Vehicle-mounted vapor recovery system compatible refueling nozzle gas-liquid ratio testing system and method

Abstract

This invention relates to the field of gas station nozzle testing technology, and discloses a gas-liquid ratio testing system and method for a gas nozzle compatible with an on-board vapor recovery system. The system includes: a refueling unit comprising a variable-diameter hose and an air pump; the variable-diameter hose has a double-layer structure and an air bladder formed by the two layers; the air pump inflates and deflates the air bladder; during refueling, the inlet end of the variable-diameter hose is connected to the refueling nozzle, and the outlet end is connected to the vehicle's fuel tank; a gas-liquid ratio testing unit for testing the gas-liquid ratio in the refueling nozzle during refueling; and a control unit configured to: shut off the air pump when it is determined that the refueling vehicle does not have an on-board vapor recovery system; and activate the air pump to inflate the air bladder when it is determined that the refueling vehicle has an on-board vapor recovery system, thereby reducing the diameter of the variable-diameter hose. The system of this invention can perform gas-liquid ratio testing for refueling vehicles meeting China V and China VI emission standards using ORVR-compatible refueling nozzles of different brands and models at gas stations.

Description

Technical Field

[0001] This invention relates to the field of gas station nozzle testing technology, specifically to a gas-liquid ratio testing system and method for a gas nozzle compatible with an on-board vapor recovery system. Background Technology

[0002] With increasingly stringent emission regulations in my country, vehicle exhaust emissions have been effectively controlled, and evaporative emissions have now exceeded the HC (carbon dioxide) content in exhaust emissions. According to GB20952-2020, "Emission Standard for Air Pollutants from Gas Stations," all gas stations selling gasoline in my country must install a secondary vapor recovery system. A gas station's vapor recovery system refers to a closed-loop collection method that uses a vacuum generator to recover the vapors generated during refueling, returning them to underground storage tanks. This system reduces the emission of pollutants into the atmosphere during refueling, thus protecting the environment. A secondary vapor recovery system mainly includes a secondary vapor recovery refueling nozzle, coaxial hose, vapor separator, vapor-liquid ratio regulating valve, and vacuum pump.

[0003] In July 2020, GB18352.6-2016, "Limits and Measurement Methods for Pollutant Emissions from Light-Duty Vehicles (China VI)," was released. This regulation added a Type VII refueling pollutant emission test for automotive fuel systems, stipulating that the evaporative pollutant emissions during refueling must not exceed 0.05 g / L. This regulation aims to reduce oil and gas pollution emissions and energy waste during refueling and requires all new China VI compliant vehicles manufactured after July 1, 2020, to meet this requirement. For gasoline vehicles, the China VI regulation primarily tightens fuel evaporation control, reducing the limit from 2 g / test (test cycle) in China V to 0.7 g / test in China VI, and adding a refueling pollutant emission test. To meet this standard, vehicles sold in China from 2020 onwards must be equipped with an on-board vapor recovery system (ORVR).

[0004] Onboard vapor recovery systems are a highly efficient control technology for reducing oil and gas pollution during refueling. By installing an activated carbon canister in the vehicle's fuel supply system, a liquid seal is formed within the narrow refueling line during refueling, preventing oil and gas from escaping. Simultaneously, oil and gas overflowing from the fuel tank during refueling is transported to the activated carbon canister through a vent valve and adsorbed, thus achieving oil and gas recovery and avoiding waste. The promotion and application of onboard vapor recovery systems are of great significance for reducing emissions from current vehicle fuel systems.

[0005] Currently, standard fuel nozzles compatible with China V emission standards feature an integrated, sealed pressure-sensing system. When the main valve opens and high-speed fuel flows through the return valve, the special design of the return valve assembly creates negative pressure within the pressure-sensing system. Under normal operating conditions, this negative pressure is continuously replenished by gas through a vent pipe located within the outlet pipe, maintaining a near-equilibrium of pressure across the pressure-sensing diaphragm. When the fuel level rises and overflows, sealing the vent pipe, the negative pressure within the system rapidly increases, causing an imbalance in pressure across the diaphragm. This imbalance moves the diaphragm towards the negative pressure side, disengaging the nozzle and allowing it to self-close within a very short time. Additionally, standard fuel nozzles offer a gas-liquid ratio adjustment function for refueling China V vehicles.

[0006] In addition to possessing the functions of ordinary refueling nozzles, vehicle-mounted vapor recovery compatible refueling nozzles adapted to the China VI emission standard must also have adjustment functions compatible with existing secondary vapor recovery systems. Since the secondary vapor recovery systems at gas stations in my country are all vacuum-assisted systems, sharing these systems with vehicle-mounted vapor recovery systems would cause the secondary system to draw large amounts of air into underground fuel tanks, resulting in excessive and incompatible emissions of vapors. Therefore, according to GB20952-2020, when the number of vehicles equipped with vehicle-mounted vapor recovery systems exceeds 20%, gas stations should use vapor recovery refueling equipment compatible with these systems. This means the secondary vapor recovery system should be able to identify vehicles with vehicle-mounted vapor recovery systems and reduce the vapor-to-liquid ratio to below 0.5 when refueling vehicles without such systems; and maintain the vapor-to-liquid ratio within the range of 1.0-1.2 when refueling vehicles without such systems.

