Monitoring System for Solid-Liquid Two-Phase Impurity Concentration in Pipeline-Transported Natural Gas Based on Microcharge Induction Technology

Abstract

The present invention discloses a monitoring system for the concentration of solid-liquid two-phase impurities in pipeline natural gas based on microcharge induction technology, belonging to the technical field of monitoring the concentration of solid-liquid two-phase impurities in pipeline natural gas, and solving the technical problems of insufficient pressure resistance and sealing performance of the microcharge sensor probe and unreasonable arrangement of measurement points when applying the microcharge induction technology to the impurity monitoring of natural gas pipelines. It includes a monitoring system and a plurality of microcharge sensor groups. Each microcharge sensor group is correspondingly arranged on each of the multiple natural gas distribution flow paths arranged in parallel in the natural gas station where it is located. An inlet filter and an outlet filter are serially arranged on each natural gas distribution flow path. Each microcharge sensor group has a first microcharge sensor located at the inlet of the inlet filter, a second microcharge sensor located at the outlet of the inlet filter or the inlet of the outlet filter, and a third microcharge sensor located at the outlet of the outlet filter.

Description

Technical Field

[0001] The present invention relates to the technical field of monitoring the concentration of solid-liquid two-phase impurities in pipeline-transported natural gas, and particularly relates to a monitoring system for the concentration of solid-liquid two-phase impurities in pipeline-transported natural gas based on micro charge induction technology. Background Art

[0002] Natural gas is one of the important sources of modern energy, and has strict requirements for cleanliness during the transportation and use processes. The solid-phase impurities (such as iron filings) and liquid-phase impurities (such as condensed oil, etc.) contained in natural gas will not only affect the quality of natural gas, but may also cause serious blockage, corrosion or wear to pipelines and related equipment, and even threaten the safe operation of the transportation system. Therefore, real-time monitoring of the concentration of solid-liquid two-phase impurities in pipeline-transported natural gas is of great significance for ensuring the efficient and stable operation of the natural gas transportation system.

[0003] In the prior art, the monitoring of natural gas impurities mainly relies on sampling analysis or on-line monitoring equipment. The sampling analysis method requires manual sampling at regular intervals and sending it to the laboratory for testing. Although the results of this method are relatively accurate, there are problems such as sampling delay, poor real-time performance, and inability to perform on-line monitoring, making it difficult to meet the requirements of modern natural gas transportation systems for real-time monitoring. On-line monitoring equipment is mostly based on detection principles such as optics, ultrasonic waves, and pressure difference to monitor the impurity concentration in the pipeline.

[0004] However, these on-line monitoring technologies often have the following disadvantages: 1) Low measurement accuracy: Traditional turbidimeters or optical sensors are easily affected by liquid-phase impurities in natural gas, resulting in distorted measurement results; 2) Poor reliability: In the natural gas transportation environment with medium and high pressure (6-12 MPa), it is difficult to ensure the sealing performance of the sensor, and leakage is likely to occur, posing a safety hazard; 3) Weak discrimination ability: It is difficult to effectively distinguish solid-phase impurities and liquid-phase impurities, which is not conducive to taking targeted treatment measures. Therefore, it is urgent to develop a monitoring system for the concentration of solid-liquid two-phase impurities that can work stably in the natural gas transportation environment, has high measurement accuracy, and can achieve multi-point monitoring.

[0005] Due to its advantages such as fast response and high detection accuracy of particulate matter concentration, micro charge induction technology has been applied in the field of particulate matter detection (reference can be made to the applicant's description of micro charge induction technology in the publication numbers CN110836839A and CN112362118A). However, when applying this technology to the monitoring of natural gas pipeline impurities at present, there are still problems such as insufficient pressure resistance and sealing performance of the micro charge sensor probe, unreasonable arrangement of measurement points, and inability to effectively distinguish solid-phase impurities and liquid-phase impurities, which restrict the popularization and application of this technology in the field of natural gas pipeline transportation. Summary of the Invention

[0006] The object of the present invention is to provide a monitoring system for the concentration of solid-liquid two-phase impurities in pipeline-transported natural gas based on micro-charge induction technology, so as to solve the technical problems of insufficient pressure resistance and sealing performance of the micro-charge sensor probe, unreasonable arrangement of measurement points, and inability to effectively distinguish solid-phase impurities and liquid-phase impurities when applying the micro-charge induction technology to the impurity monitoring of natural gas pipelines. In addition, the present invention also provides a micro-charge sensor and a pressure-resistant probe of the micro-charge sensor that can be used for the above-mentioned monitoring system for the concentration of solid-liquid two-phase impurities in pipeline-transported natural gas based on micro-charge induction technology.

