Leakage detection system and leakage detection method

Abstract

The invention provides a leak detection system and a leak detection method. The leak detection system comprises a tracer gas detection probe, a tracer gas collection assembly and a detection cabin assembly. Wherein the detection cabin assembly comprises a detection chamber, the detection chamber is provided with a cabin door structure used for loading or taking out a to-be-detected tank container filled with tracer gas, and the cabin door structure is closed in a detection state; the top of the detection chamber is also provided with a gas outlet; the tracer gas collection assembly comprises a collection pipeline and a collection gas pump, and the collection gas pump carries out pumping gas collection through the collection pipeline; the tracer gas detection probe comprises a sensor chip used for detecting tracer gas. The leak detection system provided by the embodiment of the invention has the advantages that the cost is obviously reduced, and particularly, the use of an expensive mass spectrometer and a complex hydrogen sensor is avoided; by simplifying the technological process and using more economical detection elements, the overall investment of equipment can be greatly reduced; and through the reasonably designed collection pipeline and the high-sensitivity sensor chip, gas leakage can be rapidly detected.

Description

Technical Field

[0001] The present invention relates to the technical field of container leakage detection, and in particular to a leakage detection system and a leakage detection method. Background Art

[0002] At present, the existing technologies for checking container leakage mainly include bubble test, pressure decay test, helium accumulation, helium sniffing, helium vacuum detection and other methods. These detection methods have some defects to a greater or lesser extent. For example, the theoretical leakage rate of bubble test and pressure decay test is relatively large, and the leakage rate range that can be detected is within 10 0 ~10 -4 mbar﹒ L / s, which is not possible to detect micro leaks in fields with extremely high sealing requirements such as aerospace and power fuel storage. Helium accumulation, helium sniffing, and helium vacuum detection have a small theoretical leak rate and a wide coverage of leak rate detection, with the lowest leak rate being 10 -12 mbar﹒ L / s leak. However, the cost of using helium is very expensive. For super large containers or non-closed pipelines, this type of detection scheme is difficult to implement and use in batches due to cost considerations. At present, common pressure vessel materials usually use pressure holding test or soapy water bubbling to test the overall sealing of the container. Some factories that have high pressure on the sealing of equipment will also use the method of filling the equipment with high-pressure air, immersing the container in water, and visually observing the bubbles to determine whether there is a leak for large-scale sealing testing. This method is inefficient and has a high rate of missed detection.

[0003] In summary, it is crucial to solve the problems of low efficiency, high cost, waste of water resources, high missed detection rate and disadvantages for large-scale industrial production in the traditional leak detection system in the prior art. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a leak detection system and a leak detection method to eliminate or improve one or more defects existing in the prior art.

[0005] In a first aspect, the present invention provides a leak detection system, the leak detection system comprising a tracer gas detection probe, a tracer gas collection assembly and a detection chamber assembly;

[0006] The detection chamber assembly includes a detection chamber, which has a hatch structure for loading or removing a tank container to be inspected filled with tracer gas, and the hatch structure is closed in the detection state; the top of the detection chamber also has a gas outlet;

[0007] The tracer gas collection assembly comprises a collection pipeline, an electromagnetic gas valve and a collection gas pump, wherein the collection gas pump collects gas by pumping through the collection pipeline, one end of the electromagnetic gas valve is installed at the gas outlet position, and the other end is connected to one end of the tracer gas detection probe, and the other end of the tracer gas detection probe is connected to the collection pipeline;

[0008] The tracer gas detection probe has an airflow channel for the tracer gas to pass through. The tracer gas detection probe includes a sensor chip for detecting the tracer gas. The sensor chip is arranged in the airflow channel.

[0009] In some embodiments, the sensor chip includes any one of a carbon nanotube field effect transistor hydrogen sensor chip, a semiconductor hydrogen sensor, an electrochemical hydrogen sensor, a catalytic combustion hydrogen sensor, a palladium alloy thin film hydrogen sensor, and a MEMS hydrogen sensor;

[0010] The tracer gas detection probe further comprises a substrate, and the substrate comprises any one of a silicon oxide substrate silicon wafer, ceramic, PCB, FPC and quartz glass substrate;

[0011] When the sensor chip adopts the carbon nanotube field effect transistor hydrogen sensor chip, the carbon nanotube field effect transistor hydrogen sensor chip is bonded to a set area of ​​the substrate, and the chip pad is connected to the substrate pad through a gold wire; the area where the gold wire is located on the substrate is coated with a resin layer.

[0012] In some embodiments, the tracer gas detection probe further includes a circuit board, the substrate is connected to the circuit board via a quick-plug connector, and the quick-plug connector includes any one of a Type-C connector, a Type-A interface, a 232 interface, and a 485 interface;

[0013] The circuit board comprises an upper circuit board and a lower circuit board, the upper circuit board is connected to the base plate via a quick-insert connector, the lower circuit board is used to be connected to a first sealing connector, and the upper circuit board is fixedly connected to the lower circuit board via a pin header;

[0014] An air flow channel is formed between the upper circuit board and the lower circuit board;

[0015] The tracer gas detection probe further comprises a signal line, wherein the signal line is connected to the circuit board, the signal line comprises at least two channels, and each channel line is provided with a metal isolation layer.

[0016] In some embodiments, the tracer gas detection probe further includes a probe housing, which is a hollow cylindrical structure for mounting the circuit board, substrate and carbon nanotube field effect transistor hydrogen sensor chip therein; a filter connection portion is formed at a first end of the probe housing, and a collection pipe connection portion is formed at a second end;

[0017] The tracer gas detection probe further comprises a joint fixing ring, which is used to be installed at the collection pipe connecting portion of the probe housing, so as to install the second sealing joint of the collection pipe at the second end of the probe housing;

[0018] The tracer gas detection probe further includes a filter, which includes a filter housing and a first fixed layer, a first dust filter layer, a first waterproof breathable membrane, an activated carbon particle layer, a second waterproof breathable membrane and a second fixed layer arranged in the filter housing and layered along the airflow direction;

[0019] The filter is connected to the filter connecting portion of the probe housing via threads.

[0020] In some embodiments, the top of the detection chamber is a narrowed inverted funnel-shaped structure, and the gas outlet is located at the center of the top of the inverted funnel-shaped structure;

[0021] The detection chamber assembly also includes an internal circulation pipeline, a circulation air pump and a fan, which are used to evenly diffuse the tracer gas leaking from the tank container to be inspected in the detection chamber;

[0022] One end of the inner circulation pipe is connected to the upper middle part of the detection chamber, and the other end is connected to the lower part of the detection chamber. The circulation air pump is arranged on the inner circulation pipe, and the fan is arranged at the bottom of the detection chamber.

[0023] In some embodiments, the collection pipeline is a gas-electric dual-path transmission pipeline, and its material is Teflon; the collection air pump adopts a PWM air pump.

[0024] In some embodiments, the leak detection system further comprises a tracer gas charging assembly, wherein the tracer gas charging assembly comprises a gas cylinder, a charging pipe, and a pressure reducing valve and an adjustable flow meter disposed on the charging pipe;

[0025] Wherein, the tracer gas filling assembly is used to fill the tank container to be inspected with tracer gas, one end of the filling pipe is connected to the gas cylinder, and the other end is used to connect to the tank container to be inspected;

[0026] The pressure reducing valve is used to reduce the gas pressure output from the gas cylinder to the pressure required for charging;

[0027] The adjustable flow meter is used to control the flow rate and flow velocity of the gas filled into the tank container to be inspected;

[0028] The tracer gas is a mixed gas containing 95% nitrogen and 5% hydrogen.

