Gas leakage detection system based on single-chain nonreciprocal circuit and detection method thereof

Abstract

The invention discloses a coal gas leakage detection system based on a single-chain nonreciprocal circuit and a detection method thereof, the system comprises a voltage source and the single-chain nonreciprocal circuit formed by a plurality of grid units which are sequentially connected in series, the voltage source is electrically connected with the single-chain nonreciprocal circuit, and the single-chain nonreciprocal circuit has a current unidirectional transmission characteristic; the voltage source is used for providing an excitation signal for the single-chain nonreciprocal circuit; every two adjacent lattice point units form a detection unit and are correspondingly connected to a detection area of the gas pipeline, and each detection unit is used for detecting the voltage distribution of the corresponding detection area under the action of an excitation signal by utilizing the current one-way transmission characteristic and judging the gas leakage condition of the corresponding detection area according to the voltage distribution. Based on the single-chain non-reciprocal circuit, real-time detection of high-speed and low-speed gas leakage can be realized, and a solution which gives consideration to high-speed and low-speed leakage detection and is simple in structure and easy to implement is provided for gas pipeline leakage detection.

Description

Technical Field

[0001] This invention relates to the field of electronic circuits, and more specifically to a gas leak detection system and method based on a single-chain non-reciprocal circuit. Background Technology

[0002] Currently, in the field of industrial and residential gas safety, leak detection of gas pipelines is a crucial step in preventing safety accidents. Existing common multi-point gas leak detection equipment mainly employs different detection principles based on different leak rates.

[0003] On the one hand, ultrasonic detectors are often used for situations with high pressure and rapid leakage. The principle is that when gas is ejected at high speed from the leak point, it generates ultrasonic signals. By detecting these ultrasonic signals, the occurrence and location of the leak can be determined. However, this detection method has significant limitations. When the pipeline leak is in a tiny pore or the pressure is low, the gas diffusion rate is slow, making it impossible to generate detectable ultrasonic waves, thus easily leading to missed detections.

[0004] On the other hand, for leaks with low-rate diffusion, current detection mainly relies on traditional sensors. These sensors are typically based on the chemical sensitivity of materials; for example, they detect leaks by causing changes in the resistivity of the internal materials of the sensor through the adsorption of specific gas molecules (such as carbon monoxide and methane). While such methods can detect low-rate leaks, their response speed is relatively slow, and the performance of the sensors may degrade due to environmental factors, requiring improvement in long-term reliability.

[0005] Therefore, there is currently a lack of a gas leak detection solution that can simultaneously detect both high-speed and low-speed leaks, and is simple in structure and easy to implement. Summary of the Invention

[0006] In view of this, the present invention provides a gas leak detection system and method based on a single-chain non-reciprocal circuit to solve the problem that existing gas leak detection technologies cannot simultaneously detect high-speed leaks and low-speed leaks.

[0007] This invention provides a gas leak detection system based on a single-chain non-reciprocal circuit. The system includes a voltage source and a single-chain non-reciprocal circuit composed of multiple grid units connected in series. The voltage source is electrically connected to the single-chain non-reciprocal circuit, and the single-chain non-reciprocal circuit has unidirectional current transmission characteristics. The voltage source is used to provide an excitation signal to the single-chain non-reciprocal circuit; In the single-chain non-reciprocal circuit, each pair of adjacent grid cells forms a detection unit and is connected to a detection area of ​​the gas pipeline. Each detection unit is used to detect the voltage distribution of the corresponding detection area in the gas pipeline under the action of the excitation signal by utilizing the unidirectional current transmission characteristic of the single-chain non-reciprocal circuit, and to determine the gas leakage situation of the corresponding detection area based on the detected voltage distribution.

[0008] Optionally, in the single-chain non-reciprocal circuit, the first grid cell includes a grid cell and a parallel resonant branch connected to the grid cell, and the remaining grid cells each include a grid cell and a unidirectional current transmission trunk and a parallel resonant branch with the grid cell as the common connection terminal. In each detection unit composed of two adjacent grid cells, the grid cells in the latter grid cell are electrically connected to the grid cells in the former grid cell through the corresponding unidirectional current transmission trunk to form the corresponding detection unit; each grid cell is also grounded through the corresponding parallel resonant branch. The unidirectional current transmission trunk is used to provide a unidirectional current transmission path for the corresponding detection unit during operation; the parallel resonant branch is used to provide a stable resonant frequency for the corresponding detection unit.

[0009] Optionally, in each detection unit, the unidirectional current transmission trunk includes a voltage follower and a first capacitor connected in series; In each unidirectional current transmission trunk, the voltage follower is specifically an operational amplifier, and the non-inverting input terminal of the operational amplifier is electrically connected to the grid point in the corresponding grid unit through the corresponding first capacitor, the inverting input terminal of the operational amplifier is electrically connected to the output terminal of the corresponding operational amplifier, and the output terminal of the operational amplifier is also electrically connected to the grid point in the previous grid unit.