[0007] In a first aspect, a monitoring system for the concentration of solid-liquid two-phase impurities in pipeline-transported natural gas based on micro-charge induction technology is provided, including a monitoring system and a plurality of micro-charge sensor groups disposed in at least one natural gas station field on a natural gas pipeline. Each micro-charge sensor group among the plurality of micro-charge sensor groups is correspondingly disposed on each natural gas distribution flow path among a plurality of parallel natural gas distribution flow paths in the corresponding natural gas station field. An upstream filter and a downstream filter are serially disposed on each natural gas distribution flow path. The solid-phase impurity filtration efficiency α1 of the upstream filter and the solid-phase impurity filtration efficiency α2 of the downstream filter are preset, and the liquid-phase impurity filtration efficiency η1 of the upstream filter is different from the liquid-phase impurity filtration efficiency η2 of the downstream filter. Each micro-charge sensor group has a first micro-charge sensor at the inlet of the upstream filter of the corresponding natural gas distribution flow path, a second micro-charge sensor at the outlet of the upstream filter of the corresponding natural gas distribution flow path or at the inlet of the downstream filter of the corresponding natural gas distribution flow path, and a third micro-charge sensor at the outlet of the downstream filter of the corresponding natural gas distribution flow path. The first micro-charge sensor, the second micro-charge sensor, and the third micro-charge sensor each include a pressure-resistant probe and a signal processing device. The pressure-resistant probe is inserted into the corresponding natural gas pipeline and generates and outputs a current signal when particulate matter in the corresponding natural gas pipeline passes through the pressure-resistant probe. The current signal serves as an input signal for the corresponding signal processing device. The signal processing device is configured to convert the received current signal into an acquisition signal and output it to the monitoring system. The pressure-resistant probe includes a signal shielding shell, a micro-charge induction probe rod, a current output structure, and an insulating and sealing bushing. The signal shielding shell includes a housing and a connecting joint. The two ends of the connecting joint are respectively connected to the housing and the corresponding natural gas pipeline through corresponding threaded connection structures. The micro-charge induction probe rod is sleeved in the connecting joint through the insulating and sealing bushing, with one end extending into the housing and the other end extending into the corresponding natural gas pipeline. The current output structure is installed in the housing and connected to the micro-charge induction probe rod. The insulating and sealing bushing has a first T-shaped insulating and sealing bushing for sleeving between the micro-charge induction probe rod and the housing and a second T-shaped insulating and sealing bushing for sleeving between the micro-charge induction probe rod and the connecting joint. The micro-charge induction probe rod is provided with a positioning flange. A first positioning shoulder axially pre-tightening against the first side of the positioning flange is provided in the housing, and a second positioning shoulder axially pre-tightening against the second side of the positioning flange is provided in the connecting joint. The T-shaped head of the first T-shaped insulating and sealing bushing is axially pressed between the first positioning shoulder and the positioning flange and forms end face sealing pairs with the first positioning shoulder and the positioning flange respectively. The T-shaped head of the second T-shaped insulating and sealing bushing is axially pressed between the second positioning shoulder and the positioning flange and forms end face sealing pairs with the second positioning shoulder and the positioning flange respectively.

[0008] In long-distance natural gas pipelines, a natural gas station is usually built every few hundred kilometers for gas filtration, pressure regulation, and flow control. In these natural gas stations, it is a common engineering layout to adopt multiple parallel natural gas distribution flow paths, and it is a standard filtration scheme to series-install a primary filter and a secondary filter on each natural gas distribution flow path. Generally speaking, the primary filter is a cyclone dust collector; the secondary filter is a cartridge filter. The solid-phase impurity filtration efficiency α1 of the primary filter and the solid-phase impurity filtration efficiency α2 of the secondary filter are preset. For example, the solid-phase impurity filtration efficiency α1 of the cyclone dust collector is usually about 90%, and the solid-phase impurity filtration efficiency α2 of the cartridge filter is usually about 99.9%. When the liquid-phase impurity filtration efficiency η1 of the primary filter is different from the liquid-phase impurity filtration efficiency η2 of the secondary filter, this differential configuration creates conditions for calculation.

[0009] Specifically, when each micro-charge sensor group has a first micro-charge sensor located at the inlet of the primary filter in the natural gas distribution flow path where it is located, a second micro-charge sensor located at the outlet of the primary filter in the natural gas distribution flow path where it is located or at the inlet of the secondary filter in the natural gas distribution flow path where it is located, and a third micro-charge sensor located at the outlet of the secondary filter in the natural gas distribution flow path where it is located, the total concentration measurement value A obtained by the first micro-charge sensor is equal to the sum of the liquid phase concentration x and the solid phase concentration y. After passing through the primary filter, the second micro-charge sensor obtains the total concentration measurement value B. At this time, the liquid phase impurities are intercepted by the filter with a filtration efficiency of η1, and the solid phase impurities are intercepted by the primary filter with a filtration efficiency of α1 (such as 90%). Therefore, B is equal to the sum of the concentration of the liquid phase impurities after primary filtration and the concentration of the solid phase impurities after primary filtration. Similarly, after passing through the secondary filter, the third micro-charge sensor obtains the total concentration measurement value C. At this time, the liquid phase impurities and the solid phase impurities are further intercepted by the second filter with a liquid phase impurity filtration efficiency of η2 and a solid phase impurity filtration efficiency of α2 (such as 99.9%). During the calculation, first use the equation at the inlet [x + y = A] to express the solid phase concentration y in terms of the liquid phase concentration x. Then substitute this relationship into the equation after primary filtration [x(1 - η1) + y(1 - α1) = B], and after arrangement, the first expression of the liquid phase concentration x can be obtained. Similarly, substitute the relationship between y and x into the equation after secondary filtration [x(1 - η1)(1 - η2) + y(1 - α1)(1 - α2) = C], and after arrangement, the second expression of the liquid phase concentration x can be obtained. Since both of these expressions represent the same liquid phase concentration x, they are equal, and thus an equation containing only η1 can be established. In this equation, the total concentration measurement values A, B, and C are known, the solid phase impurity filtration efficiency α1 of the primary filter and the solid phase impurity filtration efficiency α2 of the secondary filter are preset known parameters, and the liquid phase impurity filtration efficiency η2 of the secondary filter is also preset. By solving this equation, the liquid phase impurity filtration efficiency η1 of the primary filter can be obtained. After obtaining η1, substitute it back into the aforementioned expression of the liquid phase concentration x to calculate the liquid phase concentration x at the inlet, and then use the relationship between the total concentration and the liquid phase concentration at the inlet to calculate the solid phase concentration y. Thus, the separate monitoring of the solid-liquid two-phase impurities is achieved.

[0010] In addition, the structural design of the pressure-resistant probe realizes the pressure-resistant sealing function of the micro-charge induction probe rod when it is in the corresponding natural gas pipeline. Specifically, the pressure-resistant probe uses a first T-shaped insulating sealing bushing and a second T-shaped insulating sealing bushing to be sleeved between the micro-charge induction probe rod and the housing, and between the micro-charge induction probe rod and the connecting joint respectively. The T-shaped head of the first T-shaped insulating sealing bushing is installed between the first positioning shoulder and the positioning flange by axial pressing and forms an end face sealing pair with them respectively. The T-shaped head of the second T-shaped insulating sealing bushing is installed between the second positioning shoulder and the positioning flange by axial pressing and forms an end face sealing pair with them respectively. This double T-shaped sealing structure, combined with the axial pre-tightening design between the positioning flange on the micro-charge induction probe rod and the housing and the connecting joint, not only ensures the reliability of the seal, but also provides stable sealing performance through the end face sealing pair design of the T-shaped head, effectively preventing the leakage of natural gas.

