A three-fan coordinated hydrogen-mixed natural gas dynamic blocking system for pipe gallery

Abstract

This invention discloses a dynamic sealing system for hydrogen-blended natural gas in underground utility tunnels using a three-fan coordinated approach, relating to the field of safety and disaster prevention technology for urban underground utility tunnels. The system includes: a double-line sliding guide rail assembly, a three-fan sliding module, several monitoring sensors, a central server, and a controller. The three-fan sliding module is slidably mounted on the exhaust rail and the supply rail, and includes: two symmetrically distributed sets of jet fan assemblies and an intake fan assembly located between the two sets of jet fan assemblies. The system calculates the real-time risk level Rm by collecting real-time hydrogen concentration (CH) and methane concentration (CM). Based on different Rm values, differentiated flow field control strategies are implemented at the leak point. This invention, by introducing the real-time risk level Rm, achieves a leap from single-component monitoring to multi-component dynamic coupling assessment. By implementing differentiated flow field control strategies based on different real-time risk levels Rm, it significantly improves exhaust efficiency, thereby achieving dynamic sealing of dynamically leaked gas.

Description

Technical Field

[0001] This invention relates to the technical field of safety and disaster prevention in urban underground integrated pipe corridors, and in particular to a dynamic sealing system for pipe corridors using hydrogen-blended natural gas with three fans working in tandem. Background Technology

[0002] With the development of the hydrogen energy industry, using existing natural gas pipelines to transport hydrogen-blended natural gas (HCNG) has become an important trend in energy transportation. However, HCNG has physical properties that are significantly different from ordinary natural gas: hydrogen has an extremely low density (only 1 / 14 the density of air) and a high diffusion coefficient, making it very easy to form high-concentration "stratified accumulation" at the top of the pipeline arch.

[0003] Existing pipe rack protection technologies have significant shortcomings in responding to HCNG leaks: current technologies propose installing fixed baffles at intervals (30-100 meters) on the top of the gas chamber. This approach has two major drawbacks: first, if the leak point is located between two baffles, the gas will still diffuse over a long distance; second, the long-term presence of physical baffles increases the frictional resistance of daily ventilation in the pipe rack, resulting in high energy consumption. Furthermore, after an HCNG leak, the composition ratio at the top will change in real time due to the buoyancy difference between hydrogen and methane. The explosion limits of the mixed gas drift with the composition changes, and a fixed threshold may lead to missed or false alarms, which will directly result in untimely containment of the leak location. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems existing in the prior art, the present invention is proposed.

[0006] To address the limitations of fixed physical barriers and the lack of dynamic containment mechanisms in existing gas leak prevention technologies, this invention provides a dynamic containment system for hydrogen-blended natural gas in pipelines with three coordinating ventilation fans. The technical solution provided by this invention is as follows: A dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in tandem includes: a double-line sliding guide rail assembly, a three-fan sliding module, several monitoring sensors, a central server, and a controller; the double-line sliding guide rail assembly includes an exhaust rail and a supply rail fixedly and parallel to each other on the top of the pipeline corridor; the three-fan sliding module is slidably disposed on the exhaust rail and the supply rail, and includes: two sets of symmetrically distributed jet fan assemblies, and an intake fan assembly located between the two sets of jet fan assemblies; several monitoring sensors are distributed below the arch of the pipeline corridor; The controller is electrically connected to the three-fan sliding module and is used to: when the monitoring sensor detects a leak, the central server calculates the real-time risk level Rm by collecting the hydrogen concentration CH and methane concentration CM in real time: Rm = (CH+CM) / Lmix, where Lmix is ​​the lower explosive limit of the mixed gas. According to different Rm values, a differentiated flow field control strategy is implemented for the leak point: when Rm < the first threshold Rm1, only the intake fan assembly is activated; when Rm ≥ the second threshold Rm2, the three-fan sliding module operates at its maximum speed, and the nozzles of the two sets of jet fans are tilted inward toward the intake fan assembly; when Rm1 ≤ Rm < Rm2, the two sets of jet fans are turned on, with the nozzles pointing vertically downward, and the middle intake fan is turned on, with a speed greater than that of the jet fans.

