An oxygen production working condition identification method and system for low consumption operation

Abstract

The application discloses an oxygen production working condition recognition method and system for low-consumption operation, and particularly relates to the technical field of oxygen production equipment operation working condition recognition. In the switching period of the oxygen production equipment, double-tower pressure, valve state, oxygen purity, oxygen production flow and compressor current are collected, the double-tower pressure difference is calculated, the pressure equalization time window and the residual pressure difference are determined, the effective oxygen production points are screened, and the corresponding consumption flow accumulation values are accumulated, and then the low-consumption working condition is output in combination with the state of the initial stage of the next switching period. The oxygen production working condition recognition method and system for low-consumption operation take the residual pressure difference convergence, the effective oxygen production flow accumulation and the compressor current accumulation as the low-consumption judgment basis, and confirm through the purity, flow and current constraints of the initial stage of the next period, so that the low-consumption operation can be avoided to be misjudged only according to the flow and current of the current period, the pseudo low-consumption period can be recognized, and the accuracy, stability and traceability of the low-consumption working condition recognition of the oxygen production equipment are improved.

Description

Technical Field

[0001] This invention relates to the field of oxygen production equipment operating condition identification technology, and in particular to an oxygen production operating condition identification method and system for low-consumption operation. Background Technology

[0002] Oxygen generator operating condition identification technology involves monitoring and determining the operating status of industrial oxygen generators during continuous operation. During operation, these devices typically undergo cyclical processes such as adsorption, desorption, pressure equalization, purging, oxygen production, exhaust, and tower switching, generating operating data including oxygen purity, oxygen flow rate, adsorption pressure, desorption pressure, inlet pressure, exhaust temperature, valve opening / closing status, compressor operating current, and molecular sieve tower switching cycle. By collecting, processing, and analyzing this operating data, the parameter ranges, trends, and temporal relationships corresponding to different operating conditions can be established, thus providing a data foundation for identifying the operating status of oxygen generators.

[0003] In existing technologies, the identification of the operating conditions of oxygen generating equipment is usually based on key parameters during equipment operation. Common methods include setting operating condition judgment conditions based on parameters such as oxygen purity, oxygen production flow rate, adsorption pressure, desorption pressure, and compressor operating current, and combining operating characteristics such as valve action sequence, molecular sieve tower switching cycle, pressure change slope, and flow change amplitude. The real-time collected operating data is compared with preset operating condition parameter ranges or operating condition sample categories to determine the current operating condition category of the oxygen generating equipment.

[0004] Current oxygen generator operating condition identification typically relies on a single or limited set of parameters, such as oxygen purity, oxygen production flow rate, adsorption pressure, desorption pressure, or compressor operating current. While these parameters reflect certain aspects of the equipment's operation, they fail to accurately represent the adequacy of pressure equalization during the dual-tower switching process and the true energy consumption relationship during the qualified oxygen production stage. Particularly in actual operation, situations may arise where the current cycle's oxygen production flow rate meets requirements and the compressor operating current is low, but a significant residual pressure difference remains at the end of the dual-tower pressure equalization phase. Directly classifying this as a low-energy-consumption operating condition can easily lead to misjudgment and may result in delayed oxygen purity recovery, insufficient oxygen production flow rate, or increased compressor load in the next switching cycle. Therefore, existing technologies lack a comprehensive low-energy-consumption operating condition identification scheme that integrates the dual-tower pressure difference convergence state, the corresponding relationship between effective oxygen production flow rate and energy consumption, and the oxygen production recovery state in the next switching cycle. Consequently, the accuracy and reliability of low-energy-consumption condition identification still need improvement. Summary of the Invention

[0005] The main objective of this invention is to provide a method and system for identifying oxygen production conditions for low-consumption operation. By collecting data on dual-tower pressure, valve status, oxygen purity, oxygen production flow rate, and compressor operating current, and combining this with pressure equalization time window identification, residual pressure difference constraint, effective oxygen production flow accumulation, and confirmation of the initial stage of the next switching cycle, this invention solves the problems in existing technologies that rely solely on a single operating parameter to determine low-consumption conditions, which can easily lead to misjudgments, inability to identify false low-consumption cycles, and insufficient accuracy and reliability in identifying low-consumption operation conditions.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A method for identifying oxygen production conditions for low-consumption operation includes:

[0008] During the oxygen production equipment switching cycle, the pressure values ​​of the first and second molecular sieve towers, the status of the equalizing valve, oxygen production valve, and exhaust valve, the oxygen purity, the oxygen production flow rate, and the compressor operating current are sampled and obtained.

[0009] The pressure difference between the first and second molecular sieve towers is obtained by taking the difference between their pressure values.

[0010] When the equalizing valve is opened and the pressure difference between the two towers continuously converges to zero, the starting point of the equalizing time window is determined. When the pressure difference between the two towers enters the preset convergence allowable range and its change is within the preset sampling error allowable range, the ending point of the equalizing time window is determined. The pressure difference between the two towers at the end of the equalizing time window is determined as the residual pressure difference.

[0011] The sampling points where the oxygen generation valve is open, the exhaust valve is closed, and the oxygen purity reaches the preset qualified lower limit are determined as effective oxygen generation points, and their oxygen generation flow rate and compressor operating current are accumulated respectively to determine the corresponding current consumption value.

[0012] When the cumulative flow rate reaches the preset cumulative oxygen supply threshold, the cumulative current does not exceed the preset cumulative current threshold, and the residual pressure difference enters the preset convergence allowable range, a low-consumption candidate period is determined. When the oxygen purity, oxygen production flow rate, and compressor operating current meet the constraints at the beginning of the next switching period, a low-consumption oxygen production condition is output.

[0013] Preferably, the switching cycle is defined by two adjacent cycle boundaries, and each cycle boundary is the sampling moment when the pressure equalization valve switches from the closed state to the open state and the pressure difference between the two towers begins to converge to zero.

[0014] Preferably, the continuous convergence of the pressure difference between the two towers to zero includes: after the equalization valve switches from the closed state to the open state, the absolute value of the pressure difference between the two towers decreases sequentially in three consecutive sampling points, and the first sampling time in the three consecutive sampling points is determined as the starting point of the equalization time window.

[0015] Preferably, the endpoint of the equalization time window is determined in the following manner:

[0016] After the start of the equalization time window, when the absolute value of the pressure difference between the two towers at three consecutive sampling points all enters the preset convergence allowable range, and the absolute value of the change in pressure difference between adjacent towers at the three consecutive sampling points is within the preset sampling error allowable range, the first sampling time among the three consecutive sampling points is determined as the end of the equalization time window.

[0017] Preferably, if the determination condition for the end of the equalization time window has not been met when the equalization valve is closed, sampling continues until the determination condition is met;

[0018] If the equalization valve remains open when the determined conditions are met, the sampling time at which the determined conditions are first met is taken as the end point of the equalization time window.

