Intelligent sensing water-soluble gas combined collection system and method

Abstract

The application discloses an intelligent sensing water-soluble gas joint sampling system and method, belongs to the technical field of water body gas sampling and intelligent sensing, and aims at solving the problems of the effective mass transfer area of the free bubble shielding film assembly and the vacuum degassing condensate entering the downstream equipment. The application realizes the first gas sampling through the closed gas-liquid separation and the drainage type metering, realizes the hydrophobic gas permeable membrane diffusion under the permission of the bubble-free stable window to form the second gas sample, and controls the main and standby liquid interception branches according to the dew point margin, the liquid interception liquid level and the liquid blocking pressure difference, so that the free gas and the dissolved gas are separately metered, the gas and water are safely isolated, and the suction path switching under the abnormal state is realized.

Description

Technical Field

[0001] This invention relates to the field of water gas sampling and intelligent sensing technology, and in particular to an intelligent sensing system and method for combined water and dissolved gas sampling. Background Technology

[0002] When gas sensors and intelligent sensing systems detect gaseous components in water, it is usually necessary to first obtain a detectable gas sample from the water sample. Gas-laden water flow may contain both free gas bubbles that can float and coalesce, and gases dissolved in the water. If both types of gases are directly introduced into the same membrane degassing process, free gas bubbles are prone to attaching to or accumulating on the membrane surface, altering the effective mass transfer area of ​​the membrane module and the wet-side flow state, leading to fluctuations in the dissolved gas sampling process.

[0003] To improve the efficiency of dissolved gas release, existing sampling front-ends can apply negative pressure to the dry side of a hydrophobic and permeable membrane, allowing dissolved gas to permeate through the membrane under the influence of partial pressure difference. However, water vapor in the sample gas may condense in the negative pressure gas path, pump body, or detection unit; when condensate accumulates or liquid breakthrough occurs in the hydrophobic liquid-blocking structure, it can easily cause vacuum pressure spikes, sample gas loss, detection drift, or liquid intrusion into downstream equipment. Using only a single liquid-blocking container makes it difficult to complete isolation, drainage, and recovery without interrupting sampling.

[0004] Furthermore, the free gas and dissolved gas obtained from membrane diffusion both originate from the same water sample, but they differ in flow path, metering method, and formation sequence. Without standardized batch and time window binding, bubble-free release conditions, and condensation risk interlocking, problems can easily arise such as insufficient free gas collection before membrane sampling, applying negative pressure before the wet side of the membrane is fully filled, or re-injecting abnormal branches before they are reset.

[0005] Therefore, there is a need for an intelligent sensing system and method for combined water and dissolved gas extraction that can overcome the shortcomings of the existing technologies. Summary of the Invention

[0006] This invention provides an intelligent sensing system and method for combined water and dissolved gas sampling. The method first performs a closed-loop phase separation on a water sample containing free air bubbles and dissolved gas, allowing the free gas to enter the upper collection chamber and push out the pre-filled isolation liquid in the drainage-type metering and acquisition unit, thereby obtaining and measuring the first gas sample. The defoamed water after phase separation only enters the hydrophobic and permeable membrane module when the bubble state, phase separation liquid level, and inlet flow rate all meet the bubble-free stability window. After the wet side of the membrane is filled, a controlled negative pressure is gradually established on the dry side, causing the dissolved gas to diffuse and form the second gas sample. The second gas sample is output after passing through a liquid interception and hydrophobic liquid barrier structure. The controller determines the condensation risk level based on the dew point margin, liquid interception level, and pressure difference of the barrier, and accordingly performs load reduction, main / backup branch switching, or isolation and shutdown of pumping. The two gas samples are measured separately and bound to the same water sample batch and sampling time window, allowing for separate sample output or combined output after separate measurement.

[0007] This invention provides an intelligent sensing method for combined water and dissolved gas extraction, comprising:

[0008] S1. Take a closed sample of water containing free gas bubbles and dissolved gas, send the water sample into the gas-liquid phase separation unit, so that the free gas is collected in the upper free gas collection chamber and the phase-separated water is output from the lower defoaming water outlet. The collected free gas pushes the pre-filled isolation liquid in the drainage metering and acquisition unit to be discharged. The first gas sample quantity is obtained according to the discharge volume and the first gas sample is output.

[0009] S2. Obtain the phase separation liquid level, the bubble state of the defoaming water and the inlet water flow rate. When the bubble state is bubble-free within a preset continuous time period, the phase separation liquid level is within a preset liquid level range and the inlet water flow rate is within a preset flow rate range, a membrane release permit is formed, and in response to the membrane release permit, the defoaming water is sent into the wet side of the hydrophobic and breathable membrane assembly.

[0010] S3. After the wet side is filled with defoaming water in response to the membrane release permission, a controlled negative pressure is established on the dry side of the hydrophobic and breathable membrane assembly, so that the dissolved gas in the defoaming water passes through the hydrophobic and breathable membrane assembly to form a second gas sample, and the second gas sample flows through the liquid interception unit and the hydrophobic and breathable liquid blocking element in sequence.

[0011] S4. Obtain the temperature and humidity of the second gas sample, the liquid level of the liquid interception unit, and the pressure difference of the hydrophobic and breathable liquid-blocking component. Determine the dew point margin based on the temperature and humidity, and determine the condensation risk level based on the dew point margin, liquid level, and pressure difference. Control the suction path of the dry side and the output path of the second gas sample based on the condensation risk level.

[0012] S5. Measure the first gas sample and the second gas sample respectively and output them.

[0013] Optionally, S1 includes:

[0014] The water sample is allowed to enter the phase separation space along the tangential or deflected water inlet channel of the gas-liquid phase separation unit, so that the free bubbles float up and gather in the upper free gas collection cavity under the action of buoyancy.

[0015] The lower defoaming water outlet is located below the liquid surface of the phase separation space. The upper free gas collection chamber is in sealed communication with the air inlet of the drainage metering and acquisition unit. The drainage end of the drainage metering and acquisition unit is equipped with a drainage volume detector. The first gas sample volume is calculated by converting the detected drainage volume with the temperature of the pre-filled isolation liquid and the pressure of the upper free gas collection chamber.

[0016] Furthermore, it also includes: a first gas sampling valve is installed at the gas outlet of the upper free gas collection chamber, and a detection switching valve is installed at the gas outlet of the drainage-type metering and acquisition unit.

[0017] When the discharge volume reaches the discharge volume corresponding to the target volume of the first gas sample, the first gas sample valve is closed, and the first gas sample is sent into the free gas detection branch or the first sample storage container through the detection switching valve.

[0018] When the phase separation liquid level reaches the preset upper limit or lower limit, water supply to the gas-liquid phase separation unit is stopped and the corresponding batch is marked as having an abnormal phase separation liquid level.

[0019] Optionally, S2 includes:

[0020] A bubble state detector is set between the lower defoaming water outlet and the membrane wet-side inlet valve, a liquid level detector is set in the gas-liquid phase separation unit, and a water flow detector is set upstream of the membrane wet-side inlet valve in a continuous flow section where water samples still flow when the inlet valve is closed.

[0021] During startup, the defoaming water flows from the lower defoaming water outlet through the continuous flow section and the pre-flow return branch before returning to the gas-liquid phase separation unit;

[0022] When the bubble state detector does not detect any bubbles of the size reaching the lower limit of bubble detection within a continuous time threshold, the phase separation liquid level is between the lower and upper limits of the liquid level, and the influent flow rate is between the lower and upper limits of the flow rate, the membrane release permission is output. The continuous time threshold, lower liquid level limit, upper liquid level limit, lower flow rate limit, and upper flow rate limit are pre-written into the controller by the sampling configuration of the current water sample batch.

[0023] Optionally, S3 includes:

[0024] After the membrane release permission is granted, the wet-side water inlet valve of the membrane is opened, and the wet-side fullness is determined by the full liquid detector located at the wet-side outlet of the hydrophobic and breathable membrane module.

[0025] After determining that the wet side is full, adjust the vacuum pump or vacuum regulating valve according to the negative pressure loading slope specified in the sampling configuration of the current water sample batch until the membrane dry side pressure reaches the target dry side pressure.

[0026] The adjustment amount of the vacuum pump or vacuum regulating valve is limited based on the difference between the wet side pressure and the dry side pressure of the membrane, and the adjustment amount is corrected by feedback based on the flow rate of the second gas sample.

[0027] Furthermore, it also includes: when the membrane release permit is revoked, the phase separation liquid level exceeds the preset liquid level range, the influent flow rate exceeds the preset flow rate range, the pressure difference across the membrane reaches the differential pressure protection threshold, or the bubble state detector detects bubbles, the negative pressure loading amount on the dry side is first reduced to the unloading set value, then the membrane wet side inlet valve is closed, and the water sample is returned to the gas-liquid phase separation unit through the reflux valve or the water sample is guided away from the hydrophobic and breathable membrane assembly through the bypass valve;

[0028] The next wet-side filling and dry-side negative pressure loading are performed only after the membrane release is re-formed.

[0029] Optionally, S4 includes:

[0030] On the dry side of the hydrophobic and breathable membrane assembly, a main liquid interception branch and a backup liquid interception branch are connected in parallel. Each liquid interception branch is sequentially equipped with an upstream branch valve, a gravity liquid interception chamber, a liquid interception level detector, a hydrophobic and breathable liquid blocking component, a liquid blocking differential detector, and a downstream branch isolation valve.

[0031] The dew point temperature is determined based on the temperature and humidity of the second gas sample, and the dew point margin is obtained by subtracting the dew point temperature from the temperature of the second gas sample.

[0032] Set successively decreasing warning margin threshold, switching margin threshold and isolation margin threshold for dew point margin. When the dew point margin is not greater than the corresponding margin threshold, it is judged as the corresponding risk level.

