Nitromethane leakage detection method and device

Abstract

The invention relates to the technical field of nitromethane leakage detection, in particular to a nitromethane leakage detection method and device. Comprising the following steps: SS01, presetting a nitromethane leakage detection device, moving the nitromethane leakage detection device to a detection area, starting a system by a microcontroller, resetting a rotating stand to enable a detection system to be aligned with a station, and establishing wireless data connection between a detection probe and the microcontroller; the flow dividing system extracts to-be-detected gas filtered by the filter element, the detection probe comprehensively detects and collects the gas in a composite motion mode, data are transmitted to the microcontroller in real time, and the cleaning brush ring synchronously cleans the detection probe. Through the innovative design of four-station circulating layout, linkage of the rotating stand and the detection system and gas circuit isolation of the flow dividing system, a cooperative and efficient detection mechanism is formed.

Description

Technical Field

[0001] This invention relates to the field of nitromethane leakage detection technology, specifically to a method and apparatus for detecting nitromethane leakage. Background Technology

[0002] Nitromethane, a commonly used chemical raw material in industrial production, storage, and transportation, is flammable, explosive, and toxic. If its leakage is not detected promptly and accurately, it can easily lead to serious accidents such as fires, explosions, poisoning of personnel, and environmental pollution. Therefore, efficient and accurate detection of nitromethane leaks is of significant practical importance. However, current technologies in the field of nitromethane leak detection still face many technical challenges in practical applications. Existing nitromethane leak detection devices mostly adopt a single-station step-by-step operation mode. That is, the same detection system must complete the process of gas collection, accuracy calibration, residual exhaust, and equipment cleaning in sequence. Only after completing one detection cycle can it enter the next round of collection. This results in a low detection frequency per unit time, which is difficult to meet the real-time and continuous monitoring needs of leaks in industrial scenarios. At the same time, due to the lack of effective gas path isolation design in the single station, the collected test gas, the standard nitromethane gas used for calibration, and the cleaning gas are prone to remain and mix with each other inside the detection system, forming cross-interference. For example, the test gas remaining from the previous round of detection may mix into the calibration gas in the next round, causing the detection value during calibration to deviate too much from the preset concentration value, making it impossible to accurately calibrate the probe sensitivity. On the other hand, the residual cleaning gas may dilute the concentration of the test gas, causing the collected leak data to be distorted, which seriously affects the reliability of the detection results. Taking the existing portable nitromethane detector as an example, each test requires manual extraction of the gas to be tested. After the test is completed, the probe needs to be disassembled for cleaning and then reinstalled to inject standard gas for calibration. The whole process takes more than 15 minutes. If the cleaning is not thorough, the gas components remaining on the probe surface will directly affect the next test data. In scenarios with multiple batches and high frequency of testing, this problem is more prominent, making it difficult to guarantee the accuracy of the test data and the testing efficiency. Based on this, the present invention provides a method and apparatus for detecting nitromethane leakage to solve the problems mentioned in the background art. Summary of the Invention

[0003] This invention addresses the technical problems existing in the prior art by providing a method and apparatus for detecting nitromethane leakage.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is: a method for detecting nitromethane leakage, comprising the following steps: SS01. A nitromethane leak detection device is preset. The nitromethane leak detection device is moved to the detection area. The microcontroller starts the system. The rotating frame is reset so that the detection system is aligned with the workstation. The detection probe establishes a wireless data connection with the microcontroller. SS02, the rotating frame drives the detection system into the acquisition station, the diversion system extracts the gas to be tested after being filtered by the filter element, the detection probe comprehensively detects the collected gas in a compound motion mode, the data is transmitted to the microcontroller in real time, and the cleaning brush ring cleans the detection probe in sync. SS03. The rotating frame drives the detection system into the calibration station, injects nitromethane gas of a preset concentration, compares the detection value of the detection probe with the preset value, and calibrates the sensitivity of the detection probe. SS04. Empty and remove residual gas samples from a nitromethane leak detection device in preparation for the next round of sampling; SS05. A nitromethane leak detection device operates in a cyclical manner, with a microcontroller storing data and automatically issuing an early warning and generating a report when the level exceeds the limit.

[0005] A nitromethane leak detection device for implementing the nitromethane leak detection method described above includes a frame, on which a sampling station, a calibration station, an exhaust station and an injection station are arranged sequentially in a clockwise direction. The frame is equipped with a transmission system, a diversion system and a rotatable rotating frame, on which four detection systems are installed. Each detection system includes a collection cylinder mounted on a rotating frame and a hollow shaft rotatably connected to the rotating frame. A vibration guide system is connected to the hollow shaft, and a vibrating frame that can vibrate up and down and a rotatable collection shaft are connected to the vibration guide system. The collection shaft is rotatably mounted on the vibrating frame, and the reciprocating stroke and reciprocating frequency of the vibrating frame change alternately. A mounting frame is provided at the bottom of the collection shaft and at a position corresponding to the inside of the collection cylinder. A collection rotating seat is rotatably mounted at the eccentric position of the mounting frame. A lower gear is mounted on the collection rotating seat. A cleaning brush ring and a lower gear ring that meshes with the lower gear are provided on the inner wall of the collection cylinder. A detection probe is mounted on the collection rotating seat. The transmission system drives the hollow shaft to rotate at a first speed at the data acquisition station and the verification station, and at a second speed at the exhaust station and the air injection station; The flow splitting system drives the gas to be tested to flow unidirectionally into the collection tube, drives nitromethane gas of a preset concentration to flow unidirectionally into the collection tube at the calibration station, drives clean gas flow into the collection tube at the exhaust station and discharges unidirectionally, and drives inert gas into the collection tube at the injection station and discharges unidirectionally.