[0019] Preferably, the residual pressure difference entering the preset convergence allowable range means that the absolute value of the residual pressure difference enters the preset convergence allowable range;

[0020] Based on whether the absolute value of the residual pressure difference falls within the preset convergence allowable range, the corresponding switching cycle is marked as a residual pressure difference convergence cycle or a residual pressure difference non-convergence cycle.

[0021] Preferably, the corresponding value of the current consumption includes the cumulative effective oxygen production flow rate and the cumulative effective oxygen production current.

[0022] The cumulative effective oxygen production flow rate is obtained by accumulating the oxygen production flow rate of the effective oxygen production points according to the sampling order. The cumulative effective oxygen production current is obtained by accumulating the compressor operating current of the effective oxygen production points according to the sampling order. Sampling points where the oxygen production valve is not open, the exhaust valve is open, or the oxygen purity does not reach the preset qualified lower limit are not included in the accumulation.

[0023] Preferably, when the cumulative flow represented by the corresponding value of the current consumption reaches the preset cumulative oxygen supply threshold, the cumulative current does not exceed the preset cumulative current threshold, but the absolute value of the residual pressure difference does not enter the preset convergence allowable range, the corresponding switching cycle is marked as a pseudo low-consumption cycle, and the pseudo low-consumption cycle is not output as a low-consumption oxygen generator.

[0024] Preferably, the initial phase of the next switching cycle begins at the first sampling point after the end of the equalization time window of the next switching cycle, when the oxygen production valve is opened and the exhaust valve is closed, and ends at the third sampling point when the oxygen purity reaches the preset lower limit for the first time in three consecutive sampling points.

[0025] The constraints include oxygen purity reaching a preset lower limit of acceptable quality, oxygen production flow meeting a preset oxygen production flow constraint, and compressor operating current not exceeding a preset current operating constraint.

[0026] An oxygen production condition identification system for low-consumption operation includes:

[0027] The operation data sampling module is used to sample and acquire the pressure values, valve status, oxygen production parameters, and compressor operating current of the first and second molecular sieve towers during the switching cycle of the oxygen generator.

[0028] The pressure equalization time window determination module is used to determine the pressure difference between the two towers based on the pressure values ​​of the first and second molecular sieve towers, and to determine the pressure equalization time window based on the status of the pressure equalization valve and the convergence status of the pressure difference between the two towers.

[0029] The residual pressure difference constraint module is used to determine the residual pressure difference based on the pressure difference between the two towers at the end of the equalization time window, and to determine its convergence state.

[0030] The current consumption corresponding value determination module is used to determine the current consumption corresponding value based on the cumulative oxygen production flow rate at the effective oxygen production point and the compressor operating current.

[0031] The low-consumption operating condition output module is used to output the low-consumption oxygen production condition based on the corresponding flow consumption value, the residual pressure difference convergence state, and the oxygen production state at the beginning of the next switching cycle.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. This invention synchronously collects data on dual-tower pressure, valve status, oxygen purity, oxygen production flow rate, and compressor operating current during the oxygen generator switching cycle. It also determines the pressure equalization time window by combining the pressure equalization valve operation with the convergence trend of the dual-tower pressure difference, enabling more accurate identification of the true pressure equalization state during tower switching. By using the residual pressure difference at the pressure equalization endpoint as a constraint for low-consumption judgment, it avoids making one-sided judgments based solely on oxygen production flow rate and compressor current, thus improving the accuracy and reliability of low-consumption operation condition identification.

[0034] 2. This invention, through effective oxygen production point screening, incorporates sampling points where the oxygen production valve is open, the exhaust valve is closed, and the oxygen purity meets the standard into the calculation of corresponding flow consumption values. This ensures that the cumulative oxygen production flow and compressor current accurately reflect the output and energy consumption relationship during the qualified oxygen production stage. Simultaneously, this invention also utilizes the purity, flow rate, and current status at the beginning of the next switching cycle to confirm low-consumption candidate cycles, identifying false low-consumption cycles, reducing misjudgments, and providing a basis for energy-saving equipment operation, maintenance diagnosis, and parameter optimization. Attached Figure Description

[0035] Figure 1 The following is an exemplary flowchart of an oxygen production condition identification method and system for low-consumption operation, as shown in some embodiments of the present invention.

[0036] Figure 2 This is a flowchart illustrating the process of sampling and switching cycle data formation in some embodiments of the present invention;

[0037] Figure 3 This is a flowchart illustrating the determination of the equalization time window and residual pressure difference in some embodiments of the present invention;

[0038] Figure 4 This is a flowchart illustrating the effective oxygen production points and cumulative flow consumption in some embodiments of the present invention;

[0039] Figure 5 This is a flowchart illustrating the low-power candidate cycle and low-power operating condition confirmation process in some embodiments of the present invention. Detailed Implementation

[0040] To more clearly illustrate the technical solutions of the embodiments in this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this specification. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the linguistic context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0041] It should be understood that the terms "system," "device," "unit," and / or "module" as used in this specification are a method of distinguishing different components, elements, parts, sections, or assemblies at different levels. However, if other terms can achieve the same purpose, they may be replaced by other expressions.

[0042] As indicated in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include the plural. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0043] Flowcharts are used in this specification to illustrate the operations performed by the system according to embodiments of this specification. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these processes, or one or more steps can be removed from them.

[0044] The oxygen production condition identification method and system for low-consumption operation provided in the embodiments of this specification will be described in detail below with reference to the accompanying drawings.

[0045] Figure 1This is an exemplary flowchart of an oxygen generation condition identification method and system for low-power operation, as shown in some embodiments of this specification. In some embodiments, the oxygen generation condition identification method and system for low-power operation can be executed by processing logic, which may include hardware (e.g., circuits, dedicated logic, programmable logic, microcode, etc.), software (instructions running on a processing device to execute hardware simulations), and any combination thereof. In some embodiments, Figure 1 One or more operations in the flowchart of the oxygen production condition identification method and system for low-consumption operation shown can be implemented by processing equipment and / or terminal equipment. For example, the oxygen production condition identification method and system for low-consumption operation can be stored in a storage device in the form of computer programs and / or instructions, and can be invoked and / or executed by processing equipment and / or terminal equipment.

[0046] First, it should be noted that the oxygen generating equipment described in this invention can be a dual-tower pressure swing adsorption (PSA) oxygen generating equipment. This equipment includes an air compressor, a first molecular sieve tower, a second molecular sieve tower, a pressure equalization pipeline, a pressure equalization valve, an oxygen generation valve, an exhaust valve, an oxygen generation output pipeline, and a controller.

[0047] An air compressor supplies compressed air to the molecular sieve towers, where the first and second molecular sieve towers alternately perform adsorption, desorption, pressure equalization, and oxygen production processes. A pressure equalization valve is installed on the pressure equalization pipeline between the first and second molecular sieve towers to connect the two towers during switching, bringing their pressures closer together. An oxygen production valve is installed on the oxygen production output path to control oxygen output. An exhaust valve is installed on the desorption exhaust path to discharge gases generated during the desorption process.