[0033] For the liquid level and pressure difference of the current working branch, set an increasing warning threshold, switching threshold and isolation threshold respectively. When the liquid level or pressure difference is not less than the corresponding threshold, it is determined to be the corresponding risk level.

[0034] The results of the judgment of dew point margin, liquid level of the current working branch and pressure difference are combined according to the priority of isolation level, switching level and warning level. The first risk level that appears is selected as the condensation risk level. The liquid level of the isolated branch to be reset and the pressure difference are only used for drainage and reset judgment.

[0035] Furthermore, it also includes: using the condensation risk level as a gas path safety interlock signal, marking the liquid interception branch where both the upstream branch valve and the downstream branch isolation valve are open and undertaking membrane suction as the current working branch, and marking another liquid interception branch that has met the reset conditions as a branch to be switched and available.

[0036] When the condensation risk level is a warning level, reduce the negative pressure loading on the dry side;

[0037] When the condensation risk level is the switching level, while keeping the upstream branch valve of the available branch to be switched closed, open its downstream branch isolation valve for pre-drainage until the difference between its branch pressure and the current working branch pressure does not exceed the preset switching pressure difference. Then open the upstream branch valve of the available branch to be switched, and then close the upstream branch valve and downstream branch isolation valve of the current working branch. Mark the newly opened liquid interception branch as the current working branch, and mark the cut-off liquid interception branch as the isolation branch to be reset.

[0038] When the condensation risk level is isolation level, close the upstream branch valve and the downstream branch isolation valve of the current working branch and stop membrane suction;

[0039] The isolated branch to be reset is discharged after bidirectional isolation by its upstream branch valve and downstream branch isolation valve. It is marked as a branch to be switched and available after the intercepted liquid level is less than the reset liquid level, the pressure difference is less than the reset pressure difference, and the airtightness test result meets the preset leakage rate threshold.

[0040] Optionally, S5 includes:

[0041] For each batch of water samples, establish a batch record that includes the sampling start and end times, influent flow rate, discharge volume, first gas sample volume, second gas sample flow rate integral value, phase level, bubble state, pressure on both sides of the membrane, dew point margin, liquid level, resistance pressure difference, branch switching events, and valve / pump status.

[0042] The first gas sample and the second gas sample are respectively bound to the same water sample batch and the sampling time window defined by the sampling start and end times, and written into the batch record;

[0043] The phase separation liquid level exceeding the lower or upper limit of the liquid level is defined as a phase separation liquid level abnormality. The event of not being marked as the current working branch or the upstream branch valve and downstream branch isolation valve of the cut-off liquid interception branch being not fully closed when the switch-off stage is triggered to the expiration of the preset switch time limit is defined as an incomplete branch switch event. The drainage and reset of the cut-off branch are recorded separately as branch reset events.

[0044] In the absence of the aforementioned abnormal phase level, continued suction event after membrane release permit revocation, isolation stage triggering event, and incomplete branch switching event, the water sample batch is marked as a qualified batch, and the first and second gas samples of the qualified batch are output according to the sampling method or combined after separate measurement and output to the detection branch or storage container.

[0045] On the other hand, the present invention also provides an intelligent sensing water-dissolved gas combined collection system, comprising:

[0046] The free gas separation and metering module includes a gas-liquid phase separation unit and a drainage-type metering and acquisition unit, used to execute step S1; the membrane release module includes a phase level detector, a bubble state detector, a water flow detector, and a membrane wet-side inlet valve, used to execute step S2; the membrane diffusion sampling module includes a hydrophobic and breathable membrane assembly, membrane side pressure detectors, and a negative pressure regulating unit, used to execute step S3; the condensation isolation module includes a parallel main liquid interception branch and a backup liquid interception branch, a temperature and humidity detector, a liquid interception level detector, a pressure differential detector, and a branch valve, used to execute step S4; the batch output module is used to meter the first gas sample and the second gas sample respectively, and execute step S5; the controller is communicatively connected to the free gas separation and metering module, the membrane release module, the membrane diffusion sampling module, the condensation isolation module, and the batch output module, used to control the valve pump, the suction path, and the gas sample output path according to the membrane release permit and the condensation risk level.

[0047] The beneficial effects of this invention are:

[0048] 1. By completing free gas collection and drainage-type metering before membrane diffusion, the shading of free gas on the membrane surface is reduced, maintaining the effective mass transfer area and wet-side flow state of the membrane module.

[0049] 2. Membrane release is determined by the bubble state, phase separation liquid level and inlet water flow rate. A control sequence of first filling the wet side and then gradually applying negative pressure to the dry side is adopted to reduce the entry of bubbles on the membrane surface and the peak of vacuum pressure.

[0050] 3. A three-level condensation risk is formed by dew point margin, liquid interception level and pressure difference, and the main and backup liquid interception branches that can be pre-pumped and switched and can be isolated and drained in both directions are used to prevent condensate from entering the vacuum pump or detection unit and reduce sample gas loss.

[0051] 4. By separately measuring the first and second gas samples and binding them to the same water sample batch and sampling time window, a consistent data basis is provided for sample testing, sample merging after measurement, and batch quality judgment. Attached Figure Description

[0052] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0053] Figure 1 This is a flowchart of the intelligent sensing water-dissolved gas combined sampling method of the present invention.

[0054] Figure 2 This is a flowchart of the S4 condensation risk interlock control of the present invention. Detailed Implementation

[0055] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0056] refer to Figures 1-2 A smart sensing method for combined water and dissolved gas extraction includes:

[0057] S1. Take a closed sample of water containing free gas bubbles and dissolved gas, send the water sample into the gas-liquid phase separation unit, so that the free gas is collected in the upper free gas collection chamber and the phase-separated water is output from the lower defoaming water outlet. The collected free gas pushes the pre-filled isolation liquid in the drainage metering and acquisition unit to be discharged. The first gas sample quantity is obtained according to the discharge volume and the first gas sample is output.

[0058] S2. Obtain the phase separation liquid level, the bubble state of the defoaming water and the inlet water flow rate. When the bubble state is bubble-free within a preset continuous time period, the phase separation liquid level is within a preset liquid level range and the inlet water flow rate is within a preset flow rate range, a membrane release permit is formed, and in response to the membrane release permit, the defoaming water is sent into the wet side of the hydrophobic and breathable membrane assembly.

[0059] S3. After the wet side is filled with defoaming water in response to the membrane release permission, a controlled negative pressure is established on the dry side of the hydrophobic and breathable membrane assembly, so that the dissolved gas in the defoaming water passes through the hydrophobic and breathable membrane assembly to form a second gas sample, and the second gas sample flows through the liquid interception unit and the hydrophobic and breathable liquid blocking element in sequence.

[0060] S4. Obtain the temperature and humidity of the second gas sample, the liquid level of the liquid interception unit, and the pressure difference of the hydrophobic and breathable liquid-blocking component. Determine the dew point margin based on the temperature and humidity, and determine the condensation risk level based on the dew point margin, liquid level, and pressure difference. Control the suction path of the dry side and the output path of the second gas sample based on the condensation risk level.

[0061] S5. Measure the first gas sample and the second gas sample respectively and output them.

[0062] In this specific embodiment, S1 includes:

[0063] After receiving the sampling start command for this water sample, the controller generates a unique water sample batch identifier, and places the sampling pipeline, gas-liquid phase separation unit, drainage metering and acquisition unit, first sample storage container and subsequent membrane sampling pipeline in a sealed state. The controller also writes the sampling start time, sampling point number, predetermined first gas sample target quantity, maximum sampling duration, maximum cumulative water inflow and sampling configuration version into the batch record. In this specific embodiment, the sampling pump delivers the water sample containing free gas bubbles and dissolved gas into the gas-liquid phase separation unit at a set flow rate of 1.0 L / min. The maximum sampling duration and maximum cumulative water inflow are set to 600s and 10 L, respectively. The set values ​​are given by the sampling configuration of the water sample batch and verified by the water inflow detector.

[0064] Water samples enter the cylindrical phase separation space through the tangential inlet channel on the side wall of the gas-liquid phase separation unit. The tangential flow forms a low-shear vortex in the phase separation space. Free bubbles with a diameter reaching the lower limit of bubble detection migrate upward under the action of buoyancy and radial pressure gradient of the vortex and coalesce in the upper free gas collection cavity. The phase-separated water is discharged from the lower defoaming water outlet located below the minimum allowable liquid level. The controller reads the phase-separated liquid level of the liquid level detector at 10 Hz and writes it into the phase-separated status cache along with the batch identifier and timestamp.

[0065] The gas outlet of the upper free gas collection chamber is connected in a sealed manner to the inlet of the drainage-type metering and acquisition unit via the first gas sample valve. The drainage-type metering and acquisition unit is pre-filled with an isolation liquid that does not react with the gas to be measured and whose vapor pressure has been calibrated. After the free gas enters, it pushes the isolation liquid out from the drain end. The drain volume detector uses a weighing or volumetric detection structure to output the cumulative drain volume. The controller performs three-point median filtering on the drain volume signal and deletes abnormal records with reversed timestamps or single-cycle increments exceeding the upper limit of the range.

[0066] Controller according to The cumulative liquid volume was converted into the first gas sample volume under standard conditions, where This indicates the first gas sample volume, in standard milliliters. This indicates the cumulative volume of fluid discharged as measured by the discharge volume detector, in milliliters. This represents the absolute pressure of the upper free gas collecting chamber, measured in kilopascals by an absolute pressure detector installed in the collecting chamber during the current control cycle. This represents the saturated vapor pressure of the insulating liquid at the current temperature, expressed in kilopascals (kPa), and can be found in the insulating liquid vapor pressure calibration table by temperature. The standard pressure is represented, and in this specific embodiment it is taken as 101.325 kPa. This represents the standard thermodynamic temperature, taken as 273.15 Kelvin. The thermodynamic temperature of the insulating liquid, expressed in Kelvin, is obtained by adding 273.15 to the measured temperature of the insulating liquid. Before performing this conversion and the inverse conversion of the target discharge volume, the controller requires... ,in This indicates the minimum positive pressure difference given by the sampling configuration, which is 0.5 kPa in this specific embodiment; if this condition is not met, the first gas sample volume and target discharge volume update are frozen, the first gas sample metering action is turned off, the original pressure value is saved, and the batch is marked as an abnormal pressure correction input.

