A fuel dispenser vapor recovery hose leak detection system and method

Abstract

The application discloses a kind of oil dispenser oil gas recovery hose leakage detection system and method, it is related to fuel oil dispenser oil gas recovery system safety detection technical field, including gas flowmeter, data acquisition terminal, online monitoring console;Pressure detection module is provided on the gas flowmeter.Occupational advantage is in that: the present application can realize oil dispenser oil gas recovery hose back gas section leakage full-automatic, non-invasive detection, is completed intelligent inspection under not to gun idle state, does not interfere with normal oiling operation;While system relies on existing hardware integrated pressure monitoring, without substantial reconstruction equipment, deployment cost is low, stability is strong, can accurately identify hose damage, sealing failure and other hidden defects, avoid measurement inaccuracy, oil dispenser number of jumps and other problems from source.Through hierarchical early warning and automatic lock mechanism, realize hidden danger early warning, risk active prevention and control, effectively prevent safety hazard and measurement dispute.

Description

Technical Field

[0001] This invention relates to the field of safety testing technology for fuel dispenser vapor recovery systems, and particularly to a system and method for detecting leaks in fuel dispenser vapor recovery hoses. Background Technology

[0002] According to the requirements of the "Air Pollutant Emission Standard for Gas Stations" and the "Technical Specification for Testing Gas Station Oil and Gas Recovery Systems", gasoline fuel dispensers must be equipped with a secondary oil and gas recovery system. The working principle of the secondary oil and gas recovery system is as follows: When refueling, the nozzle of the fuel dispenser seals the opening of the car's fuel tank. The oil and gas in the fuel tank are transported to the gas station's storage tank through the return air pipe inside the fuel dispenser, the inner air pipe of the oil and gas recovery hose, the oil and gas separation joint, the copper pipe, and the oil and gas recovery pump.

[0003] The vapor recovery hose has a double-layer structure, with an inner layer being a return vent pipe and an outer layer being a fuel delivery pipe. The return vent pipe is sealed to the fuel nozzle via an O-ring. In actual use, the return vent pipe is prone to defects such as aging, damage, cracking, and creases, and the O-ring is prone to sealing failure. Leaks can cause the vapor recovery pump to draw fuel into the return vent pipe, resulting in inaccurate metering. In addition, the hose is made of black opaque material, making leaks difficult to identify with the naked eye. When the nozzle is not lifted, the backflow of leaking fuel can trigger the flow converter and encoder, causing the fuel dispenser to jump the meter reading without reason, leading to metering disputes.

[0004] Existing technologies can only achieve online monitoring of oil and gas recovery and closed-loop control of gas-liquid ratio. They cannot actively detect leaks in the return gas pipeline and seals when the fuel dispenser is idle and the nozzle is not picked up. They lack early warning and automatic protection mechanisms, making it difficult to meet the management needs of safe operation and accurate metering at gas stations. Summary of the Invention

[0005] The purpose of this invention is to solve the problems in the background art, and to propose a leak detection system and method for fuel dispenser vapor recovery hoses.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A leak detection system for fuel dispenser vapor recovery hoses includes a gas flow meter, a data acquisition terminal, and an online monitoring control console; The gas flow meter is equipped with a pressure detection module, which is installed in the fuel dispenser's vapor recovery return gas pipeline to collect the gas flow rate signal and pipeline pressure signal of the return gas pipeline. The data acquisition terminal is communicatively connected to the gas flow meter, the fuel dispenser motherboard, and the oil and gas recovery pump control board, respectively. It is used to receive the signals collected by the gas flow meter and the fuel dispenser's refueling volume signal, send pump start / stop and speed control commands to the oil and gas recovery pump control board, and send alarm and lock control commands to the fuel dispenser motherboard. The online monitoring console is communicatively connected to the data acquisition terminal, and is used to send detection commands to the data acquisition terminal, receive and process the detection data uploaded by the data acquisition terminal, and complete the leakage determination, graded early warning and visual display of alarm information.