[0048] The controller can be a programmable logic controller (PLC), an embedded controller, an industrial computer, or an edge control terminal. The controller has data acquisition, data storage, logical judgment, and result output functions, and is connected to the pressure acquisition unit, valve status acquisition unit, oxygen purity detection unit, oxygen production flow detection unit, and compressor current acquisition unit in the oxygen generator. The controller acquires the operating data of the oxygen generator during continuous operation through the aforementioned acquisition units and identifies low-consumption oxygen generation conditions according to the method described in this invention.

[0049] The first molecular sieve column is equipped with a first pressure acquisition unit, and the second molecular sieve column is equipped with a second pressure acquisition unit. The first pressure acquisition unit is used to acquire the pressure value of the first molecular sieve column, and the second pressure acquisition unit is used to acquire the pressure value of the second molecular sieve column. The pressure acquisition unit can be a pressure sensor, a pressure transmitter, or an acquisition module with pressure detection function. The pressure acquisition unit can be set at the top, bottom, or side pressure sampling port of the corresponding molecular sieve column, or it can be set on the pressure sampling pipeline connected to the corresponding molecular sieve column. To ensure the accuracy of the pressure difference judgment between the two columns, the first and second pressure acquisition units preferably have the same or similar range and accuracy, and their pressure data are read by the controller at the same sampling time.

[0050] The opening and closing states of the equalizing valve, oxygen generating valve, and exhaust valve can be determined by the valve control output signal of the controller, or by the feedback signal from the valve position feedback switch, magnetic switch, limit switch, or solenoid valve installed on the valve body. In embodiments with valve position feedback signals, the controller can preferentially use the valve position feedback signal as the actual valve state; when the valve control signal and the valve position feedback signal are inconsistent, the controller can mark the corresponding sampling point as an abnormal valve state point, preventing it from participating in the low-power operating condition confirmation, thereby reducing the impact of valve action lag, valve core jamming, or feedback abnormalities on the identification results.

[0051] An oxygen purity detection unit and an oxygen production flow detection unit are installed on the oxygen production output pipeline. The oxygen purity detection unit is used to collect the oxygen purity of the output gas and can employ an oxygen cell type, zirconia type, paramagnetic type, or other sensors suitable for oxygen concentration detection. The oxygen production flow detection unit is used to collect the oxygen production flow rate and can employ a thermal mass flow meter, differential pressure flow meter, float flow meter, vortex flow meter, or other detection device capable of reflecting the output oxygen production flow rate. A current acquisition unit is installed on the compressor power supply circuit. The current acquisition unit can employ a current transformer, Hall current sensor, or electrical parameter acquisition module to collect the compressor operating current. The above detection data are input to the controller via an analog input interface, a digital input interface, or a communication interface.

[0052] Based on the hardware equipment mentioned above, please refer to Figure 1 This invention discloses a method for identifying oxygen production conditions for low-consumption operation, comprising the following steps:

[0053] Step 1: During the oxygen production equipment switching cycle, sample and obtain the pressure values ​​of the first and second molecular sieve towers, as well as the status of the equalizing valve, oxygen production valve, and exhaust valve, oxygen purity, oxygen production flow rate, and compressor operating current.

[0054] Step 2: Calculate the pressure difference between the first and second molecular sieve towers to obtain the pressure difference between the two towers;

[0055] Step 3: When the pressure equalization valve is opened and the pressure difference between the two towers continuously converges to zero, determine the starting point of the pressure equalization time window; when the pressure difference between the two towers enters the preset convergence allowable range and its change is within the preset sampling error allowable range, determine the ending point of the pressure equalization time window; and determine the pressure difference between the two towers at the end of the pressure equalization time window as the residual pressure difference.

[0056] Step 4: Determine the sampling points where the oxygen production valve is open, the exhaust valve is closed, and the oxygen purity reaches the preset qualified lower limit as effective oxygen production points, and accumulate their oxygen production flow rate and compressor operating current respectively to determine the corresponding current consumption value.

[0057] Step 5: When the cumulative flow rate reaches the preset cumulative oxygen supply threshold, the cumulative current does not exceed the preset cumulative current threshold, and the residual pressure difference enters the preset convergence allowable range, a low-consumption candidate period is determined. When the oxygen purity, oxygen production flow rate, and compressor operating current meet the constraints at the beginning of the next switching period, the low-consumption oxygen production condition is output.

[0058] Specifically, such as Figure 2 As shown, in some embodiments of the present invention, step 1 is carried out as follows:

[0059] In this embodiment, during the continuous operation of the oxygen generator, the controller reads the pressure values ​​of the first molecular sieve tower, the pressure values ​​of the second molecular sieve tower, the opening and closing status of the equalizing valve, the opening and closing status of the oxygen generation valve, the opening and closing status of the exhaust valve, the oxygen purity, the oxygen generation flow rate, and the compressor operating current according to the set sampling cycle.

[0060] The controller maps the pressure values ​​of the first and second molecular sieve towers at the same sampling time to pressure point groups, maps the opening and closing states of the equalizing valve, oxygen generation valve, and exhaust valve at the same sampling time to valve state groups, and maps the oxygen purity, oxygen generation flow rate, and compressor operating current at the same sampling time to oxygen generation energy consumption groups.

[0061] Therefore, each sampling point can simultaneously reflect the pressure status of the two towers, the valve operation status, the oxygen production status, and the compressor load status, providing a data foundation for subsequent switching cycle identification, pressure equalization time window interception, and low-consumption operating condition judgment.

[0062] It should be noted that the switching cycle of the oxygen generator is defined by the boundaries of two adjacent cycles. Each cycle boundary is the sampling moment when the pressure equalization valve switches from the closed to the open state and the pressure difference between the two towers begins to converge to zero. In other words, the controller does not divide the switching cycle by a fixed time length, but rather determines the cycle boundary by combining the changes in the pressure equalization valve state and the pressure change trends of the two towers. The starting point of the current switching cycle is determined by the cycle boundary that meets the above conditions once, and the ending point of the current switching cycle is determined by the cycle boundary that meets the above conditions again next. Through this division method, the switching cycle can correspond to the actual tower switching process of the dual-tower oxygen generator, avoiding inaccurate cycle division due to fluctuations in the equipment's operating cycle.

[0063] In some embodiments of the present invention, after determining the current switching cycle, the controller calls the pressure values ​​of the first molecular sieve tower and the second molecular sieve tower within the switching cycle, and performs a difference calculation on the two to obtain the pressure difference between the two towers at each sampling time.

[0064] Since the pressure in the first molecular sieve tower may be higher than that in the second molecular sieve tower at different operating stages, and vice versa, the controller can use the absolute magnitude of the pressure difference between the two towers as the criterion for determining whether the pressures are approaching each other. This avoids interference from changes in the direction of the pressure difference on the convergence determination, allowing the pressure difference between the two towers to more accurately reflect the degree of pressure closure between them.

