Multi-parameter fusion gas-liquid separation effect online evaluation method

Abstract

The invention relates to the technical field of alkaline water electrolysis hydrogen production, and discloses a multi-parameter fusion gas-liquid separation effect online evaluation method, which comprises the following steps: acquiring alkali liquor mass fraction concentration, fluid temperature, actual mixing density and mass flow signals on a backflow alkali liquor pipeline of a gas-liquid separator in real time; dynamically calculating the theoretical density of the bubble-free sodium carbonate solution under the current working condition according to the mass fraction concentration of the alkali solution and the fluid temperature which are collected in real time; calculating the absolute deviation between the theoretical density and the actual mixing density; performing real-time noise level analysis on the mass flow signals; according to a comparison result of the absolute deviation and a preset density deviation threshold value; and outputting a separation result judgment result and executing corresponding alarm or interlocking control. The theoretical density of the bubble-free sodium carbonate liquid is dynamically calculated in the control unit in real time according to the online measured mass fraction concentration and temperature of the alkali liquid, and reliable separation result evaluation under the real-time concentration change working condition is achieved.

Description

Technical Field

[0001] This invention relates to the field of alkaline water electrolysis for hydrogen production technology, and in particular to an online evaluation method for gas-liquid separation effect using a multi-parameter fusion approach. Background Technology

[0002] Alkaline electrolysis of water is one of the mainstream technologies for large-scale green hydrogen production. During the operation of the alkaline electrolyzer, hydrogen and oxygen generated at the electrodes enter the gas-liquid separator as a gas-liquid mixture with the alkaline solution. The separation result of the gas-liquid separator directly determines whether the reflux alkaline solution carries gas bubbles. If gas bubbles enter the circulation system with the alkaline solution, it will cause cross-contamination between the hydrogen and oxygen sides, resulting in an increase in the concentration of oxygen in hydrogen or hydrogen in oxygen, posing an explosion risk and triggering a safety interlock shutdown.

[0003] There is no effective method for evaluating gas-liquid separation performance online. Some technical solutions attempt to evaluate gas-liquid separation performance offline, such as the quick-closing valve method, but these methods suffer from problems such as difficulty in disassembling and assembling pipe sections, large deviations in measurement accuracy, and inability to be effectively used for online control. Summary of the Invention

[0004] To overcome the above shortcomings, this invention provides a multi-parameter fusion method for online evaluation of gas-liquid separation performance, aiming to improve the problem that existing technologies cannot effectively evaluate gas-liquid separation performance online.

[0005] In a first aspect, the present invention provides the following technical solution: an online evaluation method for gas-liquid separation effect based on multi-parameter fusion, comprising the following steps:

[0006] S1. Real-time acquisition of alkaline solution mass fraction concentration, fluid temperature, actual mixing density and mass flow rate signals on the alkaline solution return pipeline of the gas-liquid separator;

[0007] S2. Based on the real-time collected alkali concentration and fluid temperature, dynamically calculate the theoretical density of bubble-free soda ash solution under the current operating conditions.

[0008] S3. Calculate the absolute deviation between the theoretical density and the actual mixing density;

[0009] S4. Perform real-time noise level analysis on the mass flow signal;

[0010] S5. Based on the comparison results of the absolute deviation and the preset density deviation threshold, and the comparison results of the noise level and the preset noise threshold, the separation result of the gas-liquid separator is determined by fusion.

[0011] S6. Output the separation result judgment result and execute the corresponding alarm or interlock control.

[0012] Preferably, the specific steps for calculating the theoretical density of the bubble-free soda ash solution under the current operating conditions are as follows:

[0013] The control unit pre-stores or programs a model for the relationship between the density, concentration, and temperature of the alkali solution. Based on the real-time collected mass fraction concentration of the alkali solution and the fluid temperature, the theoretical density of the bubble-free soda ash solution under the current operating conditions is calculated by looking up tables or formulas.

[0014] Preferably, the method further includes:

[0015] When the absolute deviation is greater than the preset density deviation threshold, the gas-liquid separation result is directly determined to be poor and an alarm is triggered.