[0007] Given the large number of China V emission standard vehicles and the increasing number of China VI emission standard vehicles, existing ORVR (Organic Vapor Recovery) fuel nozzle gas-liquid ratio testing equipment for vehicle-mounted vapor recovery systems (ORVR) all use a single testing device. This means that China V and China VI vehicle fuel tanks require two different gas-liquid ratio testing devices, making it impossible to achieve a universal gas-liquid ratio test for both vehicle models. To ensure the performance of the vehicle-mounted vapor recovery system while simultaneously verifying the gas-liquid ratio of ORVR fuel nozzles for both China V and China VI vehicle models, there is an urgent need to develop a portable ORVR-compatible fuel nozzle gas-liquid ratio testing method and verification device applicable to both China V and China VI vehicles. Summary of the Invention

[0008] The purpose of this invention is to provide a gas-liquid ratio testing system and method for fuel nozzles compatible with vehicle-mounted vapor recovery systems. By setting up a variable-diameter oil pipe and using an air pump, this invention can complete the diameter change operation of the fuel pipe adapted to China V and China VI fuel tanks, combining the two fuel tank assemblies of China V and China VI vehicles into one. This enables the function of testing the gas-liquid ratio of fuel tanks of China V and China VI B vehicles without switching fuel nozzles, thereby efficiently realizing the system's diagnostic analysis of the working status of fuel nozzles compatible with vehicle-mounted vapor recovery systems.

[0009] To achieve the above objectives, the present invention provides a fuel nozzle gas-liquid ratio testing system compatible with vehicle-mounted vapor recovery systems, the system comprising:

[0010] The refueling unit includes a variable diameter oil pipe and an air pump. The variable diameter oil pipe has a double-layer structure and an air bladder formed by the two layers. The air pump can inflate and deflate the air bladder. During refueling, the oil inlet end of the variable diameter oil pipe is connected to the refueling nozzle, and the oil outlet end is connected to the vehicle's fuel tank.

[0011] A gas-liquid ratio testing unit is used to test the gas-liquid ratio in the refueling nozzle during refueling; and

[0012] The control unit is configured to: shut down the air pump when it is determined that the refueling vehicle does not have an on-board vapor recovery system; and start the air pump to inflate the airbag when it is determined that the refueling vehicle has an on-board vapor recovery system, thereby reducing the diameter of the refueling pipe of the variable diameter oil pipe.

[0013] Preferably, the double-layer structure of the variable diameter tubing includes a metal outer layer and a rubber inner layer.

[0014] Preferably, the variable diameter oil pipe also has a hose for connecting to the vehicle's fuel tank. The hose has a five-layer structure, and the materials from the inner layer to the outer layer are, in order, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), a polymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride (THV), and chlorosulfonated polyethylene (CSM).

[0015] Preferably, the gas-liquid ratio testing unit includes an oil-gas flow meter, which is connected to a sealing adapter installed at the nozzle of the refueling gun.

[0016] Preferably, the gas-liquid ratio testing unit further includes a calculation module, which is configured to calculate the gas-liquid ratio based on the gas volume obtained by the gas flow meter and the refueling volume provided by the refueling device that delivers gasoline to the refueling nozzle.

[0017] Preferably, the oil and gas flow meter is a Roots flow meter.

[0018] Preferably, the system further includes a data acquisition and display unit for acquiring, displaying and storing various parameters during the refueling process. These parameters include: refueling volume, oil-gas volume, air pump status, detection time, gas-liquid ratio, real-time refueling flow rate, real-time return flow rate and real-time gas-liquid ratio.

[0019] A second aspect of the present invention provides a method for testing the gas-liquid ratio of a fuel dispenser compatible with an on-board vapor recovery system. This method utilizes the aforementioned on-board vapor recovery system compatible fuel dispenser gas-liquid ratio testing system and includes the following steps:

[0020] Connect the variable diameter oil pipe to the vehicle's fuel tank and refuel using a refueling nozzle;

[0021] When the system determines that the refueling vehicle does not have an on-board vapor recovery system, the air pump is turned off, the air bladder of the variable diameter oil pipe is not inflated, and the inner tube of the variable diameter oil pipe is in a relaxed state; when the system determines that the refueling vehicle has an on-board vapor recovery system, the air pump is turned on to inflate the air bladder, so that the inner tube of the variable diameter oil pipe is in a taut state.

[0022] The volume of oil and gas in the refueling nozzle is detected during refueling, and the gas-liquid ratio of the refueling nozzle is determined based on the volume of refueling volume.

[0023] Preferably, the method further includes: comparing the gas-liquid ratio detection value with a preset gas-liquid ratio value to determine whether the gas-liquid ratio regulating valve function of the refueling nozzle is effective.

[0024] Preferably, the process of determining whether the gas-liquid ratio regulating valve of the refueling nozzle is effective includes:

[0025] When a refueling vehicle does not have an on-board vapor recovery system, if the vapor-liquid ratio detection value is greater than or equal to 1.2, the vapor-liquid ratio adjustment valve of the refueling nozzle is deemed to be effective.

[0026] When a refueling vehicle is equipped with an on-board vapor recovery system, if the vapor-liquid ratio detection value is less than or equal to 0.5, the vapor-liquid ratio adjustment valve of the refueling nozzle is deemed to be effective.