[0065] like Figure 3 As shown, in some embodiments of the present invention, the starting point of the equalization time window is determined by the state of the equalization valve and the trend of the pressure difference change between the two towers.

[0066] When the controller detects that the equalizing valve has switched from closed to open, it continues to read the pressure difference changes between the two towers after that moment. If the absolute magnitude of the pressure difference between the two towers decreases sequentially in three consecutive sampling points, it indicates that the pressures in both towers have begun to converge after the equalizing valve opened. At this point, the controller determines the first sampling moment among these three consecutive sampling points as the starting point of the equalizing time window. By simultaneously using valve state changes and pressure difference convergence trends as judgment conditions, it avoids misjudging moments before pressure response occurs as the starting point of the equalizing time window simply due to changes in the equalizing valve control signal.

[0067] After the starting point of the pressure equalization time window is determined, the controller continues to read the pressure values ​​of the first molecular sieve tower and the second molecular sieve tower, and continuously judges whether the pressure difference between the two towers has entered a stable closed state. When the absolute magnitude of the pressure difference between the two towers at three consecutive sampling points all enters the preset convergence allowable range, and the change in the pressure difference between adjacent towers within these three consecutive sampling points is within the preset sampling error allowable range, it indicates that the pressure of the two towers has entered the allowable convergence state, and the pressure difference change tends to stabilize. At this time, the controller determines the first sampling time among the three consecutive sampling points as the end point of the pressure equalization time window.

[0068] Specifically, the preset convergence allowance range can be denoted as: The preset allowable sampling error range can be denoted as: When there are three consecutive sampling points i, i+1, and i+2, such that the absolute values ​​of the pressure difference between the two towers all satisfy the following relationship:

[0069]

[0070]

[0071]

[0072] Furthermore, the pressure difference change between the two towers at adjacent sampling points satisfies the following relationship:

[0073]

[0074]

[0075] The controller determines that the pressure difference between the two towers has entered a stable convergence state and determines the sampling time corresponding to sampling point i as the end point of the equalization time window. It can be determined based on the rated working pressure of the molecular sieve tower, the range of the pressure sensor, and the allowable residual pressure difference during stable operation of the equipment; The pressure can be determined based on the pressure sensor's detection error, the controller's sampling cycle, and the on-site sampling noise. For example, in a dual-tower pressure swing adsorption oxygen generator with a rated adsorption pressure of 0.25 MPa to 0.45 MPa, It can be set from 0.005MPa to 0.03MPa. It can be set to 0.001MPa to 0.01MPa. The above values ​​are only one possible implementation method, and in actual applications, they can be configured according to equipment specifications and debugging data.

[0076] The above endpoint determination takes into account both the magnitude of the pressure difference and the stability of the pressure difference change, which can avoid misjudgment of pressure equalization completion due to fluctuations at a single sampling point.

[0077] In actual operation, when the equalizing valve is closed, the pressure in both towers may not yet meet the criteria for determining the end point of the equalizing time window. To address this, the controller can continue reading the pressure difference between the two towers at subsequent sampling points after the equalizing valve closes, until the pressure difference enters a preset convergence range and its change is within a preset sampling error range, before determining the end point of the equalizing time window. Conversely, if the pressure difference between the two towers has already met the criteria for determining the end point of the equalizing time window, but the equalizing valve remains open, the controller uses the sampling moment when the criteria are first met as the end point of the equalizing time window, without waiting for the equalizing valve to close. Therefore, the end point of the equalizing time window is primarily determined by the closed state of the two towers, while also considering valve state changes, thus more accurately reflecting the completion time of the equalization process.

[0078] After the end point of the pressure equalization time window is determined, the controller reads the pressure values ​​of the first and second molecular sieve towers at the sampling time of that end point and performs a difference calculation between them to obtain the residual pressure difference at the end of the current switching cycle. The residual pressure difference is used to characterize the pressure difference that still exists between the first and second molecular sieve towers at the end of the pressure equalization process. When determining whether the residual pressure difference meets the requirements, the controller can use whether the absolute value of the residual pressure difference enters the preset convergence allowable range as the judgment criterion. When the absolute value of the residual pressure difference enters the preset convergence allowable range, the controller marks the current switching cycle as a residual pressure difference convergence cycle; when the absolute value of the residual pressure difference does not enter the preset convergence allowable range, the controller marks the current switching cycle as a residual pressure difference non-convergence cycle.

[0079] Furthermore, the controller can also read the pressure values ​​of the first and second molecular sieve towers at the sampling time at the start of the current switching cycle, and determine the cycle start pressure difference. The cycle start pressure difference reflects the initial pressure difference between the two towers at the beginning of the current switching cycle, and the residual pressure difference at the end of the pressure equalization reflects the remaining pressure difference between the two towers when the pressure equalization is completed.

[0080] By recording the pressure difference at the beginning of the cycle and the residual pressure difference at the end of the pressure equalization, the process of the pressure difference between the two towers changing from the initial state to the closed state during the current switching cycle can be fully reflected. This also facilitates the subsequent tracking of the results of pressure equalization sufficiency, cycle stability, and low power consumption identification.

[0081] like Figure 4 As shown, in some embodiments of the present invention, within the same switching cycle, the controller also calls the oxygen production valve opening / closing status, the exhaust valve opening / closing status, oxygen purity, oxygen production flow rate, and compressor operating current to determine the effective oxygen production point.

[0082] When the oxygen production valve at a certain sampling point is in the open state, the exhaust valve is in the closed state, and the oxygen purity reaches the preset qualified lower limit, the controller determines this sampling point as a valid oxygen production point. Among them, the opening of the oxygen production valve indicates that the oxygen production output path is in the conducting state, the closing of the exhaust valve indicates that this sampling point is not in the exhaust or desorption emission state, and the oxygen purity reaching the preset qualified lower limit indicates that the output gas of this sampling point meets the qualified oxygen production requirements. The above conditions jointly define the valid oxygen production point, which can prevent data in the exhaust stage, non-oxygen production stage, or oxygen purity recovery stage from entering the valid oxygen production statistics.

[0083] For the sampling points determined as valid oxygen production points, the controller accumulates the corresponding oxygen production flow rate in the sampling order to obtain the cumulative amount of valid oxygen production flow; at the same time, it accumulates the corresponding compressor operating current in the sampling order to obtain the cumulative amount of valid oxygen production current. The cumulative amount of valid oxygen production flow is used to represent the effective output level in the qualified oxygen production stage during the current switching cycle, and the cumulative amount of valid oxygen production current is used to represent the compressor load level in the qualified oxygen production stage during the current switching cycle.