[0016] Only when the absolute deviation is not greater than the preset density deviation threshold will the step of real-time noise level analysis of the mass flow signal be initiated.

[0017] Preferably, the specific steps for performing real-time noise level analysis on the mass flow signal are as follows:

[0018] Within a fixed time window, the standard deviation, variance, or peak-to-peak value of the mass flow signal is calculated to obtain the noise level characterizing the degree of signal fluctuation.

[0019] Preferably, the specific steps for determining the separation result of the gas-liquid separator are as follows:

[0020] When the absolute deviation is greater than a preset density deviation threshold, or the noise level is greater than a preset noise threshold, the gas-liquid separation result is determined to be poor.

[0021] The gas-liquid separation result is considered good only when the absolute deviation is not greater than a preset density deviation threshold and the noise level is not greater than a preset noise threshold.

[0022] Preferably, the mass fraction concentration of the alkali solution is acquired in real time by an online refractometer installed on the alkali solution return pipeline of the gas-liquid separator, and the actual mixing density, mass flow rate signal and fluid temperature are simultaneously provided by the same Coriolis mass flow meter.

[0023] Preferably, the method involves independently configuring the alkali return pipelines for the hydrogen-side separator and the oxygen-side separator, respectively, to achieve online evaluation of the separation results of the hydrogen-side separator and the oxygen-side separator.

[0024] Better options also include:

[0025] Real-time comparison of the deviation between the theoretical density calculated on the hydrogen side and the theoretical density calculated on the oxygen side;

[0026] When the deviation exceeds a preset consistency threshold, an instrument consistency anomaly warning is triggered.

[0027] Preferably, when an instrument consistency anomaly warning is triggered, the theoretical density calculated from the side with the smaller deviation is automatically used as the global theoretical density benchmark, and the subsequent gas-liquid separation result evaluation steps are continued.

[0028] Preferably, the output separation result judgment result and the execution of corresponding alarm or interlock control include:

[0029] The human-machine interface displays the separation result status level, triggers audible and visual alarms, records process data for trend analysis, and automatically adjusts the frequency of the alkali circulation pump to increase the gas-liquid separation residence time.

[0030] The present invention has the following beneficial results:

[0031] 1. This invention dynamically calculates the theoretical density of bubble-free soda ash solution in real time in the control unit based on the online measured soda ash concentration and temperature, and compares it with the actual mixing density measured by the Coriolis mass flow meter. This eliminates the influence of soda ash concentration fluctuations caused by water replenishment or reaction consumption on the density benchmark, and realizes reliable separation result evaluation under real-time concentration change conditions.

[0032] 2. This invention uses density deviation as the primary judgment parameter and mass flow signal noise level as the auxiliary judgment parameter. It employs a two-level fusion judgment logic that directly alarms when density deviation exceeds the standard and then confirms the result a second time based on noise level when density is normal. This allows the system to respond quickly when bubble entrainment is severe and to provide early warning when bubble entrainment is slight, thus achieving continuous and accurate monitoring of the separation results across the entire range.

[0033] 3. After independently measuring and calculating the theoretical density on both sides of hydrogen and oxygen, this invention utilizes the physical characteristic that the theoretical densities on both sides must be highly consistent to perform real-time mutual calibration. When the deviation exceeds the standard, it automatically switches to the theoretical density on the reliable side as the global benchmark and issues an instrument abnormality warning. This enables the system to have online fault self-diagnosis and redundant operation capabilities for concentration meter and temperature measurement without the need for additional instrument calibration, thereby improving the reliability of long-term operation. Attached Figure Description

[0034] Figure 1 This is a flowchart of an online evaluation method for gas-liquid separation effect based on multi-parameter fusion proposed in this invention. Detailed Implementation

[0035] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Reference Figure 1 In the first embodiment of the present invention, the present invention provides a method for online evaluation of gas-liquid separation effect by multi-parameter fusion, comprising the following steps:

[0037] S1. Real-time acquisition of alkaline solution mass fraction concentration, fluid temperature, actual mixing density and mass flow rate signals on the alkaline solution return pipeline of the gas-liquid separator;

[0038] S2. Based on the real-time collected alkali concentration and fluid temperature, dynamically calculate the theoretical density of bubble-free soda ash solution under the current operating conditions.