[0027] If the gas-liquid ratio detection value is greater than 0.5 and less than 1.2, the gas-liquid ratio regulating valve of the refueling nozzle is deemed to be malfunctioning.

[0028] Preferably, the method further includes: when the system determines that the refueling vehicle does not have an on-board vapor recovery system, setting the gas-liquid ratio of the refueling nozzle to 1-1.2; when the system determines that the refueling vehicle has an on-board vapor recovery system, setting the gas-liquid ratio of the refueling nozzle to below 0.5.

[0029] The vehicle-mounted vapor recovery system (ORVR) compatible refueling nozzle gas-liquid ratio testing system of this invention mainly includes a refueling unit, a gas-liquid ratio testing unit, and a control unit. The refueling unit includes a variable-diameter fuel hose and an air pump. The air pump allows for adjustment of the inner diameter of the variable-diameter fuel hose, controlling the fuel inlet rate to match the fuel inlet rate requirements of China V / China VI fuel tanks. The control unit controls the air pump's on / off operation based on whether the refueling vehicle has an ORVR system, thereby adjusting the inner diameter of the variable-diameter fuel hose. The gas-liquid ratio testing unit tests the gas-liquid ratio in the refueling nozzle. The entire testing system can perform functions such as adjusting the refueling hose diameter for China V / China VI fuel tanks and verifying the gas-liquid ratio of the fuel nozzle.

[0030] Because the maximum inlet flow rate of fuel tanks differs between China V and China VI emission standard vehicles—50L / min for China V tanks and 38L / min for China VI tanks—when a fuel refueling nozzle compatible with an onboard vapor recovery system is refueling a China V vehicle, the air pump in the refueling unit is off, and the air bladder is not inflated. Without the air bladder, the inner tube of the variable-diameter fuel line is in a relaxed, uncompressed state, resulting in a larger diameter and faster refueling rate. However, when the same nozzle is refueling a China VI vehicle equipped with an onboard vapor recovery system, the air bladder in the variable-diameter fuel line is rapidly inflated by the air pump. The air bladder compresses the inner tube of the variable-diameter fuel line, tightening it and reducing its diameter, thus creating a liquid seal and lowering the refueling flow rate to meet the maximum inlet flow rate requirement for China VI fuel tanks. According to the technical solution of this invention, an air pump is used to inflate and deflate the air bladder inside the variable diameter oil pipe, thereby stretching and contracting the inner diameter of the variable diameter oil pipe and adjusting the oil flow rate during refueling. By setting different gas-liquid ratios for refueling nozzles depending on whether they have an on-board vapor recovery system, the vapor recovery requirements of China V and China VI fuel tanks are met. A calibration device is used to determine fault signals, and statistical analysis of the gas-liquid ratio values ​​for each refueling process is performed to obtain the gas-liquid ratio pass rate data for each refueling nozzle, thus achieving on-site gas-liquid ratio testing for ORVR-compatible refueling nozzles.

[0031] The technical solution of this invention can efficiently complete the gas-liquid ratio calibration of ORVR-compatible refueling nozzles at gas stations. By detecting the gas-liquid ratio of the fuel tank, the recovery effect of the oil and gas recovery system can be understood, ensuring the connection reliability of refueling operations at gas stations and facilitating the safe use of oil products. It has long-term economic and social benefits in promoting social development and stimulating the market economy. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the gas-liquid ratio testing system for a vehicle-mounted oil and gas recovery system compatible with the present invention.

[0033] Explanation of reference numerals in the attached figures

[0034] 1. Fuel nozzle; 2. Air pump; 3. Variable diameter fuel line; 4. Vehicle fuel tank; 5. Fuel flow meter; 6. Three-way valve. Detailed Implementation

[0035] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0036] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0037] In this document, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0038] Currently, vehicle-mounted vapor recovery systems determine whether a vehicle has a vapor recovery system by using the mechanical structure of a compatible vapor recovery refueling nozzle. The nozzle then uses its internal structure to adjust the vapor-to-liquid ratio. However, when refueling vehicles, compatible vapor recovery refueling nozzles require separate nozzle tests for both China V and China VI B fuel tank assemblies. Different vehicle types have different fuel tank structures and fuel line diameters, necessitating separate vapor-to-liquid ratio tests for each nozzle. This testing process is time-consuming, labor-intensive, and inefficient. To enable the gas-liquid ratio calibration function of ORVR-compatible refueling nozzles at gas stations, this invention configures a variable-diameter oil pipe. Through the coordination of status signals (whether the refueling vehicle has an on-board vapor recovery system) and an air pump, the diameter of the refueling pipe adapted to China V and China VI fuel tanks is changed, combining the two fuel tank assemblies of China V and China VI vehicles into one. This allows for the gas-liquid ratio testing of fuel tanks for China V and China VI B vehicles without switching fuel nozzles, thereby efficiently enabling the system to diagnose and analyze the working status of refueling nozzles compatible with on-board vapor recovery systems.