[0006] As a preferred technical solution of the present invention, the vibration guiding system includes a first belt shaft and a second belt shaft rotatably connected to the rotating frame. A spline shaft is installed at the top of the acquisition shaft. A spline groove with open ends and slidably connected to the spline shaft is fixedly opened inside the hollow shaft. The cross-section of the spline groove and the spline shaft are both regular hexagonal. The first belt shaft and the second belt shaft are both linked with the hollow shaft. A rotating wheel is installed on the second belt shaft. Two sector tooth segments and two hollow tooth segments are alternately arranged on the rotating wheel. The vibration frame is slidably connected to the rotating frame. A spring is installed on the bottom surface of the vibration frame. The other end of the spring is fixedly connected to the rotating frame. A rack plate is installed on the vibration frame. The two sector tooth segments alternately mesh with the rack plate.

[0007] As a preferred technical solution of the present invention, a first bevel gear is installed on both the first belt shaft and the hollow shaft, the two first bevel gears mesh orthogonally, and pulleys are installed on both the first belt shaft and the second belt shaft, and a first synchronous toothed belt is connected between the two pulleys.

[0008] As a preferred technical solution of the present invention, the central angle of one sector tooth segment is 40°, the central angle of the other sector tooth segment is 60°, the central angles of the two empty tooth segments are both 130°, and a rubber buffer coating is provided on both the sector tooth segment and the rack plate, the thickness of the rubber buffer coating being 0.35mm.

[0009] As a preferred embodiment of the present invention, the transmission system includes four gear shafts rotatably connected to the inspection frame. The positions of the four gear shafts correspond to the positions of the sampling station, the verification station, the exhaust station, and the gas injection station, respectively. A rotating cylinder is rotatably mounted on the inspection frame, and a driving gear ring is installed on the rotating cylinder. Each gear shaft is equipped with a driven gear that meshes with the driving gear ring. Low-ratio internal gears are installed on the gear shafts in the sampling station and the verification station, and high-ratio internal gears are installed on the gear shafts in the exhaust station and the gas injection station. A low-ratio external gear that meshes with the low-ratio internal gear and a high-ratio external gear that meshes with the high-ratio internal gear are respectively installed on the hollow shaft. Two servo motors are installed on the inspection frame, and the output shafts of the two servo motors are drivenly connected to a second synchronous toothed belt. The two second synchronous toothed belts are drivenly connected to the rotating frame and the rotating cylinder, respectively.

[0010] As a preferred technical solution of the present invention, the radius of the low-speed ratio external gear is 3 to 5 times the radius of the low-speed ratio internal gear, the radius of the high-speed ratio external gear is 1.1 to 1.5 times the radius of the high-speed ratio internal gear, and the second rotational speed is 2.0 to 4.55 times the first rotational speed.

[0011] As a preferred technical solution of the present invention, the diversion system includes a top cylinder, a bottom cylinder, and a tail gas collection pipe installed on the test rack. The top cylinder has two mutually isolated exhaust channels with open bottom ends. Both exhaust channels are connected to the tail gas collection pipe through a first one-way exhaust valve. The bottom cylinder has a collection chamber, a calibration chamber, an exhaust chamber, and an injection chamber. The bottom cylinder has four valve holes that are connected to the collection chamber, calibration chamber, exhaust chamber, and injection chamber, respectively. Valve cylinders are rotatably installed on both the top and bottom cylinders. The inlet port of the collection cylinder is connected to the valve cylinder on the bottom cylinder, and the outlet port of the collection cylinder is connected to the valve cylinder on the top cylinder. The test rack is equipped with a nitromethane storage tank, a clean gas storage tank, and an inert gas storage tank. The nitromethane storage tank is connected to the calibration chamber, the clean gas storage tank is connected to the exhaust chamber, and the inert gas storage tank is connected to the injection chamber. A collection pipe is connected to the collection chamber, and a filter element is installed at the end of the collection pipe.

[0012] As a preferred technical solution of the present invention, the positions of the two exhaust channels correspond to the positions of the exhaust station and the gas injection station, respectively. The positions of the collection chamber, the calibration chamber, the exhaust chamber, and the gas injection chamber correspond to the positions of the collection station, the calibration station, the exhaust station, and the gas injection station, respectively. A second one-way exhaust valve and a solenoid valve are provided at the connection between the nitromethane storage tank and the calibration chamber, the connection between the clean gas storage tank and the exhaust chamber, and the connection between the inert gas storage tank and the gas injection chamber. An axial flow fan is installed in both the collection pipe and the tail gas collection pipe. A tail gas storage tank connected to the tail gas collection pipe is installed on the test rack.

[0013] As a preferred technical solution of the present invention, a microcontroller is installed on the inspection rack, and four omnidirectional casters are installed on the bottom surface of the inspection rack. The data terminal of each detection probe is connected to the microcontroller via a wireless signal. The inner wall of the cleaning brush ring is evenly covered with rubber bristles, and the central angle corresponding to the cleaning brush ring is 180°.