[0039] S3. Calculate the absolute deviation between the theoretical density and the actual mixing density;

[0040] S4. Perform real-time noise level analysis on the mass flow signal;

[0041] S5. Based on the comparison results of the absolute deviation and the preset density deviation threshold, and the comparison results of the noise level and the preset noise threshold, the separation result of the gas-liquid separator is judged by fusion.

[0042] S6. Output the separation result judgment result and execute the corresponding alarm or interlock control.

[0043] Specifically, S1: Real-time data collection of alkali mass fraction concentration C, fluid temperature T, and actual mixing density is performed on the alkali return pipeline of the gas-liquid separator. and mass flow signal ;

[0044] S2: Based on the real-time collected alkali concentration C and fluid temperature T, dynamically calculate the theoretical density of the bubble-free soda ash solution under the current operating conditions. ;

[0045] S3: Calculate the absolute deviation between the theoretical density and the actual mixture density. The calculation formula is:

[0046]

[0047] In the formula, Density deviation, unit: g / cm³; The theoretical density calculated for S2, in g / cm³; The actual mixing density collected by S1;

[0048] S4: For mass flow signal Perform real-time noise level analysis to obtain the noise level σ;

[0049] S5: Obtained from S3 Deviation threshold from preset density The results are compared, and the σ obtained from S4 is compared with the preset noise threshold. The results of the comparison are combined to determine the separation result of the gas-liquid separator;

[0050] S6: Output the separation result judgment result to the control system, and execute alarm or interlock control according to the judgment result.

[0051] The above steps S1 to S6 are executed cyclically within the control unit, constituting a continuous online evaluation of the gas-liquid separator's separation results. S2 eliminates the influence of alkaline solution composition fluctuations on the density benchmark by using real-time concentration and temperature. S3 and S4 provide evaluation criteria based on two independent physical quantities: density reduction and fluid disturbance, respectively. S5 logically integrates the two criteria, and S6 enables closed-loop application of the evaluation results.

[0052] The method of this embodiment is applicable to single-sided evaluation of the alkali return pipeline of the hydrogen-side separator or the alkali return pipeline of the oxygen-side separator, and also applicable to dual-sided evaluation in which the hydrogen and oxygen sides are performed simultaneously and independently. When dual-sided evaluation is performed simultaneously, the hydrogen-side parameters are marked with the subscript H, and the oxygen-side parameters are marked with the subscript O, and each is executed independently from S1 to S6.

[0053] Furthermore, the specific steps for calculating the theoretical density of the bubble-free soda ash solution under the current operating conditions are as follows:

[0054] The density-concentration-temperature relationship model of alkali solution is pre-stored or programmed in the control unit. Based on the real-time collected mass fraction concentration of alkali solution and fluid temperature, the theoretical density of bubble-free soda ash solution under the current operating conditions is calculated by looking up tables or formulas.

[0055] Specifically, the online refractometer is installed on the reflux alkali pipeline between the gas-liquid separator outlet and the alkali circulation pump inlet. Its measuring probe directly contacts the alkali solution and outputs the alkali solution mass fraction concentration C in real time, in wt%. This concentration meter uses the refractive principle, measuring the refractive index of the alkali solution and converting it according to a preset refractive index-concentration correspondence to obtain the concentration value. The output signal is a digital signal and is transmitted to the control unit.

[0056] The Coriolis mass flow meter and the online refractometer are installed in series or parallel on the same reflux alkali solution pipeline section, with the alkali solution flow direction in the measuring tube consistent with the normal circulation direction of the system. The flow meter simultaneously outputs the following three real-time signals:

[0057] Actual mixing density Unit: g / cm³;

[0058] mass flow signal Unit: kg / h;

[0059] The fluid temperature T is generated by the vibration tube sensor and the platinum resistance temperature sensor in the same measuring tube. The density is directly calculated by the relationship between the Coriolis force and the vibration frequency, the mass flow rate is calculated by the phase difference of the vibration tube, and the temperature is measured by the built-in platinum resistance.