[0007] In the above-mentioned fuel dispenser oil and gas recovery hose leakage detection system, the data acquisition terminal is also equipped with a data preprocessing module, which is used to filter, denoise and calculate feature values ​​of the pressure signal collected by the gas flow meter, and then upload the processed data to the online monitoring console.

[0008] In the above-mentioned fuel dispenser vapor recovery hose leakage detection system, the online monitoring console is also equipped with a historical data storage module, a report generation module, and a remote notification module, which are used to store historical detection data, automatically generate compliance detection reports, and send remote notification information to management personnel when an alarm is triggered.

[0009] A method for detecting leaks in the vapor recovery hose of a fuel dispenser, based on the aforementioned fuel dispenser vapor recovery hose leak detection system, includes the following steps: S1. Establishing the benchmark value: After confirming that there is no leakage in the oil and gas recovery return gas pipeline, complete multiple standard tests, extract the pipeline pressure data of each test, and calculate the average value of the core pressure characteristic value as the benchmark value for leakage judgment. S2. Detection Trigger: When the fuel dispenser is idle and the nozzle is not being picked up, an active detection command is issued through the online monitoring console, or the detection process is automatically started according to the preset automatic detection cycle or the gas-liquid ratio exceeding the standard trigger condition. S3. Data Acquisition: After receiving the detection command, the data acquisition terminal sends a start command to the oil and gas recovery pump control board to control the oil and gas recovery pump to run for a preset time. At the same time, it collects real-time pipeline pressure data of the return gas pipeline through the gas flow meter. S4. Leakage Detection: The data acquisition terminal calculates the core pressure characteristic value from the collected real-time pressure data, compares it with the preset benchmark value, and determines whether there is a leak in the return gas pipeline according to the preset judgment rules. S5. Early Warning and Protection: When a leakage risk is detected, the data acquisition terminal sends an alarm and lock command to the fuel dispenser motherboard, displays the leakage alarm information on the fuel dispenser panel, and uploads the alarm information to the online monitoring control console for graded early warning and recording.

[0010] In the above-mentioned method for detecting leaks in the vapor recovery hose of a fuel dispenser, the specific process for establishing the baseline value in step S1 is as follows: S11. Ensure that there is no leakage in the oil and gas recovery return pipeline, conduct 3 complete standard tests, control the oil and gas recovery pump to run normally for 60 seconds in each test, and collect pipeline pressure data at 30 time points. S12. Calculate the core pressure characteristic value for each test, including the pressure mean, pressure median, pressure standard deviation, coefficient of variation, and pressure range. S13. Take the average value of each core pressure characteristic value from the three tests as the final leakage judgment benchmark value.

[0011] In the above-mentioned method for detecting leaks in the vapor recovery hose of a fuel dispenser, the preset judgment rule for step S4 is a graded early warning judgment rule, which specifically includes: Level 1 warning determination: If the average pressure value detected in real time is lower than 88% of the benchmark value, or the median pressure value is lower than 88% of the benchmark value, either of these conditions will be determined as a Level 1 leakage risk, and a shutdown inspection command will be immediately triggered. Level 2 warning determination: If the pressure standard deviation detected in real time is higher than 150% of the benchmark value, or the coefficient of variation is higher than 200% of the benchmark value, either of which is triggered simultaneously, it is determined to be a Level 2 leakage risk, triggering an instruction to shorten the detection cycle and re-inspect within 24 hours; Level 3 warning determination: If the real-time detected pressure difference is higher than 150% of the benchmark value, it is determined to be a Level 3 leakage risk, triggering instructions to monitor equipment operation and conduct key verification in the next inspection; Among them, triggering the Level 3 warning twice consecutively will upgrade it to the Level 2 warning, and triggering the Level 2 warning three times consecutively will determine that there is a leak, triggering the shutdown and inspection command corresponding to the Level 1 warning.