[0010] Optionally, in each detection unit, the unidirectional current transmission trunk includes a voltage follower and a first capacitor connected in series; In each unidirectional current transmission trunk, the voltage follower is specifically an operational amplifier, and the non-inverting input terminal of the operational amplifier is electrically connected to the grid point in the previous grid unit through the corresponding first capacitor. The inverting input terminal of the operational amplifier is electrically connected to the output terminal of the corresponding operational amplifier, and the output terminal of the operational amplifier is also electrically connected to the grid point in the corresponding grid unit.

[0011] Optionally, the capacitance of the first capacitor in all unidirectional current transmission trunks is equal.

[0012] Optionally, in each detection unit, the parallel resonant branch includes an inductor and a second capacitor connected in parallel; The first parallel terminal of the inductor and the second capacitor is electrically connected to the grid point in the corresponding grid cell, and the second parallel terminal of the inductor and the second capacitor is grounded.

[0013] Optionally, the capacitance values ​​of the second capacitors in all parallel resonant branches are equal; and / or, the inductance values ​​of the inductors in all parallel resonant branches are equal.

[0014] Optionally, the number of grid cells in the single-chain non-reciprocal circuit is greater than or equal to 2.

[0015] Optionally, the first terminal of the voltage source is electrically connected to the first grid cell in the single-chain non-reciprocal circuit, and the second terminal of the voltage source is grounded; Alternatively, the first terminal of the voltage source is electrically connected to the last grid cell in the single-chain non-reciprocal circuit, and the second terminal of the voltage source is grounded.

[0016] In addition, the present invention also provides a gas leak detection method based on a single-chain non-reciprocal circuit, which uses the aforementioned gas leak detection system based on a single-chain non-reciprocal circuit to detect gas leaks. The method includes: A voltage source is used to provide an excitation signal to a single-chain non-reciprocal circuit composed of multiple lattice units connected in series. Based on the unidirectional current transmission characteristic of the single-chain non-reciprocal circuit, the detection unit composed of every two adjacent grid units in the single-chain non-reciprocal circuit detects the voltage distribution of the detection area connected to the detection unit in the gas pipeline under the action of the excitation signal, and judges the gas leakage situation in the corresponding detection area based on the detected voltage distribution.

[0017] The beneficial effects of this invention are: Multiple lattice units connected in series form a single-chain non-reciprocal circuit with unidirectional current transmission characteristics. A voltage source is electrically connected to this circuit, providing a stable excitation signal to keep it in a stable operating state. In its stable operating state, the single-chain non-reciprocal circuit utilizes the unidirectional current transmission characteristic to achieve directional transmission and isolation of the current signal. Because the current signal can only flow in one direction, the energy is confined to a specific direction of transmission. Under undisturbed conditions, the voltage concentrates in specific lattice units, forming a stable eigenstate distribution. However, when a leak occurs in a detection area of ​​a gas pipeline, the external perturbation introduced by the leaking gas alters the dielectric properties of that area, causing the system to enter a specific state (such as resonance or singularity). Due to the single-chain non-reciprocal nature of the circuit... The non-reciprocal nature of the circuit amplifies external perturbations, causing significant changes in the voltage distribution of the detection unit. This allows for highly sensitive detection of gas leaks by monitoring the voltage distribution. Furthermore, the unidirectional current transmission characteristic of this single-chain non-reciprocal circuit effectively avoids crosstalk between adjacent detection units, improving the accuracy of parallel detection across multiple regions. In addition, the combination of the single-chain non-reciprocal circuit with a voltage source allows for chain-like expansion using a modular grid unit design. By increasing or decreasing the number of grid units, the system can adapt to the detection needs of gas pipelines of different lengths, helping to reduce system debugging complexity and hardware costs while achieving gas leak detection. The gas leak detection system and method based on a single-chain non-reciprocal circuit of the present invention do not rely on the chemically sensitive materials of traditional sensors, have a faster response speed, and are less affected by environmental factors. They can reliably and stably achieve real-time detection of both high-speed and low-speed gas leaks. They can maintain stable detection performance under complex working conditions for a long time, effectively making up for the shortcomings of existing technologies, such as the insensitivity of ultrasonic detection to low-speed leaks and the slow response and insufficient reliability of traditional sensors. This provides a simple and easy-to-implement solution for gas pipeline leak detection that can detect both high-speed and low-speed leaks. Attached Figure Description