[0011] In a second aspect, a micro-charge sensor is provided, which includes a pressure-resistant probe and a signal processing device. The pressure-resistant probe is inserted into the corresponding high-pressure gas pipeline (such as the aforementioned natural gas pipeline), and when the particulate matter in the corresponding high-pressure gas pipeline passes through the pressure-resistant probe, it generates and outputs a current signal. The current signal is used as the input signal of the corresponding signal processing device. The signal processing device is used to convert the received current signal into an acquisition signal and output it; the pressure-resistant probe includes a signal shielding shell, a micro-charge induction probe rod, a current output structure, and an insulating sealing bushing. The signal shielding shell includes a housing and a connecting joint. The two ends of the connecting joint are respectively connected to the housing and the corresponding natural gas pipeline through corresponding threaded connection structures. The micro-charge induction probe rod is sleeved in the connecting joint through the insulating sealing bushing, with one end extending into the housing and the other end extending into the corresponding high-pressure gas pipeline. The current output structure is installed in the housing and is connected to the micro-charge induction probe rod. The insulating sealing bushing has a first T-shaped insulating sealing bushing for sleeving between the micro-charge induction probe rod and the housing and a second T-shaped insulating sealing bushing for sleeving between the micro-charge induction probe rod and the connecting joint. The micro-charge induction probe rod is provided with a positioning flange. The housing is provided with a first positioning shoulder that is axially pre-tightened with the first side of the positioning flange. The connecting joint is provided with a second positioning shoulder that is axially pre-tightened with the second side of the positioning flange. The T-shaped head of the first T-shaped insulating sealing bushing is axially pressed between the first positioning shoulder and the positioning flange and forms an end face sealing pair with the first positioning shoulder and the positioning flange respectively. The T-shaped head of the second T-shaped insulating sealing bushing is axially pressed between the second positioning shoulder and the positioning flange and forms an end face sealing pair with the second positioning shoulder and the positioning flange respectively.

[0012] In a third aspect, a pressure-resistant probe for a micro-charge sensor is provided, which includes a signal shielding case, a micro-charge induction probe rod, a current output structure, and an insulating and sealing bushing. The signal shielding case includes a case body and a connection joint. The two ends of the connection joint are respectively connected to the case body and the corresponding natural gas pipeline through corresponding threaded connection structures. The micro-charge induction probe rod is sleeved in the connection joint through the insulating and sealing bushing, with one end extending into the case body and the other end extending into the corresponding high-pressure gas pipeline (such as the aforementioned natural gas pipeline). The current output structure is installed in the case body and connected to the micro-charge induction probe rod. The insulating and sealing bushing has a first T-shaped insulating and sealing bushing for sleeving between the micro-charge induction probe rod and the case body, and a second T-shaped insulating and sealing bushing for sleeving between the micro-charge induction probe rod and the connection joint. A positioning flange is provided on the micro-charge induction probe rod. A first positioning shoulder for axially pre-tightening the first side of the positioning flange is provided in the case body. A second positioning shoulder for axially pre-tightening the second side of the positioning flange is provided in the connection joint. The T-shaped head of the first T-shaped insulating and sealing bushing is axially pressed between the first positioning shoulder and the positioning flange and forms end face sealing pairs with the first positioning shoulder and the positioning flange respectively. The T-shaped head of the second T-shaped insulating and sealing bushing is axially pressed between the second positioning shoulder and the positioning flange and forms end face sealing pairs with the second positioning shoulder and the positioning flange respectively.

[0013] The following further describes the present invention in conjunction with the accompanying drawings and specific embodiments. The additional aspects and advantages provided by the present invention are partially given in the following description, partially will become apparent from the following description, or will be understood through practice. Description of the Drawings

[0014] The drawings forming a part of this specification are used to assist in understanding the present invention. The content provided in the drawings and the related descriptions in this specification can be used to explain the present invention, but do not constitute an improper limitation to the present invention.

[0015] Figure 1 It is a schematic diagram of the installation positions of the first micro-charge sensor, the second micro-charge sensor, and the third micro-charge sensor in an embodiment of a pipeline natural gas solid-liquid two-phase impurity concentration monitoring system based on micro-charge induction technology of the present invention.

[0016] Figure 2 It is a schematic diagram of the connection relationship between the pressure-resistant probes, signal processing devices, and monitoring systems of each micro-charge sensor in an embodiment of a pipeline natural gas solid-liquid two-phase impurity concentration monitoring system based on micro-charge induction technology of the present invention.

[0017] Figure 3 It is a schematic diagram of the structure of Embodiment 1 of the pressure-resistant probe of the micro-charge sensor of the present invention.

[0018] Figure 4 This is a schematic structural diagram of Embodiment 2 of the voltage-resistant probe of the micro charge sensor in the present invention.

[0019] Figure 5 This is a schematic structural diagram of Embodiment 3 of the voltage-resistant probe of the micro charge sensor in the present invention.

[0020] Figure 6 This is a schematic structural diagram of Embodiment 4 of the voltage-resistant probe of the micro charge sensor in the present invention.