[0012] In the above-mentioned method for detecting leaks in the vapor recovery hose of a fuel dispenser, in step S2, the automatic detection cycle is set by gas station personnel through an online monitoring console; the trigger condition for the excessive gas-liquid ratio is: when the gas-liquid ratio of the fuel dispenser exceeds the specified range of 0.9 to 1.3:1 three times consecutively, the detection process is automatically triggered.

[0013] In the above-mentioned method for detecting leakage in the vapor recovery hose of a fuel dispenser, in step S3, the preset running time of the vapor recovery pump is 60 seconds. Each detection process involves 5 consecutive pump operation tests. Only when the leakage judgment condition is triggered in all 5 consecutive tests is the leakage in the return gas pipeline finally determined.

[0014] The above-mentioned method for detecting leaks in the vapor recovery hose of a fuel dispenser also includes step S6: After the maintenance and inspection are completed and deemed satisfactory, a release command is sent through the online monitoring control console or fuel dispenser panel, and the data acquisition terminal releases the fuel dispenser from its locked state, restoring the normal refueling function of the fuel dispenser.

[0015] Compared with existing technologies, the advantages of this invention are as follows: This invention enables fully automated, non-invasive detection of leaks in the return gas section of the fuel dispenser's vapor recovery hose. Intelligent inspections are completed even when the nozzle is idle, without interfering with normal refueling operations. Simultaneously, the system integrates pressure monitoring based on existing hardware, requiring no significant equipment modifications, resulting in low deployment costs and high stability. It can accurately identify hidden defects such as hose damage and seal failure, preventing metering inaccuracies and fuel dispenser misreading at the source. Through tiered early warning and automatic machine locking mechanisms, it achieves early warning of potential hazards and proactive risk control, effectively preventing safety risks and metering disputes. System data can be automatically archived and compliant reports generated, fully meeting environmental standards and significantly improving the safety operation level, environmental compliance capabilities, and management efficiency of gas stations. Attached Figure Description

[0016] Figure 1 This is a flowchart of a method for detecting leaks in the fuel dispenser's vapor recovery hose, as proposed in this invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Reference Figure 1 A leak detection system for fuel dispenser vapor recovery hoses includes a gas flow meter, a data acquisition terminal, and an online monitoring control console; it requires no new hardware, only reuses the existing gas flow meter and integrates pressure detection, resulting in low modification costs.

[0019] The gas flow meter is equipped with a pressure detection module, which is installed in the fuel dispenser's vapor recovery return gas pipeline to collect the gas flow rate signal and pipeline pressure signal.

[0020] The data acquisition terminal is connected to the gas flow meter, the fuel dispenser motherboard, and the vapor recovery pump control board. It receives signals from the gas flow meter and the fuel dispenser's refueling volume signal, sends pump start / stop and speed control commands to the vapor recovery pump control board, and sends alarm and lock commands to the fuel dispenser motherboard. The data acquisition terminal is also equipped with a data preprocessing module, which filters, denoises, and performs eigenvalue calculations on the pressure signals collected by the gas flow meter before uploading the processed data to the online monitoring console.

[0021] The online monitoring console communicates with the data acquisition terminal, serving as the visual operation front end of the entire system. It is used to issue detection commands to the data acquisition terminal, receive and process the detection data uploaded by the data acquisition terminal, and complete the visualization display of leakage determination, graded early warning, and alarm information. The online monitoring console is also equipped with a historical data storage module, a report generation module, and a remote notification module, which are used to store historical detection data, automatically generate compliant detection reports, and send remote notification information to management personnel when an alarm is triggered.