[0018] The features and advantages of the invention will be more clearly understood by referring to the accompanying drawings, which are schematic and should not be construed as limiting the invention in any way. In the drawings: Figure 1 The diagram shows a structural diagram of a gas leak detection system based on a single-chain non-reciprocal circuit according to Embodiment 1 of the present invention. Figure 2 The diagram shows a structural diagram of another gas leak detection system based on a single-chain non-reciprocal circuit according to Embodiment 1 of the present invention; Figure 3 A structural diagram of a gas leak detection system with 7 grid units according to Embodiment 1 of the present invention is shown; Figure 4The diagram shows the design of the unidirectional current transmission trunk and the parallel resonant branch in two adjacent grid cells in Embodiment 1 of the present invention; Figure 5 A flowchart of a gas leak detection method based on a single-chain non-reciprocal circuit according to Embodiment 2 of the present invention is shown. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] In this embodiment of the invention, the term "and / or" describes the relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following associated objects have an "or" relationship.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0022] In this embodiment of the invention, the term "multiple" refers to two or more, and other quantifiers are similar.

[0023] Example 1 A gas leak detection system based on a single-chain non-reciprocal circuit, such as Figure 1 As shown, the system includes a voltage source and a single-chain non-reciprocal circuit composed of multiple grid units connected in series. The voltage source is electrically connected to the single-chain non-reciprocal circuit, and the single-chain non-reciprocal circuit has a unidirectional current transmission characteristic. The voltage source is used to provide an excitation signal to the single-chain non-reciprocal circuit; In the single-chain non-reciprocal circuit, each pair of adjacent grid cells forms a detection unit and is connected to a detection area of ​​the gas pipeline. Each detection unit is used to detect the voltage distribution of the corresponding detection area in the gas pipeline under the action of the excitation signal by utilizing the unidirectional current transmission characteristic of the single-chain non-reciprocal circuit, and to determine the gas leakage situation of the corresponding detection area based on the detected voltage distribution.

[0024] In this embodiment, multiple grid cells connected in series form a single-chain non-reciprocal circuit with unidirectional current transmission characteristics. A voltage source is electrically connected to this circuit, providing a stable excitation signal to keep it in a stable operating state. In its stable operating state, the single-chain non-reciprocal circuit utilizes the unidirectional current transmission characteristic to achieve directional transmission and isolation of the current signal. Since the current signal can only flow in one direction, the energy is confined to a specific direction of transmission. Under undisturbed conditions, the voltage concentrates in specific grid cells, forming a stable eigenstate distribution. However, when a leak occurs in a detection area of ​​the gas pipeline, the external perturbation introduced by the leaking gas changes the dielectric properties of that area, causing the system to be in a specific state (such as resonance or singularity). The non-reciprocal nature of the chain non-reciprocal circuit amplifies external perturbations, causing significant changes in the voltage distribution of the detection unit. This allows for highly sensitive detection of gas leaks by detecting the voltage distribution. Furthermore, the unidirectional current transmission characteristic of this single-chain non-reciprocal circuit effectively avoids signal crosstalk between adjacent detection units, improving the accuracy of parallel detection in multiple regions. In addition, the combination of the single-chain non-reciprocal circuit with a voltage source allows for chain-like expansion using a modular grid unit design. By increasing or decreasing the number of grid units, the system can adapt to the detection needs of gas pipelines of different lengths, helping to reduce system debugging complexity and hardware costs while achieving gas leak detection.

[0025] The gas leak detection system based on a single-chain non-reciprocal circuit in this embodiment does not rely on the chemically sensitive materials of traditional sensors, has a faster response speed, and is less affected by environmental factors. It can reliably and stably achieve real-time detection of both high-speed and low-speed gas leaks. It can maintain stable detection performance under complex operating conditions for a long time, effectively making up for the shortcomings of existing technologies, such as the insensitivity of ultrasonic detection to low-speed leaks and the slow response and insufficient reliability of traditional sensors. It provides a simple and easy-to-implement solution for gas pipeline leak detection that takes into account both high-speed and low-speed leak detection.

[0026] The following is a further description of each unit of the gas leak detection system based on a single-chain non-reciprocal circuit in this embodiment.

[0027] In this embodiment, the number of grid cells in a single-chain non-reciprocal circuit is set to n, which is greater than or equal to 2.

[0028] By connecting two or more grid cells in series to form a single-chain non-reciprocal circuit, at least one detection unit can be formed in the circuit, thus enabling leak detection in at least one detection area of ​​the gas pipeline. When the number of grid cells is two, one detection unit can be formed, corresponding to the detection of a specific area of ​​the gas pipeline; if the number of grid cells increases to three, two detection units can be formed, corresponding to two different detection areas on the pipeline, and so on. This design allows the system to flexibly adjust the number of grid cells according to actual detection needs, thereby expanding the coverage of the detection area and meeting the detection scenarios of gas pipelines of different lengths or complex layouts. For example, for long urban gas trunk pipelines, by increasing the number of grid cells, simultaneous monitoring of multiple segments along the entire pipeline can be achieved, improving the comprehensiveness and timeliness of leak detection.