[0007] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic blockade system of the present invention, the jet fan assembly includes: a jet fan, the jet fan being slidably connected to the gas supply rail via two sets of explosion-proof dual servo drive wheel sets, the gas supply pipe being connected to the gas inlet end of the jet fan, the gas supply pipe being suspended along the exhaust rail via a suspension trolley, and the jet angle at the gas outlet end of the jet fan being controlled by a servo motor.

[0008] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic blockade system of the present invention, the intake fan assembly includes: an intake fan, the intake fan being slidably connected to the exhaust rail via two sets of explosion-proof dual servo drive wheel sets, the exhaust end of the intake fan being connected to an exhaust pipe, and the exhaust pipe being suspended along the gas supply rail via a suspension trolley.

[0009] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic blocking system described in this invention, wherein: the Lmix is ​​designed as follows: Lmix = (CH + CM) / (CH / LH + CM / LM); In the formula, LH is the lower explosive limit of hydrogen; LM is the lower explosive limit of methane.

[0010] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic sealing system of the present invention, wherein: the gas supply pipe and the exhaust pipe are both corrugated pipes.

[0011] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic sealing system of the present invention, wherein: the controller controls the three-fan sliding module to move along the double-line sliding rail assembly to the leakage coordinate point P(x); The leakage coordinate point P(x) is obtained through a high-precision leakage source localization method based on a convolutional neural network, specifically including: The central server captures data from the alarm point and its preceding and following nodes over the past 10 sampling periods, generating an N×10 normalized spatiotemporal feature matrix. The normalized spatiotemporal feature matrix is ​​input into the convolutional layer of a pre-trained convolutional neural network, and the matrix is ​​scanned by multiple convolutional kernels to identify and obtain an initial feature map containing information on abrupt changes in concentration gradients. The initial feature map is input into the pooling layer of the convolutional neural network. Through dimensionality reduction, the amount of data in the initial feature map is compressed, and background disturbances caused by the airflow in the pipe gallery are suppressed in the process, and the purified edge space distribution pattern is output. The purified edge spatial distribution pattern is input into the fully connected layer at the end of the convolutional neural network. The fully connected layer maps the edge spatial distribution pattern based on the learned weight parameters and outputs it as the precise vertical coordinate P(x) of the leakage source.

[0012] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic blocking system of the present invention, wherein: the monitoring sensors are composed of multiple hydrogen / methane composite sensors, which are arranged at equal intervals of 10 meters to form a spatial sensing array.

[0013] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic blockade system described in this invention, when Rm≥Rm2, the controller controls the three-fan sliding module to perform micro-amplitude reciprocating motion near P(x) or slowly approach the center from the far end.

[0014] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic blockade system described in this invention, when Rm < Rm1, the controller controls the servo motor inside the jet fan to make the jet angle θ 90°; when Rm ≥ Rm2, the controller controls the servo motor inside the jet fan to make the jet angle θ 15°. When Rm1≤Rm<Rm2, the controller controls the servo motor inside the jet fan, causing the jet angle θ to tilt inward, continuously decreasing from 90° to 15° as Rm increases, and following the following: θ = max[15°, min[90°, 90° - 75° × (Rm-Rm1) / (Rm2 - Rm1)]].

[0015] As a preferred embodiment of the three-fan coordinated pipeline hydrogen-blended natural gas dynamic blockade system of the present invention, the system further includes: a gas sensor installed in the exhaust pipe and a dilution pipe connected to the exhaust pipe, wherein a nitrogen solenoid valve is installed in the dilution pipe and the nitrogen solenoid valve is controlled by a controller. When implementing a differentiated flow field control strategy, if the gas sensor in the exhaust pipe detects a concentration exceeding 50% of the lower explosive limit, the controller controls the nitrogen solenoid valve to open, injecting high-pressure nitrogen into the exhaust pipe for inerting and dilution.