[0084] In a specific embodiment, the controller can determine whether a sampling point participates in the calculation of the corresponding value of the consumed current through the valid oxygen production flag E(i). When VO(i) represents that the oxygen production valve is open, VD(i) represents that the exhaust valve is closed, and C(i) ≥ Cmin, = 1; otherwise = 0. The judgment relationship can be expressed as:

[0085]

[0086] Among them, = 1 indicates that the i-th sampling point is a valid oxygen production point.

[0087] When VO(i) does not represent that the oxygen production valve is open, or VD(i) does not represent that the exhaust valve is closed, or C(i) < Cmin, the judgment relationship can be expressed as:

[0088]

[0089] Among them, indicates that the i-th sampling point is a non-valid oxygen production point. If the oxygen production flow rate Q(i) is an instantaneous flow rate, the cumulative amount of valid oxygen production flow during the current switching cycle can be calculated according to the following relationship:

[0090]

[0091] If the oxygen production flow rate detection unit outputs a cumulative flow rate, then the cumulative flow rate difference between the start and end sampling points in the valid oxygen production stage can be used for calculation. The cumulative amount of valid oxygen production current during the current switching cycle The calculation can be performed according to the following relationship:

[0092]

[0093] With a fixed sampling period, the cumulative amount of effective oxygen-generating current Alternatively, the following relationship can be used as a cumulative indicator to characterize the duration of compressor load:

[0094]

[0095] The controller will and Together they serve as the corresponding value for flow consumption, and according to Whether the preset cumulative oxygen supply threshold has been reached and Whether the current accumulation threshold is exceeded is used to determine low-power candidate.

[0096] If the oxygen production flow detection unit outputs an instantaneous flow rate, the controller can combine this with the sampling time interval to form a cumulative value. If the oxygen production flow detection unit outputs a cumulative flow rate, the controller can take the flow rate increment corresponding to the effective oxygen production stage as the effective oxygen production flow rate cumulative value. The compressor operating current can also be accumulated according to the sampled value corresponding to the effective oxygen production point, or combined with the sampling time interval to form a cumulative index reflecting the load duration.

[0097] When the oxygen production valve is not open, the exhaust valve is open, or the oxygen purity does not reach the preset lower limit of qualification at a certain sampling point, the controller determines that sampling point as an ineffective oxygen production point. The oxygen production flow rate corresponding to an ineffective oxygen production point is not included in the effective oxygen production flow rate accumulation, and the compressor operating current corresponding to an ineffective oxygen production point is not included in the effective oxygen production current accumulation. By excluding ineffective oxygen production points, the subsequent established current consumption values ​​can only reflect the output and compressor load relationship during the qualified oxygen production stage, avoiding interference from non-oxygen production states, exhaust states, or low purity states on the low consumption identification results.

[0098] like Figure 5 As shown, in some embodiments of the present invention, the corresponding values ​​of current consumption include the cumulative effective oxygen production flow rate and the cumulative effective oxygen production current.

[0099] The cumulative effective oxygen production flow rate serves as output-side data, while the cumulative effective oxygen production current serves as energy consumption-side data. The compressor operating current reflects the compressor's load level during oxygen production. When power supply conditions are within the equipment's allowable fluctuation range, the cumulative compressor operating current can serve as energy consumption-side characterization data in low-consumption identification. Therefore, the corresponding current consumption value can simultaneously reflect whether the qualified oxygen production output meets the requirements within the current switching cycle, and whether the compressor load corresponding to obtaining this qualified oxygen production output is within the allowable range.

[0100] After obtaining the current consumption value and residual pressure difference convergence status of the current switching cycle, the controller performs a low-consumption candidate judgment for the current switching cycle. When the cumulative effective oxygen production flow reaches the preset cumulative oxygen supply threshold, the cumulative effective oxygen production current does not exceed the preset cumulative current threshold, and the residual pressure difference at the pressure equalization endpoint enters the preset convergence allowable range, it indicates that the current switching cycle meets the basic conditions for low-consumption operation in terms of effective oxygen production output, compressor load, and dual-tower pressure closure status. The controller marks this switching cycle as a low-consumption candidate cycle. A low-consumption candidate cycle only indicates that the current cycle has the candidate conditions for low-consumption operation and is not directly used as the final low-consumption oxygen production condition output.

[0101] If the cumulative effective oxygen production flow rate of the current switching cycle reaches the preset cumulative oxygen supply threshold, and the cumulative effective oxygen production current does not exceed the preset cumulative current threshold, but the absolute magnitude of the residual pressure difference at the pressure equalization endpoint does not enter the preset convergence allowable range, then the controller marks this switching cycle as a pseudo-low-consumption cycle. A pseudo-low-consumption cycle indicates that the cycle appears to meet the low-consumption requirements from the perspective of effective oxygen production flow rate and compressor operating current, but the pressure of the two towers at the pressure equalization endpoint has not been fully closed. Subsequent switching cycles may experience problems such as delayed oxygen purity recovery, insufficient oxygen production flow rate, or increased compressor load. Therefore, pseudo-low-consumption cycles are not output as low-consumption oxygen production conditions. By setting this judgment, false low-consumption judgments can be avoided based solely on the current cycle's flow rate and current indicators.

[0102] After the start of the next switching cycle, the controller continues to determine the pressure equalization time window for the next switching cycle in the aforementioned manner. The initial phase of the next switching cycle begins at the sampling point where the first oxygen production valve is open and the exhaust valve is closed after the end of the pressure equalization time window of the next switching cycle. This starting point indicates that the pressure equalization process has been completed and the oxygen production output state has been entered for the next switching cycle. The initial phase of the next switching cycle ends at the third sampling point when the oxygen purity reaches the preset lower limit of qualification for the first time among three consecutive sampling points. Using three consecutive sampling points to determine the termination position can reduce misjudgments caused by single-point purity fluctuations, allowing the initial phase of the next switching cycle to reflect the process of oxygen production purity returning to a qualified state after the tower switching.

[0103] At the beginning of the next switching cycle, the controller reads the oxygen purity, oxygen production flow rate, and compressor operating current, and determines whether these parameters meet the corresponding constraints. These constraints include oxygen purity reaching a preset lower limit, oxygen production flow rate meeting a preset oxygen production flow rate constraint, and compressor operating current not exceeding a preset current operating constraint. If, at the beginning of the next switching cycle, the oxygen purity reaches the preset lower limit, the oxygen production flow rate meets the preset oxygen production flow rate constraint, and the compressor operating current does not exceed the preset current operating constraint, it indicates that the previous low-consumption candidate cycle did not adversely affect the oxygen production recovery, output capacity, and compressor load of the next cycle, and the controller confirms the previous low-consumption candidate cycle as a low-consumption oxygen production condition. If, at the beginning of the next switching cycle, the oxygen purity does not reach the preset lower limit, the oxygen production flow rate does not meet the preset oxygen production flow rate constraint, or the compressor operating current exceeds the preset current operating constraint, the controller does not confirm the previous cycle as a low-consumption oxygen production condition and may output a non-low-consumption oxygen production condition or a pseudo-low-consumption cycle based on the residual pressure difference status of the previous cycle.