[0029] Preferably, such as Figure 2 As shown, in the single-chain non-reciprocal circuit, the first grid cell includes a grid cell and a parallel resonant branch connected to the grid cell, and the remaining grid cells all include a grid cell and a unidirectional current transmission trunk and a parallel resonant branch with the grid cell as the common connection terminal. In each detection unit composed of two adjacent grid cells, the grid cells in the latter grid cell are electrically connected to the grid cells in the former grid cell through the corresponding unidirectional current transmission trunk to form the corresponding detection unit; each grid cell is also grounded through the corresponding parallel resonant branch. The unidirectional current transmission trunk is used to provide a unidirectional current transmission path for the corresponding detection unit during operation; the parallel resonant branch is used to provide a stable resonant frequency for the corresponding detection unit.

[0030] exist Figure 2In the single-chain non-reciprocal circuit shown, unidirectional coupling can be achieved. That is, the unidirectional current transmission trunk of the subsequent grid cell only allows current to flow from the preceding grid cell to the subsequent grid cell, and cannot transmit in the reverse direction. This unidirectional characteristic effectively avoids signal interference between adjacent detection cells. When the excitation signal is injected into the single-chain non-reciprocal circuit from the voltage source, the current will be transmitted sequentially along the grid cells. The parallel resonant branch in each detection cell resonates at a specific frequency, putting the detection cell in a stable operating state. At this time, changes in the dielectric properties of the detection area will be directly reflected in the grid voltage value. For example, when a gas leak occurs in a detection area, the leaked gas causes a change in the dielectric constant of that area, which is equivalent to introducing a bidirectional coupling capacitor between the two grid cells of the detection cell, disrupting the original resonant balance and causing abnormal fluctuations in the grid voltage of the detection cell. Due to the isolation effect of the unidirectional current transmission trunk, the voltage fluctuation will not interfere with the detection units in the preceding or following stages. This ensures the independence and accuracy of the detection results of each detection unit, providing a reliable signal basis for subsequent voltage distribution analysis to locate the leak. On the other hand, it can also generate high-order energy singularities, ensuring that even small couplings can produce voltage responses of several orders of magnitude, thereby effectively improving the sensitivity of gas leak detection.

[0031] For ease of explanation, the number of grid cells in this embodiment is 7, such as... Figure 3 As shown. In Figure 3 In the diagram, the first grid unit (the leftmost grid unit) includes a grid point and a parallel resonant branch connected to it. The remaining grid units each include a grid point, a unidirectional current transmission trunk line with the grid point as a common connection terminal, and a parallel resonant branch. The grid points in each unit are labeled A1 to A7. Each pair of adjacent grid units forms a detection unit, so 7 grid units can form 6 detection units, corresponding to the detection of gas leaks in detection areas 1 to 6 of the gas pipeline. Figure 3 In the single-chain non-reciprocal circuit shown, the current flows from right to left. When there is no gas leak, since only the current flows to the left, the voltage is only distributed at the first grid point (i.e., grid point A1). However, when there is a gas leak, due to the difference in dielectric constant, it is equivalent to introducing a bidirectional coupling capacitor between the corresponding two grid points (e.g., ...). Figure 3 and Figure 4 The coupling capacitance between two grid points will change the voltage distribution at that location, thus detecting the location of the gas leak.

[0032] In other embodiments, the current transmission direction can also be from left to right. In this case, only the direction of the unidirectional current transmission main circuit needs to be adjusted to ensure that the current can only be transmitted from left to right and cannot flow in the opposite direction. This can also achieve gas leak detection. This directional flexibility allows the system to select a suitable current transmission direction during actual installation based on the layout of the gas pipeline and the detection requirements, better adapting to the pipeline route and the distribution of the detection area. For example, when the gas pipeline is laid from left to right, setting the current transmission direction to left to right ensures that the signal transmission path of the detection unit is consistent with the pipeline route, reducing the impact of factors such as line bends on signal transmission, and further improving the stability and reliability of the detection system.

[0033] In one alternative embodiment, such as Figures 2-4 As shown, in each detection unit, the unidirectional current transmission trunk includes a voltage follower and a first capacitor connected in series; In each unidirectional current transmission trunk, the voltage follower is specifically an operational amplifier, and the non-inverting input terminal of the operational amplifier is electrically connected to the grid point in the corresponding grid unit through the corresponding first capacitor, the inverting input terminal of the operational amplifier is electrically connected to the output terminal of the corresponding operational amplifier, and the output terminal of the operational amplifier is also electrically connected to the grid point in the previous grid unit.