[0029] In some embodiments, the leak detection system further includes a sensor driving circuit and an acquisition circuit;

[0030] The sensor driving circuit is used to provide a driving voltage to the sensor chip and collect the current fed back by the sensor chip;

[0031] The acquisition circuit includes an MCU microcontroller unit, a crystal oscillator peripheral circuit, a buck circuit, a DAC output circuit, an ADC sensor acquisition circuit, a PWM air pump control circuit, a voltage source module, a signal filtering module and a constant voltage module;

[0032] The MCU microcontroller unit and the crystal oscillator peripheral circuit include a control circuit that leads from each IO port of the MCU to each module and a drive circuit that provides a drive voltage for the MCU;

[0033] The step-down circuit is used to reduce the fixed voltage provided by the voltage source module to the working voltage required by various components and sensors;

[0034] The DAC output circuit includes an output bias voltage circuit and an output control voltage circuit, which are used to provide a bias voltage and a control voltage to the sensor chip respectively;

[0035] The ADC sensor acquisition circuit is used to collect the output current of the sensor chip and convert the analog signal into a digital signal;

[0036] The PWM air pump control circuit is used to provide a voltage of 0V-5V to the air pump by adjusting the duty cycle of the high level in the pulse period;

[0037] The voltage source module is used to supply power to the sensor chip driving circuit through an external 220V mains power supply and a voltage step-down and voltage stabilizing circuit;

[0038] The signal filtering module is used to filter noise signals and stabilize reference signals;

[0039] The constant voltage module is used to provide a constant voltage to the sensor chip.

[0040] In a second aspect, the present invention provides a leak detection method, which is implemented based on the above leak detection system, and the method comprises the following steps:

[0041] Using the tracer gas filling assembly, a mixed gas containing 95% nitrogen and 5% hydrogen at a set pressure is filled into the interior of the tank container to be inspected, and then the tank container to be inspected is placed in the inspection chamber and the hatch structure of the inspection chamber is closed;

[0042] Control the electromagnetic air valve to remain closed, and start the fan and circulating air pump in the test chamber;

[0043] After the mixing time is set, the electromagnetic valve is controlled to open, and the collection pump of the tracer gas collection component is controlled to start, so that the hydrogen leaked from the tank container to be inspected passes through the carbon nanotube field effect transistor hydrogen sensor chip and completes the detection;

[0044] After the detection is completed, the hatch structure of the detection chamber is opened, the mixed gas in the detection chamber is emptied by the collection gas pump of the tracer gas collection assembly, and the carbon nanotube field effect transistor hydrogen sensor chip enters the recovery stage.

[0045] In some embodiments, the step of detecting the hydrogen concentration by the carbon nanotube field effect transistor hydrogen sensor chip includes:

[0046] After the device is turned on, it is determined whether the detection reference value of the carbon nanotube field effect transistor hydrogen sensor chip is within the set range;

[0047] If yes, preheat the carbon nanotube field effect transistor hydrogen sensor chip for one minute, take the benchmark average value within one minute, and determine whether the benchmark average value is within the valid range of the blank environment;

[0048] If yes, assign a value to the reference average value and calibrate it to zero point;

[0049] During the hydrogen detection process, the current value of the carbon nanotube field effect transistor hydrogen sensor chip is updated in real time, with 5 seconds as a group;

[0050] When the current value is inversely proportional to the time, it is determined that hydrogen is detected, and the data is put into the calibrated formula to calculate the current hydrogen concentration value;

[0051] When the current value is proportional to the time, it is determined that the carbon nanotube field effect transistor hydrogen sensor chip has entered the recovery stage.

[0052] Compared with the traditional mass spectrometer detection method, the cost of the leak detection system of the embodiment of the present invention is significantly reduced, especially avoiding the use of expensive mass spectrometers and complex hydrogen sensors. By simplifying the process and using more economical detection elements, the overall investment in equipment can be greatly reduced. Through a reasonably designed collection pipeline and a highly sensitive sensor chip, the system can quickly detect gas leaks and provide precise positioning to ensure high-precision detection. Since there is no need to use large-scale gas analysis instruments, the design of the leak detection system is more compact and easy to carry, and is suitable for leak detection in a variety of environments. Compared with the traditional complex manufacturing process (such as the high process requirements of silicon-based field effect hydrogen sensors), the sensor chip design used in the present invention can greatly simplify the manufacturing process and reduce production costs.

[0053] Additional advantages, purposes, and features of the present invention will be described in part in the following description, and will become apparent to those skilled in the art after studying the following, or may be learned from the practice of the present invention. The purposes and other advantages of the present invention may be achieved and obtained by the structures specifically indicated in the specification and the accompanying drawings.

[0054] Those skilled in the art will appreciate that the objectives and advantages that can be achieved with the present invention are not limited to the above specific description, and the above and other objectives that can be achieved by the present invention will be more clearly understood from the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of this application, and do not constitute a limitation of the present invention. The components in the drawings are not drawn to scale, but are only for illustrating the principles of the present invention. In order to facilitate the illustration and description of some parts of the present invention, the corresponding parts in the drawings may be enlarged, that is, they may become larger relative to other components in the exemplary device actually manufactured according to the present invention. In the drawings:

[0056] Figure 1 Schematic diagram of the composition of a leak detection system in one embodiment of the present invention.

[0057] Figure 2 It is a schematic structural diagram of a detection chamber assembly in another embodiment of the present invention.

[0058] Figure 3 FIG. 4 is a schematic structural diagram of a sensor chip and a substrate in an embodiment of the present invention.

[0059] Figure 4 Schematic diagram of the circuit and structure inside the probe in one embodiment of the present invention.

[0060] Figure 5The figure is a schematic diagram of the packaging structure of the probe housing, the filter and the joint fixing ring in one embodiment of the present invention.

[0061] Figure 6 Schematic diagram of the composition of the functional circuit of the leakage detection system in one embodiment of the present invention.

[0062] Figure 7 The figure is a schematic diagram of the composition of the power supply circuit of the leakage detection system in one embodiment of the present invention.

[0063] Figure 8 It is a flowchart of a leak detection method in one embodiment of the present invention.

[0064] Fig. 9 This is a flowchart of a chip detecting hydrogen concentration in one embodiment of the present invention.

[0065] Fig.10 FIG. 4 is an algorithm flow chart of a leak detection method in one embodiment of the present invention.

[0066] Reference numerals:

[0067] 1. Tracer gas detection probe; 111. Substrate; 112. Sensor chip; 113. Gold wire; 114. Quick-connect connector; 115. Upper circuit board; 116. Lower circuit board; 117. Pin header; 118. First sealing connector;

[0068] 121. probe housing; 122. filter; 123. connector fixing ring;

[0069] 122-1, first fixed layer; 122-2, first dust filtering layer; 122-3, first waterproof breathable membrane; 122-4, activated carbon particle layer; 122-5, second waterproof breathable membrane; 122-6, second fixed layer;

[0070] 2. Detection cabin assembly; 21. Detection chamber; 211. Gas outlet; 22. Internal circulation pipeline; 23. Circulation air pump; 24. Fan;

[0071] 3. Tracer gas collection assembly; 31. Collection gas pump; 32. Collection pipeline; 33. Solenoid gas valve;

[0072] 4. Tracer gas charging assembly; 41. Gas cylinder; 42. Gas charging pipeline; 43. Pressure reducing valve; 44. Adjustable flow meter;

[0073] 9. Tank container to be inspected. DETAILED DESCRIPTION

[0074] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments and the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0075] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0076] It should be emphasized that the term “include / comprises” when used herein refers to the presence of features, elements, steps or components, but does not exclude the presence or addition of one or more other features, elements, steps or components.