[0067] The vapor pressure calibration table for the isolation liquid is stored in the read-only parameter area of ​​the controller. Its record fields include isolation liquid type, temperature node, saturated vapor pressure, effective temperature range, calibration date, and version number. The temperature node is in degrees Celsius, and the saturated vapor pressure is in kilopascals. The table is generated by piecewise linear fitting of pressure data measured at 5-degree Celsius intervals in a constant temperature bath for the same batch of isolation liquid. In this specific embodiment, one record is a temperature node of 20 degrees Celsius, a saturated vapor pressure of 2.34 kilopascals, an effective range of 17.5 degrees Celsius to 22.5 degrees Celsius, and a version of VP-01. When the measured temperature exceeds the effective range or the lookup key does not match, the measurement of the first gas sample is paused, and the batch is marked as having abnormal isolation liquid parameters.

[0068] When the aforementioned minimum positive pressure difference condition is met, the controller follows the current pressure and temperature. The volume of liquid discharged in real time corresponding to the target volume of the first gas sample is obtained, where This indicates the target volume of fluid to be drained, in milliliters. This indicates the target volume of the first gas sample specified in the sampling configuration, in standard milliliters. The other symbols follow the aforementioned conversion relationship of the first gas sample volume. When the cumulative discharge volume reaches the target discharge volume and does not drop for three consecutive sampling cycles, the controller first closes the first gas sample valve, then drives the detection switching valve to send the metered first gas sample into the free gas detection branch or the first sample storage container with the batch label, and sets the first gas sample volume lock flag to 1. If the second gas sample volume is not locked at this time, the controller opens the free gas bypass recovery valve set in the upper free gas collection chamber, and introduces the subsequently separated free gas into a closed auxiliary recovery container that does not participate in the metering of the first gas sample in this batch. The pressure is continuously maintained at 80 kPa to 130 kPa according to the pressure feedback of the collection chamber until the second gas sample volume is locked and then the bypass recovery valve is closed. If the bypass valve or container status is invalid, the water intake is immediately stopped and a free gas recovery path abnormal event is generated.

[0069] The controller simultaneously compares the phase separation liquid level with the lower and upper limits of the liquid level in the sampling configuration. In this specific embodiment, the lower and upper limits of the liquid level are set to 30% and 70% of the effective height of the phase separation space, respectively. When the phase separation liquid level reaches any boundary, the controller stops the sampling pump and closes the inlet valve, writes the event time, boundary crossing direction, liquid level detection value, and valve and pump status into the phase separation liquid level abnormal event, and no longer issues membrane release permits for this batch.

[0070] The discharge volume, the temperature of the isolation liquid, and the pressure of the collection chamber constitute the first gas sample metering state vector in each control cycle. The state vector also stores the sensor quality flag, the cumulative value of the previous cycle, and the increment of the current cycle. The controller uses the following validity conditions: the cumulative discharge volume does not decrease monotonically, the temperature changes no more than 1 degree Celsius in a single cycle, and the pressure is between 80 kPa and 130 kPa. If any of the conditions are not met, the first gas sample volume is frozen and updated, and the original sampling value is retained for batch quality verification.

[0071] After each replacement of the isolation fluid or discharge volume detector, the maintenance procedure performs a three-point volume calibration using traceable measuring instruments of 10 mL, 50 mL, and 100 mL, respectively, and verifies the conversion input using a standard pressure gauge and thermometer. The calibration record saves the detector number, the readings at each calibration point, the linear correction factor, the maximum permissible error of 0.5%, the calibrator's identification, and the effective version. The controller only calls the calibration record that matches the current hardware number and is within the validity period. If no match is found, a new batch is prohibited from starting.

[0072] After the first gas sample valve is closed and the detection is switched, the controller writes the standard state first gas sample volume, cumulative drained volume, isolation liquid temperature, collection chamber pressure, first gas sample output path, and status code into the batch record. It also defines the phase-separated water still continuously output from the lower defoaming water outlet as defoaming water and assigns it to the bubble-free stability window of S2 for judgment. When the target volume has not yet been reached, the drainage-type metering and acquisition unit remains connected to the upper free gas collection chamber and continues to accumulate drained liquid until the target volume is reached, a phase-separated liquid level anomaly occurs, the sampling time reaches the maximum sampling time, or the cumulative volume... When the water intake reaches the maximum cumulative water intake, the controller stops the sampling pump and closes the water inlet valve when either of the latter two limits is reached. If the first gas sample quantity is still lower than the target quantity, the first gas sample valve is closed, the actual obtained quantity is locked, and a first gas sample insufficiency event and an invalid quality flag are generated. If the first gas sample quantity is locked but the second gas sample quantity is still lower than the target quantity, a batch sampling limit expiration event is generated and handed over to S3 and S5. S3 locks the actual second gas sample quantity and performs unloading. The time of the event that the limit is reached is the sampling termination time of the corresponding insufficient gas sample.

[0073] In this specific embodiment, S2 includes:

[0074] The membrane release module takes the defoaming water and phase separation state buffer output from S1 as input. The bubble state detector is installed between the lower defoaming water outlet and the membrane wet-side inlet valve. The liquid level detector is installed in the gas-liquid phase separation unit. The water flow detector is installed in the continuous flow section upstream of the membrane wet-side inlet valve. The continuous flow section maintains water sample flow through the pre-flow return branch when the membrane wet-side inlet valve is closed, so that the judgment objects of bubble state and inlet flow rate are consistent with the defoaming water about to enter the membrane wet side. The gas-liquid phase separation unit is also equipped with a liquid phase net discharge valve and a discharge flow detector. The wet-side outlet of the hydrophobic and breathable membrane module is connected to the upstream of the liquid phase net discharge valve through a check valve, so that the continuous new water will not only circulate in the pre-flow return branch or the membrane wet side.

[0075] After system startup or completion of the previous batch, the controller closes the membrane wet-side inlet valve and opens the pre-flow return valve, allowing defoaming water to flow sequentially from the lower defoaming water outlet through the bubble status detector, water flow detector, and pre-flow return branch before returning to the gas-liquid phase separation unit. Simultaneously, the controller opens the liquid phase net discharge valve, sets the discharge volume based on the cumulative inlet water volume minus the gas phase volume corresponding to the first gas sample, and the net liquid volume obtained by the phase separation unit's allowable liquid level increment. The controller then corrects the discharge valve opening using a phase separation liquid level closed-loop adjustment, ensuring that the difference between the discharge flow rate and the net inlet water flow rate within the statistical window does not exceed 5% of the net inlet water flow rate. If the discharge flow rate is continuously lower than 90% of the net inlet water flow rate for 2 seconds or the phase separation liquid level reaches the upper limit, the inlet valve is immediately closed, pre-flow return is maintained, and a liquid phase net discharge abnormality event is recorded. The controller collects bubble detection amplitude, phase separation liquid level, and instantaneous inlet water flow rate at 20 Hz, uses batch identifier and incremental sampling sequence number to form a buffer key, and applies a moving average of 10 sampling points to the flow data to suppress pump pulsation.

[0076] The bubble state detector adopts an optical transmission detection structure. The controller judges bubble events based on the amplitude threshold obtained from a calibration water sample containing bubbles of known size before deployment. In this specific embodiment, the lower limit of bubble detection is set to an equivalent diameter of 0.5 mm. The bubble detection calibration record includes the detector number, equivalent bubble diameter, transmission amplitude decrease rate, judgment threshold, effective temperature range, and version number. When the current amplitude exceeds the threshold, the bubble state of the current sampling period is set to detected, and the continuous bubble-free timer is cleared.

[0077] The sampling configuration for the current water sample batch is written into the batch parameter area of ​​the controller before sampling begins. Its fields include continuous duration threshold, lower liquid level limit, upper liquid level limit, lower flow rate limit, upper flow rate limit, and lower bubble detection limit. In this specific embodiment, the continuous duration threshold is set to 5 s, the lower and upper liquid level limits are 30% and 70% of the effective height, respectively, and the lower and upper flow rate limits are 0.8 L / min and 1.2 L / min, respectively. The parameter record also saves the unit, allowable range, configuration version, and effective time.

[0078] Controller Press Forming membrane release permits, among which A dimensionless quantity that represents the membrane release clearance status and is either 0 or 1. Indicates a continuous bubble-free condition indicator quantity. Indicates the condition of the phase separation liquid level range. The three condition indicators are dimensionless quantities, all of which are either 0 or 1. When the continuous bubble-free time reaches the continuous duration threshold, the bubble-free condition indicator is set to 1. When the phase-separated liquid level is strictly between the lower and upper limits of the liquid level, the liquid level interval condition indicator is set to 1. When the moving average influent flow rate is between the lower and upper limits of the flow rate, the flow rate interval condition indicator is set to 1. In other cases, the corresponding condition indicator is set to 0.

[0079] The controller latches the membrane release permit only after the membrane release permit status has been continuously held at 1 for two control cycles to avoid frequent valve operation caused by boundary jitter. If bubbles are detected, the phase level touches the interval boundary, or the sliding average influent flow exceeds the limit before the permit is latched, the membrane wet side influent valve is kept closed, the pre-flow return valve is kept open, and the continuous bubble-free time is re-accumulated from zero.