[0034] In the unidirectional current transmission trunk of the above embodiment, the voltage follower composed of operational amplifiers has extremely high input impedance and extremely low output impedance, which can effectively realize distortion-free signal transmission. Meanwhile, the first capacitor (i.e....) Figures 2-4 The connection of Ca in the circuit utilizes its AC-passing and DC-blocking characteristics to ensure that only AC excitation signals can pass through, avoiding interference from DC components on the circuit's operating state. When current is transmitted from the next stage grid cell to the previous stage grid cell (e.g., ... Figure 3 When the current is transmitted unidirectionally from grid point 7 to grid point 1 from right to left, the AC signal is first coupled to the non-inverting input of the operational amplifier through the first capacitor. Since the inverting input and output of the operational amplifier are shorted to form a voltage follower, the voltage at its output is consistent with the voltage at the non-inverting input, thus accurately transmitting the AC signal from the next stage grid point to the previous stage grid point, achieving unidirectional current transmission. This design not only ensures the unidirectionality and stability of current transmission, but also reduces the impact on the voltage distribution of the preceding grid units through the high input impedance characteristics of the voltage follower, ensuring that each detection unit can independently and accurately reflect the changes in the dielectric properties of the corresponding detection area during the detection process.

[0035] In another alternative embodiment, in each detection unit, the unidirectional current transmission trunk includes a voltage follower and a first capacitor connected in series; In each unidirectional current transmission trunk, the voltage follower is specifically an operational amplifier, and the non-inverting input terminal of the operational amplifier is electrically connected to the grid point in the previous grid unit through the corresponding first capacitor. The inverting input terminal of the operational amplifier is electrically connected to the output terminal of the corresponding operational amplifier, and the output terminal of the operational amplifier is also electrically connected to the grid point in the corresponding grid unit.

[0036] Similar to the previous optional embodiment, in the unidirectional current transmission trunk of this embodiment, the operational amplifier also functions as a voltage follower to achieve stable signal transmission, and the first capacitor also serves to block DC and pass AC. The difference lies in the adjustment of the signal transmission direction. When the current needs to be transmitted unidirectionally from left to right (i.e., from grid point 1 to grid point 7), the non-inverting input of the operational amplifier is connected to the grid point of the previous grid unit through the first capacitor, and the output is connected to the grid point of the current grid unit. At this time, the AC signal of the previous grid point is coupled to the non-inverting input of the operational amplifier through the first capacitor, and after voltage following processing, it is transmitted to the current grid point, ensuring that the current can only flow in the direction from left to right. This structural design, by changing the input and output connection method of the operational amplifier, flexibly adapts to different current transmission direction requirements, further enhancing the layout flexibility of the single-chain non-reciprocal circuit in practical applications. This allows the system to select the optimal signal transmission path according to the actual conditions such as the direction of the gas pipeline and the installation space, improving the engineering practicality of the detection system.

[0037] Regardless of whether the current transmission direction is from right to left or from left to right, the unidirectional current transmission trunk can achieve directional and low-loss transmission of AC excitation signals by taking advantage of the high input impedance and low output impedance characteristics of the voltage follower and the frequency selectivity characteristics of the first capacitor, thus laying the foundation for the detection unit to accurately detect changes in voltage distribution.

[0038] The above embodiments only require Figures 2-4 The connection direction of the voltage follower and the first capacitor in the medium current unidirectional transmission trunk, as well as the operational amplifier direction of the voltage follower, can be changed, which will not be shown here. Furthermore, the power input terminals of the voltage follower are connected to the corresponding power supply according to actual needs, which will not be elaborated here.

[0039] Furthermore, in the above optional embodiments, the capacitance value of the first capacitor in all unidirectional current transmission trunks is equal.

[0040] By setting the capacitance value of the first capacitor to a uniform standard, it is possible to ensure that each unidirectional current transmission circuit has consistent frequency response characteristics during signal transmission. This ensures that the entire single-chain non-reciprocal circuit has a suitable resonant frequency, avoiding deviations in the transmission efficiency or phase of the excitation signal caused by differences in capacitance values. This consistent design allows each detection unit to perform voltage distribution detection based on a unified reference under the same excitation signal, reducing system errors introduced by inconsistent hardware parameters and improving the comparability and reliability of detection data among multiple detection units. For example, when the excitation signal is an AC signal of a specific frequency, the first capacitor with the same capacitance value will resonate with that frequency signal, ensuring that the attenuation and phase shift of the excitation signal in each unidirectional current transmission circuit remain consistent. This results in a regular initial voltage distribution for each detection unit when no leakage occurs, facilitating rapid identification of abnormal voltage changes through subsequent comparative analysis and providing a stable circuit parameter basis for accurately locating the gas leak. Simultaneously, the selection of capacitors with uniform capacitance values ​​also helps reduce the cost of component procurement and screening, simplifies circuit design and debugging processes, and improves system maintainability and the feasibility of mass production.