[0077] It should also be noted that, unless otherwise specified, the term “connection” herein may refer not only to a direct connection but also to an indirect connection with an intermediate.

[0078] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals represent the same or similar components, or the same or similar steps.

[0079] In the current container leak detection industry, existing products have the following deficiencies:

[0080] 1. Currently, nitrogen and hydrogen tracing mainly uses mass spectrometer as the tracer gas detector, which is costly and has poor portability;

[0081] 2. Silicon-based field effect hydrogen sensors have complex processes, high manufacturing costs, and large equipment investments;

[0082] 3. The field effect hydrogen sensor based on traditional semiconductor technology has low sensitivity and poor leak detection accuracy.

[0083] The leak detection system and leak detection method in the embodiments of the present invention provide a low-cost, fast and high-precision leak detection solution for pressure vessels and tanks.

[0084] In a first aspect, the present invention provides a leak detection system, such as Figure 1 As shown, the leak detection system includes a tracer gas detection probe 1, a tracer gas collection component 3 and a detection chamber component 2.

[0085] The detection chamber assembly 2 includes a detection chamber 21, which has a hatch structure for loading or removing the tank container 9 to be inspected filled with tracer gas. During the inspection process, the hatch remains closed to prevent gas leakage. The top of the detection chamber 21 also has a gas outlet 211 for discharging and collecting gas.

[0086] The tracer gas collection assembly 3 includes a collection pipeline 32, an electromagnetic gas valve 33 and a collection gas pump 31. The collection gas pump 31 pumps gas through the collection pipeline 32. One end of the electromagnetic gas valve 33 is installed at the position of the gas outlet 211, and the other end is connected to one end of the tracer gas detection probe 1. The other end of the tracer gas detection probe 1 is connected to the collection pipeline 32. The electromagnetic gas valve 33 can be used to control the opening and closing of the gas outlet 211. The collection gas pump 31 is responsible for pumping the gas in the chamber through the collection pipeline 32 to ensure that the gas can be guided to the gas detection probe in time.

[0087] The tracer gas detection probe 1 has an air flow channel for the tracer gas to pass through. The tracer gas detection probe 1 includes a sensor chip 112 for detecting the tracer gas, and the sensor chip 112 is arranged in the air flow channel. This design ensures that any tracer gas that may leak will pass through the air flow channel in the tracer gas detection probe and can be adsorbed and sensed by the sensor chip 112 arranged in the air flow channel. The sensor chip 112 transmits the collected data to the control unit of the system for real-time analysis. If an abnormal gas concentration is detected, the control system will determine that there is a leak in the container, and issue an alarm or display the specific leak location.

[0088] In the above embodiment, compared with the traditional mass spectrometer detection method, the cost of the leak detection system is significantly reduced, especially avoiding the use of expensive mass spectrometers and complex hydrogen sensors. By simplifying the process and using more economical detection elements, the overall investment in equipment can be greatly reduced. Through the reasonably designed collection pipeline 32 and the highly sensitive sensor chip 112, the system can quickly detect gas leaks and provide accurate positioning to ensure high-precision detection. Since there is no need to use large-scale gas analysis instruments, the design of the leak detection system is more compact and easy to carry, and is suitable for leak detection in a variety of environments. Compared with the traditional complex manufacturing process (such as the high process requirements of silicon-based field effect hydrogen sensors), the sensor chip 112 design adopted in the present invention can greatly simplify the manufacturing process and reduce production costs.

[0089] In some embodiments, the sensor chip 112 includes any one of a carbon nanotube field effect transistor hydrogen sensor chip, a semiconductor hydrogen sensor, an electrochemical hydrogen sensor, a catalytic combustion hydrogen sensor, a palladium alloy thin film hydrogen sensor, and a MEMS hydrogen sensor. The embodiment of the present invention may be a carbon nanotube field effect transistor hydrogen sensor chip. The carbon nanotube field effect transistor hydrogen sensor chip adopts carbon nanotube process manufacturing technology. The process route only requires four steps to complete chip manufacturing. The process is simple and the cost is not high. The carbon nanotube field effect transistor hydrogen sensor chip is only 2 square millimeters in size, which is very small. The detection equipment is portable and reliable. The carbon nanotube field effect transistor hydrogen sensor chip has a very high hydrogen detection capability and can currently detect hydrogen concentrations at the 1ppm level. Using a 95% nitrogen and 5% hydrogen mixed gas as a tracer gas, the hydrogen tracer leak detection equipment prepared with the carbon nanotube field effect transistor hydrogen sensor chip, the nitrogen-hydrogen tracer leak detection technology can detect 10 -8 The leak detection capability of the leak hole with a leak rate of mbar﹒L / s far exceeds the bubble test and pressure decay test, which is sufficient to meet the sealing leak detection requirements of aerospace, power fuel storage, etc.

[0090] In addition, with the development of the hydrogen energy industry, the cost of using hydrogen-nitrogen mixed gas is much lower than that of pure helium. In the application scenarios of filling super-large containers or continuously infusing gas in non-closed pipeline environments, rapid batch detection can be achieved; and a 95% nitrogen and 5% hydrogen mixed gas is used as a tracer gas. The hydrogen content in this ratio is much lower than the explosion limit of hydrogen, and it is very safe to use in the detection industry.

[0091] The leak detection system in the embodiment of the present invention mainly utilizes the ultra-high detection capability of the carbon nanotube field effect transistor hydrogen sensor chip for hydrogen, and fills the tank container with a mixed gas of 95% nitrogen and 5% hydrogen, and detects the leaked hydrogen to realize the positioning of the leak hole in the entire tank and the detection of the leakage rate. The present invention is based on a high-sensitivity carbon nanotube field effect transistor hydrogen sensor, in conjunction with a detection chamber 21, by filling the tank container 9 to be inspected with a nitrogen-hydrogen mixed gas, and through the sensor detection chamber 21 and a signal processing algorithm, accurately detects the leakage rate of the tank container 9 to be inspected.

[0092] The tracer gas detection probe 1 in the embodiment of the present invention can use a carbon nanotube field effect transistor hydrogen sensor chip, which is the core of the entire detection system. The main purpose is to detect extremely low concentrations of hydrogen. It has the advantages of high sensitivity, low power consumption, and fast response, and is particularly suitable for container leakage detection. Compared with traditional hydrogen sensors, the sensor chip 112 can still maintain high sensitivity at low power consumption and is suitable for leak detection systems that work for a long time. The chip can quickly respond to changes in hydrogen concentration, greatly improving the detection speed, and is suitable for real-time monitoring and rapid judgment.

[0093] The manufacturing process of the sensor chip 112 is simple, mainly including four steps: plating the source and drain metal layers, etching the carbon nanotubes, depositing the insulating dielectric layer and plating the gate metal layer. First, a layer of metal material (such as aluminum or gold) is deposited on the substrate material (such as a silicon wafer) to form source and drain electrodes. These metal layers will be used to connect the circuits of the chip to ensure the transmission and processing of signals. Through the etching process, the carbon nanotubes are precisely arranged between the source and drain. The arrangement of the carbon nanotubes can be single-walled carbon nanotubes or multi-walled carbon nanotubes, which have extremely high electron mobility under the action of the electric field and can effectively improve the sensitivity of hydrogen detection. In order to ensure the stability of the current signal and prevent short circuit or noise interference, a thin layer of insulating dielectric material (such as silicon dioxide) needs to be deposited on the surface of the carbon nanotubes. This step helps to ensure that the electrical performance of the sensor is not interfered by the outside world. Finally, a layer of gate metal (alloy of metals such as gold, aluminum, magnesium and metal palladium) is plated on top of the carbon nanotubes. The function of the gate is to adjust the conductivity of the carbon nanotubes, control the flow of electrons through voltage, and thus detect the presence of hydrogen. When hydrogen molecules react with the surface of carbon nanotubes, the voltage change of the gate can reflect the change in hydrogen concentration, thereby achieving high-precision hydrogen detection.