[0016] The beneficial effects of this invention are as follows: By introducing a real-time risk level Rm, this invention achieves a leap from single-component monitoring to multi-component dynamic coupling assessment. Based on different real-time risk levels Rm, differentiated flow field control strategies are implemented. The different working modes of the three-fan sliding module compress the original 50-100 meter fixed control zone into a 10-meter "microenvironment" centered on the leak point, which greatly improves the exhaust efficiency and thus achieves dynamic sealing of dynamically leaked gas. This solves the problem of untimely response caused by alarm threshold drift due to fluctuations in hydrogen doping ratio. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein: Figure 1 This is a schematic diagram of the overall structure of a dynamic blockade system for hydrogen-blended natural gas in a pipeline corridor, proposed in this invention, with three fans working in tandem. Figure 2 A schematic diagram of the overall structure of a dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in tandem; Figure 3 for Figure 2 A schematic diagram of the structure of the jet fan assembly and the air supply rail.

[0018] In the diagram: 101-exhaust rail, 102-air supply rail, 201-jet blower, 202-explosion-proof dual servo drive wheel set, 203-air supply pipe, 204-suspension trolley, 205-servo motor, 206-intake blower, 207-exhaust pipe, 301-monitoring sensor. Detailed Implementation

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0020] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0021] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0022] Example 1 Reference Figures 1-3 As one embodiment of the present invention, a dynamic blocking system for hydrogen-blended natural gas in a pipeline corridor with three fans working in tandem is provided. This system includes: The system includes a dual-line sliding rail assembly, a three-fan sliding module, several monitoring sensors 301, a central server, and a controller. The central server is deployed in the pipe gallery monitoring center and communicates with the detectors and sliding modules via industrial Ethernet. The server runs control algorithm software developed based on Python / C++. The dual-line sliding rail assembly includes an exhaust rail 101 and an air supply rail 102 that are fixedly installed parallel to each other on the top of the pipe gallery. The dual-line sliding rail effectively solves the problems of entanglement and interference that easily occur when multiple corrugated pipes run on the same rail in subsequent layouts.

[0023] For example, exhaust rail 101 is a C-shaped rail made of high-strength aluminum alloy or galvanized steel, with specifications that are fixed every 1.5 meters to the left side of the pipe rack arch at a distance of -300mm from the center line. This rail is specifically designed for suspending gas supply pipelines. The inner side of the rail integrates a 4-pole sliding contact line with 3-phase power supply and +1 signal ground, providing a continuous and stable power supply to the mobile module through a current collector, eliminating the safety hazards associated with mobile cables. Gas supply rail 102 is a C-shaped rail of the same specifications, fixed to the right side of the pipe rack arch at a distance of +300mm from the center line. This rail is specifically designed for suspending exhaust pipelines with larger diameters. The two rails are set parallel to each other, typically spanning 200 meters throughout the entire fire compartment.

[0024] The three-fan sliding module is slidably mounted on the exhaust rail 101 and the supply rail 102. It includes two symmetrically distributed sets of jet fan assemblies and an intake fan assembly located between the two sets of jet fan assemblies. Monitoring sensors 301 are distributed below the arch of the pipe gallery, consisting of multiple hydrogen / methane composite sensors arranged at 10-meter intervals to form a spatial sensing array. Each sensor node is connected to the central server via an industrial Ethernet network. The system acquires concentration data from each node in real time at a sampling rate of at least 1Hz.

[0025] Specifically, the jet fan assembly includes: a jet fan 201, which can be an explosion-proof centrifugal fan, an explosion-proof mixed-flow fan, or an explosion-proof duct fan, with a preferred rated air volume of 2500–3500 m³ / h. 3 / h, total pressure preferably 400~700 Pa, explosion-proof rating not lower than Ex d IIB T4 Gb, rated air volume 3000m³ / h 3 / h, total pressure 500Pa, externally connected waterproof and explosion-proof servo motor 205 with torque 30kg·cm, the jet angle of the jet fan 201 is controlled by the servo motor 205, and can be continuously adjusted from vertical downward 90° to inward tilt 15° under the command of the central server controller. The jet fan 201 is slidably connected to the air supply rail 102 through two sets of explosion-proof dual servo drive wheel sets 202, and the controller realizes synchronous control of multiple explosion-proof dual servo drive wheel sets 202, such as a maximum of 1.5m / s. The air supply pipe 203 is connected to the air inlet of the jet fan 201, and the air supply pipe 203 is suspended along the exhaust rail 101 through the suspension trolley 204. The intake fan assembly includes an intake fan 206, which is slidably connected to the exhaust rail 101 through two sets of explosion-proof dual servo drive wheel sets 202. The rated exhaust volume of the intake fan 206 is preferably 6000~9000 m 3 The rated exhaust volume is greater than the rated air supply volume of a single jet fan on the left and right sides, in order to form a stable negative pressure zone between the two air curtains. Furthermore, a laminar flow suction hood can be installed at the intake end of the suction fan 206, with a metal flame arrestor mesh at the hood opening to prevent flames or high-temperature particles from entering the exhaust duct. An exhaust pipe 207 is connected to the exhaust end of the suction fan 206, and the exhaust pipe 207 is suspended along the air supply rail 102 via a suspension trolley 204. Both the air supply pipe 203 and the exhaust pipe 207 are corrugated pipes.