[0041] Preferably, such as Figures 2-4 As shown, in each detection unit, the parallel resonant branch includes an inductor and a second capacitor connected in parallel; The first parallel terminal of the inductor and the second capacitor is electrically connected to the grid point in the corresponding grid cell, and the second parallel terminal of the inductor and the second capacitor is grounded.

[0042] In the parallel resonant branch of the above structure, the inductance (i.e. Figures 2-4 L1~Ln) and the second capacitor (i.e. Figures 2-4 The circuit (C1~Cn) forms an LC parallel resonant circuit. When the frequency of the excitation signal in the circuit is equal to the natural resonant frequency of the LC circuit, the circuit will resonate in parallel. At this time, the impedance of the circuit reaches its maximum value and exhibits pure resistance. This characteristic allows the detection unit to obtain a stable operating point in the resonant state, and the grid voltage remains at a relatively constant level. When a gas leak occurs in the detection area, the change in the dielectric properties caused by the leaking gas will effectively change the equivalent capacitance or inductance parameters of the detection unit, causing the natural frequency of the LC parallel resonant circuit to shift from the excitation signal frequency. This results in a decrease in the circuit impedance, and a significant change in the grid voltage. By monitoring this voltage change, it is possible to accurately determine whether a gas leak exists in the corresponding detection area. At the same time, the introduction of the LC parallel resonant branch can also enhance the selectivity of the circuit for excitation signals of specific frequencies, suppress interference signals of other frequencies, improve the anti-interference capability of the system, and ensure stable and reliable detection of gas leaks even in complex electromagnetic environments.

[0043] Furthermore, the capacitance of the second capacitor in all parallel resonant branches is equal.

[0044] Furthermore, the inductance values ​​of all inductors in the parallel resonant branches are equal.

[0045] By setting the second capacitor value to be equal in all parallel resonant branches, the LC parallel resonant circuits of each detection unit have a consistent inherent resonant frequency base. This avoids deviations in the response frequency of different detection units to the excitation signal due to differences in capacitor parameters, ensuring synchronous detection of the system under a unified excitation frequency. Similarly, making the inductance value equal in all parallel resonant branches further enhances the consistency of the inherent resonant frequency of each LC circuit. When the excitation signal frequency is fixed, the parallel resonant branches of each detection unit can reach resonance simultaneously. At this time, the voltage at each grid point is at a stable reference level, providing a unified reference standard for subsequent detection of voltage changes caused by leakage. This parameter-unified design not only reduces system errors caused by component discreteness but also simplifies the frequency tuning process of the excitation signal. By simply setting an excitation frequency that matches the inherent resonant frequency of the LC circuit, all detection units can enter the optimal working state, improving the overall detection accuracy and stability of the system.

[0046] In the aforementioned unidirectional current transmission trunk and parallel resonant branch, capacitors can be surface-mount capacitors, ceramic capacitors, multilayer ceramic capacitors, etc., and inductors can be surface-mount inductors, I-type inductors, color-coded inductors, etc. Their specific types, specifications, and packages can be selected according to the actual situation. There are also no restrictions on the package and model of the operational amplifier; they are also selected based on the actual situation. By selecting different specifications of capacitors and inductors, the system sensitivity, operating bandwidth, and response characteristics can be customized.

[0047] In one alternative embodiment, such as Figure 2 and Figure 3 As shown, the first terminal of the voltage source is electrically connected to the first grid cell in the single-chain non-reciprocal circuit, and the second terminal of the voltage source is grounded.

[0048] The voltage source provides a stable AC excitation signal to the entire single-chain non-reciprocal circuit. Its output frequency must match the inherent resonant frequency of the LC circuit in the parallel resonant branch to ensure that each detection unit is in a stable resonant operating state when no leakage occurs. After the voltage source is connected to the circuit, the excitation signal is injected from the first grid cell and transmitted sequentially between grid cells through the unidirectional current transmission trunk, causing the parallel resonant branch of each detection unit to resonate and form a stable initial voltage distribution. This connection method ensures that the excitation signal can be transmitted efficiently and directionally in the circuit, providing a continuous and stable energy input for the system's gas leak detection. It is a crucial energy supply link for the normal operation of the entire detection system.

[0049] In another alternative embodiment, the first terminal of the voltage source is electrically connected to the last grid cell in the single-chain non-reciprocal circuit, and the second terminal of the voltage source is grounded.