[0014] This invention has beneficial effects: 1. Aiming at the problems in the prior art that the single-station step-by-step operation leads to low detection efficiency and the lack of air circuit isolation causes gas cross-interference, the present invention forms a collaborative and efficient detection mechanism through innovative designs such as a four-station circular layout, a turntable, the linkage of the detection system, and the air circuit isolation of the shunt system. First, the inspection rack is arranged clockwise with four functionally independent stations: collection, calibration, exhaust, and cleaning. The four detection systems installed on the turntable rotate synchronously under the drive of a double servo motor. The turntable drives the detection system to enter each station in turn. At the same time, the rotating cylinder drives the corresponding tooth shaft of the station through the driving gear ring to achieve the automatic linkage of station switching and power adaptation. This design enables the four detection systems to complete the collection, calibration, exhaust, and cleaning processes in parallel, breaking the limitation that the traditional single station needs to complete one cycle before entering the next round. The existing portable detector requires more than 15 minutes for a single detection, while the present invention through the four-station cycle can increase the detection frequency by 3 - 4 times per unit time, greatly meeting the real-time monitoring requirements of industrial scenarios. At the same time, the shunt system through the precise cooperation of the top cylinder, bottom cylinder, and valve cylinder realizes the automatic isolation and switching of the air circuit. When collecting, it is docked with the collection chamber to extract the待测气体 (to-be-detected gas), when calibrating, it is switched to the calibration chamber to inject the standard gas, when exhausting and cleaning, it is respectively docked with the exhaust chamber and the gas injection chamber, and each air circuit is equipped with a one-way valve to prevent backflow, avoiding the cross-residue of the to-be-detected gas, calibration gas, and cleaning gas.

[0015] 2. Aiming at the problems in the prior art that the fixed probe or single-trajectory probe has collection dead angles and the probe cleaning requires interrupting the detection, the present invention constructs a collaborative mechanism for all-round collection and real-time cleaning through the designs of the composite movement of the detection system, the linkage of the vibration guide system, and the synchronous cleaning structure. Under the drive of the vibration guide system, the hollow shaft drives the first belt shaft to rotate through the first bevel gear meshing orthogonally, and then it is transmitted to the second belt shaft through the first synchronous belt. The 40° and 60° fan-shaped tooth segments on the runner alternately mesh with the rack plate to push the vibration rack to slide up and down. At the same time, the regular hexagon spline shaft at the top of the collection shaft slides配合 (cooperates) with the regular hexagon spline groove of the hollow shaft, enabling the collection shaft to vibrate up and down synchronously with the vibration rack while rotating with the hollow shaft. This linkage design of rotational power transmission and axial sliding adaptation realizes the composite movement of the collection probe vibrating up and down and eccentrically rotating through only one set of transmission structures, covering the collection dead angles of the traditional fixed probe or single straight-line movement probe, and increasing the gas contact rate inside the collection cylinder. In addition, the cleaning brush ring with a 180° central angle on the inner wall of the collection cylinder is precisely adapted to the movement trajectory of the collection probe. During the collection process, the rubber bristles of the cleaning brush ring wipe the surface of the probe synchronously with the rotation of the probe, not only avoiding the detection interruption caused by the traditional cleaning after collection, but also not interfering with the contact between the probe and the gas due to the 180° central angle design, solving the contradiction between cleaning and collection.

[0016] 3. Addressing the problems of existing technologies where gas path switching relies on manual valves, is prone to backflow, and results in direct exhaust pollution, this invention constructs a high-precision, leak-proof, and environmentally friendly gas path control system through the coordinated design of a diversion system, solenoid valves, check valves, and an exhaust gas collection system. Rotatable valve cylinders are installed on both the top and bottom cylinders of the diversion system. When the rotating frame drives the collection cylinder to rotate, the valve cylinder automatically connects to the corresponding gas chamber in the bottom cylinder and the exhaust channel in the top cylinder. Combined with the precise control of the solenoid valves, automatic gas path switching is achieved without manual operation. Furthermore, a second check valve is installed at the connection points between the nitromethane storage tank, the clean gas storage tank, the inert gas storage tank, and the corresponding gas chamber. The exhaust valve and top cylinder exhaust channel are connected to the tail gas collection pipe through the first one-way exhaust valve to prevent gas backflow and avoid the problem of the test gas contaminating the standard gas and the clean gas flowing back into the collection pipeline. In addition, the axial flow fan in the collection pipe and the tail gas collection pipe forms an airflow drive, so that the test gas flows in efficiently and the residual gas and waste gas are discharged quickly. Finally, the exhaust gas is collected and treated centrally through the tail gas storage tank. Compared with the defects of direct discharge or incomplete collection of waste gas in the prior art, the present invention achieves zero direct discharge of nitromethane waste gas, which meets environmental protection requirements. At the same time, the filter element at the end of the collection pipe can filter dust impurities in the test gas, avoid probe contamination, and further ensure detection accuracy. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of a nitromethane leak detection device; Figure 2 for Figure 1 A magnified schematic diagram of the partial structure at point A in the middle; Figure 3 This is a schematic diagram of the cross-sectional structure of the exhaust gas collection pipe and filter element; Figure 4 for Figure 3 A magnified view of the structure at point B in the middle; Figure 5 for Figure 3 A magnified schematic diagram of the local structure at point C; Figure 6 This is a schematic diagram of the rotating cylinder and the driving gear ring. Figure 7 A schematic diagram of the rack and pinion structure; Figure 8 This is a schematic diagram of the hollow tooth section and the second belt shaft. Figure 9 This is a schematic diagram of the gear shaft structure; Figure 10 This is a schematic diagram of the exploded structure of the top and bottom cylinders.