[0026] Specifically, one side has a DN150 air supply pipe 203, 100 meters long, covering half of the zone. Its fixed end connects to a fresh air intake on the left wall of the pipe rack, with one intake spaced every 100 meters, and its movable end connects to the left-side jet fan 201 of the module. The other side has a DN150 air supply pipe 203, installed parallel to the main air supply pipe 203. Its fixed end connects to a fresh air intake on the right wall of the pipe rack, and its movable end connects to the right-side jet fan 201 of the module. The exhaust pipe 207 is a central exhaust pipe with a DN250 diameter. To reduce exhaust resistance, the diameter is increased, and it is installed independently. Its fixed end connects to the access shaft of the main exhaust pipe of the pipe rack, and its movable end connects to the central intake fan 206 of the module. The air supply pipe 203 is mounted on the exhaust rail 101 via a double-pipe parallel suspension trolley. The trolley is equipped with nylon rollers to ensure quiet operation and no sparks. The exhaust pipe 207 is mounted on the air supply rail 102 via a single-pipe heavy-duty suspension trolley. The trolleys are connected by stainless steel wire ropes, limiting the maximum deployment distance to 1.5 meters to prevent excessive stretching of the hose.

[0027] The controller is electrically connected to the three-fan sliding module and is used to: when the monitoring sensor 301 detects a leak, the central server calculates the dynamic lower explosive limit Lmix of the central mixed combustible gas and the central risk level Rm by collecting the hydrogen concentration CH and methane concentration CM in real time: Rm=(CH+CM) / Lmix, where Lmix is ​​the lower explosive limit of the mixed gas, and Lmix is ​​designed as: Lmix=(CH+CM) / (CH / LH+CM / LM).

[0028] In the formula, LH is the lower explosive limit of hydrogen, preferably 4.0%; LM is the lower explosive limit of methane, preferably 5.0%.

[0029] To enable the three-fan sliding module to move to the precise leak location, this embodiment also provides a method for accurately locating the leak coordinate point P(x): the leak coordinate point P(x) is obtained through a high-precision leak source location method based on a convolutional neural network, specifically including: Feature extraction: The central server extracts data from the alarm point and its preceding and following nodes over the past 10 sampling periods, generating an N×10 normalized spatiotemporal feature matrix. Specifically, the central server stacks the spatial distribution data of discrete sensors within a continuous time window, such as T seconds, along the time axis to construct a two-dimensional "space-time" feature matrix. This matrix transforms the invisible gas leak evolution process into a digital image with topological features, providing a standardized input source for CNN feature recognition.

[0030] Edge feature recognition: The normalized spatiotemporal feature matrix is ​​input into the convolutional layer of a pre-trained convolutional neural network. The matrix is ​​scanned by multiple convolutional kernels to identify and obtain an initial feature map containing information on abrupt changes in concentration gradient edges. Disturbance-resistant feature purification: The initial feature map is input into the pooling layer of the convolutional neural network. Through dimensionality reduction, the amount of data in the initial feature map is compressed, and the background disturbance caused by the airflow in the pipe gallery is suppressed in the process. The purified edge space distribution pattern is output. Coordinate mapping output: The purified edge spatial distribution pattern is input into the fully connected layer at the end of the convolutional neural network. The fully connected layer maps the edge spatial distribution pattern based on the learned weight parameters and outputs it as the accurate vertical coordinate P(x) of the leakage source.

[0031] This allows the controller to move the three-fan sliding module along the double-line sliding rail assembly to the leakage coordinate point P(x).