[0080] After the membrane release permit is latched, the controller first records the permit formation time and the most recent window of the three condition indicators, then confirms that the path from the membrane wet-side outlet to the liquid phase net discharge valve has been opened. Subsequently, the membrane wet-side inlet valve is opened and the pre-flow return valve is closed after 200 ms, so that the defoaming water that has completed the detection through the same continuous flow section enters the wet side of the hydrophobic and breathable membrane module and is discharged net from the wet-side outlet. If the valve position feedback is not confirmed in place within 1 s, the membrane wet-side outlet flow rate is lower than 90% of the wet-side inlet flow rate for 2 consecutive s, or the phase level continues to rise, the membrane release permit is revoked, the inlet valve is closed, the pre-flow return path is restored, and the abnormal operation of the membrane wet-side inlet valve or the abnormal liquid phase net discharge event is written.

[0081] The membrane release permit record is constructed according to the batch identifier and permit sequence number. The fields include three condition indicators, continuous bubble-free start time, permit formation time, sensor quality flag, various threshold values, configuration version, membrane wet-side inlet valve command and feedback. The record generation predicate is that the product of the three condition indicators is equal to 1 and lasts for two control cycles. The controller retains the earlier timestamp of the duplicate records with the same batch identifier and permit sequence number, and writes the latched record to the append-only permit queue for S3 to read.

[0082] The controller responds to the membrane release permission by sending defoaming water into the wet side of the hydrophobic and breathable membrane module. The specific action sequence is as follows: first, verify that the batch identifier of the permission record is consistent with the current water sample batch; then, write an opening command to the membrane wet side inlet valve; and only close the pre-flow return valve after receiving the opening feedback. If the permission record version is inconsistent with the current configuration version, the batch identifier is inconsistent, or any sensor quality mark is invalid, the water delivery action will not be performed and the pending permission record will be deleted.

[0083] After a bubble event is resolved, the continuous bubble-free timer must be re-accumulated from zero for 5 seconds. After a level or flow rate exceedance is resolved, the synchronization window for the three conditions must also be met again. The controller will not use the bubble-free time accumulated before the exceedance. When permission is revoked due to valve position feedback failure, the controller will maintain backflow for no less than 10 seconds and complete a self-check to close the valve in place. Resumption is only allowed if the valve self-check passes and the three conditions are met again. Otherwise, the batch will be marked as abnormal in the membrane release mechanism and subsequent membrane sampling will be stopped.

[0084] The sensor window formed at the end of the bubble-free stabilization window includes the most recent 100 bubble amplitudes, 100 liquid level values, and 100 flow rate values. The controller calculates the minimum, maximum, and average values ​​of each channel and saves them along with the permit record. This window is used to verify the permit generation process and also to locate the trigger source for S3 when the permit is revoked. If the window lacks a continuous sampling sequence number or has a time gap of more than two control cycles, the data is determined to be incomplete and the permit status is kept at 0.

[0085] The controller writes the membrane release permission status, continuous bubble-free duration, phase level, sliding average feed water flow rate, each threshold version, and the feedback status of the membrane wet-side feed water valve into the membrane release status record, and hands over this record, along with the defoaming water that has entered the membrane wet side, to S3. During the operation of S3, the three condition indicators are continuously updated. When any condition becomes 0, the membrane release permission is immediately revoked and an unloading request is sent to S3.

[0086] In this specific embodiment, S3 includes:

[0087] The membrane diffusion sampling module reads the membrane release status record written by S2. When the membrane release permission is 1 and the feedback of the membrane wet-side water inlet valve is open, it receives defoaming water. The full liquid detector set at the wet-side outlet of the hydrophobic and breathable membrane module judges the wet-side status by combining conductivity and bubble transmission signal. When the outlet conductivity is in the water sample calibration range for 2 consecutive seconds and no bubbles are detected, the wet-side full state is set to 1. Otherwise, the dry-side vacuum pump is kept off, the vacuum regulating valve is kept at the unloading valve opening setting value, and the residual gas on the wet side continues to be discharged through the low-pressure exhaust path.

[0088] After the wet side is filled to 1, the controller reads the target dry side absolute pressure, negative pressure loading slope, membrane differential pressure protection threshold, target second gas sample flow rate, target second gas sample volume, unloading valve opening setting, and unloading pressure range from the current water sample batch sampling configuration. In this specific embodiment, the target dry side absolute pressure is set to 35 kPa, the negative pressure loading slope is set to 5 kPa / s, the membrane differential pressure protection threshold is set to 80 kPa, the target second gas sample volume is set to 100 standard milliliters, the unloading valve opening setting is set to 5%, the unloading pressure range is set to 90 kPa to 105 kPa absolute pressure, and the control cycle is set to 0.1 s. The vacuum pump start / stop status is an independent Boolean control quantity. The unloading completion condition is that the vacuum regulating valve reaches the unloading valve opening setting and the dry side pressure enters the unloading pressure range. At this time, the vacuum pump must be in a stopped state. Each parameter, along with its unit, allowable range, configuration version, and effective time, is stored in the negative pressure control parameter record.

[0089] Controller according to The dry-side pressure setpoint is generated cycle by cycle, where Indicates the first The dry-side absolute pressure setpoint for each control cycle, in kilopascals. This represents the control cycle sequence number counting from the start of negative pressure loading, and is a dimensionless positive integer index. This represents the target dry-side absolute pressure, expressed in kilopascals (kPa). This represents the dry-side absolute pressure setpoint for the previous control cycle, in kilopascals. This indicates the slope of the negative pressure loading, expressed in kilopascals per second. Indicates the control cycle, in seconds. This indicates that the pressure value returned from the two pressure parameters within the parentheses is not less than the other parameter. It is a mathematical function operator rather than a physical quantity, so units and dimensions are not applicable. The initial value for recursion is the absolute pressure of the dry side measured and latched by the membrane dry side pressure detector in the zero-point calibration state before the start of negative pressure loading. The unit is kPa. When the quality mark is invalid, the vacuum pump is kept off and the recursion is not entered. This decrement setting rule makes the absolute pressure of the dry side approach the target value with a limited slope.

[0090] The membrane wet-side pressure detector and the membrane dry-side pressure detector use the same pressure acquisition module and perform atmospheric pressure zero-point calibration before the start of each batch. The controller follows... Calculate the pressure difference across the membrane, where This represents the control cycle sequence number counting from the start of negative pressure loading, and is a dimensionless positive integer index. Indicates the first The pressure difference across the membrane during each control cycle, expressed in kilopascals (kPa). The membrane wet-side pressure detector indicates that the membrane wet-side pressure detector is at the first The wet-side absolute pressure measured during each control cycle, in kilopascals. Indicates the membrane dry-side pressure detector at the first The absolute pressure on the dry side measured in each control cycle, in kPa; when the pressure difference reaches the pressure difference protection threshold across the membrane, it is prohibited to continue increasing the negative pressure loading;

[0091] The controller uses the vacuum regulating valve opening as the negative pressure loading amount, and follows... Feedback and corrections were made, among which This represents the control cycle sequence number counting from the start of negative pressure loading, and is a dimensionless positive integer index. Indicates the first The vacuum regulating valve opening is controlled for each control cycle, ranging from 0% to 100%. This indicates the opening degree of the vacuum regulating valve in the previous control cycle, expressed as a percentage. Indicates the membrane dry-side pressure detector at the first The dry-side absolute pressure measured in kilopascals during each control cycle. This indicates that the aforementioned pressure setting recursive formula generates the first... The absolute pressure setpoint for the dry side in each control cycle, in kPa. This represents the pressure error gain, expressed as a percentage per kPa. This indicates the target second gas sample flow rate, expressed in standard milliliters per minute. Indicates that the second gas sample flow detector is at the... The flow rate measured in one control cycle, in standard milliliters per minute. This indicates the flow error gain, expressed as a percentage per minute per standard milliliter. and These represent the lower and upper limits of the valve opening, respectively, in percentage form. This means that the calculation result is restricted to the upper and lower limits of the opening. It is a mathematical limiting function operator rather than a physical quantity, so the unit and dimension are not applicable. This indicates the initial valve opening value used in the first feedback cycle. It is the unloading valve opening setting value confirmed by valve position feedback at the beginning of this negative pressure loading, and the unit is a percentage. If the valve position feedback is invalid, the vacuum pump is kept stopped and this recursion is prohibited.

[0092] In this specific embodiment, the pressure error gain and flow error gain are calibrated by the membrane module in the clean water calibration test and then written into the negative pressure control parameter record. The pressure error gain must be greater than 0 and the allowable range is 0.1% / kPa to 2.0% / kPa. The flow error gain must be greater than 0 and the allowable range is 0.01%·min / mL to 0.5%·min / mL. The lower limit and upper limit of the valve opening are set to 5% and 85%, respectively. When any gain is zero, negative, or exceeds the corresponding allowable range, the vacuum pump is kept off and feedback recursion is prohibited. When the measured dry side pressure is higher than the set value or the flow rate of the second gas sample is lower than the target value, the aforementioned correction rule increases the opening of the vacuum regulating valve. When the pressure difference between the two sides of the membrane is less than 5 kPa from the protection threshold, the controller freezes the correction amount of the increased opening and only allows the opening to be reduced.

[0093] The negative pressure control parameter record is generated from the calibration data of the same model membrane module under three wet-side flow rates and three dry-side pressures. The record fields include membrane module number, target dry-side pressure, target second gas sample flow rate, pressure error gain, flow error gain, negative pressure loading slope, differential pressure protection threshold, valve opening boundary, and version number. The controller searches for records according to membrane module number and water sample batch configuration version. When multiple valid records match simultaneously, the record with the latest effective time is selected. If the effective times are the same, the record with the highest version number value is selected. If no match is found, the unloaded state is maintained and the vacuum pump is prohibited from starting.

[0094] Under the influence of the partial pressure difference across the membrane formed by the controlled negative pressure, the dissolved gas in the defoaming water passes through the hydrophobic and breathable membrane and enters the dry side to form a second gas sample. The controller sequentially introduces the second gas sample into the gravity liquid interception chamber and the hydrophobic and breathable liquid blocking device marked as the current working branch in S4, and then sends it to the second sample storage container or detection branch through the second gas sample flow detector, and continuously records the dry side pressure, wet side pressure, pressure difference across the membrane, vacuum regulating valve opening and second gas sample flow.