[0039] The vehicle-mounted vapor recovery system compatible refueling nozzle gas-liquid ratio testing system of the present invention includes:

[0040] The refueling unit includes a variable diameter oil pipe 3 and an air pump 2. The variable diameter oil pipe 3 has a double-layer structure and an air bladder formed by the two layers. The air pump 2 can inflate and deflate the air bladder. During refueling, the oil inlet end of the variable diameter oil pipe 3 is connected to the refueling nozzle 1, and the oil outlet end is connected to the vehicle's fuel tank 4.

[0041] A gas-liquid ratio testing unit is used to test the gas-liquid ratio in the refueling nozzle 1 during refueling; and

[0042] The control unit is configured to: shut down the air pump 2 when it is determined that the refueling vehicle does not have an on-board vapor recovery system; and start the air pump 2 to inflate the airbag when it is determined that the refueling vehicle has an on-board vapor recovery system, thereby reducing the diameter of the refueling pipe 3 of the variable diameter oil pipe.

[0043] In the system described in this invention, the fuel nozzle 1 is an ORVR-compatible fuel nozzle, which can determine whether the vehicle has an on-board vapor recovery system and transmit the obtained status signal (i.e. whether the refueling vehicle has an on-board vapor recovery system) to the air pump 2. By controlling the opening and closing of the air pump 2, the inner diameter of the variable diameter oil pipe 3 can be adjusted.

[0044] In the system described in this invention, preferably, the inner layer of the variable diameter oil pipe 3 is made of rubber, and the outer layer is made of metal. This double-layer structure has a simple manufacturing process and zero fuel permeation. Both oil pipes have built-in air bladders, which can be inflated and deflated by the air pump 2.

[0045] In the system described in this invention, preferably, the variable diameter oil pipe 3 also includes a hose for connecting to the vehicle's fuel tank. More preferably, the hose has a five-layer structure, with the materials from the innermost layer to the outermost layer being, in order: nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), a polymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV), and chlorosulfonated polyethylene (CSM). This hose structure reduces fuel permeation.

[0046] In the system described in this invention, the gas-liquid ratio testing unit includes an oil-gas flow meter 5, which is connected to a sealing adapter installed at the nozzle of the refueling nozzle 1. The oil and gas generated during refueling passes through the oil-gas flow meter 5, and the volume of oil and gas measured by the calibration device is recorded.

[0047] In the system described in this invention, the gas-liquid ratio testing unit further includes a calculation module, which is configured to calculate the gas-liquid ratio based on the gas volume obtained by the gas flow meter 5 and the refueling volume provided by the refueling device that delivers gasoline to the refueling nozzle 1.

[0048] In the system described in this invention, the gas-liquid ratio testing unit also includes a three-way valve 6. The oil and gas from the fuel nozzle 1 enter the three-way valve 6 after passing through the oil and gas flow meter 5. On the one hand, it can return to the vehicle's fuel tank through the three-way valve 6, and on the other hand, it can be recovered through an oil and gas recovery device, such as recovering the gasoline in the fuel tank after the test to an underground oil tank to achieve oil reuse.

[0049] In the system described in this invention, the oil and gas flow meter 5 can be a conventional flow meter in the art. In a preferred embodiment, to obtain higher testing accuracy, the oil and gas flow meter 5 is a Roots flow meter. The accuracy class of the Roots flow meter is 2 or higher.

[0050] In the system described in this invention, the system may further include a data acquisition and display unit for acquiring, displaying and storing various parameters during the refueling process. The parameters include: refueling volume, oil-gas volume, air pump status, detection time, gas-liquid ratio, real-time refueling flow rate, real-time return flow rate and real-time gas-liquid ratio.

[0051] This invention also provides a method for testing the gas-liquid ratio of a fuel dispenser compatible with an on-board vapor recovery system using the aforementioned on-board vapor recovery system compatible fuel dispenser gas-liquid ratio testing system. Specifically, the method includes:

[0052] Connect the variable diameter oil pipe 3 to the vehicle's fuel tank 4, and refuel through the refueling nozzle 1;

[0053] When the system determines that the refueling vehicle does not have an on-board vapor recovery system, the air pump 2 is turned off, the air bladder of the variable diameter oil pipe 3 is not inflated, and the inner tube of the variable diameter oil pipe 3 is in a relaxed state; when the system determines that the refueling vehicle has an on-board vapor recovery system, the air pump 2 is turned on to inflate the air bladder, so that the inner tube of the variable diameter oil pipe 3 is in a taut state.

[0054] The volume of oil and gas in the refueling nozzle 1 is detected during refueling, and the gas-liquid ratio of the refueling nozzle is determined based on the volume of refueling volume of the refueling nozzle 1.

[0055] In this invention, the gas-liquid ratio testing method for the vehicle-mounted vapor recovery system compatible refueling nozzle may further include: comparing the gas-liquid ratio detection value with a preset gas-liquid ratio value to determine whether the gas-liquid ratio regulating valve function of the refueling nozzle 1 is effective.

[0056] Specifically, the process of determining whether the gas-liquid ratio regulating valve of the refueling nozzle 1 is effective includes:

[0057] When the refueling vehicle does not have an on-board vapor recovery system, if the vapor-liquid ratio detection value is greater than or equal to 1.2, the vapor-liquid ratio adjustment valve of refueling nozzle 1 is deemed to be effective.

[0058] When a refueling vehicle is equipped with an on-board vapor recovery system, if the vapor-liquid ratio detection value is less than or equal to 0.5, the vapor-liquid ratio adjustment valve of refueling nozzle 1 is deemed to be effective.