[0021] In the figure, the markings are as follows: natural gas station 1; primary filter 11; secondary filter 12; first micro charge sensor 21; second micro charge sensor 22; third micro charge sensor 23; voltage-resistant probe 3; signal shielding shell 31; housing 311; connecting joint 312; intermediate joint 313; micro charge induction probe rod 32; positioning flange 321; first rod body 322; second rod body 323; first T-shaped insulating sealing bushing 33; second T-shaped insulating sealing bushing 34; T-shaped sleeve 341; end cover 342; T-shaped ceramic sleeve 343; first positioning shoulder 35; second positioning shoulder 36; signal processing device 4; monitoring system 5. Detailed implementation manners

[0022] The present invention will be clearly and completely described below with reference to the accompanying drawings. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. Before describing the present invention with reference to the accompanying drawings, it should be particularly noted that:

[0023] In each part including the following description, the technical solutions and technical features provided can be combined with each other without conflict. In addition, where possible, these technical solutions, technical features and related combinations can be given specific technical subjects and protected by relevant patents.

[0024] The embodiments of the present invention involved in the following description are usually only some embodiments rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on these embodiments should fall within the scope of patent protection.

[0025] The terms "including", "comprising", "having" and any variations thereof in this specification, the corresponding claims and the relevant parts are intended to cover non-exclusive inclusion. Other relevant terms and units can be reasonably explained based on the relevant content provided in this specification.

[0026] Figure 1Schematic diagram of the installation positions of the first microcharge sensor, the second microcharge sensor, and the third microcharge sensor in an embodiment of a monitoring system for the concentration of solid-liquid two-phase impurities in pipeline natural gas based on the microcharge induction technology in the present invention. Figure 2 Schematic diagram of the connection relationship between the pressure-resistant probes, signal processing devices, and monitoring systems of each microcharge sensor in an embodiment of a monitoring system for the concentration of solid-liquid two-phase impurities in pipeline natural gas based on the microcharge induction technology in the present invention. As Figure 1 - Figure 2 shown, a monitoring system for the concentration of solid-liquid two-phase impurities in pipeline natural gas based on the microcharge induction technology includes a monitoring system 5 and multiple microcharge sensor groups provided in at least one natural gas station 1 on the natural gas pipeline. Each microcharge sensor group in the multiple microcharge sensor groups is correspondingly provided on each of the multiple natural gas distribution flow paths arranged in parallel in the corresponding natural gas station 1. An primary filter 11 and a secondary filter 12 are connected in series on each natural gas distribution flow path. The solid-phase impurity filtration efficiency α1 of the primary filter 11 and the solid-phase impurity filtration efficiency α2 of the secondary filter 12 are preset, and the liquid-phase impurity filtration efficiency η1 of the primary filter 11 is different from the liquid-phase impurity filtration efficiency η2 of the secondary filter 12. Each microcharge sensor group has a first microcharge sensor 21 located at the inlet of the primary filter 11 of the corresponding natural gas distribution flow path, a second microcharge sensor 22 located at the outlet of the primary filter 11 of the corresponding natural gas distribution flow path or the inlet of the secondary filter 12 of the corresponding natural gas distribution flow path, and a third microcharge sensor 23 located at the outlet of the secondary filter 12 of the corresponding natural gas distribution flow path. The first microcharge sensor 21, the second microcharge sensor 22, and the third microcharge sensor 23 each include a pressure-resistant probe 3 and a signal processing device 4. The pressure-resistant probe 3 is inserted into the corresponding natural gas pipeline and generates and outputs a current signal when particulate matter in the corresponding natural gas pipeline passes through the pressure-resistant probe 3. The current signal is used as the input signal of the corresponding signal processing device 4. The signal processing device 4 is configured to convert the received current signal into an acquisition signal and output it to the monitoring system 5.

[0027] In long-distance natural gas pipelines, a natural gas station 1 is usually built every few hundred kilometers for gas filtration, pressure regulation, and flow control. In these natural gas stations 1, it is a common engineering layout to adopt multiple parallel natural gas distribution flow paths, and it is a standard filtration scheme to series-connected a primary filter 11 and a secondary filter 12 on each natural gas distribution flow path. Generally speaking, the primary filter is a cyclone dust collector; the secondary filter is a cartridge filter. The solid-phase impurity filtration efficiency α1 of the primary filter and the solid-phase impurity filtration efficiency α2 of the secondary filter are preset. For example, the solid-phase impurity filtration efficiency α1 of the cyclone dust collector is usually about 90%, and the solid-phase impurity filtration efficiency α2 of the cartridge filter is usually about 99.9%. When the liquid-phase impurity filtration efficiency η1 of the primary filter is different from the liquid-phase impurity filtration efficiency η2 of the secondary filter, this differential configuration creates conditions for calculation.

[0028] Specifically, when each micro-charge sensor group has a first micro-charge sensor 21 located at the inlet of the primary filter 11 of the natural gas distribution flow path where it is located, a second micro-charge sensor 22 located at the outlet of the primary filter 11 of the natural gas distribution flow path where it is located or at the inlet of the secondary filter 12 of the natural gas distribution flow path where it is located, and a third micro-charge sensor 23 located at the outlet of the secondary filter 12 of the natural gas distribution flow path where it is located, if we set: the total concentration measurement value A of the first micro-charge sensor; the total concentration measurement value B of the second micro-charge sensor; the total concentration measurement value C of the third micro-charge sensor; the liquid-phase impurity filtration efficiency η1 of the primary filter; the liquid-phase impurity filtration efficiency η2 of the secondary filter; the solid-phase impurity filtration efficiency α1 of the primary filter (such as 90%); the solid-phase impurity filtration efficiency α2 of the secondary filter (such as 99.9%); x is the liquid-phase concentration at the inlet; y is the solid-phase concentration at the inlet; then we can get:

[0029] x + y = A (1)

[0030] x(1 - η1) + y(1 - α1) = B (2)

[0031] x(1 - η1)(1 - η2) + y(1 - α1)(1 - α2) = C (3)

[0032] From equation (1), we get: y = A – x;

[0033] Substitute into equation (2):

[0034] x(1 - η1) + (A - x)(1 - α1) = B

[0035] x(1 - η1) + A(1 - α1) - x(1 - α1) = B

[0036] x[(1 - η1) - (1 - α1)] = B - A(1 - α1)

[0037] x(α1 - η1)=B - A(1 - α1)

[0038] x = [B - A(1 - α1)] / (α1 - η1) (4)