[0018] The attached diagram lists the components represented by each number as follows: 1. A nitromethane leak detection device; 2. Detection frame; 3. Rotating frame; 4. Collection cylinder; 5. Hollow shaft; 6. Vibration frame; 7. Collection shaft; 8. Mounting frame; 9. Collection rotating seat; 10. Lower gear; 11. Cleaning brush ring; 12. Lower gear ring; 13. Detection probe; 14. First belt shaft; 15. Second belt shaft; 16. Splined shaft; 17. Rotating wheel; 18. Sector gear section; 19. Hollow gear section; 20. Spring; 21. Rack plate; 22. Gear shaft; 23. Rotating cylinder; 24. Driving gear ring; 25. Driven gear; 26. Low-speed ratio internal gear; 27. High-speed ratio internal gear; 28. Low-speed ratio external gear; 29. ​​High-speed ratio external gear; 30. Servo motor; 31. Bottom cylinder; 32. Exhaust gas collection pipe; 33. Exhaust flow channel; 34. Collection chamber; 35. Calibration chamber; 36. Exhaust chamber; 37. Injection chamber; 38. Valve orifice; 39. Valve cylinder; 40. Nitromethane storage tank; 41. Clean gas storage tank; 42. Inert gas storage tank; 43. Collection pipe; 44. Filter element; 45. Exhaust gas storage tank; 46. Microcontroller; 47. Top cylinder. Detailed Implementation

[0019] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0020] The present invention provides the following preferred embodiments. A method for detecting nitromethane leaks includes the following steps: SS01. A nitromethane leak detection device 1 is preset. The nitromethane leak detection device 1 is moved to the detection area. The microcontroller 46 starts the system. The rotating frame 3 is reset so that the detection system is aligned with the work station. The detection probe 13 establishes a wireless data connection with the microcontroller 46. SS02 and the rotating frame 3 drive the detection system into the collection station. The diversion system extracts the gas to be tested after being filtered by the filter element 44. The detection probe 13 comprehensively detects the collected gas in a compound motion mode. The data is transmitted to the microcontroller 46 in real time. The cleaning brush ring 11 cleans the detection probe 13 in sync. SS03 and the rotating frame 3 drive the detection system into the calibration station, inject nitromethane gas of a preset concentration, compare the detection value of the detection probe 13 with the preset value, and calibrate the sensitivity of the detection probe 13. SS04. Empty and remove residual gas samples from a nitromethane leak detection device 1 to prepare for the next round of sampling; SS05, A nitromethane leak detection device 1 operates in a cyclic manner, with a microcontroller 46 storing data and automatically issuing an early warning and generating a report when the limit is exceeded.

[0021] like Figure 1-10As shown, a nitromethane leak detection device for implementing the nitromethane leak detection method described above includes a frame 2, on which a microcontroller 46 is installed, and four omnidirectional casters are installed on the bottom surface of the frame 2. The inspection frame 2 is arranged in a clockwise direction with a collection station, a verification station, an exhaust station and an air injection station. The inspection frame 2 is equipped with a transmission system, a flow distribution system and a rotatable rotating frame 3. Four detection systems are installed on the rotating frame 3. The rotating frame 3 drives the four detection systems to enter the data acquisition station, calibration station, exhaust station and air injection station in a clockwise direction in sequence. The rotating cylinder 23 drives the gear shaft 22 of the four corresponding stations to rotate synchronously through the active gear ring 24, realizing the automatic linkage of station switching and transmission adaptation. This structure breaks through the limitations of traditional single-station testing devices that require separate steps for testing, calibration, and cleaning. By operating in a four-station cycle with four testing systems simultaneously, it significantly improves testing efficiency. At the same time, the functions of each station are independently separated, avoiding cross-interference between the gas to be tested, the calibration gas, and the cleaning gas, thus ensuring the accuracy of the test data. Each detection system includes a collection cylinder 4 mounted on a rotating frame 3 and a hollow shaft 5 rotatably connected to the rotating frame 3. A vibration guiding system is connected to the hollow shaft 5, and a vibrating frame 6 and a rotatable collection shaft 7 are connected to the vibration guiding system. The collection shaft 7 is rotatably mounted on the vibrating frame 6. The reciprocating stroke and reciprocating frequency of the vibrating frame 6 change alternately. A mounting frame 8 is provided at the bottom of the collection shaft 7 and at a position corresponding to the inner side of the collection cylinder 4. A collection rotating seat 9 is rotatably mounted at an eccentric position on the mounting frame 8. A lower gear 10 is mounted on the collection rotating seat 9. A cleaning brush ring 11 and a lower gear ring 12 that meshes with the lower gear 10 are provided on the inner wall of the collection cylinder 4. A detection probe 13 is mounted on the collection rotating seat 9. The data terminal of each detection probe 13 is connected to the microcontroller 46 via a wireless signal.

