to the current equipment operating conditions are output simultaneously. This calculation method can realize the real-time dynamic matching of operating parameters and control parameters, and eliminate the problems of insufficient regeneration or oxygen waste caused by fixed parameter control.

[0077] Specifically, an evaluation index for the marginal desorption efficiency of backflushing oxygen is constructed based on the first dynamic component obtained in the previous step. The core statistical logic of this index is to take the change in nitrogen content discharged from the desorption tower within one collection cycle as the instantaneous change rate of nitrogen discharge, and to take the oxygen flow volume of the finished oxygen backflushing pipeline within the same collection cycle as the backflushing oxygen flow rate. The comparison result of the two types of values ​​is used as a complete evaluation index for the marginal desorption efficiency of backflushing oxygen. The index value can intuitively reflect the nitrogen desorption and removal capacity corresponding to a single unit of backflushing oxygen.

[0078] Understandably, the core optimization objective is to take the peak value of the evaluation index of the marginal desorption efficiency of backflushing oxygen as the core optimization objective. The entropy generation rate and feature ratio parameters in the real-time feature parameter set are continuously retrieved for comparison and screening of the entire operating condition. The higher the parameter matching degree, the more the screening result fits the real-time desorption operating condition. Finally, the optimal airflow ratio coefficient corresponding to the current steady-state operating condition is obtained.

[0079] As a preferred embodiment of the present invention, the extreme value of the evaluation index is set as the main optimization objective. At the same time, the pressure equalization oxygen enrichment recovery efficiency constraint condition is introduced to help limit the optimization range. The preset minimum standard for pressure equalization oxygen enrichment recovery efficiency is 85%. This preset value is determined through 120 sets of multi-cycle working condition tests. It can maximize the oxygen recovery rate while ensuring the molecular sieve regeneration effect. A fixed dual objective collaborative solution domain is defined based on the main and secondary dual constraint conditions.

[0080] If the operating parameters fall within the dual-objective collaborative solution domain, all suitable airflow ratio parameters within the domain are traversed and screened one by one. The parameter values ​​that simultaneously meet the peak desorption efficiency and the 85% recovery efficiency requirements are selected first. Finally, the optimal airflow ratio coefficient that balances backflushing desorption efficiency and pressure equalization recovery rate is obtained. This coefficient can simultaneously balance the regeneration effect and gas production energy consumption.

[0081] Then, the regeneration completion verification threshold is generated. Specifically, during the continuous stage of the desorption and regeneration process, three axial positions at the top, middle and bottom of the molecular sieve bed in the low-pressure desorption tower are selected as detection points. Real-time temperature parameters and tail gas concentration parameters at each point are collected simultaneously. In this embodiment, the sampling interval is preferably set to 50 milliseconds. High-frequency sampling can accurately capture the details of local mass and heat transfer changes in the bed.

[0082] Then, the temperature and concentration parameters of each collection point were statistically analyzed over time. The temperature fluctuation difference and concentration fluctuation difference within one collection cycle were continuously statistically analyzed and arranged to form a continuous and complete bed temperature change rate sequence and concentration change rate sequence. The two types of sequences can completely restore the dynamic change law of parameters in the entire process of bed regeneration.

[0083] Next, phase matching analysis is performed on the temperature change rate sequence and the concentration change rate sequence. Specifically, the temporal differences of the numerical fluctuation start time, peak time and fall time of the two types of sequences are compared. The quantitative result of the temporal difference is defined as the phase difference parameter. The larger the value of the phase difference parameter, the worse the synchronization between the bed mass transfer process and the heat transfer process, and the worse the regeneration uniformity.

[0084] It should be noted that a fixed judgment standard for the pre-set mass transfer and heat transfer coupling convergence threshold is used. This threshold is obtained by calibrating 200 sets of regeneration experiments under the rated operating conditions of the equipment. Specifically, the phase difference parameter is less than or equal to 0.05 seconds. When the phase difference parameter continues to converge to the range of this mass transfer and heat transfer coupling convergence threshold, it is determined that the bed mass transfer and heat transfer processes are becoming synchronized and the conditions for regeneration to be completed are initially met.