[0094] In the above embodiment, by adopting the carbon nanotube field effect transistor hydrogen sensor chip, the present invention can realize the accurate detection of extremely low concentration hydrogen. Its manufacturing process is simple and efficient, and its sensing performance is excellent. It can not only improve the accuracy of leak detection, but also reduce the overall cost of the system, providing an innovative technical solution for industrial leak detection.

[0095] In some embodiments, the tracer gas detection probe 1 further includes a substrate 111, such as Figure 3 and Figure 4 As shown, the substrate 111 includes any one of silicon oxide substrates, ceramics, PCB, FPC and quartz glass, or any combination thereof, and is used to provide mechanical support and interconnection functions for the sensor chip 112 .

[0096] In some embodiments, the sensor chip 112 preferably adopts a carbon nanotube field effect transistor hydrogen sensor chip, such as Figure 3 As shown, the carbon nanotube field effect transistor hydrogen sensor chip is bonded to a set area (such as Figure 3The upper position of the substrate 111), and the connection between the chip pad and the substrate 111 pad is achieved through the gold wire 113; the area where the gold wire 113 on the substrate 111 is located is coated with a resin layer. Furthermore, the substrate 111 binding package of the sensor chip 112 is to bind the carbon nanotube field effect transistor hydrogen sensor chip to the integrated PCB circuit board (i.e., substrate 111) through gold wire ball welding to achieve electrical connection of the sensor chip 112. Its manufacturing process is: the chip is adhered to a fixed position on the binding substrate 111 through the backing glue, the backing glue is cured by a hot plate to achieve chip fixation, and then the Pad (pad) of the substrate 111 and the Pad of the chip are connected by an ultrasonic gold wire ball welding machine, and the resin is coated around the gold wire 113 position with a dispensing machine to fix the gold wire 113, and finally heated and cured to complete the chip substrate 111 packaging binding.

[0097] In the above embodiment, the carbon nanotube field effect transistor hydrogen sensor chip is used as the core element of the sensor, which is fixed to a specific area of ​​the substrate 111 by bonding. This ensures that the sensor chip 112 is stably in the detection area during operation and is not affected by external environmental factors. The gold wire 113 is used to connect the chip pad to the pad on the substrate 111 to ensure the transmission of electrical signals. The gold wire 113 welding process can achieve a more accurate and firm connection, avoiding the signal loss or short circuit phenomenon of the chip during use. The coating of the resin layer is used to protect the welding area and the sensitive electrical connection part. The resin layer can prevent the corrosion or damage of the welding point by external environmental factors (such as moisture, dust, etc.), thereby improving the reliability and service life of the system. In addition, the coating of the resin layer can also play the role of electrical insulation, avoiding short circuits between the gold wire 113 welding points or between the surrounding components. The selection of resin materials (such as epoxy resin, polyurethane resin, etc.) should have good electrical insulation, temperature resistance and corrosion resistance to meet the long-term working requirements of the sensor in different environments.

[0098] In some embodiments, Figure 4 As shown, the tracer gas detection probe 1 also includes a circuit board, and the substrate 111 is connected to the circuit board through a quick-plug connector 114, and the quick-plug connector 114 includes any one of a Type-C connector, a Type-A interface, a 232 interface, and a 485 interface. The quick-plug connector 114 can be optionally a Type-C male connector. In addition to being used to connect the substrate 111, the circuit board can also be used to connect various circuits of the sensor, such as an acquisition circuit and a voltage stabilizing circuit. In order to realize the replaceable probe design, the communication between the probe and the acquisition circuit adopts an electrical and pneumatic dual-channel, and the interfaces at both ends are pluggable sealed interfaces (the candidate descriptions are uniformly referred to as sealed interfaces).

[0099] The substrate 111 is connected to the circuit board via a quick-plug connector 114. This design allows the circuit board and the substrate 111 to be easily installed, removed or replaced. The quick-plug connector 114 can provide quick connection and disconnection while ensuring good contact during use, avoiding the problem of poor contact or damage that may be caused by traditional welding joints. The advantages of this method can improve assembly efficiency and maintenance convenience.

[0100] Furthermore, the circuit board includes an upper circuit board 115 and a lower circuit board 116, the upper circuit board 115 is connected to the substrate 111 via a quick-plug connector 114, the lower circuit board 116 is used to connect to a first sealing connector 118, and the upper circuit board 115 and the lower circuit board 116 are fixedly connected via a pin header 117; an air flow channel is formed between the upper circuit board 115 and the lower circuit board 116. The upper circuit board 115 is mainly responsible for connecting to the substrate 111, while the lower circuit board 116 is used to connect to the first sealing connector 118. This layered design can effectively disperse complex electrical connections to different board layers, avoiding the situation where a single-layer circuit board is too complex or crowded. Specifically, the upper circuit board 115 may be in a strip-shaped structure and arranged along the axis of the probe housing 121; the lower circuit board may be in a disc-shaped structure, arranged along the radial direction of the probe housing 121 and located on one side of the upper circuit board 115. In order to avoid closing the internal channel of the probe housing 121, a hole may be opened in the middle to serve as an air flow channel. The upper circuit board 115 and the lower circuit board are fixedly connected by a pin header 117. The pin header 117 is used to provide a stable connection point to ensure a stable connection between the circuit boards. The pin header 117 connection method can simplify the installation and disassembly between the circuit boards while providing good electrical contact. The design of the air flow channel can improve the sensitivity of gas detection and reduce the risk of gas leakage or uneven gas flow, ensuring that the probe can accurately and quickly detect the required tracer gas.

[0101] In the above embodiment, the first sealing joint 118 is connected to the lower circuit board, which can be used to ensure the sealing and protection of the inside of the probe. In the application scenario of gas leakage detection, sealing is crucial. The first sealing joint 118 can be used to isolate the gas influence of the external environment, while ensuring that the gas in the gas detection channel will not leak, thereby ensuring the detection accuracy. The sealing joint can also effectively prevent external contaminants or moisture from entering the system, protect electronic components from damage, and extend the service life of the sensor.

[0102] In some embodiments, the tracer gas detection probe 1 also includes a signal line, which is connected to the circuit board, and the signal line includes at least two channels, and each channel line is provided with a metal isolation layer. The probe can process multiple signal input or output channels, and these channels can be used for the transmission of different signals. For example, the circuit between the probe and the acquisition circuit board can achieve up to 8 channels of connection, and each circuit is separated by a metal shielding layer to ensure that the weak electrical signal is not interfered with. This shielding design is particularly important for high-frequency signals or low-voltage signals, because any slight interference may cause data errors and affect the accuracy of the sensor. Each channel is independently shielded, which can effectively avoid signal interference, and is particularly suitable for gas detection systems that need to process weak electrical signals and complex signal environments. Through such a design, the tracer gas detection probe 1 can provide high-quality and reliable detection results, and is suitable for a variety of application scenarios with high precision and high anti-interference requirements.