[0060] When evaluating the hydrogen-side separator and the oxygen-side separator separately, install an instrument group consisting of an online refractometer and a Coriolis mass flow meter on both the hydrogen-side and oxygen-side reflux alkali lines. The two instrument groups operate independently, and the parameters output by the hydrogen-side instruments are labeled as follows: The parameters output by the oxygen-side instrument are marked as follows: .

[0061] All instruments are connected to the control unit via hardwiring or fieldbus. The control unit is a PLC or DCS, ensuring that all signals are acquired synchronously in real time.

[0062] Based on the above instrument configuration, the system obtains the actual mixing density. The mass fraction concentration C and temperature T reflect the true density of the alkaline solution containing bubbles, and are used for subsequent theoretical density calculations. The mass flow rate signal is also relevant. Used for noise analysis.

[0063] Furthermore, the methods also include:

[0064] When the absolute deviation is greater than the preset density deviation threshold, the gas-liquid separation result is directly judged to be poor and an alarm is triggered.

[0065] Only when the absolute deviation is not greater than the preset density deviation threshold will the step of real-time noise level analysis of the mass flow signal begin.

[0066] Specifically, a density deviation threshold is set within the control unit. . The density was determined during the system debugging phase through experiments with known bubble entrainment amounts and stored as a fixed parameter in the control unit.

[0067] when > Upon receiving the signal, the control unit immediately sends a separation result difference status signal to the operator station and simultaneously outputs a switch signal to the alarm system, triggering the on-site audible and visual alarm. The event is then recorded in the historical database, including a timestamp and current information. Numerical value, corresponding side, hydrogen side or oxygen side.

[0068] This direct judgment logic is based on the following physical principle: the increased proportion of bubble volume leads to a significantly lower density of the mixed fluid than the theoretical density of bubble-free soda ash solution. When the amount of entrained bubbles reaches a certain level, the density decreases by more than [a certain percentage]. This indicates that the gas volume in the liquid phase has exceeded the safe allowable range, and the deterioration of the separation results can be confirmed without further verification.

[0069] Only when ≤ In this case, the density of the mixed fluid is basically consistent with the theoretical density. At this point, the amount of entrained bubbles is at a low level or non-existent, and the control unit continues to execute S4, using the noise level σ of the mass flow signal to perform a more sensitive secondary confirmation of the separation result. This two-stage judgment structure ensures rapid response when the separation result deteriorates significantly and provides higher resolution detection capability when the separation result fluctuates slightly. When performing separate evaluations on both the hydrogen and oxygen sides, the hydrogen side... and Comparison, oxygen side and The comparisons are conducted independently, without affecting each other, on either side. Exceed All of these trigger the corresponding side's separation result difference judgment and alarm.

[0070] Furthermore, the specific steps for real-time noise level analysis of the mass flow signal are as follows:

[0071] Within a fixed time window, the standard deviation, variance, or peak-to-peak value of the mass flow signal is calculated to obtain the noise level characterizing the degree of signal fluctuation.

[0072] Specifically, the control unit measures the mass flow signal output by the Coriolis mass flow meter within a fixed time window τ. Perform continuous sampling, with τ set to 30 to 60 seconds. The sampling frequency is consistent with the internal update rate of the flow meter.

[0073] At the end of each time window, the control unit calculates the noise level σ using the following formula:

[0074] ;

[0075] In the formula, For noise level, This represents the total number of sampling points within the time window τ. Let be the instantaneous mass flow rate at the i-th sampling time, in kg / h. The arithmetic mean of N sampled values ​​within this time window is calculated using the following formula:

[0076] ;

[0077] The control unit internally maintains a length of A circular buffer is used to store data from the most recent τ seconds. Instantaneous value. When a new sampled value arrives, the oldest value is removed, thus implementing a sliding window update.