[0085] In practice, after the phase difference parameter converges to the target, the instantaneous entropy generation rate in the real-time feature parameter set is retrieved for dual joint verification, which completely avoids the verification error caused by single parameter judgment and improves the accuracy of regeneration judgment.

[0086] An irreversible desorption baseline range is preset. This range is obtained by calibrating 80 sets of standard desorption conditions under the new state of the molecular sieve. Specifically, it is the range where the instantaneous entropy generation rate falls back to 0 to 0.2 J / (mol・K). This range represents the stability of the disordered changes of substances in the molecular sieve desorption process and the basic termination of the desorption reaction.

[0087] When the instantaneous entropy generation rate synchronously falls back to within the irreversible desorption baseline range, a regeneration completion verification threshold adapted to the current working conditions is finally generated. This threshold is a unique judgment standard for the current cycle, which can accurately match the real-time desorption process and avoid premature termination of the process causing incomplete molecular sieve regeneration or delayed termination of the process causing energy waste.

[0088] S300. With the equalizing gas path open, the flow cross-sectional area of ​​the equalizing gas path and the backflush gas path are adjusted according to the optimal airflow ratio coefficient, so that the equalizing oxygen-enriched flow and the finished oxygen backflush flow are introduced into the desorption tower in proportion, forming a coordinated purging airflow field that matches the desorption process.

[0089] The process involves introducing a pressure-equalizing oxygen-enriched flow and a finished oxygen backflushing flow into the desorption tower in a specific ratio to form a coordinated purge flow field that matches the desorption process. This includes:

[0090] The finished oxygen backflush gas is accelerated through a converging channel and then injected into the confluence area between the equalizing gas path and the desorption tower to form a high-speed jet flow field.

[0091] By utilizing the local negative pressure formed in the confluence region by the high-speed jet flow field, the low kinetic energy equalizing airflow at the end of the equalizing gas path is drawn in, and the low kinetic energy equalizing airflow enters the desorption tower together with the backflush airflow, forming a coordinated purging airflow field that matches the desorption process.

[0092] In this embodiment of the invention, after the pipeline valve of the equalizing gas path is fully opened and maintained in a conductive state, the optimal airflow ratio coefficient calculated in the previous process is retrieved, and the valve core opening and closing amplitude of the equalizing gas path matching regulating valve and the backflush gas path matching regulating valve are adjusted synchronously according to the coefficient, thereby changing the corresponding flow cross-sectional area of ​​the two gas paths.

[0093] For example, when the optimal airflow ratio coefficient is 0.6, the cross-sectional area of ​​the equalizing gas path is locked at 60% of the standard fully open cross-sectional area, and the cross-sectional area of ​​the backflush gas path is locked at 100% of the standard fully open cross-sectional area. The two types of airflow are synchronously sent into the desorption tower according to this fixed flow ratio, and finally a coordinated purging airflow field matching the real-time desorption process is generated. The fixed ratio adjustment method can prevent oxygen loss or incomplete nitrogen desorption caused by excessive single airflow.

[0094] It is understandable that the finished oxygen backflushing gas flow will first be delivered to the gradually narrowing flow channel fixedly installed inside the pipeline. As a preferred embodiment of the present invention, the inlet cross-sectional area of ​​the gradually narrowing flow channel is set to 40 square centimeters and the outlet cross-sectional area is set to 10 square centimeters. These dimensional parameters have been calibrated through 50 sets of airflow tests and can stably increase the airflow velocity. When the airflow passes through the narrow outlet of the gradually narrowing flow channel, the flow velocity continues to increase. The high-speed airflow is directly injected into the confluence area connected to the outlet of the equalizing gas path and the inlet of the desorption tower, continuously generating a stable high-speed jet flow field in the confluence area.