[0050] The difference between this connection method and the previous embodiment lies in the injection position of the excitation signal. When the voltage source is connected to the last grid cell, the excitation signal is injected from the end of the circuit and then propagates forward sequentially along the direction of the unidirectional current transmission trunk. This flexibility in excitation signal injection allows the system to be installed by injecting the excitation signal from either the beginning or the end, depending on factors such as the voltage source's location and the circuit trace length, further enhancing the system's adaptability to different application scenarios. Whether injected from the beginning or the end, as long as the excitation signal frequency matches the inherent frequency of the LC parallel resonant circuit, stable resonance conditions can be provided for the detection unit, ensuring the normal operation of the detection system.

[0051] This invention innovatively introduces the tight-binding model from condensed matter physics into circuit design. Specifically, each lattice unit corresponds to an atomic lattice point in the tight-binding model of condensed matter physics, and its parallel resonant units provide the eigenenergy (corresponding to the resonant frequency) of that lattice point. The coupling elements between adjacent lattice units (including a bidirectionally coupled first capacitor and a non-reciprocal voltage follower) correspond to the jump integral in the tight-binding model, where the introduction of the voltage follower enables non-reciprocal jumps, breaking the double-hop symmetry of the traditional tight-binding model. The voltage distribution of the entire circuit chain corresponds to the probability amplitude distribution of the electron wave function in the tight-binding model. Through this mapping, this invention can accurately describe and predict circuit behavior using the mathematical framework of the tight-binding model, and by adjusting the coupling parameters, make the system operate near singularities, thereby achieving an ultra-high sensitivity response to small external disturbances (such as leakage).

[0052] Example 2 A gas leak detection method based on a single-chain non-reciprocal circuit is provided, which uses the gas leak detection system based on a single-chain non-reciprocal circuit in Example 1 to detect gas leaks. like Figure 5 As shown, the method includes: S1: Using a voltage source, an excitation signal is provided to a single-chain non-reciprocal circuit composed of multiple grid units connected in series. S2: Based on the unidirectional current transmission characteristic of the single-chain non-reciprocal circuit, the detection unit composed of every two adjacent grid units in the single-chain non-reciprocal circuit detects the voltage distribution of the detection area connected to the detection unit in the gas pipeline under the action of the excitation signal, and judges the gas leakage situation of the corresponding detection area based on the detected voltage distribution.

[0053] In this embodiment, a voltage source is used to provide a stable excitation signal to a single-chain non-reciprocal circuit composed of multiple grid units connected in series, enabling it to operate stably. In this stable operating state, the single-chain non-reciprocal circuit utilizes the unidirectional current transmission characteristic to achieve directional transmission and isolation of the current signal. Because the current signal can only flow in one direction, energy is confined to a specific direction of transmission. Under undisturbed conditions, the voltage concentrates in specific grid units, forming a stable eigenstate distribution. However, when a leak occurs in a detection area of ​​the gas pipeline, the external perturbation introduced by the leaking gas alters the dielectric properties of that area, causing the system to enter a specific state (such as resonance or singularity). Due to the non-reciprocal nature of the single-chain non-reciprocal circuit... The single-chain non-reciprocal circuit amplifies external perturbations, causing significant changes in the voltage distribution of the detection unit. This allows for highly sensitive detection of gas leaks by monitoring the voltage distribution. Furthermore, the unidirectional current transmission characteristic of this single-chain non-reciprocal circuit effectively avoids crosstalk between adjacent detection units, improving the accuracy of parallel multi-region detection. In addition, the combination of the single-chain non-reciprocal circuit and voltage source allows for chain-like expansion using a modular grid unit design. Adjusting the number of grid units adapts to the detection needs of gas pipelines of different lengths, helping to reduce system debugging complexity and hardware costs while achieving gas leak detection.

[0054] The gas leak detection method based on a single-chain non-reciprocal circuit in this embodiment does not rely on the chemically sensitive materials of traditional sensors, has a faster response speed, and is less affected by environmental factors. It can reliably and stably achieve real-time detection of both high-speed and low-speed gas leaks. It can maintain stable detection performance under complex working conditions for a long time, effectively making up for the shortcomings of existing technologies, such as the insensitivity of ultrasonic detection to low-speed leaks and the slow response and insufficient reliability of traditional sensors. It provides a simple and easy-to-implement solution for gas pipeline leak detection that takes into account both high-speed and low-speed leak detection.

[0055] The gas leak detection system based on a single-chain non-reciprocal circuit used in the gas leak detection method based on a single-chain non-reciprocal circuit described in this embodiment has the same structure as the gas leak detection system based on a single-chain non-reciprocal circuit in Embodiment 1. Therefore, for details not covered in this embodiment, please refer to Embodiment 1 and... Figures 1 to 4 The specific details will not be elaborated here.