[0022] The axis of the detection probe 13 is parallel to the axis of the acquisition tube 4; The detection probe 13 is an electrochemical sensor with a detection accuracy of ±0.1ppm. The detection probe 13 is used for nitromethane leakage detection. The detection probe 13 can be customized or selected according to actual needs. The inner wall of the cleaning brush ring 11 is evenly covered with rubber bristles, and the central angle of the cleaning brush ring 11 is 180°. When the hollow shaft 5 rotates, it will synchronously drive the vibration guiding system to operate. On the one hand, the vibration guiding system drives the vibrating frame 6 to slide up and down with alternating reciprocating stroke and frequency, and on the other hand, it drives the acquisition shaft 7 to rotate. When the acquisition shaft 7 rotates, the acquisition spindle 9, which is eccentrically set at the bottom mounting bracket 8, will rotate eccentrically due to the meshing of the lower gear 10 and the lower gear ring 12 on the inner wall of the acquisition cylinder 4. This causes the detection probe 13 to move up and down while rotating eccentrically around the axis of the acquisition cylinder 4, making full contact with the gas inside the acquisition cylinder 4. During the acquisition process, the cleaning brush ring 11 will flexibly wipe the surface of the detection probe 13. This structure solves the problem of gas contact dead angle in traditional fixed detection probe 13 by combining up-and-down vibration and eccentric rotation for acquisition, making the acquisition more uniform and the data more representative. The tooth height of the lower gear ring 12 is 10 times that of the lower gear 10, ensuring that the meshing does not disengage when the vibrating frame 6 slides up and down, thus guaranteeing motion stability; The 180° central angle design of the cleaning brush ring 11 achieves a balance between non-interference in data acquisition and thorough cleaning, avoiding the impact of the cleaning structure on data acquisition accuracy. The vibration guiding system includes a first belt shaft 14 and a second belt shaft 15 rotatably connected to the rotating frame 3. A spline shaft 16 is installed at the top of the acquisition shaft 7. A spline groove with open ends and slidably connected to the spline shaft 16 is fixedly opened inside the hollow shaft 5. The cross-sections of the spline groove and the spline shaft 16 are both regular hexagonal. Both the first belt shaft 14 and the second belt shaft 15 are linked to the hollow shaft 5; First bevel gears are installed on both the first belt shaft 14 and the hollow shaft 5. The two first bevel gears mesh orthogonally. Pulleys are installed on both the first belt shaft 14 and the second belt shaft 15. A first synchronous toothed belt is connected between the two pulleys. A rotating wheel 17 is mounted on the second belt shaft 15. Two sector tooth segments 18 and two empty tooth segments 19 are alternately arranged on the rotating wheel 17. The vibrating frame 6 is slidably connected to the rotating frame 3. A spring 20 is mounted on the bottom surface of the vibrating frame 6. The other end of the spring 20 is fixedly connected to the rotating frame 3. A rack plate 21 is mounted on the vibrating frame 6. The two sector tooth segments 18 alternately mesh with the rack plate 21. The central angle of one sector tooth segment 18 is 40°, the central angle of the other sector tooth segment 18 is 60°, and the central angles of the two empty tooth segments 19 are both 130°. Both the sector tooth segments 18 and the rack plate 21 are provided with a rubber buffer coating with a thickness of 0.35mm. The hollow shaft 5 drives the first belt shaft 14 to rotate through two orthogonally meshing first bevel gears, and the first belt shaft 14 then drives the second belt shaft 15 to rotate through the first synchronous toothed belt. When the rotating wheel 17 on the second belt shaft 15 rotates, its alternately arranged 40° and 60° sector tooth segments 18 will mesh with the rack plate 21 of the vibrating frame 6 in sequence, pushing the vibrating frame 6 to compress the spring 20 and slide downward. When the empty tooth segment 19 rotates, the spring 20 resets and drives the vibrating frame 6 to slide upward, realizing the reciprocating motion of the vibrating frame 6. Meanwhile, the regular hexagonal spline shaft 16 at the top of the acquisition shaft 7 slides in conjunction with the regular hexagonal spline groove of the hollow shaft 5, ensuring that the acquisition shaft 7 can slide up and down with the vibrating frame 6 while rotating with the hollow shaft 5. The fit between the regular hexagonal spline shaft 16 and the spline groove achieves rotational power transmission and axial sliding adaptation through only one transmission structure, simplifying the complex structure that traditionally requires multiple power sources. The design of the sector tooth segments 18 with different central angles enables the reciprocating stroke and frequency of the vibrating frame 6 to change automatically, avoiding uneven gas collection caused by a single motion trajectory; The 0.35mm thick rubber buffer coating on the sector tooth section 18 and rack plate 21 effectively alleviates the impact load during meshing and extends the service life of the components. The spring 20 provides stable reset power for the vibrating frame 6, ensuring the continuity of motion. The transmission system drives the hollow shaft 5 to rotate at a first speed at the data acquisition station and the verification station, and at a second speed at the exhaust station and the air injection station; In a preferred embodiment, the second rotational speed is 3.08 times the first rotational speed; The transmission system includes four gear shafts 22 rotatably connected to the inspection frame 2. The positions of the four gear shafts 22 correspond to the positions of the data acquisition station, the verification station, the exhaust station, and the air injection station, respectively. A rotating cylinder 23 is rotatably mounted on the inspection frame 2. A driving gear ring 24 is installed on the rotating cylinder 23. Each gear shaft 22 is equipped with a driven gear 25 that meshes with the driving gear ring 24. Low-speed internal gears 26 are installed on the gear shafts 22 in the data acquisition station and the verification station. High-speed internal gears 27 are installed on the gear shafts 22 in the exhaust station and the air injection station. A low-speed external gear 28 that meshes with the low-speed internal gear 26 and a high-speed external gear 29 that meshes with the high-speed internal gear 27 are respectively installed on the hollow shaft 5. Two servo motors 30 are installed on the inspection frame 2. The output shafts of the two servo motors 30 are connected to a second synchronous toothed belt. The two second synchronous toothed belts are connected to the rotating frame 3 and the rotating cylinder 23 respectively.