[0078] As an alternative implementation, the control unit can also calculate the peak-to-peak value within the same time window. ,Right now ,in, and These represent the maximum and minimum mass flow rates within the window, respectively, and... It can be used directly as the noise level.

[0079] When bubbles randomly pass through the measuring tube of the Coriolis mass flow meter, the vibrating tube is instantaneously subjected to both density and flow velocity disturbances, leading to... High-frequency random pulsations exceeding normal process fluctuations occurred, and these pulsations were within the standard deviation range. or peak-to-peak value The above shows a significant increase. Conversely, when the liquid phase is pure or there are very few bubbles, It is only affected by slow, low-frequency changes caused by pump frequency or liquid level regulation. or Keep it at a low value.

[0080] Calculated or With the preset noise threshold in the control unit Compare them. During the system debugging phase, the parameters were determined through multiple measurements under both bubble-free normal operating conditions and known slight bubble entrainment conditions, and stored as fixed parameters.

[0081] When hydrogen and oxygen are evaluated separately on both sides, the hydrogen-side mass flow rate signal... oxygen-side mass flow signal Each enters its own independent sliding time window and calculates separately. and and respectively with the same Compare them.

[0082] Through the above calculation process, the control unit obtains a quantitative noise level σ that reflects the degree of disturbance in the gas-liquid two-phase flow. This provides a second criterion for subsequent fusion judgments, independent of density deviation.

[0083] Furthermore, the specific steps for determining the separation results of the gas-liquid separator are as follows:

[0084] When the absolute deviation is greater than the preset density deviation threshold, or the noise level is greater than the preset noise threshold, the gas-liquid separation result is judged to be poor.

[0085] The gas-liquid separation result is considered good only when the absolute deviation is not greater than the preset density deviation threshold and the noise level is not greater than the preset noise threshold.

[0086] Specifically, when the absolute deviation calculated by S3 Greater than the preset density deviation threshold Or, the noise level σ calculated by S4 is greater than the preset noise threshold. When the separation result of the corresponding gas-liquid separator is poor, it is determined that the separation result is poor.

[0087] Only when ≤ And at the same time ≤ Only when the time is right can the separation result of the corresponding gas-liquid separator be judged to be good.

[0088] The control unit uses the following logical decision table to achieve fusion judgment:

[0089] The above judgment is performed once in each calculation cycle, the same as the S1 acquisition cycle, and immediately after completion. When > At this time, the control unit directly skips the subsequent noise calculation and immediately outputs the separation result difference to shorten the response time.

[0090] The separation results are divided into two sub-levels:

[0091] Depend on > When triggered alone, it indicates that there is obvious bubble entrainment, which is a deterministic degradation;

[0092] Depend on ≤ but > When triggered, it indicates that the density has not yet decreased significantly, but two-phase flow disturbances have already occurred, which is considered early-stage degradation.

[0093] The control unit simultaneously outputs one of three states to the human-machine interface:

[0094] "Separation results are good" (green indicator);

[0095] "Early deterioration of separation results" (yellow indicator, only σ exceeds the standard);

[0096] "The separation results have deteriorated significantly" (red indicator). (Exceeding the standard).

[0097] When performing separate evaluations on both the hydrogen and oxygen sides, the complete fusion judgment logic described above is executed independently on both the hydrogen and oxygen sides, resulting in separation statuses of "good / early degradation / significant degradation" and "good / early degradation / significant degradation" on the oxygen side, respectively. The overall system separation status is the worst state between the hydrogen and oxygen sides; that is, if significant degradation occurs on either side, the whole system is judged as significantly degraded, and if early degradation occurs on either side while the other side is good, the whole system is judged as early degradation.

[0098] Through this fusion judgment logic, the system can quickly and deterministically alarm when the bubble entrainment is large, and can provide early warning when the bubble entrainment is small, relying on mass flow noise. This ensures continuous and effective evaluation of the separation results throughout the entire bubble entrainment range.

[0099] The mass fraction concentration of the alkali solution is collected in real time by an online refractometer installed on the alkali return pipeline of the gas-liquid separator. The actual mixing density, mass flow rate signal and fluid temperature are provided simultaneously by the same Coriolis mass flow meter.