[0039] Substitute into Equation (3):

[0040] x(1 - η1)(1 - η2)+(A - x)(1 - α1)(1 - α2)=C

[0041] After simplification, we get:

[0042] x[(1 - η1)(1 - η2)-(1 - α1)(1 - α2)]=C - A(1 - α1)(1 - α2) (5)

[0043] From Equation (4) and Equation (5), we get:

[0044] [B - A(1 - α1)] / (α1 - η1)=[C - A(1 - α1)(1 - α2)] / [(1 - η1)(1 - η2)-(1 - α1)(1 - α2)]

[0045] This equation can solve the liquid - phase impurity filtration efficiency η1 of the primary filter, and then we can obtain:

[0046] The liquid - phase concentration x at the inlet = [B - A(1 - α1)] / (α1 - η1); the solid - phase concentration y at the inlet = A - x. Thus, the separate monitoring of solid - liquid two - phase impurities is realized.

[0047] Since the solid-phase impurity filtration efficiency α1 of the primary filter 11 and the solid-phase impurity filtration efficiency α2 of the secondary filter 12 will vary with factors such as the usage duration of the filter, fluctuations in the intake pressure, changes in the gas flow rate, temperature changes, and the characteristics of impurity particles, this affects the accuracy of the calculation results based on the system of equations. Therefore, as an improvement, the monitoring system generates the natural gas solid-phase impurity content and the natural gas liquid-phase impurity content according to a pre-trained AI model. The AI model is trained by the following method: Under preset multiple sets of solid-phase impurity and liquid-phase impurity ratio conditions, corresponding natural gas samples are collected, and the solid-phase impurity content and the liquid-phase impurity content in each natural gas sample are recorded as label data. Feature extraction is performed on the acquisition signals of the first micro-charge sensor, the second micro-charge sensor, and the third micro-charge sensor corresponding to each natural gas sample. The features include the acquisition signal amplitude feature, the frequency-domain feature obtained through fast Fourier transform, the acquisition signal waveform feature, and the acquisition signal energy feature. Moreover, the solid-phase impurity content and the liquid-phase impurity content calculated based on the solid-phase impurity filtration efficiency α1 of the primary filter, the solid-phase impurity filtration efficiency α2 of the secondary filter, the liquid-phase impurity filtration efficiency η1 of the primary filter, and the liquid-phase impurity filtration efficiency η2 of the secondary filter are used as supplementary features. The feature data obtained from the feature extraction and the supplementary features are used as inputs, and the corresponding solid-phase impurity content and liquid-phase impurity content are used as outputs to construct a training dataset. The training dataset is used to train a neural network model. The neural network model includes a feature extraction layer and a prediction layer. The feature extraction layer is used to perform dimensionality reduction and feature fusion on the input feature data. The prediction layer is used to output the solid-phase impurity content and the liquid-phase impurity content. The parameters of the neural network model are optimized by the backpropagation algorithm until convergence.

[0048] Since the changes in the solid-phase impurity filtration efficiency α1 of the primary filter 11 and the solid-phase impurity filtration efficiency α2 of the secondary filter 12 will affect the accuracy of the system of equations calculation results, and in addition to using the basic measurement values of the first micro-charge sensor 21, the second micro-charge sensor 22, and the third micro-charge sensor 23, the AI model also obtains richer information such as the acquisition signal amplitude feature, frequency-domain feature, waveform feature, and energy feature through feature extraction, and performs dimensionality reduction and feature fusion through the feature extraction layer of the neural network model, and then the prediction layer outputs the natural gas solid-phase impurity content and the natural gas liquid-phase impurity content, so as to better adapt to the changes in α1 and α2 and improve the monitoring accuracy.

[0049] Specifically, when training the above AI model, in the data preparation stage, 50 groups of sample data with different ratios need to be set in a standard laboratory environment, where the solid-phase impurity content ranges from 5 to 50 mg / m³, and the liquid-phase impurity content ranges from 5 to 50 mg / m³. Each ratio is sampled 3 times to consider random errors, resulting in a total of 150 samples. Each sample collects 1 second of data through the first micro-charge sensor 21, the second micro-charge sensor 22, and the third micro-charge sensor 23, and the sampling frequency is set to 1000 Hz.

[0050] The feature extraction stage includes two parts: First, four types of features are extracted from the original signals collected by each sensor: amplitude features (including mean, standard deviation, maximum value, minimum value, and peak-to-peak value), frequency-domain features obtained through fast Fourier transform (taking the first 10 main frequency components), waveform features (including average slope, rising point ratio, and peak position), and energy features (including sum of squared signal energy and absolute value sum). In this way, each sensor can obtain 20 feature values. Second, based on the solid-phase impurity filtration efficiency α1 of the primary filter, the solid-phase impurity filtration efficiency α2 of the secondary filter, the liquid-phase impurity filtration efficiency η1 of the primary filter, and the liquid-phase impurity filtration efficiency η2 of the secondary filter, the solid-phase impurity content and liquid-phase impurity content calculated using the previous equations are used as supplementary features.

[0051] The neural network structure adopts a typical three-layer feedforward neural network. The input layer contains 62 nodes (corresponding to 20 features for each of the three sensors, plus 2 supplementary features), the first hidden layer contains 64 nodes and uses the ReLU activation function, the second hidden layer contains 32 nodes and also uses the ReLU activation function, and the final output layer contains 2 nodes corresponding to the predicted values of the solid-phase and liquid-phase impurity contents respectively.

[0052] In the training process, first, the 150 samples are randomly divided into a training set and a validation set in a ratio of 7:3. Then, the mean squared error is selected as the loss function, and the Adam optimization algorithm is used for parameter optimization (the initial learning rate is set to 0.001). A total of 1000 rounds of training are performed. Each round uses all the training data, and an early stopping mechanism is set, that is, when the validation set error does not improve for 10 consecutive rounds, the training is stopped in advance.