[0059] If the gas-liquid ratio detection value is greater than 0.5 and less than 1.2, the gas-liquid ratio regulating valve of fuel nozzle 1 is deemed to be malfunctioning.

[0060] In this invention, the gas-liquid ratio test method for the fuel nozzle compatible with the vehicle-mounted vapor recovery system may further include: when the system determines that the refueling vehicle does not have a vehicle-mounted vapor recovery system, the gas-liquid ratio of the fuel nozzle 1 is set to 1-1.2; when the system determines that the refueling vehicle has a vehicle-mounted vapor recovery system, the gas-liquid ratio of the fuel nozzle 1 is set to below 0.5.

[0061] The following examples further illustrate the vehicle-mounted vapor recovery system-compatible refueling nozzle gas-liquid ratio testing system and method of the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0062] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0063] Example 1

[0064] like Figure 1 As shown in the figure, the vehicle-mounted vapor recovery system compatible refueling nozzle gas-liquid ratio testing system described in this embodiment includes: a refueling unit, a gas-liquid ratio testing unit, and a control unit. The refueling unit includes a variable-diameter oil pipe 3 and an air pump 2. The variable-diameter oil pipe 3 has a double-layer structure and an air bladder formed by the two layers. The air pump 2 can inflate and deflate the air bladder. During refueling, the inlet end of the variable-diameter oil pipe 3 is connected to the refueling nozzle 1, and the outlet end is connected to the vehicle's fuel tank 4. The gas-liquid ratio testing unit is used to test the gas-liquid ratio in the refueling nozzle 1 during refueling. The control unit is configured to: shut down the air pump 2 when it is determined that the refueling vehicle does not have a vehicle-mounted vapor recovery system; and start the air pump 2 to inflate the air bladder when it is determined that the refueling vehicle has a vehicle-mounted vapor recovery system, thereby reducing the diameter of the variable-diameter oil pipe 3. The variable diameter oil pipe 3 has a double-layer structure including a metal outer layer and a rubber inner layer. The variable diameter oil pipe 3 also has a hose for connecting to the automobile fuel tank. The hose has a five-layer structure, and the materials from the inner layer to the outer layer are, in order, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), a polymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride (THV), and chlorosulfonated polyethylene (CSM).

[0065] Example 2

[0066] like Figure 1 As shown in this embodiment, the vehicle-mounted vapor recovery system compatible refueling nozzle gas-liquid ratio testing system includes: a refueling unit, a gas-liquid ratio testing unit, and a control unit. The refueling unit includes a variable-diameter oil pipe 3 and an air pump 2. The variable-diameter oil pipe 3 has a double-layer structure and an air bladder formed by the two layers. The air pump 2 can inflate and deflate the air bladder. During refueling, the inlet end of the variable-diameter oil pipe 3 is connected to the refueling nozzle 1, and the outlet end is connected to the vehicle's fuel tank 4. The gas-liquid ratio testing unit is used to test the gas-liquid ratio in the refueling nozzle 1 during refueling. The system includes an oil / gas flow meter 5 and a calculation module. The oil / gas flow meter 5 is connected to a sealing adapter installed at the nozzle of the fuel dispenser 1. The calculation module is configured to calculate the gas-liquid ratio based on the oil / gas volume obtained from the oil / gas flow meter 5 and the refueling volume provided by the refueling device supplying gasoline to the fuel dispenser 1. The control unit is configured to: shut down the air pump 2 when it is determined that the refueling vehicle does not have an on-board oil / gas recovery system; and start the air pump 2 to inflate the airbag when it is determined that the refueling vehicle has an on-board oil / gas recovery system, thereby reducing the diameter of the refueling pipe 3. The variable diameter oil pipe 3 has a double-layer structure including a metal outer layer and a rubber inner layer. The variable diameter oil pipe 3 also has a hose connecting to the vehicle's fuel tank. The hose has a five-layer structure, with the materials from the inner layer to the outer layer being, in order: nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), a polymer of tetrafluoroethylene, hexafluoropropylene, and vinylidene fluoride (THV), and chlorosulfonated polyethylene (CSM).

[0067] Example 3

[0068] like Figure 1As shown in this embodiment, the vehicle-mounted vapor recovery system compatible refueling nozzle gas-liquid ratio testing system includes: a refueling unit, a gas-liquid ratio testing unit, a control unit, and a data acquisition and display unit. The refueling unit includes a variable-diameter oil pipe 3 and an air pump 2. The variable-diameter oil pipe 3 has a double-layer structure and an air bladder formed by the two layers. The air pump 2 can inflate and deflate the air bladder. During refueling, the inlet end of the variable-diameter oil pipe 3 is connected to the refueling nozzle 1, and the outlet end is connected to the vehicle's fuel tank 4. The gas-liquid ratio testing unit is used to test the gas-liquid ratio in the refueling nozzle 1 during refueling. The gas-liquid ratio testing unit includes an oil-gas flow meter 5 and a calculation module. The oil-gas flow meter 5 is connected to a sealing adapter installed at the nozzle of the refueling nozzle 1. The calculation module is configured to calculate the gas-liquid ratio based on the gas volume obtained by the gas flow meter 5 and the refueling volume provided by the refueling device that delivers gasoline to the refueling nozzle 1, wherein the gas flow meter 5 is a Roots flow meter; the control unit is configured to: shut down the air pump 2 when it is determined that the refueling vehicle does not have an on-board gas recovery system; and start the air pump 2 to inflate the airbag when it is determined that the refueling vehicle has an on-board gas recovery system, thereby reducing the refueling pipe diameter of the variable diameter oil pipe 3; the data acquisition and display unit is used to acquire, display, and store various parameters during the refueling process, including: refueling volume, gas volume, air pump status, detection time, gas-liquid ratio, real-time refueling flow rate, real-time return flow rate, and real-time gas-liquid ratio. The variable diameter oil pipe 3 has a double-layer structure including a metal outer layer and a rubber inner layer. The variable diameter oil pipe 3 also has a hose for connecting to the automobile fuel tank. The hose has a five-layer structure, and the materials from the inner layer to the outer layer are, in order, nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluororubber (FKM), a polymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride (THV), and chlorosulfonated polyethylene (CSM).