[0023] In a preferred embodiment, the radius of the low-speed ratio external gear 28 is 4 times the radius of the low-speed ratio internal gear 26, and the radius of the high-speed ratio external gear 29 is 1.3 times the radius of the high-speed ratio internal gear 27. A servo motor 30 drives the rotating drum 23 to rotate via a second synchronous toothed belt. The active toothed ring 24 on the rotating drum 23 meshes with the driven gears 25 of the four toothed shafts 22, driving the four toothed shafts 22 to rotate synchronously. Another servo motor 30 drives the rotating frame 3 to rotate via a second synchronous toothed belt, enabling the detection system to precisely connect with each workstation; When the detection system is in the acquisition station and the verification station, the low-speed ratio internal gear 26 on the gear shaft 22 meshes with the low-speed ratio external gear 28 on the hollow shaft 5, driving the hollow shaft 5 to rotate at the first speed. When in the exhaust position and the air injection position, the high-speed ratio internal gear 27 meshes with the high-speed ratio external gear 29, driving the hollow shaft 5 to rotate at the second speed. Through the precise design of the gear radius ratio, speed adjustment on demand is achieved for different workstations; The data acquisition and calibration stations need to rotate at low speeds to ensure that the probes are in full contact with the gas and that data acquisition is stable. The exhaust station and the air injection station need to rotate at high speed to accelerate airflow and improve cleaning and exhaust efficiency. The speed can be automatically switched without the need for an additional speed adjustment mechanism, which simplifies the control logic. Dual servo motors 30 drive the rotating frame 3 and the rotating drum 23 respectively, enabling the workstation switching and transmission speed regulation to be coordinated and synchronized, further improving the automation level and operational stability of the device.

[0024] The flow splitting system drives the gas to be tested to flow unidirectionally into the collection cylinder 4, drives the nitromethane gas of a preset concentration to flow unidirectionally into the collection cylinder 4 at the calibration station, drives the clean gas flow to flow into the collection cylinder 4 at the exhaust station and discharges unidirectionally, and drives the inert gas to flow into the collection cylinder 4 at the injection station and discharge unidirectionally.

[0025] The diversion system includes a top cylinder 47, a bottom cylinder 31, and an exhaust gas collection pipe 32 installed on the test rack 2. The top cylinder 47 has two isolated exhaust channels 33 inside, each open at the bottom. Both exhaust channels 33 are connected to the exhaust gas collection pipe 32 via a first one-way exhaust valve. The bottom cylinder 31 has a collection chamber 34, a calibration chamber 35, an exhaust chamber 36, and an injection chamber 37 inside. The bottom cylinder 31 has four valve holes 38, which are connected to the collection chamber 34, calibration chamber 35, exhaust chamber 36, and injection chamber 37 respectively. Valve cylinders 39 are rotatably mounted on both cylinder 47 and bottom cylinder 31. The air inlet of the collection cylinder 4 is connected to the valve cylinder 39 on the bottom cylinder 31, and the air outlet of the collection cylinder 4 is connected to the valve cylinder 39 on the top cylinder 47. Nitromethane storage tank 40, clean gas storage tank 41 and inert gas storage tank 42 are respectively installed on the test rack 2. Nitromethane storage tank 40 is connected to the calibration chamber 35, clean gas storage tank 41 is connected to the exhaust chamber 36, and inert gas storage tank 42 is connected to the injection chamber 37. A collection pipe 43 is connected to the collection chamber 34, and a filter element 44 is installed at the end of the collection pipe 43.

[0026] The gases in the nitromethane storage tank 40, the clean gas storage tank 41, and the inert gas storage tank 42 are all high-pressure gases; The positions of the two exhaust channels 33 correspond to the positions of the exhaust station and the gas injection station, respectively. The positions of the collection chamber 34, the calibration chamber 35, the exhaust chamber 36, and the gas injection chamber 37 correspond to the positions of the collection station, the calibration station, the exhaust station, and the gas injection station, respectively. A second one-way exhaust valve and a solenoid valve are provided at the connection between the nitromethane storage tank 40 and the calibration chamber 35, the connection between the clean gas storage tank 41 and the exhaust chamber 36, and the connection between the inert gas storage tank 42 and the gas injection chamber 37. An axial flow fan is installed in both the collection pipe 43 and the tail gas collection pipe 32. The tail gas storage tank 45, which is connected to the tail gas collection pipe 32, is installed on the test rack 2.