[0103] In some embodiments, Figure 5 As shown, the tracer gas detection probe 1 also includes a probe housing 121, which is a hollow cylindrical structure for installing the circuit board, substrate 111 and carbon nanotube field effect transistor hydrogen sensor chip inside; the first end of the probe housing 121 is formed with a filter 122 connection part, and the second end is formed with a collection pipe 32 connection part. As at least one achievable method, the filter 122 connection part can be designed as an external thread structure, and both ends of the probe housing 121 also have internal threads, and the interior is hollow, mainly for protecting the chip substrate 111 binding package. The probe housing 121 adopts a hollow cylindrical structure, which is not only convenient for the installation of internal components (such as circuit boards, substrates 111 and hydrogen sensor chips, etc.), but also has the characteristics of lightness, firmness and compactness, which helps to improve the service life of the equipment and the ability to resist external environmental interference. The hollow design also facilitates the circulation of gas, ensuring sufficient contact of gas during the detection process and accurate response of the sensor.

[0104] In some embodiments, Figure 5As shown, the tracer gas detection probe 1 also includes a joint fixing ring 123, which is used to be installed at the connection part of the collection pipe 32 of the probe housing 121, so as to install the second sealing joint of the collection pipe 32 at the second end of the probe housing 121. As at least one achievable manner, the joint fixing ring 123 is a funnel-shaped cylinder, one end of which is an internal thread, and the sealing joint is rotated and fixed, and the other end is an external thread, which is connected to the probe housing 121. The joint fixing ring 123 is used to be installed at the connection part of the collection pipe 32 of the probe housing 121, so as to fix and seal the second sealing joint of the collection pipe 32. This design ensures a stable connection between the collection pipe 32 and the probe housing 121, avoids loosening or leakage of the connection part, and provides good sealing to prevent external gas from entering the collection pipe 32 and the inside of the probe.

[0105] In some embodiments, Figure 5 As shown, the tracer gas detection probe 1 also includes a filter 122, which includes a filter 122 housing and a first fixed layer 122-1, a first dust filter layer 122-2, a first waterproof breathable membrane 122-3, an activated carbon particle layer 122-4, a second waterproof breathable membrane 122-5, and a second fixed layer 122-6 arranged in the filter 122 housing and arranged layer by layer along the airflow direction; the filter 122 is connected to the filter 122 connection part of the probe housing 121 through a thread. Among them, the first fixed layer 122-1 and the second fixed layer 122-6 can be made of steel mesh, which is mainly used to reinforce the rigidity of the interlayer, protect the internal filter layer from mechanical damage, and play a fixing role, and also has the function of filtering large particle impurities. The first dust filter layer 122-2 can be made of absorbent cotton, which is used to filter dust and impurities; the first waterproof breathable membrane 122-3 and the second waterproof breathable membrane 122-5 can be made of PTFE waterproof breathable membrane, which prevents water or liquid from entering the filter 122 from both sides but allows gas to pass freely, and its function is to filter dust and impurities. The activated carbon particle layer 122-4 filled in the middle is mainly used to absorb toxic and harmful acid and alkali gases to prevent them from corroding the chip and delaying the service life of the chip. In this embodiment, this multi-layer filtering structure helps to remove possible pollutants, dust and moisture before the gas enters the detection probe, avoids sensor contamination, and ensures detection accuracy and stability.

[0106] In the probe structure of the above embodiment, each threaded connection of the probe is sealed with a sealing ring to ensure that there is only one position of the filter 122 at the entire probe air inlet.

[0107] In some embodiments, Figure 1 and Figure 2As shown, the top of the detection chamber 21 is a narrowed inverted funnel-shaped structure, and the gas outlet 211 is located at the center of the top of the inverted funnel-shaped structure. The inverted funnel-shaped structure can help hydrogen to converge upward.

[0108] In some embodiments, the detection chamber assembly 2 further includes an inner circulation pipe 22, a circulation air pump 23 and a fan 24, which are used to evenly diffuse the tracer gas leaked from the tank container 9 to be inspected in the detection chamber 21; one end of the inner circulation pipe 22 is connected to the upper middle part of the detection chamber 21, and the other end is connected to the lower part of the detection chamber 21, the circulation air pump 23 is arranged on the inner circulation pipe 22, and the fan 24 is arranged at the bottom of the detection chamber 21. In this embodiment, a fan 24 is placed at the bottom of the chamber, and its main function is to quickly stir the hydrogen and the air in the chamber to evenly diffuse the hydrogen. At the same time, a gas internal circulation system is set at the top and bottom of the cavity. The gas internal circulation system mainly consists of three parts, a chamber gas outlet 211, a chamber gas inlet and a circulation air pump 23. The chamber gas outlet 211 is located at the top of the detection chamber 21, and the chamber gas inlet is located at the bottom of the detection chamber 21. The circulation air pump 23 is a speed-adjustable micro air pump. The internal circulation gas flows as follows: detection chamber 21 - chamber top outlet - circulation air pump 23 - chamber bottom inlet - detection chamber 21. This circulation mainly cooperates with the fan 24 to make the hydrogen evenly diffuse inside the detection chamber 21.

[0109] In addition, each external connection of the detection chamber 21 can be sealed with a silicone gasket to create a static environment in the chamber.

[0110] In some embodiments, Figure 1 and 2 As shown, the electromagnetic valve 33 is arranged at the gas outlet 211 to control the opening and closing of the gas outlet 211. An electromagnetic valve 33 is connected to the upper end of the inverted funnel convergence port, and the electromagnetic valve 33 is connected to the probe of the hydrogen detector. The electromagnetic valve 33 is used to temporarily close the chamber's external gas outlet, so that the detection chamber 21 is a completely sealed chamber during the hydrogen leakage stage, and the interior is a static environment relative to the outside. After the hydrogen leaks for a certain period of time and the hydrogen in the chamber is completely mixed, the electromagnetic valve 33 is opened, and the hydrogen diffuses upward into the probe of the hydrogen detector and is detected by the carbon nanotube field effect transistor hydrogen sensor chip, completing the entire detection process.

[0111] In some embodiments, the collection pipeline 32 is a gas-electric dual-path transmission pipeline, and its material is Teflon; the collection air pump 31 adopts a PWM air pump. Optionally, the tracer gas collection component 3 is a pump suction gas collection system in which the air pump flow is controlled by a PWM air pump control circuit. The collection air pump 31 can be arranged in the main body of the gas collection equipment, and the gas collection pipeline is divided into two parts. The gas collection pipeline outside the main body of the gas collection equipment is a gas-electric dual-path transmission line, which connects the sensor probe and the equipment air inlet sealing joint. The gas collection pipeline inside the main body of the gas collection equipment is a Teflon pipeline, one section connects the equipment air inlet sealing joint and the air pump inlet, and the other section connects the air pump outlet and the equipment outlet hole; the collection air pump 31 is a micro air pump that can be adjusted by PWM; the collection gas path is: test position environment - filter 122 - sensor chip 112 - gas-electric dual-path transmission line - PWM air pump - gas collection equipment main body outlet hole. Since a sealed joint is used between the probe and the main unit, and each joint inside the probe is sealed with a sealing rubber ring, the gas inlet of the entire gas path is only located at one position, the filter 122 of the sensor probe, and the gas outlet 211 is the gas outlet of the main body of the gas collection equipment, thereby ensuring the pumping efficiency; the PWM gas pump control circuit can control the gas pump flow rate and can adjust the pumping rate in real time during the detection process to improve the detection efficiency. At the same time, the pumping function can quickly switch the gas environment inside the probe, so that the sensor can quickly recover from the response state to the monitoring state (blank environment stable baseline state), thereby reducing the sensor recovery time and quickly starting the second detection.