[0104] The aforementioned preset convergence range can be determined based on the rated adsorption pressure of the molecular sieve tower, the detection accuracy of the pressure acquisition unit, the response characteristics of the pressure equalization valve, and historical data of stable equipment operation.

[0105] The preset sampling error allowable range can be determined based on the pressure acquisition unit's detection error, sampling noise, and the controller's sampling cycle. The preset acceptable lower limit can be determined based on the oxygen generator's application, rated oxygen concentration requirements, or user settings. The preset cumulative oxygen supply threshold can be determined based on the equipment's rated oxygen supply demand, switching cycle length, and effective oxygen production phase duration. The preset cumulative current threshold can be determined based on the compressor's rated operating current, effective oxygen production phase duration, and allowable load margin. The preset oxygen production flow constraint and preset current operating constraint can be determined based on the equipment's rated oxygen production flow rate and the compressor's rated operating current, respectively. The above preset parameters can be written into the controller at the factory or configured during equipment commissioning or operation and maintenance.

[0106] To improve adaptability to industrial environments, the controller can filter the collected pressure values, oxygen purity, oxygen production flow rate, and compressor operating current. Filtering can include moving averages, outlier removal, valve debouncing, or delay compensation. If the oxygen purity detection unit experiences a response delay, the controller can determine whether the oxygen purity has reached the preset lower limit of acceptable levels using multiple consecutive sampling points, rather than relying solely on a single sampling point. If there are short-term valve fluctuations, the controller can confirm valve stability through consecutive sampling points before using that valve state to determine the pressure equalization time window or the effective oxygen production point.

[0107] When the controller fails to determine the starting point of the pressure equalization time window within the preset search range, or fails to determine the ending point of the pressure equalization time window after the starting point, it can mark the current switching cycle as an invalid cycle or a pressure equalization abnormal cycle, and will not output the cycle as a low-consumption oxygen production condition. When pressure sampling values ​​are missing, exceed the sensor range, or there are sudden changes between adjacent sampling points that do not conform to the equipment's operating rules, the controller can mark the corresponding sampling point as an invalid sampling point. If an invalid sampling point affects the identification of the pressure equalization time window or the determination of the corresponding current consumption value in the current switching cycle, the controller can abandon the low-consumption identification result for that cycle, or output a sensor abnormality prompt. Through the above processing, the impact of sensor failure, communication interruption, or valve status abnormality on the final operating condition identification result can be reduced.

[0108] If the current switching cycle has been marked as a low-consumption candidate cycle, but the equipment stops before the beginning of the next switching cycle, or the data at the beginning of the next switching cycle is insufficient to determine oxygen purity, oxygen production flow rate, and compressor operating current, the controller can mark this low-consumption candidate cycle as a cycle to be confirmed, instead of directly outputting it as a low-consumption oxygen production condition. Confirmation will be performed based on the corresponding constraints after the data at the beginning of the next switching cycle is complete. If the equipment remains shut down, this cycle can be saved as a historical candidate record and will not participate in the final low-consumption oxygen production condition statistics.

[0109] Furthermore, this invention also discloses an oxygen production condition identification system for performing the above-described method, oriented towards low-consumption operation. This system includes an operating data sampling module, a pressure equalization time window determination module, a residual pressure difference constraint module, a flow consumption corresponding value determination module, and a low-consumption condition output module. These modules can be implemented by a processor in the controller executing program instructions stored in the memory, or they can be implemented collaboratively by the controller, data acquisition module, communication module, and host computer.

[0110] The operation data sampling module is used to sample and obtain the pressure values, valve status, oxygen production parameters, and compressor operating current of the first and second molecular sieve towers during the switching cycle of the oxygen generator.

[0111] The pressure equalization time window determination module is used to determine the pressure difference between the two molecular sieve towers based on the pressure values ​​of the first and second molecular sieve towers, and to determine the pressure equalization time window based on the status of the pressure equalization valve and the convergence status of the pressure difference between the two towers.

[0112] The residual pressure difference constraint module is used to determine the residual pressure difference based on the pressure difference between the two towers at the end of the equalization time window, and to determine the convergence state of the residual pressure difference.

[0113] The current consumption corresponding value determination module is used to determine the current consumption corresponding value based on the cumulative oxygen production flow rate of the effective oxygen production point and the compressor operating current.

[0114] The low-consumption operating condition output module is used to output the low-consumption oxygen production condition based on the corresponding flow consumption value, the residual pressure difference convergence status, and the initial state of the next switching cycle.

[0115] Therefore, the above five modules correspond to data sampling, pressure equalization process identification, residual pressure difference constraint, effective oxygen production flow statistics, and low-consumption operation condition confirmation process, respectively, and can completely execute the oxygen production operation condition identification method described in this invention.

[0116] The output of the low-consumption operating condition output module can include low-consumption oxygen production conditions, non-low-consumption oxygen production conditions, pseudo-low-consumption cycles, residual pressure differential non-convergence cycles, pressure equalization abnormal cycles, or cycles awaiting confirmation. Output results can be displayed on the equipment screen, indicator lights, audible and visual alarms, via a host computer, remote monitoring platform, or communication interface. They can also be stored in the controller's memory for subsequent operational analysis, maintenance diagnosis, or control parameter optimization. By associating and saving the identification results with the equipment's operating process, maintenance personnel can trace the dual-tower pressure differential closure status, effective oxygen production accumulation status, and compressor load status for each switching cycle, thereby determining whether the oxygen production equipment is in a stable low-consumption operating state.

[0117] In other embodiments, the system can also collect auxiliary parameters such as inlet pressure, ambient temperature, ambient humidity, compressor discharge pressure, or oxygen storage tank pressure. These auxiliary parameters can be used for operational status recording, anomaly diagnosis, or threshold correction. However, even without collecting these auxiliary parameters, the system can still identify low-consumption oxygen production conditions based on the pressure values ​​of the first and second molecular sieve towers, valve status, oxygen purity, oxygen production flow rate, and compressor operating current. This configuration makes the present invention applicable to both fully equipped industrial oxygen production equipment and oxygen production equipment with only basic pressure, valve status, purity, flow rate, and current acquisition capabilities.

[0118] Through the above embodiments, this invention not only examines the current consumption correspondence between the effective oxygen production flow rate and the compressor operating current during the oxygen production equipment switching cycle, but also uses the residual pressure difference at the pressure equalization endpoint as a pressure closure constraint, and confirms the previous low-consumption candidate cycle by the oxygen production status at the beginning of the next switching cycle. Therefore, it avoids misjudging a low-consumption oxygen production condition solely based on the current cycle's oxygen production flow rate meeting the standard and the compressor operating current being low, and can identify pseudo-low-consumption cycles that appear low-consumption but have insufficient pressure equalization closure, thereby improving the reliability of identifying low-consumption oxygen production conditions.