[0027] When the rotating frame 3 drives the collection tube 4 to rotate, the air inlet of the collection tube 4 connects to different valve holes 38 through the valve tube 39 on the bottom tube 31; The sampling station is connected to the sampling chamber 34. An axial flow fan in the sampling tube 43 draws the gas to be tested after the impurities are filtered by the filter element 44. The gas to be tested flows into the sampling cylinder 4 in one direction. The calibration station is connected to the calibration chamber 35. The solenoid valve controls the nitromethane storage tank 40 to release a preset concentration of gas in one direction to determine the data acquisition sensitivity of the detection probe 13. Specifically, during operation, the nitromethane storage tank 40 can be opened according to a set cycle to realize the periodic calibration of the sensitivity of the detection probe 13. The exhaust station is connected to the exhaust chamber 36. The gas from the clean gas storage tank 41 flows into the collection cylinder 4, and then through the valve cylinder 39 at the top cylinder 47 to connect to the exhaust channel 33. It is discharged into the tail gas collection pipe 32 through the first one-way exhaust valve. The gas stored in the clean gas storage tank 41 is compressed air that has been fully purified. After the clean gas is introduced into the collection tube 4, the remaining gas sample and nitromethane gas in the collection tube 4 are completely discharged to avoid gas sample contamination during the next test. The gas injection station connects to the gas injection chamber 37. The gas from the inert gas storage tank 42 flows in to replace the residual gas and is discharged from the exhaust channel 33. The gas stored in the inert gas storage tank 42 is nitrogen. By filling with nitrogen, the residual gas sample in the collection tube 4 can be completely discharged. The linkage design between valve cylinder 39 and the workstation enables automatic switching of the air circuit, eliminating the need for manual disassembly or connection of pipelines and improving operational convenience. The sampling tube 43 and filter element 44 effectively filter dust and impurities in the gas to be tested, avoiding contamination of the detection probe 13. The first and second check valves prevent gas backflow and ensure that the gas flow direction is controllable, especially for verifying the accurate and stable gas concentration. The exhaust gas collection pipe 32 avoids the direct emission of nitromethane exhaust gas, which meets environmental protection requirements.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for detecting nitromethane leakage, characterized in that, Includes the following steps: SS01. A nitromethane leak detection device (1) is preset. The nitromethane leak detection device (1) is moved to the detection area. The microcontroller (46) starts the system. The rotating frame (3) is reset so that the detection system is aligned with the work station. The detection probe (13) establishes a wireless data connection with the microcontroller (46). SS02, the rotating frame (3) drives the detection system into the collection station, the diversion system extracts the gas to be tested filtered by the filter element (44), the detection probe (13) comprehensively detects the collected gas in a compound motion mode, the data is transmitted to the microcontroller (46) in real time, and the cleaning brush ring (11) cleans the detection probe (13) simultaneously. SS03, the rotating frame (3) drives the detection system into the calibration station, injects nitromethane gas of preset concentration, compares the detection value of the detection probe (13) with the preset value, and calibrates the sensitivity of the detection probe (13); SS04. Empty and remove residual gas samples from a nitromethane leak detection device (1) to prepare for the next round of sampling; SS05, A nitromethane leak detection device (1) operates in cycles, a microcontroller (46) stores data, and automatically issues an early warning and generates a report when the limit is exceeded.

2. A nitromethane leak detection device, suitable for implementing the nitromethane leak detection method as described in claim 1, comprising a detector rack (2), characterized in that, The inspection frame (2) is arranged in a clockwise direction with a collection station, a verification station, an exhaust station and an injection station. The inspection frame (2) is equipped with a transmission system, a flow distribution system and a rotatable rotating frame (3). Four detection systems are installed on the rotating frame (3). Each detection system includes a collection cylinder (4) mounted on a rotating frame (3) and a hollow shaft (5) rotatably connected to the rotating frame (3). A vibration guide system is connected to the hollow shaft (5). A vibrating frame (6) that can vibrate up and down and a rotatable collection shaft (7) are connected to the vibration guide system. The collection shaft (7) is rotatably mounted on the vibrating frame (6). The reciprocating stroke and reciprocating frequency of the vibrating frame (6) change alternately. A mounting frame (8) is provided at the bottom of the collection shaft (7) and at the position corresponding to the inside of the collection cylinder (4). A collection rotating seat (9) is rotatably mounted at the eccentric position of the mounting frame (8). A lower gear (10) is mounted on the collection rotating seat (9). A cleaning brush ring (11) and a lower gear ring (12) that meshes with the lower gear (10) are provided on the inner wall of the collection cylinder (4). A detection probe (13) is mounted on the collection rotating seat (9). The transmission system drives the hollow shaft (5) to rotate at a first speed at the data acquisition station and the verification station, and at a second speed at the exhaust station and the gas injection station. The diversion system drives the gas to be tested to flow into the collection tube (4) in one direction, drives the nitromethane gas of a preset concentration to flow into the collection tube (4) in one direction at the calibration station, drives the clean gas flow into the collection tube (4) at the exhaust station and discharges in one direction, and drives the inert gas into the collection tube (4) at the injection station and discharges in one direction.

3. The nitromethane leak detection device according to claim 2, characterized in that: The vibration guiding system includes a first belt shaft (14) and a second belt shaft (15) rotatably connected to the rotating frame (3). A spline shaft (16) is installed at the top of the acquisition shaft (7). A spline groove with open ends and slidably connected to the spline shaft (16) is fixedly opened inside the hollow shaft (5). The cross-section of the spline groove and the spline shaft (16) are both regular hexagonal. The first belt shaft (14) and the second belt shaft (15) are both linked with the hollow shaft (5). A rotating wheel (17) is installed on the second belt shaft (15). Two sector tooth segments (18) and two hollow tooth segments (19) are alternately arranged on the rotating wheel (17). The vibration frame (6) is slidably connected to the rotating frame (3). A spring (20) is installed on the bottom surface of the vibration frame (6). The other end of the spring (20) is fixedly connected to the rotating frame (3). A rack plate (21) is installed on the vibration frame (6). The two sector tooth segments (18) alternately mesh with the rack plate (21).