[0112] In actual use, the tracer gas collection component 3 can be used and the pumping pressure, flow rate, etc. can be adjusted according to actual conditions. For example, during the detection process, the tracer gas collection component 3 can be used or not; when the detection time is long, the pumping function can be turned on or the pumping pressure can be increased to assist in collecting tracer gas and increase the detection speed; after the detection process is completed, the detection chamber 21 is opened and the pumping function is turned on to make the sensor recover quickly.

[0113] In some embodiments, Figure 1As shown, the leak detection system also includes a tracer gas filling component 4, which includes a gas cylinder 41, a gas filling pipe 42, a pressure reducing valve 43 and an adjustable flow meter 44 arranged on the gas filling pipe 42; wherein, the tracer gas filling component 4 is used to fill the tank container 9 to be inspected with tracer gas, one end of the gas filling pipe 42 is connected to the gas cylinder 41, and the other end is used to connect the tank container 9 to be inspected; the pressure reducing valve 43 is used to reduce the gas pressure output by the gas cylinder 41 to reduce it to the pressure required for filling, and can control the switch of the entire tracer gas filling component 4. The adjustable flow meter 44 is used to control the gas flow and flow rate filled into the tank container 9 to be inspected; the tracer gas is a mixed gas containing 95% nitrogen and 5% hydrogen. In this embodiment, the gas cylinder 41 is a standard tracer gas source, which is mainly used to fill the tank container to be inspected with 1 MPa tracer gas. The gas filling pipe 42 is a Teflon pressure-resistant pipe, which is used to connect the pressure reducing valve and the flow meter. The adjustable flow meter 44 is a flow meter that can adjust the gas flow and flow rate, and is used to control the gas flow and flow rate filled into the tank.

[0114] In actual use, the process of filling the tank container 9 to be inspected with tracer gas can be completed in the detection chamber 21 or outside the detection chamber 21. In order to improve the automation function, the tracer gas filling component 4 can also be connected to the detection chamber 21 using a dedicated pipe or joint, and a certain length of the gas filling pipe 42 is left in the detection chamber 21. As long as the gas filling pipe 42 is connected to the tank container 9 to be inspected, the function of completing the gas filling in the detection chamber 21 can be realized by controlling the valve.

[0115] In some embodiments, the leak detection system further includes a sensor driving circuit and an acquisition circuit. Figure 6 Schematic diagram of the composition of the functional circuit of the leakage detection system in one embodiment of the present invention. Figure 7 The figure is a schematic diagram of the composition of the power supply circuit of the leakage detection system in one embodiment of the present invention.

[0116] The sensor driving circuit is used to provide a driving voltage to the sensor chip 112 and collect the current fed back by the sensor chip 112. In this embodiment, the sensor driving circuit has two main functions: one is to provide a driving voltage to the carbon nanotube field effect transistor hydrogen sensor chip and collect the current fed back, and after analysis by the algorithm program, the detection data is displayed and output through the host computer. The second is to provide an adjustable voltage for the gas collection system to control the gas flow rate sucked by the pump.

[0117] The acquisition circuit includes an MCU microcontroller unit, a crystal oscillator peripheral circuit, a buck circuit, a DAC output circuit, an ADC sensor acquisition circuit, a PWM air pump control circuit, a voltage source module, a signal filtering module and a constant voltage module.

[0118] The MCU micro control unit and the crystal oscillator peripheral circuit include a control circuit that leads from each IO port of the MCU to each module and a drive circuit that provides a drive voltage for the MCU.

[0119] The step-down circuit is used to reduce the fixed voltage provided by the voltage source module to the operating voltage required by various components and sensors.

[0120] The DAC output circuit includes an output bias voltage circuit and an output control voltage circuit, which are used to provide a bias voltage and a control voltage to the sensor chip 112, respectively. In this embodiment, the DAC output circuit refers to the peripheral circuit of the DAC digital-to-analog converter, which converts the digital signal into an analog signal and outputs it to the voltage output circuit of each component. The DAC output circuit is divided into an output bias voltage circuit and an output control voltage circuit, which provide a bias voltage and a control voltage to the sensor, respectively, to ensure that the carbon nanotube field effect transistor hydrogen sensor chip operates within the optimal operating voltage range.

[0121] The ADC sensor acquisition circuit is used to collect the output current of the sensor chip 112 and convert the analog signal into a digital signal; in this embodiment, the ADC sensor acquisition circuit refers to the peripheral circuit of the ADC analog-to-digital converter, which is a data acquisition circuit that converts the analog signal into a digital signal by collecting the sensor output current. The main function of the ADC sensor acquisition circuit is to collect the changing current fed back from the sensor end, which is read by the MCU, analyzed and processed by the algorithm, and finally the detected gas concentration is displayed and output on the host computer.

[0122] The PWM air pump control circuit is used to provide a voltage of 0V-5V to the air pump by adjusting the duty cycle of the high level in the pulse period, so as to achieve gas flow control of the air pump from 0L / min-5L / min.

[0123] The voltage source module is used to supply power to the sensor chip 112 driving circuit through an external 220V mains power supply and a voltage step-down and voltage stabilization circuit; the voltage source module can also be a battery connected to a rated voltage.

[0124] The signal filter module refers to a filter circuit composed of a series of capacitors, inductors, and resistors, and its main function is to filter noise signals and stabilize reference signals; the constant voltage module refers to a module composed of a DAC output circuit and a voltage stabilization circuit that provides a constant voltage for the sensor. Since the voltage of the sensor changes with the gas environment during operation, in order to ensure that the sensor stably outputs effective signals, a constant voltage needs to be provided to the sensor input. This module is connected to an operational amplifier at the output of the sensor, and the operational amplifier clamps the input and output voltages of the sensor. The DAC output circuit provides a driving voltage for the operational amplifier, and the sensor input is amplified and followed by the operational amplifier, thereby providing a constant potential difference for the sensor to drive the sensor to work.

[0125] In a second aspect, the present invention provides a leak detection method, the implementation of which is based on the above leak detection system. Figure 8 The flowchart of the leak detection method in one embodiment of the present invention comprises the following steps:

[0126] The tracer gas filling assembly 4 is used to fill the interior of the tank container 9 to be inspected with a mixed gas containing 95% nitrogen and 5% hydrogen at a set pressure, and then the tank container 9 to be inspected is placed in the detection chamber 21 and the hatch structure of the detection chamber 21 is closed; the setting of this gas mixture can ensure that hydrogen is easy enough to detect when it leaks, because hydrogen is a very light and easily diffused gas. The set pressure is generally positive pressure, that is, greater than or equal to atmospheric pressure. By setting a suitable pressure, it is ensured that the mixed gas exists stably in the tank container 9 to be inspected, and a reliable gas source is provided for subsequent leak detection.

[0127] The electromagnetic valve 33 is controlled to remain closed, and the fan 24 and the circulating air pump 23 of the detection chamber 21 are controlled to start; the purpose is to promote the uniform distribution and flow of gas in the detection chamber 21. In this way, it can be ensured that the hydrogen leaked from the container to be inspected quickly enters the chamber and is evenly distributed, thereby improving the detection speed.

[0128] After setting the mixing time, the electromagnetic valve 33 is controlled to open, and the collection air pump 31 of the tracer gas collection component 3 is controlled to open, so that the hydrogen leaked from the tank container 9 to be inspected can be detected by adsorbing the carbon nanotube field effect transistor hydrogen sensor chip; the sensor has a high sensitivity to hydrogen and can accurately detect hydrogen leakage at very low concentrations.