[0053] During actual application, the real-time signals collected by the three micro-charge sensors are extracted for features in the same way as during training. At the same time, the supplementary features based on the filtration efficiency are calculated. All the features are input into the trained neural network model, and the predicted values of the current solid-phase impurity content and liquid-phase impurity content in the natural gas can be obtained, and the whole process can achieve real-time monitoring.

[0054] To further improve the accuracy and robustness of the model, optimization can be carried out from the following aspects: expanding the sample size and ensuring that the samples cover a wider range of operating conditions, exploring and extracting more effective signal features, optimizing the calculation method of supplementary features, adjusting the number of layers and the number of nodes in each layer of the neural network, using cross-validation to more accurately evaluate the model performance, and at the same time considering using environmental parameters such as temperature and pressure as additional input features.

[0055] Figure 3 FIG. 4 is a schematic structural diagram of Embodiment 1 of the pressure-resistant probe of the micro charge sensor in the present invention. Figure 4 FIG. 5 is a schematic structural diagram of Embodiment 2 of the pressure-resistant probe of the micro charge sensor in the present invention. Figure 5 FIG. 6 is a schematic structural diagram of Embodiment 3 of the pressure-resistant probe of the micro charge sensor in the present invention. Figure 6 FIG. 7 is a schematic structural diagram of Embodiment 4 of the pressure-resistant probe of the micro charge sensor in the present invention. As Figure 3 - Figure 6 shown, the pressure-resistant probe 3 includes a signal shielding shell 31, a micro charge induction probe rod 32, a current output structure, and an insulating and sealing bushing. The signal shielding shell 31 includes a shell body 311 and a connection joint 312. The two ends of the connection joint 312 are respectively connected to the shell body 311 and the corresponding natural gas pipeline through corresponding threaded connection structures. The micro charge induction probe rod 32 is sleeved in the connection joint 312 through the insulating and sealing bushing, with one end extending into the shell body 311 and the other end extending into the corresponding natural gas pipeline. The current output structure is installed in the shell body 311 and is connected to the micro charge induction probe rod 32. The insulating and sealing bushing has a first T-shaped insulating and sealing bushing 33 for sleeving between the micro charge induction probe rod 32 and the shell body 311 and a second T-shaped insulating and sealing bushing 34 for sleeving between the micro charge induction probe rod 32 and the connection joint 312. A positioning flange 321 is provided on the micro charge induction probe rod 32. A first positioning shoulder 35 axially pre-tightening the first side of the positioning flange 321 is provided in the shell body 311. A second positioning shoulder 36 axially pre-tightening the second side of the positioning flange 321 is provided in the connection joint 312. The T-shaped head of the first T-shaped insulating and sealing bushing 33 is axially pressed between the first positioning shoulder 35 and the positioning flange 321 and forms end face sealing pairs with the first positioning shoulder 35 and the positioning flange 321 respectively. The T-shaped head of the second T-shaped insulating and sealing bushing 34 is axially pressed between the second positioning shoulder 36 and the positioning flange 321 and forms end face sealing pairs with the second positioning shoulder 36 and the positioning flange 321 respectively.

[0056] The above-mentioned pressure-resistant probe 3 uses a first T-shaped insulating seal bushing 33 and a second T-shaped insulating seal bushing 34 to be sleeved between the micro-charge induction probe rod 32 and the housing 311 and between the micro-charge induction probe rod 32 and the connecting joint 312 respectively. The T-shaped head of the first T-shaped insulating seal bushing 33 is installed between the first positioning shoulder 35 and the positioning flange 321 by axial pressing and forms an end face seal pair with them respectively. The T-shaped head of the second T-shaped insulating seal bushing 34 is installed between the second positioning shoulder 36 and the positioning flange 321 by axial pressing and forms an end face seal pair with them respectively. This double T-shaped sealing structure, combined with the axial pre-tightening design between the positioning flange 321 on the micro-charge induction probe rod 32 and the housing 311 and the connecting joint 312, not only ensures the reliability of the seal, but also provides stable sealing performance through the end face seal pair design of the T-shaped head, effectively preventing the leakage of natural gas.

[0057] Optionally, the first T-shaped insulating seal bushing 33 and the second T-shaped insulating seal bushing 34 are made of ceramic or plastic. For example, the first T-shaped insulating seal bushing 33 and the second T-shaped insulating seal bushing 34 are made of polytetrafluoroethylene, perfluoroalkoxy resin or polyether ether ketone.

[0058] As Figure 3 shown, in the pressure-resistant probe 3 of Embodiment 1, the inner hole of the connecting joint 312 is a stepped hole, and the counterbore part of the stepped hole forms the second positioning shoulder 36. The outer peripheral surface of the second T-shaped insulating seal bushing 34 is connected to the small hole channel of the stepped hole through a threaded structure that cooperates with each other.

[0059] In the structure of the pressure-resistant probe 3 of Embodiment 1, the inner hole of its connecting joint 312 adopts a stepped hole design. The second positioning shoulder 36 is directly formed by the counterbore part of the stepped hole, and a threaded structure that cooperates with each other is arranged between the outer peripheral surface of the second T-shaped insulating seal bushing 34 and the small hole channel of the stepped hole. This structural design eliminates the process of additionally machining the second positioning shoulder 36 and can accurately control the axial pressing force of the second T-shaped insulating seal bushing 34 through the threaded structure, ensuring that its T-shaped head can reliably form a stable end face seal pair with the second positioning shoulder 36 and the positioning flange 321.

[0060] In addition, as Figure 3 shown, the edge of the T-shaped head of the second T-shaped insulating seal bushing 34 has a radial seal part that surrounds the outer peripheral surface of the positioning flange 321. A radial seal part that can surround the outer peripheral surface of the positioning flange 321 is provided at the edge of the T-shaped head of the second T-shaped insulating seal bushing 34, so as to realize radial sealing by the fitting of the radial seal part and the outer peripheral surface of the positioning flange 321, thus constituting double sealing protection of the end face and the radial direction, and further improving the reliability and stability of the overall seal.