[0069] Example 4

[0070] This embodiment illustrates the gas-liquid ratio testing method for a vehicle-mounted vapor recovery system compatible refueling nozzle according to the present invention. This method is implemented in the vehicle-mounted vapor recovery system compatible refueling nozzle gas-liquid ratio testing system described in Embodiment 3. Specifically, the method includes:

[0071] Connect the variable diameter oil pipe 3 to the vehicle's fuel tank 4, and refuel through the refueling nozzle 1;

[0072] When the system determines that the refueling vehicle does not have an on-board vapor recovery system, the air pump 2 is turned off, the air bladder of the variable diameter oil pipe 3 is not inflated, the inner tube of the variable diameter oil pipe 3 is in a relaxed state, and the gas-liquid ratio of the refueling nozzle 1 is set to 1-1.2; when the system determines that the refueling vehicle has an on-board vapor recovery system, the air pump 2 is turned on to inflate the air bladder, so that the inner tube of the variable diameter oil pipe 3 is in a taut state, and the gas-liquid ratio of the refueling nozzle 1 is set to below 0.5.

[0073] The volume of oil and gas in the refueling nozzle 1 is detected during refueling, and the gas-liquid ratio of the refueling nozzle is determined based on the volume of refueling volume of the refueling nozzle 1.

[0074] The gas-liquid ratio detection value is compared with the preset gas-liquid ratio value to determine whether the gas-liquid ratio adjustment valve function of the refueling nozzle 1 is effective. Specifically, when the refueling vehicle does not have an on-board oil vapor recovery system, if the gas-liquid ratio detection value is greater than or equal to 1.2, the gas-liquid ratio adjustment valve function of the refueling nozzle 1 is determined to be effective.

[0075] When a refueling vehicle is equipped with an on-board vapor recovery system, if the vapor-liquid ratio detection value is less than or equal to 0.5, the vapor-liquid ratio adjustment valve of refueling nozzle 1 is deemed to be effective.

[0076] If the gas-liquid ratio detection value is greater than 0.5 and less than 1.2, the gas-liquid ratio regulating valve of fuel nozzle 1 is deemed to be malfunctioning.

[0077] Example 5

[0078] This embodiment illustrates the gas-liquid ratio testing method for a vehicle-mounted vapor recovery system compatible refueling nozzle according to the present invention. The main implementation steps of the testing method in this embodiment are the same as in Embodiment 4, and the detailed operation is as follows:

[0079] Fuel tanks and reservoirs for vehicles meeting China V and China VI B emission standards consist of the tank body (usually a multi-layered material structure), a valve assembly, a tank opening, and an ORVR (Organic Refrigerant Regulator) carbon canister. A valve and return pipe are connected to the bottom of the tank, allowing for gravity flow of fuel back to the reservoir. The carbon canister assembly has an effective volume approximately twice that of a non-ORVR carbon canister, ensuring complete adsorption of fuel vapors generated during refueling. It also features low venting resistance to ensure smooth refueling and prevent spillage or backflow. The return pipe and reservoir design prevent fuel waste and enable fuel recycling. Various fuel tank assemblies can be used to test the gas-liquid ratio compatibility of fuel tanks for different vehicle models. Grounding is required during use.

[0080] Before testing, the airtightness and reliability of all components of the entire system must be checked. The battery level and operating status of the testing device must be confirmed in advance, and the device must be properly grounded. Furthermore, the airtightness test of the gas-liquid ratio adapter must be conducted within an explosion-proof area.

[0081] When the vehicle-mounted vapor recovery system-compatible fuel dispenser is not refueling (i.e., the fuel flow signal is 0), the air pump 2 in the refueling unit is stationary, the variable diameter fuel line 3 is stationary, and the air pump 2 is not working. If the air pump 2 is not stationary at this time, the online vapor recovery detection system can determine that the fuel dispenser connection to the air pump is faulty, and the air pump needs to be repaired or replaced. After checking that all equipment in the testing system is correct, the parameters such as the single refueling test time, fuel inlet flow rate, and number of repetitions are set. The fuel dispenser gas-liquid ratio testing fixture is connected to the fuel tank assembly of the test vehicle. 15-20L of gasoline is added to the vehicle's fuel tank 4 in advance to create initial conditions containing vapors. The ORVR-compatible fuel dispenser number is then set.