[0095] In practice, the high-speed jet flow field continuously compresses the air inside the confluence area, and the air pressure inside the confluence area continues to decrease, forming a stable local negative pressure. The negative pressure value is stably maintained at -0.02 MPa. This negative pressure value is sufficient to pull the low kinetic energy equalization airflow, whose kinetic energy has greatly decreased at the end of the equalization process, out of the equalization gas pipeline. Under the traction of the negative pressure, the low kinetic energy equalization airflow will be completely transported forward synchronously with the high-speed finished oxygen backflushing airflow. After the two airflows are fully mixed in the confluence area, they flow into the desorption tower as a whole.

[0096] It is important to emphasize that the two mixed airflows will evenly sweep across all axial positions of the molecular sieve bed, simultaneously completing the two processes of pressure equalization oxygen enrichment recovery and molecular sieve desorption purging. Ultimately, a synergistic purging airflow field matching the real-time desorption process is formed. Relying on the negative pressure suction effect, the residual pressure equalization gas at the end of the process can be fully utilized, reducing the gas production loss caused by the direct discharge of oxygen-enriched gas, and simultaneously improving the overall regeneration uniformity of the molecular sieve.

[0097] S400. The real-time feature parameter set and the regeneration completion verification threshold are used to verify the regeneration completion degree and generate a verification result signal. When the verification result meets the regeneration completion condition, the pressure equalization gas path and the backflush gas path are cut off simultaneously to obtain the dual tower state of pressure equalization recovery and molecular sieve regeneration.

[0098] After obtaining the dual-tower state after completing pressure equalization recovery and molecular sieve regeneration, the process also includes:

[0099] Extract the remaining parameters of the dual-tower status at the time of termination of the current collaborative process, and use them as the actual regeneration completion status feedback quantity;

[0100] The actual regeneration completion status feedback quantity is compared with the ideal completion status benchmark calibrated by the process to obtain the working condition correction quantity;

[0101] The optimal airflow ratio coefficient and regeneration completion verification threshold for the next cycle are adaptively corrected using the operating condition correction.

[0102] The adaptive correction of the optimal airflow ratio coefficient and regeneration completion verification threshold for the next cycle using operating condition corrections also includes:

[0103] By fitting the evolution trend of the actual regeneration completion status feedback quantity over multiple historical cycles, the degradation trend parameter of molecular sieve adsorption performance is obtained.

[0104] Based on the attenuation trend parameter, the regeneration completion verification threshold is dynamically compensated by feedforward to obtain an updated verification threshold that adapts to the current performance state of the molecular sieve.

[0105] In this embodiment of the invention, the two core parameters included in the real-time feature parameter set, namely the dynamic component feature ratio and the instantaneous entropy generation rate, are first compared with the regeneration completion verification threshold generated under the current working condition to carry out a full-domain regeneration completion verification operation. The real-time values ​​of each parameter are compared with the threshold standard to determine their compliance status. Based on the compliance status of all parameters, a unified high- or low-level verification result signal is output, which can effectively avoid the misjudgment problem caused by the judgment of a single parameter.

[0106] When all parameter values ​​stably meet the regeneration completion conditions for 10 consecutive acquisition cycles, with the acquisition cycle preset to 50 milliseconds (this duration was determined through 80 sets of calibration experiments and can filter out instantaneous operating condition fluctuations), the pressure equalization gas path control valve and the backflush gas path control valve are simultaneously closed, instantly cutting off the continuous flow of the two gas streams, thus obtaining a dual-tower state that has fully completed pressure equalization recovery and molecular sieve regeneration.

[0107] In practice, after the dual-tower process is completely terminated, the residual values ​​of dual-tower pressure, exhaust gas concentration, and entropy generation rate at the end of the current collaborative process are accurately retained. All steady-state residual parameters are integrated and summarized as the actual regeneration completion status feedback quantity. This type of feedback quantity can truly restore the actual regeneration quality and operating condition deviation of a single process.

[0108] Understandably, the ideal completion state benchmark for process calibration is obtained in advance through the equipment's rated standard operating conditions. This benchmark includes fixed standard residual pressure values, standard exhaust gas concentration values, and standard entropy generation rate values. The actual regeneration completion state feedback values ​​collected in real time are compared with the ideal completion state benchmark item by item, and the deviation between the actual values ​​and the standard values ​​is statistically analyzed item by item. Finally, the corresponding operating condition correction amount is obtained by integrating them.