[0100] Specifically, the online refractometer's measuring head employs a prism-type structure, directly inserted into the reflux alkali solution pipeline or bypass measuring chamber. Incident light is refracted through the prism at the alkali solution interface, and the critical angle position is captured by a photoelectric array detector. The detector's output signal is converted into a mass fraction concentration C by an internal processor based on a pre-calibrated refractive index-concentration curve, covering an output range of 25 wt% to 33 wt%. The meter probe is made of high-temperature alkali-resistant material and is fixed to the pipeline via a flange or threaded connection. The signal is transmitted to the control unit.

[0101] The Coriolis mass flow meter employs a U-shaped or straight-tube vibrating tube structure, with the tube diameter determined based on the circulating flow rate. The same vibrating tube maintains a constant frequency vibration under the action of the drive coil. When the alkaline solution flows through, a Coriolis force is generated, resulting in a phase difference between the two sides of the vibrating tube. This phase difference is proportional to the mass flow rate. The vibration frequency is inversely proportional to the square root of the fluid density, thus allowing direct calculation of the actual mixture density. A platinum resistance thermometer is integrated both inside and outside the vibrating tube to measure the fluid temperature T. All three signals are generated by the same sensor at the same measurement point and at the same time, ensuring... , The three correspond to each other: T, T, and T.

[0102] Both instruments are installed on the same horizontal pipe section after the liquid outlet at the bottom of the gas-liquid separator and before the inlet of the alkali circulation pump, with no other branches or valves between them, ensuring that both instruments measure the same alkali flow. The installation direction allows the fluid to flow from bottom to top or horizontally to avoid gas accumulation in the measuring pipe. The vibrating tube axis of the Coriolis mass flow meter is kept coaxial with the pipe axis, and the mounting bracket is rigidly fixed to prevent external vibration interference.

[0103] When performing separate evaluations on both the hydrogen and oxygen sides, each side of the hydrogen-side separator return pipeline is equipped with an identical online refractometer and Coriolis mass flow meter. The installation method, selection requirements, and signal output methods for both instrument sets are identical. The output signals of the two instrument sets are connected to different I / O channels or different communication addresses of the control unit to achieve hydrogen-side... and oxygen side Independent acquisition and processing of parameters.

[0104] By selecting and installing the instruments as described above, the system can directly obtain the accurate concentration and temperature required for dynamic theoretical density calculation, as well as the actual mixing density and mass flow rate disturbance signals required for separation result evaluation, without the need to add additional sensors.

[0105] Furthermore, the method involves independently setting up the alkali return pipeline for the hydrogen-side separator and the alkali return pipeline for the oxygen-side separator, so as to achieve online evaluation of the separation results of the hydrogen-side separator and the oxygen-side separator respectively.

[0106] Also includes:

[0107] Real-time comparison of the deviation between the theoretical density calculated on the hydrogen side and the theoretical density calculated on the oxygen side;

[0108] When the deviation exceeds the preset consistency threshold, an instrument consistency anomaly warning is triggered.

[0109] Specifically, an online refractometer and a Coriolis mass flow meter are installed on the hydrogen-side reflux alkali solution pipeline, while another identical online refractometer and Coriolis mass flow meter are installed independently on the oxygen-side reflux alkali solution pipeline. The two instrument sets collect parameters on the hydrogen side respectively. and oxygen-side parameters .

[0110] The control unit calculates the hydrogen concentration in each calculation cycle based on the real-time hydrogen concentration. and temperature The theoretical hydrogen density was calculated using the same alkali solution density-concentration-temperature relationship model. Simultaneously, based on the real-time oxygen concentration... and temperature The theoretical oxygen density was calculated. .

[0111] The theoretical density deviation between the two sides was then calculated. The formula is:

[0112] ;

[0113] Preset consistency threshold within the control unit , The value ranges from 0.001 g / cm³ to 0.003 g / cm³, and is determined by simultaneously measuring the same standard alkali solution on both sides of the instrument during the system calibration stage.