[0082] The test begins by setting the refueling time in the gas-liquid ratio test unit, zeroing the reading on the fuel dispenser, and opening the fuel nozzle to start refueling at a flow rate that starts at a high level and then decreases. The fuel pump starts, and the vapor recovery system starts simultaneously, as does the vapor recovery vacuum pump. Fuel is pumped from the storage tank through the fuel dispenser and the fuel delivery pipe into the vehicle-mounted vapor recovery compatible fuel nozzle 1, and then from the fuel nozzle through the adapter and the variable diameter fuel line 3 into the vehicle's fuel tank 4. Since the fuel injection pipe diameter for vehicles meeting the China V emission standard is generally φ(28~35)mm, and the exhaust pipe is φ16mm, when the system determines that the vehicle is not equipped with a vehicle-mounted vapor recovery system (i.e., the refueling vehicle does not have a vehicle-mounted vapor recovery system), the air pump 2 is stationary, the air pump does not work, the air bladder in the variable diameter fuel line 3 is not inflated, and the inner tube of the variable diameter fuel line 3 is in a relaxed state. For vehicles meeting the China VI emission standard, the diameter of the fuel injection pipe is generally less than φ28mm. Therefore, when the system determines that the vehicle is equipped with an on-board vapor recovery system (i.e., the vehicle is refueling with an on-board vapor recovery system), the air pump 2 is in operation. The air pump inflates the air bladder of the variable diameter fuel pipe 3, and the inner tube of the variable diameter fuel pipe 3 is taut, compressing the inner diameter of the fuel pipe to approximately φ25mm to achieve a sealing effect and prevent fuel vapor from being released into the atmosphere from the fuel injection pipe. At the same time, the exhaust pipe shrinks to φ(2~3)mm under the pressure to ensure smooth refueling and reduce the workload of the carbon canister. The gas-liquid ratio regulating valve is opened to the maximum, and the fuel nozzle is automatically switched on and off through the trigger lifting mechanism and crankshaft deceleration to achieve a cyclic test of the refueling process. When the refueling volume reaches 15-20L, refueling is stopped, and the refueling volume of the fuel dispenser is input into the gas-liquid ratio test unit. The gas-liquid ratio of the refueling process is calculated based on the gas-liquid volume detected by the gas flow meter 5. The measurement results can be saved or not saved as needed.

[0083] If the gas-liquid ratio is greater than 1.2, the ORVR-compatible fuel nozzle is deemed to have a qualified gas-liquid ratio for refueling vehicles meeting China V emission standards, and its gas-liquid ratio adjustment capability is normal. A second and third test can be performed, and the average gas-liquid ratio will be displayed after all three tests. If the gas-liquid ratio is less than 0.5, the ORVR-compatible fuel nozzle is deemed to have a qualified gas-liquid ratio for refueling vehicles meeting China VI emission standards, and its gas-liquid ratio adjustment capability is normal. A second and third test can be performed, and the average gas-liquid ratio will be displayed after all three tests. If the gas-liquid ratio is greater than 0.5 but less than 1.2, the gas-liquid ratio adjustment valve of the ORVR-compatible fuel nozzle is deemed to be malfunctioning.

[0084] This invention can automatically perform continuous gas-liquid ratio testing on ORVR-compatible fuel nozzles for China V and China VI fuel tanks. Before the test begins, a short refueling time N is set in the gas-liquid ratio testing unit, the reading on the fuel dispenser is reset to zero, and the fuel nozzle is opened to start refueling at a flow rate that starts at a high level and then decreases. The fuel pump starts, and the vapor recovery system starts simultaneously, as does the vapor recovery vacuum pump. Fuel is pumped from the storage tank through the fuel dispenser and the fuel delivery pipe into the vehicle-mounted vapor recovery compatible fuel nozzle 1, and then from the fuel nozzle through the adapter and the variable diameter fuel line 3 into the vehicle's fuel tank 4. The tester detects the gas-liquid ratio of the ORVR fuel nozzle corresponding to the China V fuel tank using the gas-liquid ratio testing unit. When the preset refueling time N is reached, the air pump 2 automatically starts, the variable diameter fuel line 3 is in a taut state, and the gas-liquid ratio testing unit automatically calculates the gas-liquid ratio of the ORVR fuel nozzle corresponding to the China VI fuel tank. When the preset refueling time 2N is reached again, the air pump 2 is turned off, the variable diameter fuel line 3 is in a relaxed state, and the gas-liquid ratio testing unit automatically recalculates the gas-liquid ratio of the ORVR fuel nozzle corresponding to the China V fuel tank. By repeating the above operations, the gas-liquid ratio can be automatically circulated and tested when refueling the fuel tanks of two different vehicle models without removing the nozzle. This allows for the determination of the service life of the vehicle-mounted vapor recovery refueling nozzle sensing valve.