[0022] A method for detecting leaks in the vapor recovery hose of a fuel dispenser, based on the aforementioned detection system, includes both active and automatic detection modes, and comprises the following steps: S1. Establishing the benchmark value: After confirming that there is no leakage in the oil and gas recovery return gas pipeline, complete multiple standard tests, extract the pipeline pressure data of each test, and calculate the average value of the core pressure characteristic value as the benchmark value for leakage judgment. The specific process for establishing the baseline value in step S1 is as follows: S11. Ensure that there is no leakage in the oil and gas recovery return pipeline, conduct 3 complete standard tests, control the oil and gas recovery pump to run normally for 60 seconds in each test, and collect pipeline pressure data at 30 time points. S12. Calculate the core pressure characteristic values ​​for each test. The core pressure characteristic values ​​include the pressure mean, pressure median, pressure standard deviation, coefficient of variation, and pressure range. S13. Take the average value of each core pressure characteristic value from the three tests as the final leakage judgment benchmark value.

[0023] S2. Detection Trigger: Active Detection Mode: When gas station personnel are idle without picking up the fuel dispenser (automatic inspection without picking up the dispenser does not affect normal refueling operations, enabling early detection of leaks, meeting the requirements of GB20952-2020 and JJF2020-2022 standards, and improving the compliance management level of gas stations), they can operate the online monitoring console to issue a leak monitoring command and start the detection process. Automatic detection mode: Gas station personnel can set the automatic detection cycle through the online monitoring control console, or the detection process will be automatically triggered when the gas-liquid ratio of the fuel dispenser exceeds the standard range of 0.9 to 1.3:1 for three consecutive times; S3. Data Acquisition: After receiving the detection command, the data acquisition terminal sends a start command to the oil and gas recovery pump control board to control the oil and gas recovery pump to run for a preset time. At the same time, it collects real-time pipeline pressure data of the return gas pipeline through the gas flow meter. In step S3, the preset running time of the oil and gas recovery pump is 60 seconds. Each detection process involves 5 consecutive pump operation tests. Only when the leakage judgment condition is triggered in all 5 consecutive tests is the leakage in the return gas pipeline finally determined.

[0024] S4. Leakage Detection: The data acquisition terminal calculates the core pressure characteristic value from the collected real-time pressure data, compares it with the preset benchmark value, and determines whether there is a leak in the return gas pipeline according to the preset judgment rules. The preset judgment rule for step S4 is a graded early warning judgment rule, which specifically includes: Level 1 warning determination: If the average pressure value detected in real time is lower than 88% of the benchmark value, or the median pressure value is lower than 88% of the benchmark value, either of these conditions will be determined as a Level 1 leakage risk, and a shutdown inspection command will be immediately triggered. Level 2 warning determination: If the pressure standard deviation detected in real time is higher than 150% of the benchmark value, or the coefficient of variation is higher than 200% of the benchmark value, either of which is triggered simultaneously, it is determined to be a Level 2 leakage risk, triggering an instruction to shorten the detection cycle and re-inspect within 24 hours; Level 3 warning determination: If the real-time detected pressure difference is higher than 150% of the benchmark value, it is determined to be a Level 3 leakage risk, triggering instructions to monitor equipment operation and conduct key verification in the next inspection; Among them, triggering the Level 3 warning twice consecutively will upgrade it to the Level 2 warning, and triggering the Level 2 warning three times consecutively will determine that there is a leak, triggering the shutdown and inspection command corresponding to the Level 1 warning.

[0025] S5. Early Warning and Protection: When a leakage risk is detected, the data acquisition terminal sends an alarm and lock command to the fuel dispenser motherboard, displays the leakage alarm information on the fuel dispenser panel, and uploads the alarm information to the online monitoring control console for graded early warning and recording; automatic alarm and lock protection can effectively avoid problems such as miscounting, inaccurate metering, and customer disputes.

[0026] It also includes step S6: After the maintenance and inspection are qualified, a release command is sent through the online monitoring console or fuel dispenser panel, and the data acquisition terminal releases the fuel dispenser from the locked state and restores the normal refueling function of the fuel dispenser.