[0114] when ≤ This indicates that the concentration and temperature measurements on the hydrogen and oxygen sides are consistent, the instruments are in normal condition, and the system continues to operate at their respective rates. and O independently performs subsequent evaluation of the separation results.

[0115] when > Upon this event, the control unit immediately sets the instrument consistency anomaly flag, sends a "Instrument Consistency Anomaly" text warning to the human-machine interface, flashes a yellow indicator light in the corresponding side display area, and records the event in the alarm log. The log content includes a timestamp, numerical value O value and Numerical value.

[0116] This mechanism is based on the following physical facts: the alkaline solutions on both the hydrogen and oxygen sides originate from the same electrolyzer, and after being mixed by a circulating pump, their concentration and temperature remain consistent in real time within the pipes on both sides. Therefore, the theoretical density calculated on both sides using the same model is consistent. and When the instruments are functioning normally, the concentration and temperature sensors must be highly consistent. Any significant deviations will result from drift or malfunction of at least one of the concentration or temperature sensors.

[0117] Through the above-mentioned dual-sided independent configuration and theoretical density mutual calibration method, the system can achieve online consistency monitoring and fault early warning of four sets of key instruments on both sides without adding additional calibration instruments.

[0118] Furthermore, when an instrument consistency anomaly warning is triggered, the theoretical density calculated from the side with the smaller deviation is automatically used as the global theoretical density benchmark, and the subsequent gas-liquid separation result evaluation steps are continued.

[0119] Output the separation result judgment result and execute the corresponding alarm or interlock control, including:

[0120] The human-machine interface displays the separation result status level, triggers audible and visual alarms, records process data for trend analysis, and automatically adjusts the frequency of the alkali circulation pump to increase the gas-liquid separation residence time.

[0121] Specifically, when > Upon that time, the control unit immediately performs the following operations:

[0122] Determine the side with the smaller deviation:

[0123] Calculate the theoretical density on the hydrogen side separately. The difference from the historical global baseline density (the average of the previous normal cycle) and oxygen side The difference between O and the same historical benchmark O. If < If O is present, the hydrogen-side instrument is considered more reliable; conversely, if O is absent, the oxygen-side instrument is considered more reliable.

[0124] Establish a global theoretical density benchmark :

[0125] The theoretical density of the side with smaller deviation is directly assigned to the global benchmark, i.e. = (when < (O time) or = O (when O ≤ hour);

[0126] Redundancy assessment continues:

[0127] In this calculation period and subsequent periods, the side with the larger deviation will no longer use its own calculations. conduct Instead of calculation, it directly uses As its theoretical density benchmark, i.e.

[0128] The side with larger deviation ;

[0129] The side with smaller deviation still uses itself. Continue calculating;

[0130] The noise level σ calculation and subsequent fusion judgment logic remain unchanged, thus ensuring that the system separation result evaluation is not interrupted when any instrument on either side drifts.

[0131] The output results and interlocking control execute one or more of the following combinations:

[0132] Human-Machine Interface Display: Independent status boxes for the hydrogen side and oxygen side are set up on the main screen of HMI, which display three colors and text in real time: "Good" (green), "Early Deterioration" (yellow), and "Significant Deterioration" (red); at the same time, when the instrument is abnormal, the text prompt "Instrument consistency abnormal - automatically switched to X side reference" is displayed.

[0133] Audible and visual alarm: When the separation result deteriorates significantly, the DO switch value is output to the field alarm light; the red light flashes slowly when there is early deterioration; the yellow light stays on when the instrument consistency is abnormal.

[0134] Data logging: The control unit writes the following variables to the historical database every cycle: timestamp, , , , , , , , 、ρ_theo,O、 , , , Currently in use The system displays the final state of hydrogen, the final state of oxygen, the overall state, and alarm indicators, facilitating future trend retrospective analysis and optimization.