[0085] In summary, the system described in this invention can perform gas-liquid ratio testing on-site at gas stations for vehicles meeting China V and China VI emission standards using ORVR-compatible refueling nozzles of different brands and models. The system controls parameters and adjusts the refueling pipe diameter to achieve oil liquid seal, flow rate regulation, and oil supply for the on-board vapor recovery system testing fixture. Different gas-liquid ratios are set for different vehicle models, regardless of whether they have an on-board vapor recovery system, to meet the vapor recovery requirements of China V and China VI vehicle fuel tanks. Data acquisition and display functions are used to statistically analyze the gas-liquid ratio parameters of the ORVR refueling nozzle. Its portable, integrated, and highly accurate features provide a basis for the gas-liquid ratio calibration of on-board vapor recovery compatible refueling nozzles in different application scenarios.

[0086] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A fuel dispenser gas-liquid ratio testing system compatible with vehicle-mounted vapor recovery systems, characterized in that, The system includes: The refueling unit includes a variable diameter oil pipe (3) and an air pump (2). The variable diameter oil pipe (3) has a double-layer structure and an air bladder formed by the two-layer structure. The air pump (2) can inflate and deflate the air bladder. During refueling, the oil inlet end of the variable diameter oil pipe (3) is connected to the refueling nozzle (1), and the oil outlet end is connected to the vehicle's fuel tank (4). A gas-liquid ratio testing unit is used to test the gas-liquid ratio in the refueling nozzle (1) during refueling; and The control unit is configured to: shut down the air pump (2) when it is determined that the refueling vehicle does not have an on-board oil vapor recovery system; and start the air pump (2) to inflate the airbag when it is determined that the refueling vehicle has an on-board oil vapor recovery system, so that the refueling pipe diameter of the variable diameter oil pipe (3) becomes smaller.

2. The system according to claim 1, characterized in that, The variable diameter tubing (3) has a double-layer structure consisting of a metal outer layer and a rubber inner layer.

3. The system according to claim 1 or 2, characterized in that, The variable diameter oil pipe (3) also has a hose for connecting to the car's fuel tank. The hose has a five-layer structure, and the materials from the inner layer to the outer layer are, in order, nitrile rubber, hydrogenated nitrile rubber, fluororubber, a polymer of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride and chlorosulfonated polyethylene.

4. The system according to claim 1 or 2, characterized in that, The gas-liquid ratio testing unit includes an oil-gas flow meter (5), which is connected to a sealing adapter installed at the nozzle of the refueling gun (1).

5. The system according to claim 4, characterized in that, The gas-liquid ratio testing unit further includes a calculation module, which is configured to calculate the gas-liquid ratio based on the gas volume obtained by the gas flow meter (5) and the refueling volume provided by the refueling device that delivers gasoline to the refueling nozzle (1).

6. The system according to claim 4, characterized in that, The oil and gas flow meter (5) is a Roots flow meter.

7. The system according to claim 1 or 2, characterized in that, The system also includes a data acquisition and display unit for acquiring, displaying and storing various parameters during the refueling process. These parameters include: refueling volume, oil-gas volume, air pump status, detection time, gas-liquid ratio, real-time refueling flow rate, real-time return flow rate and real-time gas-liquid ratio.

8. A method for testing the gas-liquid ratio of a fuel nozzle compatible with an on-board vapor recovery system, characterized in that, This method employs the vehicle-mounted vapor recovery system compatible refueling nozzle gas-liquid ratio testing system described in any one of claims 1-7, and the method includes: Connect the variable diameter oil pipe (3) to the vehicle's fuel tank (4) and refuel through the fuel nozzle (1); When the system determines that the refueling vehicle does not have an on-board vapor recovery system, the air pump (2) is turned off, the air bladder of the variable diameter oil pipe (3) is not inflated, and the inner tube of the variable diameter oil pipe (3) is in a relaxed state; when the system determines that the refueling vehicle has an on-board vapor recovery system, the air pump (2) is turned on to inflate the air bladder, so that the inner tube of the variable diameter oil pipe (3) is in a taut state. The volume of oil and gas in the refueling nozzle (1) is detected during refueling, and the gas-liquid ratio of the refueling nozzle is determined based on the volume of refueling volume of the refueling nozzle (1).

9. The method according to claim 8, characterized in that, The method further includes: comparing the gas-liquid ratio detection value with the preset gas-liquid ratio value to determine whether the gas-liquid ratio regulating valve function of the refueling gun (1) is effective.

10. The method according to claim 9, characterized in that, The process of determining whether the gas-liquid ratio regulating valve of the refueling nozzle (1) is effective includes: When the refueling vehicle does not have an on-board vapor recovery system, if the vapor-liquid ratio detection value is greater than or equal to 1.2, the vapor-liquid ratio regulating valve function of the refueling nozzle (1) is determined to be effective. When a refueling vehicle is equipped with an on-board vapor recovery system, if the vapor-liquid ratio detection value is less than or equal to 0.5, the vapor-liquid ratio regulating valve function of the refueling nozzle (1) is deemed to be effective. If the gas-liquid ratio detection value is greater than 0.5 and less than 1.2, it is determined that the gas-liquid ratio regulating valve function of the refueling gun (1) is malfunctioning.

11. The method according to any one of claims 8-10, characterized in that, The method further includes: when the system determines that the refueling vehicle does not have an on-board vapor recovery system, setting the gas-liquid ratio of the refueling nozzle (1) to 1-1.2; When the system determines that the refueling vehicle has an on-board vapor recovery system, the gas-liquid ratio of the refueling nozzle (1) is set to below 0.5.

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