[0027] To further verify the effectiveness of the detection system and method provided by this invention, the inventors collected pressure data under different fuel dispensers and different environmental conditions, under two states: no leakage in the oil and gas recovery hose (baseline value established) and artificially created leakage (simulating hose damage or O-ring failure). The core pressure characteristic value was calculated according to the method of step S1 of this invention. The test results are shown in Table 1.

[0028] Table 1 Comparison of pressure characteristic values ​​of hose before and after leakage under different test conditions ; Test Result Analysis: As shown in Table 1, under various test conditions, once a leak occurs in the return gas pipeline, all core pressure characteristic values ​​change significantly.

[0029] First, the mean and median pressures, which reflect the sealing performance of the pipeline, showed a significant decrease, dropping to 67.23% to 84.45% of the baseline values ​​in the four test environments, respectively. When the pressure cannot be effectively maintained, it indicates that there is a leak in the pipeline.

[0030] Secondly, the pressure standard deviation, coefficient of variation, and pressure range, which characterize the severity of pressure fluctuations, all increase exponentially after leakage. For example, in environment 3, the pressure standard deviation increases to 742.91% of the baseline value, and the coefficient of variation increases to 1165.38%. This indicates that leakage causes severe and irregular pressure fluctuations within the pipeline during pump operation. This phenomenon provides direct experimental evidence for establishing secondary and tertiary early warning systems (such as standard deviation exceeding 150% and coefficient of variation exceeding 200%) as described in claim 6 of this invention.

[0031] Based on the test examples in the four independent environments mentioned above, it can be concluded that the method proposed in this invention for determining hose leakage by monitoring pipeline pressure characteristic values ​​is accurate and reliable. The system can sensitively detect the decrease in average pressure and sudden increase in fluctuation caused by leakage, and issue graded warnings or execute machine lock-up protection before interfering with normal refueling operations, thereby effectively verifying the effectiveness and universality of the technical solution of this invention.

[0032] To further clarify, the aforementioned fixed connection should be interpreted broadly unless otherwise explicitly specified and limited. For example, it may be welding, gluing, or integral molding, or other conventional methods well known to those skilled in the art.

[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A leak detection system for the vapor recovery hose of a fuel dispenser, characterized in that, This includes gas flow meters, data acquisition terminals, and online monitoring control consoles; The gas flow meter is equipped with a pressure detection module, which is installed in the fuel dispenser's vapor recovery return gas pipeline to collect the gas flow rate signal and pipeline pressure signal of the return gas pipeline. The data acquisition terminal is communicatively connected to the gas flow meter, the fuel dispenser motherboard, and the oil and gas recovery pump control board, respectively. It is used to receive the signals collected by the gas flow meter and the fuel dispenser's refueling volume signal, send pump start / stop and speed control commands to the oil and gas recovery pump control board, and send alarm and lock control commands to the fuel dispenser motherboard. The online monitoring console is communicatively connected to the data acquisition terminal, and is used to send detection commands to the data acquisition terminal, receive and process the detection data uploaded by the data acquisition terminal, and complete the leakage determination, graded early warning and visual display of alarm information.

2. The fuel dispenser vapor recovery hose leakage detection system according to claim 1, characterized in that, The data acquisition terminal is also equipped with a data preprocessing module, which is used to filter, denoise and calculate feature values ​​of the pressure signal collected by the gas flow meter, and then upload the processed data to the online monitoring console.

3. The fuel dispenser vapor recovery hose leakage detection system according to claim 1, characterized in that, The online monitoring console is also equipped with a historical data storage module, a report generation module, and a remote notification module, which are used to store historical testing data, automatically generate compliance testing reports, and send remote notification information to management personnel when an alarm is triggered.