4. The nitromethane leak detection device according to claim 3, characterized in that: First bevel gears are installed on the first belt shaft (14) and the hollow shaft (5), and the two first bevel gears mesh orthogonally. Pulleys are installed on the first belt shaft (14) and the second belt shaft (15), and a first synchronous toothed belt is connected between the two pulleys.

5. The nitromethane leak detection device according to claim 3, characterized in that: The central angle of one of the sector tooth segments (18) is 40°, the central angle of the other sector tooth segment (18) is 60°, and the central angles of the two empty tooth segments (19) are both 130°. Both the sector tooth segments (18) and the rack plate (21) are provided with a rubber buffer coating, and the thickness of the rubber buffer coating is 0.35mm.

6. The nitromethane leak detection device according to claim 3, characterized in that: The transmission system includes four gear shafts (22) rotatably connected to the inspection frame (2). The positions of the four gear shafts (22) correspond to the positions of the sampling station, the verification station, the exhaust station, and the air injection station, respectively. A rotating cylinder (23) is rotatably mounted on the inspection frame (2). A driving gear ring (24) is installed on the rotating cylinder (23). Each gear shaft (22) is equipped with a driven gear (25) that meshes with the driving gear ring (24). Low-ratio internal gears (26) are installed on the gear shafts (22) in the sampling station and the verification station. Both the exhaust station and the air injection station have a high-speed ratio internal gear (27) installed on the gear shaft (22). The hollow shaft (5) has a low-speed ratio external gear (28) meshing with the low-speed ratio internal gear (26) and a high-speed ratio external gear (29) meshing with the high-speed ratio internal gear (27). The inspection frame (2) has two servo motors (30). The output shaft ends of the two servo motors (30) are connected to a second synchronous toothed belt. The two second synchronous toothed belts are connected to the rotating frame (3) and the rotating cylinder (23) respectively.

7. The nitromethane leak detection device according to claim 6, characterized in that: The radius of the low-speed ratio external gear (28) is 3 to 5 times the radius of the low-speed ratio internal gear (26), the radius of the high-speed ratio external gear (29) is 1.1 to 1.5 times the radius of the high-speed ratio internal gear (27), and the second rotational speed is 2.0 to 4.55 times the first rotational speed.

8. The nitromethane leak detection device according to claim 7, characterized in that: The diversion system includes a top cylinder (47), a bottom cylinder (31), and a tail gas collection pipe (32) installed on the test rack (2). The top cylinder (47) has two mutually isolated exhaust channels (33) inside, with the bottom end of each exhaust channel (33) open. Both exhaust channels (33) are connected to the tail gas collection pipe (32) through a first one-way exhaust valve. The bottom cylinder (31) has a collection chamber (34), a calibration chamber (35), an exhaust chamber (36), and an injection chamber (37) inside. The bottom cylinder (31) has four valve holes (38) on it, which are connected to the collection chamber (34), calibration chamber (35), exhaust chamber (36), and injection chamber (37) respectively. The top cylinder (47) and A valve cylinder (39) is rotatably installed on the bottom cylinder (31). The air inlet of the collection cylinder (4) is connected to the valve cylinder (39) on the bottom cylinder (31). The air outlet of the collection cylinder (4) is connected to the valve cylinder (39) on the top cylinder (47). A nitromethane storage tank (40), a clean gas storage tank (41), and an inert gas storage tank (42) are respectively installed on the inspection rack (2). The nitromethane storage tank (40) is connected to the calibration chamber (35). The clean gas storage tank (41) is connected to the exhaust chamber (36). The inert gas storage tank (42) is connected to the gas injection chamber (37). A collection pipe (43) is connected to the collection chamber (34). A filter element (44) is installed at the end of the collection pipe (43).

9. The nitromethane leak detection device according to claim 8, characterized in that: The positions of the two exhaust channels (33) correspond to the positions of the exhaust station and the gas injection station, respectively. The positions of the collection chamber (34), the verification chamber (35), the exhaust chamber (36), and the gas injection chamber (37) correspond to the positions of the collection station, the verification station, the exhaust station, and the gas injection station, respectively. The connection between the nitromethane storage tank (40) and the verification chamber (35), the connection between the clean gas storage tank (41) and the exhaust chamber (36), and the connection between the inert gas storage tank (42) and the gas injection chamber (37) are all equipped with a second one-way exhaust valve and a solenoid valve. The collection pipe (43) and the tail gas collection pipe (32) are both equipped with axial flow fans. The inspection rack (2) is equipped with a tail gas storage tank (45) that is connected to the tail gas collection pipe (32).

10. A nitromethane leakage detection device according to claim 8, characterized in that: The inspection rack (2) is equipped with a microcontroller (46) and four omnidirectional casters are installed on the bottom surface of the inspection rack (2). The data terminal of each detection probe (13) is connected to the microcontroller (46) via wireless signal. The inner wall of the cleaning brush ring (11) is evenly covered with rubber bristles. The central angle of the cleaning brush ring (11) is 180°.

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