[0056] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A gas leak detection system based on a single-chain non-reciprocal circuit, characterized in that, The system includes a voltage source and a single-chain non-reciprocal circuit composed of multiple grid units connected in series. The voltage source is electrically connected to the single-chain non-reciprocal circuit, and the single-chain non-reciprocal circuit has unidirectional current transmission characteristics. The voltage source is used to provide an excitation signal to the single-chain non-reciprocal circuit; In the single-chain non-reciprocal circuit, each pair of adjacent grid cells forms a detection unit and is connected to a detection area of ​​the gas pipeline. Each detection unit is used to detect the voltage distribution of the corresponding detection area in the gas pipeline under the action of the excitation signal by utilizing the unidirectional current transmission characteristic of the single-chain non-reciprocal circuit, and to determine the gas leakage situation of the corresponding detection area based on the detected voltage distribution.

2. The gas leak detection system based on a single-chain non-reciprocal circuit according to claim 1, characterized in that, In the single-chain non-reciprocal circuit, the first grid cell includes a grid cell and a parallel resonant branch connected to the grid cell, and the remaining grid cells all include a grid cell and a unidirectional current transmission trunk and a parallel resonant branch with the grid cell as the common connection terminal. In each detection unit composed of two adjacent grid cells, the grid cells in the latter grid cell are electrically connected to the grid cells in the former grid cell through the corresponding unidirectional current transmission trunk to form the corresponding detection unit; each grid cell is also grounded through the corresponding parallel resonant branch. The unidirectional current transmission trunk is used to provide a unidirectional current transmission path for the corresponding detection unit during operation; the parallel resonant branch is used to provide a stable resonant frequency for the corresponding detection unit.

3. The gas leak detection system based on a single-chain non-reciprocal circuit according to claim 2, characterized in that, In each detection unit, the unidirectional current transmission trunk includes a voltage follower and a first capacitor connected in series; In each unidirectional current transmission trunk, the voltage follower is specifically an operational amplifier, and the non-inverting input terminal of the operational amplifier is electrically connected to the grid point in the corresponding grid cell through the corresponding first capacitor. The inverting input terminal of the operational amplifier is electrically connected to the output terminal of the corresponding operational amplifier, and the output terminal of the operational amplifier is also electrically connected to the grid point in the previous grid cell.

4. The gas leak detection system based on a single-chain non-reciprocal circuit according to claim 2, characterized in that, In each detection unit, the unidirectional current transmission trunk includes a voltage follower and a first capacitor connected in series; In each unidirectional current transmission trunk, the voltage follower is specifically an operational amplifier, and the non-inverting input terminal of the operational amplifier is electrically connected to the grid point in the previous grid unit through the corresponding first capacitor. The inverting input terminal of the operational amplifier is electrically connected to the output terminal of the corresponding operational amplifier, and the output terminal of the operational amplifier is also electrically connected to the grid point in the corresponding grid unit.

5. The gas leak detection system based on a single-chain non-reciprocal circuit according to claim 3 or 4, characterized in that, The capacitance of the first capacitor in all unidirectional current transmission circuits is the same.

6. The gas leak detection system based on a single-chain non-reciprocal circuit according to claim 2, characterized in that, In each detection unit, the parallel resonant branch includes an inductor and a second capacitor connected in parallel; The first parallel terminal of the inductor and the second capacitor is electrically connected to the grid point in the corresponding grid cell, and the second parallel terminal of the inductor and the second capacitor is grounded.

7. The gas leak detection system based on a single-chain non-reciprocal circuit according to claim 6, characterized in that, The capacitance of the second capacitor in all parallel resonant branches is equal; and / or, the inductance of the inductor in all parallel resonant branches is equal.

8. The gas leak detection system based on a single-chain non-reciprocal circuit according to claim 1, characterized in that, The number of grid cells in the single-chain non-reciprocal circuit is greater than or equal to 2.

9. The gas leak detection system based on a single-chain non-reciprocal circuit according to claim 1, characterized in that, The first terminal of the voltage source is electrically connected to the first grid cell in the single-chain non-reciprocal circuit, and the second terminal of the voltage source is grounded. Alternatively, the first terminal of the voltage source is electrically connected to the last grid cell in the single-chain non-reciprocal circuit, and the second terminal of the voltage source is grounded.

10. A gas leak detection method based on a single-chain non-reciprocal circuit, characterized in that, Gas leak detection is performed using the gas leak detection system based on a single-chain non-reciprocal circuit as described in any one of claims 1 to 9; The method includes: A voltage source is used to provide an excitation signal to a single-chain non-reciprocal circuit composed of multiple lattice units connected in series. Based on the unidirectional current transmission characteristic of the single-chain non-reciprocal circuit, the detection unit composed of every two adjacent grid units in the single-chain non-reciprocal circuit detects the voltage distribution of the detection area connected to the detection unit in the gas pipeline under the action of the excitation signal, and judges the gas leakage situation in the corresponding detection area based on the detected voltage distribution.

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