[0061] Of course, the radial sealing portion may also be provided at the edge of the T-shaped head of the first T-shaped insulating sealing bushing 33 and surround the outer peripheral surface of the positioning flange 321.

[0062] As Figure 4 shown, in the pressure-resistant probe 3 of Embodiment 2, one end face of the connection joint 312 serves as the second positioning shoulder 36; the signal shielding case 31 further includes an intermediate joint 313 connected between the case 311 and the connection joint 312, and both ends of the intermediate joint 313 are respectively connected to the case 311 and the connection joint 312 through corresponding threaded connection structures; the first positioning shoulder 35 is provided in the intermediate joint.

[0063] In the pressure-resistant probe 3 of Embodiment 2, by designing an intermediate joint 313 added in the signal shielding case 31, the first positioning shoulder 35 is provided in the intermediate joint 313 and is respectively connected to the case 311 and the connection joint 312 through threaded connection structures. When maintenance or component replacement is required, it can be achieved by disassembling the corresponding threaded connections, improving the maintainability of the device.

[0064] In addition, as Figure 4 shown, the microcharge induction probe rod 32 is composed of a first rod body 322 and a second rod body 323 that are detachably butt-connected. The positioning flange 321 is entirely located on the first rod body 322, and the first T-shaped insulating sealing bushing 33 is sleeved between the first rod body 322 and the case 311.

[0065] The microcharge induction probe rod 32 adopts a split structure in which the first rod body 322 and the second rod body 323 are detachably butt-connected, and the positioning flange 321 is entirely provided on the first rod body 322. In this way, the length of the microcharge induction probe rod 32 can be adjusted by replacing the second rod body 323 with different lengths.

[0066] Correspondingly, the second T-shaped insulating sealing bushing 34 may be composed of a head and a neck that are detachably butt-connected (specifically, threaded connection may be adopted). The T-shaped head of the second T-shaped insulating sealing bushing 34 is entirely located on the head, so as to adapt to the second rod body 323 with different lengths by replacing the neck with different lengths.

[0067] As Figure 5 - Figure 6As shown, in the high-voltage resistant probe 3 of Embodiment 3 and the high-voltage resistant probe 3 of Embodiment 4, the second T-shaped insulating sealing bushing 34 completely wraps the micro charge induction probe rod 32. In the high-voltage resistant probe 3 of Embodiment 3, the second T-shaped insulating sealing bushing 34 adopts a combined structure (the second T-shaped insulating sealing bushing 34 includes a T-shaped sleeve 341 made of polytetrafluoroethylene and an end cap 342 installed at the outer end of the T-shaped sleeve 341) to seal the micro charge induction probe rod 32. In the high-voltage resistant probe 3 of Embodiment 4, the second T-shaped insulating sealing bushing 34 adopts an integral structure to seal the micro charge induction probe rod 32. Specifically, the second T-shaped insulating sealing bushing 34 of this integral structure is a T-shaped ceramic sleeve 343 with a closed outer end.

[0068] The above describes the relevant content of the present invention. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. Based on the above content of this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the scope of the present invention.

Claims

1. A solid-liquid two-phase impurity concentration monitoring system for pipeline natural gas based on micro-charge induction technology, characterized by: It comprises a monitoring system and a plurality of micro-charge sensor groups arranged in at least one natural gas station on a natural gas transmission pipeline, each of the plurality of micro-charge sensor groups is arranged one-to-one on each natural gas distribution flow path of a plurality of natural gas distribution flow paths arranged in parallel in the natural gas station, each natural gas distribution flow path is provided with a primary filter and a secondary filter in series, the solid phase impurity filtration efficiency α1 of the primary filter and the solid phase impurity filtration efficiency α2 of the secondary filter are preset, and the liquid phase impurity filtration efficiency η1 of the primary filter and the liquid phase impurity filtration efficiency η2 of the secondary filter are different, each micro-charge sensor group comprises a first micro-charge sensor located at the inlet of the primary filter of the natural gas distribution flow path, a second micro-charge sensor located at the outlet of the primary filter of the natural gas distribution flow path or at the inlet of the secondary filter of the natural gas distribution flow path, and a third micro-charge sensor located at the outlet of the secondary filter of the natural gas distribution flow path; The first micro-charge sensor, the second micro-charge sensor and the third micro-charge sensor each include a pressure-resistant probe and a signal processing device, wherein the pressure-resistant probe is inserted into a corresponding natural gas pipeline and generates and outputs a current signal when particulate matter in the corresponding natural gas pipeline passes through the pressure-resistant probe, and the current signal is used as an input signal of the corresponding signal processing device, and the signal processing device is used to convert the received current signal into a collection signal and output it to the monitoring system; The pressure-resistant probe comprises a signal shielding shell, a micro-charge sensing probe, a current output structure and an insulating sealing bushing. The signal shielding shell comprises a shell and a connecting joint. The two ends of the connecting joint are respectively connected to the shell and the corresponding natural gas pipeline through corresponding threaded connection structures. The micro-charge sensing probe is sleeved in the connecting joint through the insulating sealing bushing and one end extends into the shell and the other end extends into the corresponding natural gas pipeline. The current output structure is installed in the shell and connected to the micro-charge sensing probe. The insulating sealing bushing has a first T-shaped insulating sealing bushing for sleeved between the micro-charge sensing probe and the shell and a second T-shaped insulating sealing bushing for sleeved on the micro-charge sensing probe. A second T-shaped insulating sealing bushing is provided between the probe rod and the connecting joint, a positioning flange is provided on the micro-charge sensing probe rod, a first positioning shoulder axially pre-tightened with the first side of the positioning flange is provided in the shell, a second positioning shoulder axially pre-tightened with the second side of the positioning flange is provided in the connecting joint, the T-shaped head of the first T-shaped insulating sealing bushing is axially pressed between the first positioning shoulder and the positioning flange and forms an end face sealing pair with the first positioning shoulder and the positioning flange respectively, the T-shaped head of the second T-shaped insulating sealing bushing is axially pressed between the second positioning shoulder and the positioning flange and forms an end face sealing pair with the second positioning shoulder and the positioning flange respectively; The first-stage filter is a cyclone dust collector, and the second-stage filter is a cartridge filter. The solid-phase impurity filtration efficiency α1 of the first-stage filter and the solid-phase impurity filtration efficiency α2 of the second-stage filter are preset known parameters. The liquid-phase impurity filtration efficiency η2 of the second-stage filter is also preset. The total concentration measurement value obtained by the first micro-charge sensor is A, the total concentration measurement value obtained by the second micro-charge sensor is B, and the total concentration measurement value obtained by the third micro-charge sensor is C. A is equal to the sum of the liquid-phase concentration x and the solid-phase concentration y. The liquid-phase impurity filtration efficiency η1 of the first-stage filter; when solving, first use the equation x+y=A, and substitute this relationship into the equation x(1-η after the first-stage filtration). 1)+y(1-α1)=B, after arrangement, the first expression of liquid concentration x can be obtained; then the relationship between y and x is substituted into the equation after secondary filtration x(1-η1)(1-η2)+y(1-α1)(1-α2)=C, after arrangement, the second expression of liquid concentration x can be obtained; since these two expressions both represent the same liquid concentration x, they are equal, so an equation containing only η1 can be established; by solving this equation, the liquid impurity filtration efficiency η1 of the first-stage filter can be obtained; after obtaining η1, substitute it back into the aforementioned expression of liquid concentration x to calculate the liquid concentration x at the inlet, and then calculate the solid concentration y.