[0095] Before supplying gas to the liquid interception unit, the controller forms a candidate suction path set using the main liquid interception branch and the backup liquid interception branch, and reads the branch identity, upstream and downstream valve feedback, reset completion flag, and airtightness flag for each candidate path. During initial commissioning, controller cold start, or flag record verification failure where neither branch has a valid reset completion flag or airtightness flag, the controller keeps the second gas sample output valve closed, the vacuum pump stopped, and the upstream and downstream valves of both branches closed. It then instructs S4 to sequentially perform liquid drainage confirmation and airtightness testing on the two cavity branches. If either branch passes the test, a reset completion flag and an airtightness pass flag are written, and the process continues. If one branch fails the test, the other branch remains isolated and the initialization of the qualified branch is not prevented. Paths with the current working branch identity and both upstream and downstream valves are open are sorted first. If there is no current working branch, the branch with the lowest branch number value is selected from the paths that have been reset and have passed the airtightness test, and S4 is notified to execute the valve sequence initialization of the first working branch. Negative pressure loading is only allowed after S4 returns confirmation that the upstream and downstream valves are in place and the current working branch identity has been written. Only one selected suction path is output at any time. If both candidates fail, the vacuum pump is stopped and the unloading valve is open, and an event of no available liquid interception branch is generated.

[0096] The controller records the negative pressure control status by combining the dry-side pressure error, the second gas sample flow error, the pressure difference across the membrane, and the valve opening. It uses the target opening of the vacuum regulating valve and the start / stop position of the vacuum pump as control action fields. It performs pressure setting, feedback correction, and differential pressure constraint every 0.1 seconds. The control objective is to make the dry-side pressure error and flow error approach zero under the condition that the differential pressure protection threshold is not exceeded. When the pressure error is greater than 10 kPa for 20 consecutive cycles, it enters the unloading state and writes the negative pressure control non-convergence event.

[0097] When the second gas sample flow detector outputs zero flow for 3 consecutive seconds and the dry side pressure has reached the target range, the controller first reduces the opening of the vacuum regulating valve by 10 percentage points and checks the valve position and pressure difference of the current working branch. When the pressure difference reaches the S4 switching threshold, a branch switching request is sent to S4. When the pressure difference does not reach the threshold and the zero flow continues for 5 seconds, membrane suction is stopped and the membrane mass transfer abnormality flag is written into the batch record to avoid replacing abnormal diagnosis with continuous increase of negative pressure.

[0098] When any of the following events occur: membrane release permit revocation, phase separation liquid level exceeding preset liquid level range, inlet water flow exceeding preset flow range, pressure difference across the membrane reaching differential pressure protection threshold, or bubble detection by bubble status detector, the controller reduces the opening of the vacuum regulating valve to the unloading valve opening set value at a rate not exceeding 10 percentage points per control cycle; after confirming that the valve position feedback has reached the opening and the dry side pressure has risen back to the unloading pressure range, the vacuum pump is stopped and the membrane wet side inlet valve is closed. Then, according to the sampling configuration, the reflux valve is opened to return the water sample to the gas-liquid phase separation unit or the bypass valve is opened to guide the water sample away from the hydrophobic and permeable membrane module.

[0099] When unloading is performed, the controller stops the effective flow integration of the second gas sample and writes the trigger source, trigger time, pressure before and after unloading, unloading valve opening setting, unloading pressure range, valve and pump status, and water sample guide path into the membrane release cancellation event; if the vacuum regulating valve does not reach the unloading valve opening setting or the dry side pressure does not enter the unloading pressure range within 1 second after the unloading command is issued, the vacuum pump is forcibly shut down and the continuation of suction event flag after membrane release permission cancellation is written to S5.

[0100] The controller clears the waiting state only after S2 re-establishes membrane release permission, and re-executes wet-side fullness detection and dry-side negative pressure slope loading, without using the wet-side fullness state or vacuum regulating valve opening before cancellation; when S5 confirms that the second gas sample integral value has reached the second gas sample target quantity and has not fallen back for three consecutive effective sampling cycles, the controller sets the second gas sample quantity lock flag to 1, stops effective flow integration, sequentially lowers the vacuum regulating valve to the unloading valve opening setting value, confirms that the dry-side pressure has entered the unloading pressure range, stops the vacuum pump, closes the membrane wet-side inlet valve and opens the pre-flow return valve; if the first gas sample quantity has not yet been locked, S1 sampling and phase metering are maintained but water is no longer supplied to the membrane wet side; when a batch sampling limit expiration event is received and the second gas sample quantity is still lower than the target quantity, the actual obtained quantity is locked, the same unloading valve sequence is executed and a second gas sample insufficiency event is generated; the stable second gas sample, the second gas sample flow time series, the pressure records on both sides of the membrane, the two lock flags and the valve pump status are written together into the membrane diffusion sampling record and handed over to S4 for condensation risk interlocking and S5 for batch metering.

[0101] In this specific embodiment, S4 includes:

[0102] The condensation isolation module has a main liquid interception branch and a backup liquid interception branch connected in parallel on the dry side of the hydrophobic and breathable membrane assembly. Each branch is equipped with an upstream branch valve, a gravity liquid interception chamber, a liquid interception level detector, a hydrophobic and breathable liquid blocking component, a pressure differential detector, and a downstream branch isolation valve in sequence according to the airflow direction. An airtightness test port with a test valve is set between the upstream branch valve and the gravity liquid interception chamber. The controller marks the branch with both upstream and downstream branch valves open and undertaking membrane suction as the current working branch, and marks the other branch that has completed liquid drainage, differential pressure recovery, and airtightness testing as the branch to be switched and available.

[0103] The temperature and humidity detector is installed before the second gas sample enters the current working branch. The controller collects the temperature and relative humidity of the second gas sample at 1 Hz, and collects the liquid level, upstream pressure and downstream pressure of the liquid blocking component of the current working branch at 5 Hz, and aligns them with the same batch identifier and timestamp. The effective temperature range is set to 0 degrees Celsius to 60 degrees Celsius, and the effective relative humidity range is set to 10% to 100%. When the effective range is exceeded, the temperature and humidity records are marked as invalid and the isolation interlock signal is directly output.

[0104] The controller uses Magnus relationships according to and Determine the dew point temperature, where This indicates an intermediate quantity in dew point calculation and is dimensionless. Let the natural logarithm function be defined and its independent variable be defined. This is a dimensionless relative humidity ratio, which is a mathematical function operator rather than a physical quantity; therefore, its units and dimensions are not applicable. This indicates the relative humidity of the second gas sample, expressed as a percentage. This represents the dimensionless dew point fitting coefficient, which is taken as 17.62 in this specific embodiment. This indicates the temperature of the second gas sample, expressed in degrees Celsius. This represents the dew point fitting temperature coefficient, and in this specific embodiment, it is taken as 243.12 degrees Celsius. This represents the dew point temperature in degrees Celsius; the dew point fitting coefficient is stored in the dew point parameter record of version DP-01 and updated after calibration with a standard humidity generator.

[0105] Controller according to Calculate the dew point margin, where This indicates the dew point margin in degrees Celsius, and the temperature of the second gas sample. and dew point temperature Using the definition from the dew point calculation above; the smaller the dew point margin, the closer the second gas sample is to the condensation state. The controller writes this value into the current working branch status record and performs a comparison that is not greater than the warning margin threshold, switching margin threshold, and isolation margin threshold in the sampling configuration.

[0106] In this specific embodiment, the warning margin threshold, the switching margin threshold, and the isolation margin threshold are set to 4 degrees Celsius, 2 degrees Celsius, and 0 degrees Celsius, respectively. When the dew point margin is not greater than 0 degrees Celsius, the dew point isolation level is obtained; when the dew point margin is greater than 0 degrees Celsius but not greater than 2 degrees Celsius, the dew point switching level is obtained; when the dew point margin is greater than 2 degrees Celsius but not greater than 4 degrees Celsius, the dew point warning level is obtained; and when the dew point margin is greater than 4 degrees Celsius, the dew point normal level is obtained.

[0107] The liquid level detector outputs the percentage of the liquid level in the gravity liquid interception chamber relative to the effective height. The hydraulic pressure differential detector obtains the hydraulic pressure differential based on the difference between the upstream absolute pressure and the downstream absolute pressure of the liquid interception component, with the unit being kPa. In this specific embodiment, the warning threshold, switching threshold, and isolation threshold of the liquid level interception are 35%, 60%, and 80%, respectively, and the warning threshold, switching threshold, and isolation threshold of the hydraulic pressure differential are 3 kPa, 6 kPa, and 10 kPa, respectively. If any detected value is not less than the corresponding threshold, the risk level corresponding to that detected value is obtained.

[0108] The liquid level detector is calibrated at three liquid levels: cavity, 50% effective height, and 80% effective height. The differential pressure detector is calibrated at three differential pressure points: 0 kPa, 5 kPa, and 10 kPa. The calibration record includes branch number, sensor number, raw output, conversion factor, maximum permissible error, validity period, and version number. The controller calls the corresponding record according to the branch number and invalidates data that exceeds the range, expires the calibration, or has a single-cycle jump exceeding 20% ​​of the range. Invalid data directly triggers the isolation level without entering the normal risk merging process.

[0109] The risk assessor uses a deterministic rule engine instead of a trained model. Its input feature vector includes dew point margin, liquid level of the current working branch, pressure differential of the current working branch, and three quality indicators. The output fields include three individual risk levels, the merged condensation risk level, the trigger source, and the action code. The rule engine compares each versioned threshold record and performs fixed-priority reasoning. The threshold records are generated from the calibration results of constant temperature and humidity test, graded liquid injection test, and pressure differential test of liquid-blocking components. The test vectors covering normal, warning, switching, isolation, and sensor failure states are verified version by version.