[0135] Automatic interlock control: When the state of any side or the whole is "significantly deteriorated" for more than the settable time, the control unit sends a frequency reduction command to the alkali circulation pump frequency converter through analog output or Modbus register, thereby reducing the circulation flow rate and extending the residence time and separation time of alkali in the gas-liquid separator until the separation result is restored to the "good" state, and then automatically restores the original frequency setting value.

[0136] Through the aforementioned redundancy switching and multi-mode output mechanism, the system maintains the continuity and accuracy of separation result evaluation even when drift occurs in a single-sided concentration meter or temperature measurement.

[0137] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for online evaluation of gas-liquid separation performance using multi-parameter fusion, characterized in that, Includes the following steps: S1. Real-time acquisition of alkaline solution mass fraction concentration, fluid temperature, actual mixing density and mass flow rate signals on the alkaline solution return pipeline of the gas-liquid separator; S2. Based on the real-time collected alkali concentration and fluid temperature, dynamically calculate the theoretical density of bubble-free soda ash solution under the current operating conditions. S3. Calculate the absolute deviation between the theoretical density and the actual mixing density; S4. Perform real-time noise level analysis on the mass flow signal; S5. Based on the comparison results of the absolute deviation and the preset density deviation threshold, and the comparison results of the noise level and the preset noise threshold, the separation result of the gas-liquid separator is determined by fusion. S6. Output the separation result judgment result and execute the corresponding alarm or interlock control.

2. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 1, characterized in that, The specific steps for calculating the theoretical density of bubble-free soda ash solution under the current operating conditions are as follows: The control unit pre-stores or programs a model for the relationship between the density, concentration, and temperature of the alkali solution. Based on the real-time collected mass fraction concentration of the alkali solution and the fluid temperature, the theoretical density of the bubble-free soda ash solution under the current operating conditions is calculated by looking up tables or formulas.

3. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 1, characterized in that, The method further includes: When the absolute deviation is greater than the preset density deviation threshold, the gas-liquid separation result is directly determined to be poor and an alarm is triggered. Only when the absolute deviation is not greater than the preset density deviation threshold will the step of real-time noise level analysis of the mass flow signal be initiated.

4. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 1, characterized in that, The specific steps for real-time noise level analysis of the mass flow signal are as follows: Within a fixed time window, the standard deviation, variance, or peak-to-peak value of the mass flow signal is calculated to obtain the noise level characterizing the degree of signal fluctuation.

5. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 1, characterized in that, The specific steps for determining the separation result of the gas-liquid separator are as follows: When the absolute deviation is greater than a preset density deviation threshold, or the noise level is greater than a preset noise threshold, the gas-liquid separation result is determined to be poor. The gas-liquid separation result is considered good only when the absolute deviation is not greater than a preset density deviation threshold and the noise level is not greater than a preset noise threshold.

6. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 1, characterized in that, The mass fraction concentration of the alkali solution is collected in real time by an online refractometer installed on the alkali solution return pipeline of the gas-liquid separator, and the actual mixing density, mass flow rate signal and fluid temperature are provided simultaneously by the same Coriolis mass flow meter.

7. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 1, characterized in that, The method involves setting up independent alkali return pipelines for the hydrogen-side separator and the oxygen-side separator, respectively, to achieve online evaluation of the separation results of the hydrogen-side separator and the oxygen-side separator.

8. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 7, characterized in that, Also includes: Real-time comparison of the deviation between the theoretical density calculated on the hydrogen side and the theoretical density calculated on the oxygen side; When the deviation exceeds a preset consistency threshold, an instrument consistency anomaly warning is triggered.

9. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 8, characterized in that, When an instrument consistency anomaly warning is triggered, the theoretical density calculated from the side with the smaller deviation is automatically used as the global theoretical density benchmark, and the subsequent gas-liquid separation result evaluation steps are continued.

10. The online evaluation method for gas-liquid separation effect based on multi-parameter fusion according to claim 9, characterized in that, The output separation result judgment result and the execution of corresponding alarm or interlock control include: The human-machine interface displays the separation result status level, triggers audible and visual alarms, records process data for trend analysis, and automatically adjusts the frequency of the alkali circulation pump to increase the gas-liquid separation residence time.

Images