[0032] Based on the different Rm values ​​calculated above, a differentiated flow field control strategy is implemented for the leakage point: When Rm < the first threshold Rm1, only the intake fan assembly is activated, and the controller controls the servo motor 205 in the jet fan 201 to make the jet angle θ 90°; when Rm ≥ the second threshold Rm2, the three-fan sliding module operates at its maximum speed, and the air outlets of the two sets of jet fans are tilted inward toward the intake fan assembly, that is, the controller controls the servo motor 205 in the jet fan 201 to make the jet angle θ 15°. At the same time, the controller controls the three-fan sliding module to perform a small reciprocating motion near P(x) or slowly approach the center from the far end; when Rm1 ≤ Rm < Rm2, the two sets of jet fans are turned on, and the air outlets are vertically downward. The middle intake fan is turned on, and its speed is greater than that of the jet fan. The controller controls the servo motor 205 in the jet fan 201 to make the jet angle θ tilt inward and continuously decrease from 90° to 15° as Rm increases.

[0033] The method of the present invention will now be described through a preferred embodiment, including the following steps: Step S1: When the detection module captures an abnormal concentration signal, the central server immediately starts the intelligent positioning program to obtain the specific coordinates P(x) of the leak based on the high-precision positioning of the leak source using the CNN image matrix.

[0034] Step S2: Dynamic Explosion Limits and Risk Assessment Since fluctuations in the hydrogen blending ratio will change the lower explosive limit of the gas mixture, the actual hazard level must be calculated in real time.

[0035] Based on the real-time hydrogen concentration (CH) and methane concentration (CM) collected by monitoring sensor 301, the lower explosive limit (Lmix) of the gas mixture is calculated using an algorithm. Lmix=(CH+CM) / (CH / LH+CM / LM).

[0036] In the formula, LH is the lower explosive limit of hydrogen, preferably 4.0%; LM is the lower explosive limit of methane, preferably 5.0%; Calculate the real-time risk level Rm: Rm = (CH + CM) / Lmix; Based on the Rm value, the system classifies the risk into three levels: micro-leakage Rm < 0.1, small leakage 0.1 Rm < 0.25, and large leakage Rm. 0.25.

[0037] Step S3: Once the system of this invention confirms a leak, the central server issues the following instruction to the sliding module closest to coordinate P(x): Start-up: The three-fan sliding module (hereinafter referred to as the module) releases its brakes, and the drive motor accelerates.

[0038] Dragging: The module slides along the guide rail to point P(x). During the sliding process, the module acts as a "locomotive" and pulls the trolley of the air supply bellows suspended on the exhaust rail 101 and the exhaust bellows trolley on the air supply rail 102, i.e., the suspension trolley 204, through mechanical connection.

[0039] Unfolded: The corrugated tube, which was originally folded and stored away, was pulled open section by section like an accordion.

[0040] Positioning: The module docks at coordinate P(x), and the positioning error is controlled within... Within 0.5 meters.

[0041] Step S4: Tiered Dual-Effect Collaborative Handling Based on the risk level Rm calculated in step S2, the system automatically executes differentiated flow field control strategies: Scenario A: Minor Leakage Rm < 0.1 – “Silent Suction and Exhaust Mode” Action: Turn off the left and right jet fans at 0 speed. Only start the central suction fan at 40% speed. Exhaust Principle: Utilizing the high buoyancy of hydrogen, it naturally rises to the dome. At this time, the air curtain is not activated to avoid dispersing the gas layer. Relying solely on the negative pressure of the central fan and the laminar flow suction hood, it silently draws in the thin layer of gas accumulated on the top plate, much like a “range hood,” and exhausts it through exhaust pipe 207. Advantages: Avoids secondary diffusion caused by artificial turbulence, resulting in the lowest energy consumption.

[0042] Scenario B: Typical leakage of 0.1 Rm < 0.25 — “Flexible Blockade Mode” Operation: Left and right jet fans are turned on to 30% speed. The middle intake fan is turned on to 60% speed. The θ of the jet fan continuously decreases from 90° to 15° as Rm increases, following the rule: θ = max[15°, min[90°, 90° - 75° × (Rm - 0.10) / (0.25 - 0.10)]]. Its exhaust principle is: the low-velocity air curtains on both sides form two flexible “air walls”, restricting the horizontal diffusion of gas to the far end of the pipe gallery; the middle fan establishes a negative pressure zone between the two walls, continuously drawing out the gas.