[0119] The present invention will be further disclosed below with reference to specific embodiments.

[0120] In one specific embodiment, the oxygen generating equipment is a dual-tower pressure swing adsorption oxygen generating equipment, in which the first molecular sieve tower and the second molecular sieve tower alternately perform adsorption, desorption, pressure equalization and oxygen production.

[0121] The oxygen generator has a rated oxygen production flow rate of 10 L / min, a rated adsorption pressure of 0.35 MPa, and a rated compressor operating current of 5.0 A. The controller's sampling period Δt is set to 1 s, the preset acceptable lower limit for oxygen purity Cmin is set to 90%, and the preset convergence allowable range is... Set to 0.02MPa, preset sampling error allowable range. Set to 0.005MPa, preset oxygen production flow rate constraint to no less than 8.5L / min, and preset current operation constraint to no more than 4.8A.

[0122] Within the current switching cycle K, the controller detects the pressure equalization valve switching from the closed to the open state at sampling time t0, and after t0, the pressure difference between the first and second molecular sieve towers gradually converges to zero. The pressure difference D(i) between the two towers at the i-th sampling point is calculated according to the following relationship:

[0123]

[0124] Where P1(i) represents the pressure value of the first molecular sieve tower at the i-th sampling point, and P2(i) represents the pressure value of the second molecular sieve tower at the i-th sampling point. During the pressure equalization phase of the current switching cycle K, some data collected by the controller are shown in Table 1.

[0125] Table 1: Partial data collected by the controller:

[0126]

[0127] As shown in the table above, at the three consecutive sampling points t0, t1, and t2, the absolute value of the pressure difference between the two towers decreases sequentially, satisfying the following relationship:

[0128]

[0129] Therefore, the controller determines t0 as the starting point of the equalization time window of the current switching cycle K.

[0130] When the pressure equalization time window ends, the absolute values ​​of the pressure difference between the two towers at the three consecutive sampling points t3, t4, and t5 are 0.015 MPa, 0.011 MPa, and 0.009 MPa, respectively, all of which are less than the preset convergence allowable range εp, i.e., they satisfy the following relationship:

[0131]

[0132]

[0133]

[0134] Meanwhile, the pressure difference changes between the two towers at adjacent sampling points between t3 and t5 were 0.004 MPa and 0.002 MPa, respectively, both less than the preset allowable sampling error range. That is, it satisfies the following relationship:

[0135]

[0136]

[0137] Therefore, the controller determines that the three consecutive sampling points t3, t4, and t5 have met the conditions for determining the end of the pressure equalization time window, and sets the first sampling time t3 among these three consecutive sampling points as the end of the pressure equalization time window. At this time, the residual pressure difference in the current switching cycle K is the pressure difference between the two towers at time t3, that is:

[0138]

[0139] The absolute value of the residual pressure difference satisfies the following relationship:

[0140]

[0141] Therefore, the controller marks the current switching period K as the residual differential pressure convergence period.

[0142] During the oxygen production phase of the current switching cycle K, the controller continues to collect data on the oxygen production valve status, exhaust valve status, oxygen purity, oxygen production flow rate, and compressor operating current. Some sampled data from the current switching cycle K are shown in Table 2.

[0143] Table 2: Partial sampled data in the current switching period K:

[0144]

[0145] In this embodiment, when a sampling point meets the conditions of an oxygen-generating valve open, an exhaust valve closed, and an oxygen purity C not less than 90%, the controller determines that sampling point as a valid oxygen-generating point. As shown in the table above, although the oxygen-generating valve is open and the exhaust valve is closed at time t4, the oxygen purity is 88.6%, which is lower than the preset acceptable lower limit of 90%. Therefore, t4 does not participate in the accumulation of effective oxygen-generating flow rate and effective oxygen-generating current. From t5 to t10, the conditions of an oxygen-generating valve open, an exhaust valve closed, and an oxygen purity not less than 90% are all met; therefore, t5 to t10 are valid oxygen-generating points.

[0146] Since the oxygen production flow rate Q in this embodiment is the instantaneous flow rate in L / min, and the sampling period Δt is 1 s, the cumulative effective oxygen production flow rate Veff is calculated according to the following relationship:

[0147]

[0148] in, =1 indicates that the i-th sampling point is an effective oxygen production point. =0 indicates that the i-th sampling point is a non-effective oxygen production point.

[0149] Substituting the oxygen production flow rates from t5 to t10 into the calculation, we get:

[0150]

[0151]

[0152]

[0153] In this embodiment, the preset cumulative oxygen supply threshold Vth is determined based on the equipment's rated oxygen production flow rate, the expected duration of the effective oxygen production stage, and the oxygen supply threshold correction coefficient. The equipment's rated oxygen production flow rate... The effective oxygen production phase is expected to last 10 L / min. The correction factor for the oxygen supply threshold is 6 seconds. If we set it to 0.85, then the preset cumulative oxygen supply threshold is... for:

[0154]

[0155] The cumulative effective oxygen production flow rate of the current switching cycle K satisfies the following relationship:

[0156]

[0157] Therefore, the controller determines that the effective oxygen production output of the current switching cycle K meets the preset cumulative oxygen supply requirements.

[0158] Cumulative effective oxygen production current during the current switching cycle K Calculated according to the following relationship:

[0159]

[0160] Substituting the compressor operating currents from t5 to t10 into the calculation, we get:

[0161]

[0162]

[0163] In this embodiment, a preset current accumulation threshold is used. The compressor's rated operating current is determined based on the compressor's rated operating current, the expected duration of the effective oxygen production phase, and a current threshold correction factor. The effective oxygen production phase is expected to last for 5.0A. With a current threshold correction factor β of 0.90 and a time limit of 6 seconds, the preset current accumulation threshold is... for:

[0164]

[0165]

[0166]

[0167] The cumulative effective oxygen production current in the current switching cycle K satisfies the following relationship:

[0168]

[0169] Therefore, the controller determines that the compressor load in the current switching cycle K meets the preset current accumulation requirement.

[0170] In summary, the current switching cycle K simultaneously meets the following three conditions: First, the cumulative effective oxygen production flow rate reaches the preset cumulative oxygen supply threshold; second, the cumulative effective oxygen production current does not exceed the preset cumulative current threshold; and third, the residual pressure difference enters the preset convergence allowable range. Therefore, the controller determines the current switching cycle K as a low-power candidate cycle.

[0171] To avoid misjudging low power consumption based solely on the oxygen production flow rate and compressor operating current in the current switching cycle K, the controller continues to collect data at the beginning of the next switching cycle K+1. In the next switching cycle K+1, the controller determines the end point of its pressure equalization time window as t16. After t16, the first sampling point where the oxygen production valve opens and the exhaust valve closes is t17; therefore, the controller determines t17 as the starting sampling point for the beginning of the next switching cycle K+1.