[0110] The controller obtains the dew point margin risk level, the liquid level risk level of the current working branch, and the pressure difference risk level of the current working branch, and merges them according to a fixed priority order of isolation level, switching level, warning level, and normal level. If an isolation level exists in any of the three determinations, the isolation level is output; if a switching level exists but no isolation level exists, the switching level is output; if only a warning level exists, the warning level is output; otherwise, the normal level is output. The liquid level and pressure difference of the isolated branch to be reset are not included in this merging and are only used for the judgment of the end of drainage and reset.

[0111] The gas circuit safety interlock status record uses batch identifier and interlock event sequence number as keys to save the current working branch number, the branch number to be switched to, the isolated branch number to be reset, the condensation risk level, the three individual risk levels, valve commands, valve feedback, vacuum pump status, and action period. The controller performs an interlock status transition every 100 ms. When the risk levels are the same, the original action is maintained. When multiple detection quantities trigger the same risk level in the same cycle, the main trigger source is recorded in the order of dew point margin, liquid level cutoff, and pressure difference, but the executed action remains consistent.

[0112] When the condensation risk level is at the warning level, the controller reduces the negative pressure loading slope of S3 to 60% of the current sampling configuration value and increases the absolute pressure of the target dry side by 5 kPa towards atmospheric pressure, thereby reducing the pressure difference across the membrane. During the warning action, a second gas sample is still collected. After the risk level returns to normal for 10 consecutive seconds, the original target dry side pressure is restored at a slope of 1 kPa per second. The warning start, recovery time, and load reduction parameters are written into the gas circuit safety interlock record.

[0113] When S3 notifies that there is no working branch, the controller performs the initialization valve sequence for the selected first candidate branch: keeping the upstream branch valve closed, first opening the downstream branch isolation valve, then starting the vacuum pump and keeping the vacuum regulating valve at the unloading valve opening set value for pre-vacuuming, comparing the branch pressure with the membrane dry side pressure every 100 ms; after the absolute difference between the two does not exceed 1 kPa and is maintained continuously for 500 ms, opening the upstream branch valve, and only after both upstream and downstream valve positions are reported as open, is the branch written as the current working branch and a negative pressure loading confirmation is returned to S3; if any step is not completed within 8 s, the upstream and downstream valves of the branch are closed, the vacuum pump is stopped, and a first working branch initialization failure event is generated;

[0114] When the condensation risk level is switching level, the controller first checks whether there is a usable branch to be switched; if not, it immediately closes the second gas sample output valve, stops membrane suction according to the S3 unloading sequence, upgrades the risk to the isolation level, and records the event of no usable switching branch; if there is, it latches the current switch according to the interlock event sequence number, keeps the upstream branch valve of the usable branch to be switched closed, opens the downstream branch isolation valve first, and uses the vacuum pump for pre-evacuation; every 100 ms, the controller compares the branch pressure of the usable branch to be switched with that of the current working branch. When the absolute difference between the two does not exceed the preset switching pressure difference of 1 kPa and is maintained continuously for 500 ms, it opens the upstream branch valve of the usable branch to be switched, and after the valve position feedback is in place, it closes the upstream branch valve and the downstream branch isolation valve of the original current working branch in sequence;

[0115] After completing the valve sequence, the controller marks the newly opened branch as the current working branch and the cut-off branch as the isolated branch awaiting reset, while maintaining the second gas sample output through the new working branch. If the main trigger source for this switch is the dew point margin shared by both branches, and the dew point margin after the switch is still no greater than 2 degrees Celsius for 2 consecutive seconds, then the generation of a reverse switch request is prohibited, and the risk is immediately upgraded to the isolation level according to the unloading sequence. Only when the dew point margin is greater than 3 degrees Celsius for 10 consecutive seconds... The common dew point event latch is cleared and a new switching event is allowed to be generated only after s, with a 1 degree Celsius hysteresis to suppress round-trip switching; if the preset switching differential pressure is not reached within 8s from the trigger of the switching stage, if the valve position feedback of any valve in the original working branch or the branch to be switched is not in place, or if the original working branch has not completed bidirectional isolation, the controller latches the numbers of the original working branch and the branch to be switched, issues a closing command to the upstream branch valve and the downstream branch isolation valve of the two branches respectively, verifies the four closing feedbacks one by one, closes the second gas sample output valve and stops the vacuum pump, and then outputs a switching failure flag containing the valve number that is not in place and raises the risk to the isolation level;

[0116] When the condensation risk level is isolation level, the controller immediately closes the upstream branch valves and downstream branch isolation valves of the current working branch and the branch to be switched, reduces the vacuum regulating valve to the unloading valve opening set value and stops the vacuum pump, and simultaneously closes the second gas sample output valve; the original current working branch clears its current identity and is relabeled as an isolation branch to be reset, and the other branch that has not been in contact with condensate and whose reset completion and airtightness indicators are both valid retains its switchable identity, otherwise it is also relabeled as an isolation branch to be reset; the isolation branch to be reset drains liquid after bidirectional isolation through its upstream branch valve and downstream branch isolation valve. The controller only opens the drain valve of the branch when both valve positions are feedback closed, draining the liquid in the gravity interception chamber into a waste liquid container with batch identification. During the draining period, the branch is not connected to the membrane dry side or downstream detection unit; if any valve of the participating branch does not feedback closed, the pump remains stopped and the output is closed, and an unresettable isolation event is generated;

[0117] During pre-sumption and switching, the controller uses the downstream pressure of the available branch to be switched, the current working branch pressure, four relevant valve position feedbacks and the switching timer to form a switching state vector, and the valve opening and closing commands to form an action vector. The control constraints are that at any given time, at least one downstream path to the vacuum pump must remain open, the upstream valve of the branch to be switched must not open before the differential pressure condition is met, and the original working branch must not close before the upstream valve of the new branch is in place. Violation of any constraint will result in the switching being terminated and entering the isolation stage.

[0118] After the branch drain is completed, the controller continuously confirms for 5 seconds that the cut-off liquid level is lower than the reset liquid level and the resistance pressure difference is lower than the reset pressure difference before performing the airtightness test. If any condition rebounds within the confirmation window, the drain valve is closed again and the test is repeated after waiting for 30 seconds. In this specific embodiment, a single branch can be retried a maximum of two times per batch. If the condition is not met twice, the branch is kept in isolation and awaits reset status and is prohibited from entering the next candidate suction path set.

[0119] After isolating the branch to be reset, when the liquid level is below 20% of the effective height and the pressure difference is below 2 kPa, the controller closes the drain valve, upstream branch valve, and downstream branch isolation valve of the branch, and confirms the closure feedback one by one. Then, a dry nitrogen source controlled by pressure reduction and dew point is connected to the airtightness test port of the branch. The controller opens the test valve, pressurizes the branch to an absolute pressure of 140 kPa, closes the gas source shut-off valve and the test valve, latches the initial absolute pressure, holds it for 60 s, and obtains the pressure decay by subtracting the absolute pressure at the end of 60 s from the initial absolute pressure, which is then converted into a leakage rate per minute. When the leakage rate is between 0 kPa / min and 0.5 kPa / min and the liquid level and pressure difference conditions are still met, the branch is marked as a usable branch to be switched. The final pressure is higher than the initial pressure or the leakage rate exceeds 0.5 kPa. When the pressure drops to kPa / min, the test is deemed invalid or the airtightness is unqualified, and the system remains in isolation. The test source number, test valve sequence, pressure at both ends, temperature, and reason for reset failure are recorded. When the risk is eliminated and at least one branch is marked as available for switching, the controller clears the identity of the current working branch and calls the first working branch mentioned above to initialize the valve sequence. Only after successful initialization is S3 allowed to resume negative pressure loading. Finally, the condensation risk level, branch identity, valve sequence event, drain event, and reset result are written into the gas circuit safety interlock record and handed over to S5.

[0120] In this specific embodiment, S5 includes:

[0121] The batch output module establishes a non-repeatable batch record for each water sample batch. The record header includes the batch identifier, sampling point number, sampling configuration version, sampling start time, and sampling end time. The sampling start time is the controller clock when the S1 sampling pump starts delivering the water sample of this batch. After locking each gas sample volume, the controller checks the two locking flags. When both are 1, the sampling pump is immediately stopped, the inlet valve and the free gas bypass recovery valve are closed, and the detection switching valve, the second gas sample output valve, and the membrane side valve are returned to the batch end state. The controller clock when the last action feedback is in place is taken as the normal sampling end time. When any gas sample shortage event occurs, after locking the actual gas sample volume, stopping the effective integration of the second gas sample, and returning all output valves to the batch end state, the controller clock when the last action feedback is in place is also taken as the sampling end time, so that the insufficient sample batch also forms a defined sampling time window.

[0122] The batch record data area is written with incremental timestamps for influent flow rate, cumulative discharge volume, first gas sample volume under standard conditions, second gas sample flow rate, phase level, bubble status, membrane wet-side pressure, membrane dry-side pressure, dew point margin, liquid interception level of main and backup branches, pressure differential of main and backup branches, branch identity, and valve / pump status. Each sampling data also saves the sensor number, value, unit, quality mark, and sampling sequence number. The controller uses the batch identifier and sampling sequence number to check for duplicate records and rejects cross-batch writing.

[0123] The second gas sample flow detector outputs the instantaneous flow rate after standard state compensation, and the controller follows... The integral value of the second gas sample flow rate is obtained, where This indicates the volume of the second gas sample, expressed in standard milliliters. This represents the index of the valid sampling point of the second gas sample, which is a dimensionless positive integer. This represents the total number of valid sampling points in this batch, and is a dimensionless positive integer. Indicates the first The second gas sample standard flow rate at each valid sampling point is expressed in standard milliliters per minute. Indicates the first Each valid sampling interval is in seconds, and is divided by 60 to convert seconds to minutes; sampling intervals in which unloading, isolation, valve switching are not completed or the flow quality flag is invalid are not counted as valid sampling points; the target volume of the second gas sample in the sampling configuration is 100 standard milliliters. When the integral value reaches the target and does not fall back for three consecutive valid sampling cycles, a second gas sample locking request is sent to S3. After receiving feedback from S3 that the unloading is completed, the second gas sample volume and the corresponding end time are locked.