[0043] Scenario C: High-risk leakage Rm 0.25 – “Centric Compression Capture Mode” Action: All three fans are running at 100% full speed and high power, with the jet fan's spray angle θ = 15°. Dynamic approximation: The module performs a small reciprocating motion near P(x) or from a distant point such as P(x). The gas slowly approaches the center at a speed of 0.2 m / s from 5 m. Its exhaust principle is as follows: using the "entrainment effect" of the high-velocity air curtain and the inward horizontal force, it forcibly "squeezes" the high-concentration leaked gas into the central area like two large hands; the high-power suction fan in the middle, together with the flow rate of the exhaust pipe 207, quickly discharges this compressed high-risk gas into the main exhaust pipe, realizing the coordinated treatment of air curtain sealing, centripetal convergence and centralized exhaust.

[0044] In summary, when the concentrations of hydrogen and methane in the middle of the air curtain blockade zone are low, such as in scenario B, the left and right variable angle nozzles maintain vertical downward spray to form a stable vertical air wall, avoiding excessive disturbance to the stratification of light gases at the top of the pipe gallery. When the concentrations of hydrogen and methane in the middle of the air curtain blockade zone increase, the central server controls the servo motor 205 to drive the left and right variable angle nozzles to gradually tilt inward, so that the airflow on both sides generates a horizontal centripetal force towards the central suction hood, compressing the hydrogen-blended natural gas in the blockade zone into the suction range of the central suction hood. When the risk level Rm in the middle reaches the high-risk threshold, such as in scenario C, the left and right variable angle nozzles are adjusted to the maximum inward tilt angle of 15° to form the strongest centripetal compression air curtain, and cooperate with the central suction fan for rapid suction and drainage.

[0045] Through the above control method, a direct correspondence is formed between the nozzle angle and the gas concentration in the middle of the air curtain, so that the injection angle can automatically enhance the centripetal compression effect as the leakage gas concentration increases, and gradually return to the vertical blockage state as the leakage gas concentration decreases, thereby realizing the dynamic coordination between air curtain blockage, centripetal capture and central suction.

[0046] Example 2 The difference from Embodiment 1 is that the system further includes: a gas sensor disposed in the exhaust pipe 207, and a dilution pipe connected to the exhaust pipe, wherein a nitrogen solenoid valve is installed in the dilution pipe and the nitrogen solenoid valve is controlled by a controller.

[0047] When implementing differentiated flow field control strategies, if the gas sensor in the exhaust pipe detects a concentration exceeding 50% of the lower explosive limit (LEL), the controller opens the nitrogen solenoid valve to inject high-pressure nitrogen into the exhaust pipe for inerting and dilution. After the alarm is cleared, the module reverses at low speed to return to the stop position. During the return process, the module pushes the suspension trolley 204 to fold and retract the three bellows, awaiting the next task.

[0048] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in tandem, characterized in that, It includes: Dual-line sliding rail assembly, three-fan sliding module, several monitoring sensors (301), central server and controller; The dual-line sliding guide rail assembly includes: an exhaust rail (101) and an air supply rail (102) fixedly and parallel to each other on the top of the pipe gallery; the three-fan sliding module is slidably disposed on the exhaust rail (101) and the air supply rail (102), and includes: two sets of jet fan assemblies symmetrically distributed, and an intake fan assembly located between the two sets of jet fan assemblies; a plurality of the monitoring sensors (301) are distributed below the arch of the pipe gallery; The controller is electrically connected to the three-fan sliding module and is used to: when the monitoring sensor (301) detects a leak, the central server calculates the real-time risk level Rm by collecting the hydrogen concentration CH and methane concentration CM in real time: Rm = (CH+CM) / Lmix, where Lmix is ​​the lower explosive limit of the mixed gas. According to different Rm values, a differentiated flow field control strategy is implemented for the leak point: when Rm < the first threshold Rm1, only the intake fan assembly is started; when Rm ≥ the second threshold Rm2, the three-fan sliding module operates at its maximum speed, and the air outlets of the two sets of jet fans are tilted inward toward the intake fan assembly; when Rm1≤Rm<Rm2, the two sets of jet fans are turned on, and the air outlets are vertically downward, the middle intake fan is turned on, and the speed is greater than the speed of the jet fan.