4. A method for detecting leaks in the vapor recovery hose of a fuel dispenser, characterized in that, The oil and gas recovery hose leakage detection system for fuel dispensers as described in claim 1 includes the following steps: S1. Establishing the benchmark value: After confirming that there is no leakage in the oil and gas recovery return gas pipeline, complete multiple standard tests, extract the pipeline pressure data of each test, and calculate the average value of the core pressure characteristic value as the benchmark value for leakage judgment. S2. Detection Trigger: When the fuel dispenser is idle and the nozzle is not being picked up, an active detection command is issued through the online monitoring console, or the detection process is automatically started according to the preset automatic detection cycle or the gas-liquid ratio exceeding the standard trigger condition. S3. Data Acquisition: After receiving the detection command, the data acquisition terminal sends a start command to the oil and gas recovery pump control board to control the oil and gas recovery pump to run for a preset time. At the same time, it collects real-time pipeline pressure data of the return gas pipeline through the gas flow meter. S4. Leakage Detection: The data acquisition terminal calculates the core pressure characteristic value from the collected real-time pressure data, compares it with the preset benchmark value, and determines whether there is a leak in the return gas pipeline according to the preset judgment rules. S5. Early Warning and Protection: When a leakage risk is detected, the data acquisition terminal sends an alarm and lock command to the fuel dispenser motherboard, displays the leakage alarm information on the fuel dispenser panel, and uploads the alarm information to the online monitoring control console for graded early warning and recording.

5. The method for detecting leakage in the fuel dispenser vapor recovery hose according to claim 4, characterized in that, The specific process for establishing the baseline value in step S1 is as follows: S11. Ensure that there is no leakage in the oil and gas recovery return pipeline, conduct 3 complete standard tests, control the oil and gas recovery pump to run normally for 60 seconds in each test, and collect pipeline pressure data at 30 time points. S12. Calculate the core pressure characteristic value for each test, including the pressure mean, pressure median, pressure standard deviation, coefficient of variation, and pressure range. S13. Take the average value of each core pressure characteristic value from the three tests as the final leakage judgment benchmark value.

6. The detection method according to claim 5, characterized in that, The preset judgment rule for step S4 is a graded early warning judgment rule, which specifically includes: Level 1 warning determination: If the average pressure value detected in real time is lower than 88% of the benchmark value, or the median pressure value is lower than 88% of the benchmark value, either of these conditions will be determined as a Level 1 leakage risk, and a shutdown inspection command will be immediately triggered. Level 2 warning determination: If the pressure standard deviation detected in real time is higher than 150% of the benchmark value, or the coefficient of variation is higher than 200% of the benchmark value, either of which is triggered simultaneously, it is determined to be a Level 2 leakage risk, triggering an instruction to shorten the detection cycle and re-inspect within 24 hours; Level 3 warning determination: If the real-time detected pressure difference is higher than 150% of the benchmark value, it is determined to be a Level 3 leakage risk, triggering instructions to monitor equipment operation and conduct key verification in the next inspection; Among them, triggering the Level 3 warning twice consecutively will upgrade it to the Level 2 warning, and triggering the Level 2 warning three times consecutively will determine that there is a leak, triggering the shutdown and inspection command corresponding to the Level 1 warning.

7. The detection method according to claim 4, characterized in that, In step S2, the automatic detection cycle is set by gas station personnel through the online monitoring console; the trigger condition for the gas-liquid ratio exceeding the standard is: when the gas-liquid ratio of the fuel dispenser exceeds the specified range of 0.9 to 1.3:1 for three consecutive times, the detection process is automatically triggered.

8. The detection method according to claim 4, characterized in that, In step S3, the preset running time of the oil and gas recovery pump is 60 seconds. Each detection process involves 5 consecutive pump operation tests. Only when the leakage judgment condition is triggered in 5 consecutive tests is the leakage in the return gas pipeline finally determined.

9. The detection method according to claim 4, characterized in that, It also includes step S6: After the maintenance and inspection are qualified, a release command is sent through the online monitoring console or fuel dispenser panel, and the data acquisition terminal releases the fuel dispenser from the locked state and restores the normal refueling function of the fuel dispenser.

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