[0124] The controller binds the first gas sample quantity and the first gas sample output path obtained by S1, as well as the aforementioned second gas sample quantity and the second gas sample output path, to the same batch identifier and the same sampling time window, and saves the two gas sample container numbers or detection branch numbers in the batch record; the first gas sample and the second gas sample are always measured separately first, so that their respective standard volumes, formation time periods and quality marks are still retained when the combined sample is output in the future.

[0125] The controller records events where the phase liquid level exceeds the lower or upper limit as phase liquid level anomalies; events where the vacuum regulating valve or vacuum pump continues to pump after the membrane release permission is revoked as continued pumping anomalies; the isolation stage interlock output by S4 as an isolation stage trigger event; and events where the first gas sample quantity is still lower than the target quantity when the maximum sampling time or maximum cumulative influent flow rate of S1 is reached as a first gas sample insufficiency event; and events where the second gas sample quantity is still lower than the target quantity when the batch sampling limit is reached are recorded as a second gas sample insufficiency event. Each type of event is configured with a current status indicator and... When the recovery conditions are met, the historical trigger latch value of this batch will only clear the current status indicator value to zero. The historical trigger latch value of this batch will be maintained from the first trigger setting to 1 until the batch record is sealed and cannot be overwritten by branch reset, step redo, or risk level recovery. Each event record includes event type, first trigger time, release time, trigger sensor value, threshold version, actual gas sample volume of two channels, target gas sample volume of two channels, relevant valve and pump commands, and feedback status. Any insufficient gas sample event cannot be released within this batch. After its trigger, it is prohibited to continue accumulating the two gas samples and to automatically combine samples.

[0126] An 8-second preset switching timeout begins from the moment the switching stage is triggered. If, upon the expiration of the timeout, the available branch to be switched has not yet been marked as the current working branch, or the upstream branch valve and downstream branch isolation valve of the branch to be switched have not yet been fully closed, an incomplete branch switching event is generated. The subsequent processes of starting and ending the drainage, performing the airtightness test, and restoring the branch to be switched as an available branch are separately constituted as a branch reset event, which does not cover the incomplete branch switching event.

[0127] Batch quality determination uses a versioned deterministic rule engine instead of a trained model. The input features are binary indicators of the existence of five types of events, completion flags for steps S1 to S4, locking of two gas sample quantities and quality flags, event timestamps and event reference numbers. The inference rule is to first incorporate the states of any incomplete step, any metering not effectively locked, or fatal anomalies not recovered into the isolation and fatal anomaly indicators of the steps, and then perform logical NOT operations on each item and then multiply them. Before the rule version is released, it is covered and verified using historical normal batches and manually injected verification batches with various anomalies. Only the version with all expected states consistent with the rule output is written to the controller. At runtime, the batch quality status, failure reason set, and rule version are output.

[0128] Controller according to Calculate the batch qualified indication quantity, where A dimensionless quantity that indicates the batch's acceptable quantity and is either 0 or 1. This indicates the historical trigger latch amount for phase separation level anomalies in this batch. This indicates the historical trigger latch-up volume for continued suction events following the revocation of membrane release permits. This indicates the historical trigger latch quantity for isolation or step-related fatal anomalies in this batch. These fatal anomalies include: abnormal pressure correction input, abnormal isolation liquid parameters, abnormal free gas recovery path, abnormal membrane release mechanism, abnormal net liquid discharge, no available liquid interception branch, negative pressure control failure to converge, abnormal membrane mass transfer, insufficient second gas sample, and any step S1 to S4 completion flag being 0 or any gas sample metering quality flag being invalid. This indicates the historical trigger latch amount for this batch of events that have not yet completed branch switching. This indicates the historical trigger latch quantity for the first insufficient gas sample event in this batch. All five event indicators are dimensionless quantities of 0 or 1, and the corresponding event is set to 1 when it was triggered in this batch. Recoverable anomalies are only released from their current state to allow controlled recovery after the affected steps are redone according to regulations and the corresponding step completion flag is restored to 1. However, the corresponding historical trigger latch quantity for this batch is not cleared. The unrecovered event number, recovered event number, and reason are all written into the batch record. If the qualified indicator quantity is equal to 1 at the end of the batch, the water sample batch is marked as a qualified batch; otherwise, it is marked as an unqualified batch and automatic sample mixing is prohibited.

[0129] Before the sample is output, the controller follows the procedure. The standard volume of the combined sample was obtained, in which This represents the sum of the standard volumes of the two gas samples that enter the combined sample container after separate measurement, with the unit being standard milliliters. This represents the first gas sample volume determined by S1, with the unit being standard milliliters. This indicates the second gas sample volume obtained by integrating the second gas sample flow rate in this step, with the unit being standard milliliters; the remaining capacity of the sample container used for capacity comparison is the standard state equivalent remaining capacity, with the unit being standard milliliters, given by the capacity calibration record bound to the container number. This record determines the rated standard state equivalent capacity using the traceable gas displacement method at a standard pressure of 101.325 kPa and a standard thermodynamic temperature of 273.15 K, and deducts the standard state equivalent volume of the gas already stored in the container; sample merging is only allowed when both metering quality marks are valid and the standard state equivalent remaining capacity is not less than 1.2 times the sample standard volume. If the capacity record, container pressure, or temperature input is invalid, the sample output is maintained and a sample container capacity reference invalid event is written.

[0130] Before batch records are sealed, the controller performs integrity verification on the sensor time series, requiring that the sampling sequence number be continuous, the sampling time be within the time window of this batch, the unit of measurement be consistent with the field definition, and that all key events can be referenced to the corresponding valve and pump feedback. Missing records are not filled in by estimation, but the data integrity flag is set to 0 and the batch status is changed to unqualified. Then, the SHA-256 digest of the record text is calculated and saved together with the configuration version, rule version and sensor calibration version to support subsequent traceability.

[0131] For qualified batches, the controller drives the detection switching valve and the second gas sample output valve according to the sampling configuration, outputting the first gas sample and the second gas sample to the free gas detection branch and the dissolved gas detection branch respectively, or after the two gas samples are measured separately, they are imported into the same sample container according to the recorded standard volume; after the output is completed, the batch record is locked and a result object containing batch identifier, sampling time window, first gas sample quantity, second gas sample quantity, two output paths, branch switching event summary and batch quality status is generated for the detection system and traceability system to read.

[0132] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0133] In this invention, the membrane release permission judgment, negative pressure loading adjustment, condensation risk classification, and branch switching control executed by the controller are not simply data processing rules, but a combination of control algorithms that work together with the gas-liquid phase separation unit, hydrophobic and permeable membrane assembly, liquid interception branch, liquid blocking device, valve pump, and various sensors. This algorithm combination uses bubble state, phase separation liquid level, and inlet water flow rate as pre-constraints for whether the membrane assembly is allowed to receive water, so that free gas is preferentially separated and metered before entering the membrane diffusion process, thereby reducing the adhesion, shading, and turbulence of free bubbles on the membrane surface; after the wet side is filled, the slope of the dry side negative pressure is applied and feedback is corrected based on the pressure difference across the membrane and the second gas sample flow rate, so that the dissolved gas release process is kept within the controlled pressure difference range; furthermore, the dew point margin is calculated by temperature and humidity, and the condensation risk level is formed by combining the liquid interception liquid level and the pressure difference of the liquid blocking device, thereby controlling the load reduction, switching, or isolation and shutdown of pumping. Therefore, the above algorithm combination directly changes the flow state, pressure state and liquid separation state of water and gas samples in the system, and can achieve the technical effects of stable collection of free gas and dissolved gas, maintenance of effective mass transfer area of ​​membrane module, reduction of risk of condensate entering downstream equipment, and safe switching of suction path under abnormal conditions.

[0134] This invention addresses the issues of membrane sampling fluctuations and condensation intrusion in negative pressure gas paths by implementing a layered interlocking improvement. Specifically, instead of relying solely on a single sensor reading for start-stop control, this invention divides the sampling process into multiple states: phase metering, bubble-free release, wet-side filling, negative pressure loading, condensation risk assessment, switching between main and backup liquid interception branches, and batch qualification assessment. Physically meaningful entry, exit, and reset conditions are established between each state. Simultaneously, the condensation risk assessment employs multi-source fusion of dew point margin, liquid interception level, and pressure differential, and outputs control actions according to the priority of isolation, switching, and warning levels. This ensures that potential condensation trends, the state of intercepted liquid, and the liquid-receiving state of the liquid-blocking components are uniformly incorporated into the gas path safety interlock. This algorithm structure enables the system to form a closed-loop control between sampling, protection, and recovery. Compared to simple timed suction or single-threshold shutdown methods, it is more suitable for the technical scenarios in this case, such as combined free and dissolved gas sampling, membrane module anti-bubble interference, and vacuum gas path anti-liquid intrusion, thereby improving the stability, traceability, and operational safety of the sampling results.