2. The dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 1, is characterized in that: The jet fan assembly includes a jet fan (201), which is slidably connected to the air supply rail (102) via two sets of explosion-proof dual servo drive wheel sets (202). The air supply pipe (203) is connected to the air inlet end of the jet fan (201). The air supply pipe (203) is suspended along the exhaust rail (101) via a suspension trolley (204). The jet angle at the air outlet end of the jet fan (201) is controlled by a servo motor (205).

3. The dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 2, is characterized in that: The suction fan assembly includes a suction fan (206), which is slidably connected to the exhaust rail (101) via two sets of explosion-proof dual servo drive wheel sets (202). The exhaust end of the suction fan (206) is connected to an exhaust pipe (207), which is suspended along the air supply rail (102) via a suspension trolley (204).

4. The dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 1, is characterized in that: The Lmix is ​​designed as follows: Lmix = (CH + CM) / (CH / LH + CM / LM); In the formula, LH is the lower explosive limit of hydrogen; LM is the lower explosive limit of methane.

5. A dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 3, is characterized in that: Both the air supply pipe (203) and the exhaust pipe (207) are corrugated pipes.

6. The dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 1, is characterized in that: The controller controls the three-fan sliding module to move along the double-line sliding rail assembly to the leakage coordinate point P(x); The leakage coordinate point P(x) is obtained through a high-precision leakage source localization method based on a convolutional neural network, specifically including: The central server captures data from the alarm point and its preceding and following nodes over the past 10 sampling periods, generating an N×10 normalized spatiotemporal feature matrix. The normalized spatiotemporal feature matrix is ​​input into the convolutional layer of a pre-trained convolutional neural network, and the matrix is ​​scanned by multiple convolutional kernels to identify and obtain an initial feature map containing information on abrupt changes in concentration gradients. The initial feature map is input into the pooling layer of the convolutional neural network. Through dimensionality reduction, the amount of data in the initial feature map is compressed, and background disturbances caused by the airflow in the pipe gallery are suppressed in the process, and the purified edge space distribution pattern is output. The purified edge spatial distribution pattern is input into the fully connected layer at the end of the convolutional neural network. The fully connected layer maps the edge spatial distribution pattern based on the learned weight parameters and outputs it as the precise vertical coordinate P(x) of the leakage source.

7. A dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 1, is characterized in that: The monitoring sensors (301) consist of multiple hydrogen / methane composite sensors, which are arranged at equal intervals of 10 meters to form a spatial sensing array.

8. A dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 6, is characterized in that: When Rm≥Rm2, the controller controls the three-fan sliding module to perform micro-amplitude reciprocating motion near P(x) or slowly approach the center from the far end.

9. A dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 2, is characterized in that: When Rm < Rm1, the controller controls the servo motor (205) inside the jet fan (201) to make the jet angle θ 90°. When Rm ≥ Rm2, the controller controls the servo motor (205) inside the jet fan (201) to make the jet angle θ 15°. When Rm1≤Rm<Rm2, the controller controls the servo motor (205) inside the jet fan (201) to tilt the jet angle θ inward continuously from 90° to 15° as Rm increases, following the following: θ = max[15°, min[90°, 90° - 75° × (Rm- Rm1) / (Rm2 -Rm1)]].

10. A dynamic sealing system for hydrogen-blended natural gas in a pipeline corridor with three fans working in coordination, as described in claim 1, characterized in that: The system also includes: a gas sensor installed in the exhaust pipe, and a dilution pipe connected to the exhaust pipe, wherein a nitrogen solenoid valve is installed in the dilution pipe and the nitrogen solenoid valve is controlled by a controller; When implementing a differentiated flow field control strategy, if the gas sensor in the exhaust pipe detects a concentration exceeding 50% of the lower explosive limit, the controller controls the nitrogen solenoid valve to open, injecting high-pressure nitrogen into the exhaust pipe for inerting and dilution.

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