2. The system for monitoring solid-liquid two-phase impurity concentration of pipeline natural gas based on micro-charge induction technology as claimed in claim 1, characterized in that: The first-level filter is a cyclone dust collector; the second-level filter is a cartridge filter.

3. The system for monitoring solid-liquid two-phase impurity concentration of pipeline natural gas based on micro-charge induction technology as claimed in claim 1, characterized in that: The first T-shaped insulating sealing bushing and the second T-shaped insulating sealing bushing are made of ceramic or plastic.

4. The system for monitoring solid-liquid two-phase impurity concentration in pipeline natural gas based on micro-charge induction technology as claimed in claim 3 is characterized by: The first T-shaped insulating sealing bushing and the second T-shaped insulating sealing bushing are made of polytetrafluoroethylene, perfluoroalkoxy resin or polyetheretherketone.

5. The system for monitoring solid-liquid two-phase impurity concentration in pipeline natural gas based on micro-charge induction technology as claimed in claim 1, characterized in that: The inner hole of the connecting joint is a stepped hole, and the countersunk part of the stepped hole forms the second positioning shoulder; the outer peripheral surface of the second T-shaped insulating sealing bushing is connected to the small hole channel of the stepped hole through a threaded structure that cooperates with each other.

6. The system for monitoring solid-liquid two-phase impurity concentration in pipeline natural gas based on micro-charge induction technology according to claim 1, characterized in that: One end surface of the connecting joint serves as the second positioning shoulder.

7. The system for monitoring solid-liquid two-phase impurity concentration in pipeline natural gas based on micro-charge induction technology according to claim 1, characterized in that: The edge of the T-shaped head of the first T-shaped insulating sealing bushing and / or the edge of the T-shaped head of the second T-shaped insulating sealing bushing has a radial sealing portion surrounding the outer peripheral surface of the positioning flange.

8. The system for monitoring solid-liquid two-phase impurity concentration in pipeline natural gas based on micro-charge induction technology as claimed in claim 1, characterized in that: The micro-charge sensing probe is composed of a first rod body and a second rod body that are detachably connected, the positioning flange is entirely located on the first rod body, and the first T-shaped insulating sealing bushing is sleeved between the first rod body and the housing; And / or, the second T-shaped insulating sealing bushing is composed of a head and a neck that are detachably butt-connected, and the T-shaped head of the second T-shaped insulating sealing bushing is entirely located on the head.

9. The system for monitoring solid-liquid two-phase impurity concentration in pipeline natural gas based on micro-charge induction technology according to claim 1, characterized in that: The signal shielding shell comprises an intermediate joint connected between the shell and the connecting joint, and two ends of the intermediate joint are respectively connected to the shell and the connecting joint through corresponding threaded connection structures; the first positioning shoulder is arranged in the intermediate joint.

10. The system for monitoring solid-liquid two-phase impurity concentration in pipeline natural gas based on micro-charge induction technology according to claim 1, characterized in that: The monitoring system generates the solid phase impurity content and the liquid phase impurity content of natural gas according to the pre-trained AI model; the AI ​​model is trained by the following method: under the preset conditions of multiple groups of solid phase impurities and liquid phase impurities, the corresponding natural gas samples are collected, and the solid phase impurity content and the liquid phase impurity content in each natural gas sample are recorded as label data; the collected signals of the first micro-charge sensor, the second micro-charge sensor and the third micro-charge sensor corresponding to each natural gas sample are subjected to feature extraction, and the features include the amplitude features of the collected signals, the frequency domain features obtained by fast Fourier transform, the waveform features of the collected signals, and the energy features of the collected signals, and according to the solid phase impurity filtration efficiency α1 of the first filter and the second filter The solid-phase impurity filtration efficiency α2 of the filter, the liquid-phase impurity filtration efficiency η1 of the first-stage filter, and the liquid-phase impurity filtration efficiency η2 of the second-stage filter are calculated as supplementary features, the feature data obtained by the feature extraction and the supplementary features are taken as input, and the corresponding solid-phase impurity content and liquid-phase impurity content are taken as output to construct a training data set; the training data set is used to train a neural network model, the neural network model includes a feature extraction layer and a prediction layer, the feature extraction layer is used for dimensionality reduction and feature fusion of the input feature data, and the prediction layer is used for outputting the solid-phase impurity content and the liquid-phase impurity content, and the neural network model parameters are optimized by a back propagation algorithm until convergence.

Images