Claims

1. A smart sensing method for combined water and dissolved gas extraction, characterized in that, include: S1. Take a closed sample of water containing free gas bubbles and dissolved gas, send the water sample into the gas-liquid phase separation unit, so that the free gas is collected in the upper free gas collection chamber and the phase-separated water is output from the lower defoaming water outlet. The collected free gas pushes the pre-filled isolation liquid in the drainage metering and acquisition unit to be discharged. The first gas sample quantity is obtained according to the discharge volume and the first gas sample is output. S2. Obtain the phase separation liquid level, the bubble state of the defoaming water and the inlet water flow rate. When the bubble state is bubble-free within a preset continuous time period, the phase separation liquid level is within a preset liquid level range and the inlet water flow rate is within a preset flow rate range, a membrane release permit is formed, and in response to the membrane release permit, the defoaming water is sent into the wet side of the hydrophobic and breathable membrane module. S3. After the wet side is filled with defoaming water in response to the membrane release permission, a controlled negative pressure is established on the dry side of the hydrophobic and breathable membrane assembly, so that the dissolved gas in the defoaming water passes through the hydrophobic and breathable membrane assembly to form a second gas sample, and the second gas sample flows through the liquid interception unit and the hydrophobic and breathable liquid blocking component in sequence. S4. Obtain the temperature and humidity of the second gas sample, as well as the liquid level of the liquid interception unit and the pressure difference of the hydrophobic and breathable liquid-blocking component. Determine the dew point margin based on the temperature and humidity, and determine the condensation risk level based on the dew point margin, liquid level, and pressure difference. Control the suction path on the dry side and the output path of the second gas sample based on the condensation risk level. S5. Measure and output the first and second gas samples respectively.

2. The intelligent sensing method for combined water and dissolved gas extraction according to claim 1, characterized in that, S1 includes: The water sample is introduced into the phase separation space along the tangential or deflected water inlet channel of the gas-liquid phase separation unit, causing free air bubbles to float and coalesce under buoyancy and into the upper free gas collection chamber. The lower defoaming water outlet is located below the liquid surface of the phase separation space. The upper free gas collection chamber is in sealed communication with the air inlet of the drainage-type metering and acquisition unit. The drainage-type metering and acquisition unit is equipped with a drainage volume detector at its drainage end. The first gas sample volume is calculated by converting the detected drainage volume with the temperature of the pre-filled isolation liquid and the pressure of the upper free gas collection chamber.

3. The intelligent sensing method for combined water and dissolved gas extraction according to claim 2, characterized in that, Step S1 further includes: setting a first gas sample valve at the gas outlet of the upper free gas collection chamber, and setting a detection switching valve at the gas outlet of the drainage metering and acquisition unit; closing the first gas sample valve when the drainage volume reaches the drainage volume corresponding to the target volume of the first gas sample, and sending the first gas sample into the free gas detection branch or the first sample storage container through the detection switching valve; stopping the water supply to the gas-liquid phase separation unit when the phase separation liquid level reaches the preset upper limit liquid level or the preset lower limit liquid level, and marking the corresponding batch as abnormal phase separation liquid level.

4. The intelligent sensing method for combined water and dissolved gas extraction according to claim 1, characterized in that, S2 includes: A bubble state detector is positioned between the lower defoaming water outlet and the membrane wet-side inlet valve. A liquid level detector is positioned at the gas-liquid phase separation unit. A water flow detector is positioned upstream of the membrane wet-side inlet valve in a continuous flow section where water samples still flow even when the inlet valve is closed. During startup, defoaming water flows from the lower defoaming water outlet through the continuous flow section and the pre-flow return branch before returning to the gas-liquid phase separation unit. When the bubble state detector does not detect any bubbles of the size reaching the lower bubble detection limit within a continuous time threshold, the phase separation liquid level is between the lower and upper liquid level limits, and the inlet water flow rate is between the lower and upper flow rate limits, a membrane release permit is output. The continuous time threshold, lower liquid level limit, upper liquid level limit, lower flow rate limit, and upper flow rate limit are pre-written into the controller by the sampling configuration of the current water sample batch.

5. The intelligent sensing method for combined water and dissolved gas extraction according to claim 4, characterized in that, S3 includes: opening the wet-side inlet valve of the membrane after obtaining the membrane release permit; determining the wet-side fullness state by using a full liquid detector located at the wet-side outlet of the hydrophobic and breathable membrane assembly; after determining the wet-side fullness state, adjusting the vacuum pump or vacuum regulating valve according to the negative pressure loading slope specified in the sampling configuration of the current water sample batch until the membrane dry-side pressure reaches the target dry-side pressure; limiting the adjustment amount of the vacuum pump or vacuum regulating valve according to the difference between the membrane wet-side pressure and the membrane dry-side pressure, and correcting the adjustment amount based on the second gas sample flow rate.

6. The intelligent sensing method for combined water and dissolved gas extraction according to claim 5, characterized in that, S4 includes: a main liquid interception branch and a backup liquid interception branch connected in parallel on the dry side of the hydrophobic and breathable membrane assembly; each liquid interception branch is sequentially equipped with an upstream branch valve, a gravity liquid interception chamber, a liquid interception level detector, a hydrophobic and breathable liquid-blocking component, a liquid-blocking differential pressure detector, and a downstream branch isolation valve; the dew point temperature is determined based on the temperature and humidity of the second gas sample, and the dew point margin is obtained by subtracting the dew point temperature from the temperature of the second gas sample; sequentially decreasing warning margin threshold, switching margin threshold, and isolation margin threshold are set for the dew point margin, and a judgment is made when the dew point margin is not greater than the corresponding margin threshold. The corresponding risk level is defined; for the liquid level and pressure difference of the current working branch, the warning threshold, switching threshold and isolation threshold are set in ascending order. When the liquid level or pressure difference is not less than the corresponding threshold, it is determined to be the corresponding risk level; the judgment results of the dew point margin, the liquid level and pressure difference of the current working branch are combined according to the priority order of isolation level, switching level and warning level, and the first risk level that appears is selected as the condensation risk level. The liquid level and pressure difference of the isolated branch to be reset are only used for drainage and reset judgment.

7. The intelligent sensing method for combined water and dissolved gas extraction according to claim 6, characterized in that, Step S4 further includes: using the condensation risk level as a gas path safety interlock signal; marking the liquid-blocking branch with both the upstream branch valve and the downstream branch isolation valve open and undertaking membrane suction as the current working branch; marking another liquid-blocking branch that has met the reset conditions as a branch to be switched and available; reducing the negative pressure loading on the dry side when the condensation risk level is a warning level; and opening the downstream branch isolation valve of the branch to be switched and available while keeping the upstream branch valve closed for pre-suction until the difference between the branch pressure and the current working branch pressure does not exceed the preset switching pressure difference, and then opening the downstream branch isolation valve of the branch to be switched and available. Switch the upstream branch valve of the available branch, then close the upstream branch valve and downstream branch isolation valve of the current working branch. Mark the newly opened liquid interception branch as the current working branch, and mark the cut-off liquid interception branch as the isolation branch to be reset. When the condensation risk level is the isolation level, close the upstream branch valve and downstream branch isolation valve of the current working branch and stop membrane suction. The isolation branch to be reset drains liquid after bidirectional isolation through its upstream branch valve and downstream branch isolation valve, and is marked as a branch to be switched after the liquid interception level is less than the reset level, the pressure difference is less than the reset pressure difference, and the airtightness test result meets the preset leakage rate threshold.

8. The intelligent sensing method for combined water and dissolved gas extraction according to claim 5, characterized in that, Step S3 further includes: when the membrane release permit is revoked, the phase separation liquid level exceeds the preset liquid level range, the influent flow rate exceeds the preset flow rate range, the pressure difference across the membrane reaches the differential pressure protection threshold, or the bubble state detector detects bubbles, the negative pressure loading amount on the dry side is first reduced to the unloading set value, then the membrane wet side inlet valve is closed, and the water sample is returned to the gas-liquid phase separation unit through the reflux valve or the water sample is guided away from the hydrophobic and permeable membrane assembly through the bypass valve; the next wet side filling and dry side negative pressure loading are only performed after the membrane release permit is re-established.

9. The intelligent sensing water-dissolved gas combined extraction method according to claim 7, characterized in that, S5 include: For each water sample batch, a batch record is established, including sampling start and end times, influent flow rate, discharge volume, first gas sample volume, second gas sample flow rate integral value, phase level, bubble state, pressure on both sides of the membrane, dew point margin, intercepted liquid level, resistance pressure difference, branch switching event, and valve / pump status. The first and second gas samples are respectively bound to the same water sample batch and the sampling time window defined by the sampling start and end times and written into the batch record. A phase level abnormality is defined as the phase level exceeding the lower or upper limit of the liquid level. An incomplete branch switching event is defined as the upstream branch valve and downstream branch isolation valve of the intercepted liquid branch not being fully closed when the branch to be switched has not been marked as the current working branch or the preset switching time limit has expired since the switching stage is triggered. The discharge and reset of the cut branch are recorded separately as branch reset events. In the absence of the aforementioned abnormal phase level, continued suction event after membrane release permit revocation, isolation stage triggering event, and incomplete branch switching event, the water sample batch is marked as a qualified batch, and the first and second gas samples of the qualified batch are output according to the sampling method or combined after separate measurement and output to the detection branch or storage container.

10. A smart sensing water-dissolved gas combined sampling system, used to execute the smart sensing water-dissolved gas combined sampling method according to any one of claims 1 to 9, characterized in that, include: The free gas separation and metering module includes a gas-liquid phase separation unit and a drainage-type metering and acquisition unit, which is used to perform step S1; The membrane release module includes a phase level detector, a bubble state detector, a water flow detector, and a membrane wet-side inlet valve, and is used to perform step S2; The membrane diffusion sampling module includes a hydrophobic and breathable membrane assembly, pressure detectors on both sides of the membrane, and a negative pressure regulating unit, and is used to execute step S3; the condensation isolation module includes a main liquid interception branch and a backup liquid interception branch connected in parallel, a temperature and humidity detector, a liquid interception level detector, a pressure differential detector, and a branch valve, and is used to execute step S4; the batch output module is used to measure the first gas sample and the second gas sample respectively, and execute step S5; the controller is communicatively connected to the free gas separation and metering module, the membrane release module, the membrane diffusion sampling module, the condensation isolation module, and the batch output module, and is used to control the valve pump, the suction path, and the gas sample output path according to the membrane release permit and the condensation risk level.

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