[0172] The partial sampling data of the first segment of the next switching cycle K+1 is shown in Table 3.

[0173] Table 3: Partial sampled data of the initial segment of the next switching cycle K+1:

[0174]

[0175] As shown in Table 3, the oxygen purity at the three consecutive sampling points t17, t18, and t19 all reached the preset lower limit of 90%. Therefore, the controller determined t19 as the termination sampling point for the initial stage of the next switching cycle K+1. During the period from t17 to t19, the oxygen purity, oxygen production flow rate, and compressor operating current satisfy the following relationships:

[0176] ; ; ;

[0177] ; ; ; ; ; .

[0178] Therefore, the controller determines that the oxygen purity in the initial stage of the next switching cycle K+1 reaches the preset lower limit of qualification, the oxygen production flow rate meets the preset oxygen production flow rate constraint, and the compressor operating current does not exceed the preset current operating constraint. This indicates that although the current switching cycle K is in a low-consumption candidate state, it has not caused a delay in the purity recovery, insufficient oxygen production flow rate, or abnormal increase in compressor load in the initial stage of the next switching cycle K+1.

[0179] Based on the above judgment, the controller confirms the current switching cycle K as a low-consumption oxygen production condition and outputs the low-consumption oxygen production condition identification result. The output result may include the current switching cycle number K, the start time t0 of the pressure equalization time window, the end time t3 of the pressure equalization time window, the residual pressure difference of 0.015MPa, the cumulative effective oxygen production flow rate of 0.97L, and the cumulative effective oxygen production current. And the confirmation results of the first phase of the next switching cycle.

[0180] Therefore, maintenance personnel can directly trace the pressure closure status, effective oxygen production output status, compressor load status, and oxygen production recovery status of the current switching cycle based on the output results.

[0181] Finally, it should be understood that the embodiments described in this specification are merely illustrative of the principles of the embodiments described herein. Other variations may also fall within the scope of this specification. Therefore, alternative configurations of the embodiments described herein are intended to be illustrative rather than limiting, and should be considered consistent with the teachings of this specification. Accordingly, the embodiments described herein are not limited to those explicitly introduced and described herein.

Claims

1. A method for identifying oxygen production conditions for low-consumption operation, characterized in that, include: During the oxygen production equipment switching cycle, the pressure values ​​of the first and second molecular sieve towers, the status of the equalizing valve, oxygen production valve, and exhaust valve, the oxygen purity, the oxygen production flow rate, and the compressor operating current are sampled and obtained. The pressure difference between the first and second molecular sieve towers is obtained by taking the difference between their pressure values. When the equalizing valve is opened and the pressure difference between the two towers continuously converges to zero, the starting point of the equalizing time window is determined. When the pressure difference between the two towers enters the preset convergence allowable range and its change is within the preset sampling error allowable range, the ending point of the equalizing time window is determined. The pressure difference between the two towers at the end of the equalizing time window is determined as the residual pressure difference. The sampling points where the oxygen generation valve is open, the exhaust valve is closed, and the oxygen purity reaches the preset qualified lower limit are determined as effective oxygen generation points, and their oxygen generation flow rate and compressor operating current are accumulated respectively to determine the corresponding current consumption value. When the cumulative flow rate reaches the preset cumulative oxygen supply threshold, the cumulative current does not exceed the preset cumulative current threshold, and the residual pressure difference enters the preset convergence allowable range, a low-consumption candidate period is determined. When the oxygen purity, oxygen production flow rate, and compressor operating current meet the constraints at the beginning of the next switching period, a low-consumption oxygen production condition is output. The switching cycle is defined by two adjacent cycle boundaries. Each cycle boundary is the sampling moment when the pressure equalization valve switches from the closed state to the open state and the pressure difference between the two towers begins to converge toward zero. The endpoint of the equalization time window is determined in the following manner: After the start of the equalization time window, when the absolute value of the pressure difference between the two towers at three consecutive sampling points all enters the preset convergence allowable range, and the absolute value of the change in pressure difference between adjacent towers at the three consecutive sampling points is within the preset sampling error allowable range, the first sampling time among the three consecutive sampling points is determined as the end of the equalization time window. If the determination condition for the end of the equalization time window has not been met when the equalization valve is closed, sampling continues until the determination condition is met; If the equalization valve remains open when the determined condition is met, the sampling time when the determined condition is first met is taken as the end point of the equalization time window; The initial phase of the next switching cycle begins at the first sampling point after the end of the equalization time window of the next switching cycle, when the oxygen production valve is opened and the exhaust valve is closed, and ends at the third sampling point when the oxygen purity of three consecutive sampling points reaches the preset qualified lower limit for the first time. The constraints include oxygen purity reaching a preset lower limit of acceptable quality, oxygen production flow meeting a preset oxygen production flow constraint, and compressor operating current not exceeding a preset current operating constraint.

2. The oxygen production condition identification method for low-consumption operation according to claim 1, characterized in that: The continuous convergence of the pressure difference between the two towers to zero includes: after the equalization valve switches from the closed state to the open state, the absolute value of the pressure difference between the two towers decreases sequentially in three consecutive sampling points, and the first sampling time in the three consecutive sampling points is determined as the starting point of the equalization time window.

3. The oxygen production condition identification method for low-consumption operation according to claim 1, characterized in that: The corresponding values ​​for the current consumption include the cumulative effective oxygen production flow rate and the cumulative effective oxygen production current; The cumulative effective oxygen production flow rate is obtained by accumulating the oxygen production flow rate of the effective oxygen production points according to the sampling order. The cumulative effective oxygen production current is obtained by accumulating the compressor operating current of the effective oxygen production points according to the sampling order. Sampling points where the oxygen production valve is not open, the exhaust valve is open, or the oxygen purity does not reach the preset qualified lower limit are not included in the accumulation.

4. An oxygen production condition identification system for low-consumption operation, used to execute the method according to any one of claims 1-3, characterized in that, include: The operation data sampling module is used to sample and acquire the pressure values, valve status, oxygen production parameters, and compressor operating current of the first and second molecular sieve towers during the switching cycle of the oxygen generator. The pressure equalization time window determination module is used to determine the pressure difference between the two towers based on the pressure values ​​of the first and second molecular sieve towers, and to determine the pressure equalization time window based on the status of the pressure equalization valve and the convergence status of the pressure difference between the two towers. The residual pressure difference constraint module is used to determine the residual pressure difference based on the pressure difference between the two towers at the end of the equalization time window, and to determine its convergence state. The current consumption corresponding value determination module is used to determine the current consumption corresponding value based on the cumulative oxygen production flow rate at the effective oxygen production point and the compressor operating current. The low-consumption operating condition output module is used to output the low-consumption oxygen production condition based on the corresponding flow consumption value, the residual pressure difference convergence state, and the oxygen production state at the beginning of the next switching cycle.

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