[0129] After the detection is completed, the hatch structure of the detection chamber 21 is opened, and the mixed gas in the detection chamber 21 is evacuated by using the gas collection pump 31 of the tracer gas collection assembly 3, and the carbon nanotube field effect transistor hydrogen sensor chip enters the recovery phase. The recovery phase can remove the residual gas on the sensor to ensure the long-term stability and accuracy of the sensor.

[0130] In the above embodiment, since the detector can respond even when the concentration of hydrogen in the air is extremely low, the use of a carbon nanotube field effect transistor hydrogen sensor chip can achieve high-sensitivity detection of hydrogen leaks. This chip can respond quickly to low-concentration hydrogen, thereby improving the accuracy and efficiency of the leak detection process. The cooperation of the fan 24 and the circulating air pump 23 ensures that the gas in the detection chamber 21 is evenly distributed throughout the space, thereby avoiding missed detections due to thin gas in certain areas. This helps to improve the overall detection sensitivity and accuracy. The evacuation and recovery steps can prevent gas from being retained in the chamber, thereby avoiding affecting subsequent detection. Especially for flammable gases such as hydrogen, evacuation work also helps to improve the safety of operation.

[0131] In some embodiments, Fig.10 As shown, the steps of detecting hydrogen concentration by the carbon nanotube field effect transistor hydrogen sensor chip include:

[0132] After the device is turned on, determine whether the detection reference value of the carbon nanotube field effect transistor hydrogen sensor chip is within the set range; this step is to ensure that the initial state of the sensor chip is normal and meets the predetermined operating conditions. If the reference value is not within the valid range, it indicates that there may be a problem with the state of the sensor chip or the environmental conditions are not suitable, and adjustment or recalibration is required.

[0133] If so, the carbon nanotube field effect transistor hydrogen sensor chip is preheated for one minute, and the baseline average value within one minute is taken to determine whether the baseline average value is within the effective range of the blank environment; the preheating process can help the sensor reach the working state, ensure that it can operate stably and reduce environmental impact. The baseline average value will be compared with the effective range under the blank environment. If the baseline value is within the effective range, it means that the sensor is not affected by external interference and is in a stable state.

[0134] If yes, the reference average value is assigned and calibrated as the zero point; this step indicates that the system has successfully calibrated the sensor and considers the hydrogen concentration at this time to be zero or the environment to be the air background concentration. The purpose of calibrating the zero point is to ensure the accuracy of subsequent detection, that is, the sensor can measure the hydrogen concentration from a known standard starting point.

[0135] During the hydrogen detection process, the current value of the carbon nanotube field effect transistor hydrogen sensor chip is updated in real time, with 5 seconds as a group;

[0136] When the current value is inversely proportional to time, it is determined that hydrogen is detected, and this set of data is substituted into the calibrated formula to calculate the current hydrogen concentration value; when the current value is proportional to time, it is determined that the carbon nanotube field effect transistor hydrogen sensor chip has entered the recovery stage.

[0137] In the above embodiment, the sensor is ensured to work in an accurate initial state by preliminarily judging the reference value, preheating, calculating the reference average value, etc. The relationship between the current value and time is used to determine whether hydrogen is detected, and the concentration is calculated using a calibrated formula. The sensor is judged to enter the recovery phase based on the trend of the current value to ensure that the system can be reset normally and perform subsequent measurements.

[0138] In the above embodiment, the gas-electric dual-path transmission line is composed of a plurality of metal cables and a gas pipeline bundle, each of the metal cables inside is individually made of an electromagnetic interference shielding metal mesh to ensure that the signal lines do not interfere with each other. After the cables are bundled, the outermost layer has a total shielding metal mesh to isolate external signal interference. The internal signal shielding mesh is led out and connected to the metal shell and grounding wire of the sealed joint. The sealed joint grounding wire is connected to the 220V AC ground wire to form a complete shielding mesh to ensure the stability of the sensor readout signal while reducing noise.

[0139] The leak detection system and method in the embodiment of the present invention mainly utilize the ultra-high detection capability of the carbon nanotube field effect transistor hydrogen sensor chip for hydrogen, and detect the leaked hydrogen by filling a mixed gas of 95% nitrogen and 5% hydrogen in the tank container to realize the detection of the leak hole of the entire tank body; the present invention is based on a high-sensitivity carbon nanotube field effect transistor hydrogen sensor, and cooperates with a leak detection studio, by filling the tank container to be inspected with nitrogen-hydrogen mixed gas, and accurately detecting the leakage rate of the tank container through sensors and signal processing algorithms. The leak detection system and method in the embodiment of the present invention are particularly suitable for the fields of sealed leak detection such as aerospace, power fuel storage, etc.

[0140] Corresponding to the above method, the present invention also provides an apparatus / system, which includes a computer device, the computer device includes a processor and a memory, the memory stores computer instructions, the processor is used to execute the computer instructions stored in the memory, and when the computer instructions are executed by the processor, the apparatus / system implements the steps of the above leakage detection method.

[0141] The embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the aforementioned leak detection method are implemented. The computer-readable storage medium can be a tangible storage medium, such as a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a floppy disk, a hard disk, a removable storage disk, a CD-ROM, or any other form of storage medium known in the technical field.

[0142] It should be understood by those skilled in the art that the exemplary components, systems and methods described in conjunction with the embodiments disclosed herein can be implemented in hardware, software or a combination of the two. Whether it is performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention. When implemented in hardware, it can be, for example, an electronic circuit, an application specific integrated circuit (ASIC), appropriate firmware, a plug-in, a function card, etc. When implemented in software, the elements of the present invention are programs or code segments used to perform the required tasks. The program or code segment can be stored in a machine-readable medium, or transmitted on a transmission medium or a communication link via a data signal carried in a carrier.

[0143] It should be clear that the present invention is not limited to the specific configuration and processing described above and shown in the figures. For the sake of simplicity, a detailed description of the known method is omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of the present invention is not limited to the specific steps described and shown, and those skilled in the art can make various changes, modifications and additions, or change the order between the steps after understanding the spirit of the present invention.

[0144] In the present invention, features described and / or illustrated for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with features of other embodiments or replace features of other embodiments.

[0145] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the embodiments of the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A leak detection system, characterized in that: The leak detection system comprises a tracer gas detection probe (1), a tracer gas collection component (3) and a detection chamber component (2); The detection chamber assembly (2) comprises a detection chamber (21), the detection chamber (21) having a hatch structure for loading or removing a tank container (9) to be inspected filled with tracer gas, the hatch structure being closed in a detection state; the top of the detection chamber (21) also has a gas outlet (211); The tracer gas collection assembly (3) comprises a collection pipeline (32), an electromagnetic gas valve (33) and a collection gas pump (31); the collection gas pump (31) collects gas by pumping through the collection pipeline (32); one end of the electromagnetic gas valve (33) is installed at the gas outlet (211) position, and the other end is connected to one end of the tracer gas detection probe (1); and the other end of the tracer gas detection probe (1) is connected to the collection pipeline (32); The tracer gas detection probe (1) has an airflow channel for the tracer gas to pass through, and the tracer gas detection probe (1) comprises a sensor chip (112) for detecting the tracer gas, wherein the sensor chip (112) is arranged in the airflow channel.

2. The leak detection system according to claim 1, characterized in that: The sensor chip (112) comprises any one of a carbon nanotube field effect transistor hydrogen sensor chip, a semiconductor hydrogen sensor, an electrochemical hydrogen sensor, a catalytic combustion hydrogen sensor, a palladium alloy thin film hydrogen sensor and a MEMS hydrogen sensor; The tracer gas detection probe (1) further comprises a substrate (111), wherein the substrate (111) comprises any one of a silicon oxide substrate, a silicon wafer, ceramics, a PCB, an FPC and quartz glass; When the sensor chip (112) adopts the carbon nanotube field effect transistor hydrogen sensor chip, the carbon nanotube field effect transistor hydrogen sensor chip is bonded to a set area of ​​the substrate (111), and the chip pad is connected to the substrate (111) pad via a gold wire (113); the area on the substrate (111) where the gold wire (113) is located is coated with a resin layer.