[0109] In a preferred embodiment of the present invention, the calculated working condition correction amount is stored in the current working condition process ledger. Before the start of the next oxygen production process, the working condition correction amount is used to superimpose and correct the optimal airflow ratio coefficient and regeneration completion verification threshold used in the previous cycle. If the deviation is too large, the correction range is increased; if the deviation is too small, the correction range is finely adjusted to achieve adaptive adaptation of control parameters.

[0110] It should be noted that the actual regeneration completion status feedback of 20 consecutive working cycles is continuously stored. The number of 20 cycles is the optimal calibration value, which can completely cover the change law of the slow decay of molecular sieve. The numerical change trajectory of the multi-cycle feedback is continuously fitted with a trend, and the slow offset direction and offset rate of the parameter are tracked throughout the process, so as to obtain an accurate molecular sieve adsorption performance decay trend parameter.

[0111] Specifically, a feedforward dynamic compensation operation is carried out based on the molecular sieve adsorption performance decay trend parameter. Before the new cycle threshold is generated, the decline in the molecular sieve adsorption and desorption capacity is predicted in advance based on the degree of decay. If the decay trend is greater, the regeneration completion verification standard is appropriately relaxed. If the decay trend is stable, the original verification standard is maintained. Finally, an updated verification threshold that is fully adapted to the current performance state of the molecular sieve is generated.

[0112] In summary, this pre-compensation method can offset the performance degradation error caused by long-term use of molecular sieves in advance, avoid the problem of premature termination of regeneration judgment and decline in oxygen purity of old molecular sieves, and ensure that the oxygen production, regeneration and pressure equalization recovery processes maintain stable operating accuracy throughout the entire cycle.

[0113] In the several embodiments provided by this invention, it should be understood that the disclosed method can be implemented in other ways.

[0114] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0115] The embodiments of this application can acquire and process relevant data based on artificial intelligence technology. Artificial intelligence is the theory, method, and technology that uses digital computers or machines controlled by digital computers to simulate, extend, and expand human intelligence, perceive the environment, acquire knowledge, and use that knowledge to obtain optimal results.

[0116] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption (PSA) oxygen generator, characterized in that, The method includes: Pressure parameters, tail gas concentration parameters, and inlet flow rate parameters of the dual towers of the pressure swing adsorption oxygen generator are collected. Process features are extracted from the collected multi-source parameters to obtain a real-time feature parameter set of the desorption process in the tower. The desorption dynamics matching calculation is performed on the real-time feature parameter set to obtain the optimal airflow ratio coefficient and the regeneration completion verification threshold under the current working condition; With the equalizing gas path open, the flow cross-sectional area of ​​the equalizing gas path and the backflush gas path are adjusted according to the optimal airflow ratio coefficient, so that the equalizing oxygen-enriched flow and the finished oxygen backflush flow are introduced into the desorption tower in proportion, forming a coordinated purging airflow field that matches the desorption process. The real-time feature parameter set is compared with the regeneration completion verification threshold to verify the regeneration completion degree and generate a verification result signal. When the verification result meets the regeneration completion condition, the pressure equalization gas path and the backflush gas path are simultaneously cut off to obtain the dual-tower state of completing pressure equalization recovery and molecular sieve regeneration.

2. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 1, characterized in that, The process feature extraction of the collected multi-source parameters yields a real-time feature parameter set of the desorption process within the tower, including: Dynamic component decoupling decomposition of the exhaust gas concentration parameters yields a first dynamic component characterizing the desorption rate of residual nitrogen in the molecular sieve bed, and a second dynamic component characterizing the dilution effect of the pressure equalization gas flow. The feature ratio between the first dynamic component and the second dynamic component is used as the feature dimension and included in the real-time feature parameter set.

3. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 1, characterized in that, The step of extracting process features from the collected multi-source parameters to obtain a real-time feature parameter set of the desorption process within the tower also includes: Irreversible thermodynamic analysis was performed on the real-time fluctuation characteristics of the first dynamic component to obtain the instantaneous entropy generation rate of the nitrogen desorption process. The instantaneous entropy generation rate is used as a characteristic parameter to characterize the irreversibility of the molecular sieve desorption process and is included in the real-time characteristic parameter set.

4. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 3, characterized in that, The process of performing desorption dynamic matching calculations on the real-time feature parameter set to obtain the optimal airflow ratio coefficient under the current operating conditions includes: An evaluation index for the marginal desorption efficiency of backflushing oxygen is constructed based on the first dynamic component. The evaluation index is the ratio of the instantaneous change rate of nitrogen discharge to the backflushing oxygen flow rate. With the evaluation index reaching its extreme value as the optimization objective, and combined with the real-time feature parameter set, the optimal airflow ratio coefficient under the current working condition is obtained through optimization.

5. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 4, characterized in that, The optimization objective is to achieve the extreme value of the evaluation index. This optimization is achieved by combining real-time feature parameter sets to obtain the optimal airflow ratio coefficient under the current operating conditions. This includes: The optimization objective is to achieve the extreme value of the evaluation index, and a dual-objective collaborative solution domain is constructed by combining the constraint of equal pressure oxygen enrichment recovery efficiency. The optimal airflow ratio coefficient, which balances backflushing desorption efficiency and pressure equalization recovery rate, is obtained by optimization and screening within the dual-objective collaborative solution domain.

6. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 5, characterized in that, The steps for generating the regeneration completion verification threshold include: Temperature parameters and corresponding tail gas concentration parameters at different axial positions of the molecular sieve bed in the low-pressure desorption tower were collected, and bed temperature change rate sequence and concentration change rate sequence were generated respectively. Phase matching analysis was performed on the temperature change rate sequence and the concentration change rate sequence to obtain the phase difference parameter between them; When the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold, the regeneration completion verification threshold is generated.

7. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 6, characterized in that, When the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold, a regeneration completion verification threshold is generated, including: When the phase difference parameter converges to the mass transfer and heat transfer coupling convergence threshold, a joint verification is performed by combining the convergence state of the instantaneous entropy generation rate. When the instantaneous entropy generation rate synchronously falls back to the irreversible desorption baseline range, a regeneration completion verification threshold is generated.

8. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 1, characterized in that, The process of introducing the uniformly pressure-enriched oxygen flow and the finished oxygen backflushing flow into the desorption tower in a specific ratio to form a coordinated purging flow field that matches the desorption process includes: The finished oxygen backflush gas is accelerated through a converging channel and then injected into the confluence area between the equalizing gas path and the desorption tower to form a high-speed jet flow field. By utilizing the local negative pressure formed in the confluence region by the high-speed jet flow field, the low kinetic energy equalizing airflow at the end of the equalizing gas path is drawn in, and the low kinetic energy equalizing airflow enters the desorption tower together with the backflush airflow, forming a coordinated purging airflow field that matches the desorption process.

9. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 1, characterized in that, After obtaining the dual-tower state where pressure equalization recovery and molecular sieve regeneration are completed, the process further includes: Extract the remaining parameters of the dual-tower state at the time of termination of the current collaborative process, and use them as the actual regeneration completion status feedback quantity; The actual regeneration completion status feedback quantity is compared with the ideal completion status benchmark calibrated by the process to obtain the working condition correction quantity; The optimal airflow ratio coefficient and regeneration completion verification threshold for the next cycle are adaptively corrected using the operating condition correction.

10. The method for coordinated timing control of pressure equalization and backflushing in a pressure swing adsorption oxygen generator according to claim 9, characterized in that, The adaptive correction of the optimal airflow ratio coefficient and regeneration completion verification threshold for the next cycle using the operating condition correction amount also includes: By fitting the evolution trend of the actual regeneration completion status feedback quantity over multiple historical cycles, the degradation trend parameter of molecular sieve adsorption performance is obtained. Based on the attenuation trend parameter, the regeneration completion verification threshold is dynamically compensated by feedforward to obtain an updated verification threshold that adapts to the current performance state of the molecular sieve.

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