3. The leak detection system according to claim 2, characterized in that: The tracer gas detection probe (1) further comprises a circuit board, the substrate (111) is connected to the circuit board via a quick-insert connector (114), and the quick-insert connector (114) comprises any one of a Type-C connector, a Type-A connector, a 232 connector, and a 485 connector; The circuit board comprises an upper circuit board (115) and a lower circuit board (116); the upper circuit board (115) is connected to the substrate (111) via a quick-insert connector (114); the lower circuit board (116) is used to be connected to a first sealing connector (118); the upper circuit board (115) and the lower circuit board (116) are fixedly connected via a pin header (117); An air flow channel is formed between the upper circuit board (115) and the lower circuit board (116); The tracer gas detection probe (1) further comprises a signal line, the signal line is connected to the circuit board, the signal line comprises at least two channels, and each channel line is provided with a metal isolation layer.

4. The leak detection system according to claim 3, characterized in that: The tracer gas detection probe (1) further comprises a probe housing (121), the probe housing (121) being a hollow cylindrical structure and being used for mounting the circuit board, the substrate (111) and the carbon nanotube field effect transistor hydrogen sensor chip therein; a filter (122) connection portion is formed at a first end of the probe housing (121), and a collection pipe (32) connection portion is formed at a second end; The tracer gas detection probe (1) further comprises a joint fixing ring (123), wherein the joint fixing ring (123) is used to be installed at a connection portion of the collection pipe (32) of the probe housing (121) so as to install a second sealing joint of the collection pipe (32) at a second end of the probe housing (121); The tracer gas detection probe (1) further comprises a filter (122), wherein the filter (122) comprises a filter (122) housing, and a first fixed layer (1221), a first dust filter layer (1222), a first waterproof breathable membrane (1223), an activated carbon particle layer (1224), a second waterproof breathable membrane (1225), and a second fixed layer (1226) which are arranged in the filter (122) housing and are arranged layer by layer along the airflow direction; The filter (122) is connected to the filter (122) connection portion of the probe housing (121) via threads.

5. The leak detection system according to claim 1, characterized in that: The top of the detection chamber (21) is a narrowed inverted funnel-shaped structure, and the gas outlet (211) is located at the center of the top of the inverted funnel-shaped structure; The detection chamber assembly (2) further comprises an internal circulation pipeline (22), a circulation air pump (23) and a fan (24), which are used to evenly diffuse the tracer gas leaking from the tank container (9) to be inspected in the detection chamber (21); One end of the inner circulation pipe (22) is connected to the upper middle part of the detection chamber (21), and the other end is connected to the lower part of the detection chamber (21); the circulation air pump (23) is arranged on the inner circulation pipe (22), and the fan (24) is arranged at the bottom of the detection chamber (21).

6. The leak detection system according to claim 5, characterized in that: The collection pipeline (32) is a dual-path transmission pipeline for gas and electricity, and its material is Teflon; the collection air pump (31) adopts a PWM air pump.

7. The leak detection system according to claim 5, characterized in that: The leak detection system further comprises a tracer gas charging assembly (4), wherein the tracer gas charging assembly (4) comprises a gas cylinder (41), a gas charging pipeline (42), and a pressure reducing valve (43) and an adjustable flow meter (44) arranged on the gas charging pipeline (42); The tracer gas charging assembly (4) is used to charge the tank container (9) to be inspected with the tracer gas, one end of the charging pipe (42) is connected to the gas cylinder (41), and the other end is used to connect to the tank container (9) to be inspected; The pressure reducing valve (43) is used to reduce the pressure of the gas output from the gas cylinder (41) to the pressure required for charging; The adjustable flow meter (44) is used to control the flow rate and flow velocity of the gas filled into the tank container (9) to be inspected; The tracer gas is a mixed gas containing 95% nitrogen and 5% hydrogen.

8. The leak detection system according to any one of claims 1 to 7, characterized in that: The leak detection system also includes a sensor driving circuit and a collection circuit; The sensor driving circuit is used to provide a driving voltage to the sensor chip (112) and collect the current fed back by the sensor chip (112); The acquisition circuit includes an MCU microcontroller unit, a crystal oscillator peripheral circuit, a buck circuit, a DAC output circuit, an ADC sensor acquisition circuit, a PWM air pump control circuit, a voltage source module, a signal filtering module and a constant voltage module; The MCU microcontroller unit and the crystal oscillator peripheral circuit include a control circuit that leads from each IO port of the MCU to each module and a drive circuit that provides a drive voltage for the MCU; The step-down circuit is used to reduce the fixed voltage provided by the voltage source module to the working voltage required by various components and sensors; The DAC output circuit comprises an output bias voltage circuit and an output control voltage circuit, which are used to provide a bias voltage and a control voltage to the sensor chip (112) respectively; The ADC sensor acquisition circuit is used to collect the output current of the sensor chip (112) and convert the analog signal into a digital signal; The PWM air pump control circuit is used to provide a voltage of 0V-5V to the air pump by adjusting the duty cycle of the high level in the pulse period; The voltage source module is used to supply power to the sensor chip (112) driving circuit through an external 220V mains power supply and a voltage step-down and voltage stabilization circuit; The signal filtering module is used to filter noise signals and stabilize reference signals; The constant voltage module is used to provide a constant voltage to the sensor chip (112).

9. A leak detection method, characterized in that: The implementation of the leak detection method is based on the leak detection system described in any one of claims 1 to 8, and the method comprises the following steps: Using the tracer gas filling assembly, a mixed gas containing 95% nitrogen and 5% hydrogen at a set pressure is filled into the interior of the tank container to be inspected, and then the tank container to be inspected is placed in the inspection chamber and the hatch structure of the inspection chamber is closed; Control the electromagnetic air valve to remain closed, and start the fan and circulating air pump in the test chamber; After the mixing time is set, the electromagnetic valve is controlled to open, and the collection pump of the tracer gas collection component is controlled to start, so that the hydrogen leaked from the tank container to be inspected passes through the carbon nanotube field effect transistor hydrogen sensor chip and completes the detection; After the detection is completed, the hatch structure of the detection chamber is opened, the mixed gas in the detection chamber is emptied by the collection gas pump of the tracer gas collection assembly, and the carbon nanotube field effect transistor hydrogen sensor chip enters the recovery stage.

10. The leak detection method according to claim 9, characterized in that: The steps of detecting hydrogen concentration by the carbon nanotube field effect transistor hydrogen sensor chip include: After the device is turned on, it is determined whether the detection reference value of the carbon nanotube field effect transistor hydrogen sensor chip is within the set range; If yes, preheat the carbon nanotube field effect transistor hydrogen sensor chip for one minute, take the benchmark average value within one minute, and determine whether the benchmark average value is within the valid range of the blank environment; If yes, assign a value to the reference average value and calibrate it to zero point; During the hydrogen detection process, the current value of the carbon nanotube field effect transistor hydrogen sensor chip is updated in real time, with 5 seconds as a group; When the current value is inversely proportional to the time, it is determined that hydrogen is detected, and the data is put into the calibrated formula to calculate the current hydrogen concentration value; When the current value is proportional to the time, it is determined that the carbon nanotube field effect transistor hydrogen sensor chip has entered the recovery stage.

Images