Testing device and testing method for the original hydrocarbon emission of automobile fuel tank refueling and verification device and verification method for the adsorption capacity of activated carbon canister

Abstract

The present invention discloses a testing device and a testing method for the original hydrocarbon emission of a fuel tank of an automobile, and a verification device and a verification method for the adsorption capacity of an activated carbon canister. The testing device comprises a constant temperature fuel tank, a test fuel tank and a data acquisition controller; a constant flow metering pump is arranged on the connecting pipe between the constant temperature fuel tank and the test fuel tank; an outlet of the test fuel tank is connected to an outlet pipe, an outlet pressure sensor, a gas flow meter and a hydrocarbon concentration detector are installed on the outlet pipe, and a fuel tank temperature sensor and a fuel tank thermostat are installed inside the test fuel tank. The device can quickly measure the original hydrocarbon emission during refueling, and provide data support for the design and development of a vehicle-mounted fuel gas recovery system, especially the design of an activated carbon canister.

Description

Technical Field

[0001] The invention relates to the field of automobile technology, in particular to a testing device and measuring device for the original hydrocarbon emission of an automobile oil tank, a measuring method and a testing method thereof, and a verification device and a verification method for the adsorption capacity of an activated carbon canister. Background Art

[0002] The hydrocarbon emissions from the evaporation of gasoline vehicle fuel account for 20% of the total hydrocarbon emissions of the vehicle, and the pollutant emissions from gasoline vehicles cannot be ignored. The pollutants from the evaporation of gasoline vehicle fuel mainly come from operating emissions, daytime emissions, hot soak emissions and refueling emissions. Among them, the pollution generated by refueling emissions in a short period of time is much greater than other evaporative emissions. The National VI emission standard specifically adds a Type VII test (i.e., refueling pollutant emission test) to control refueling pollutant emissions, and stipulates that the refueling emissions of a single vehicle are less than 0.05g / test. The existing National V fuel system is difficult to meet the requirements.

[0003] For the control of refueling emissions, the current tendency is to add an on-board refueling gas recovery device. The design of this device involves the redesign of the fuel tank, refueling pipe, activated carbon canister, etc., especially the matching of the activated carbon canister and the fuel tank. For different models, in order to match the overall vehicle layout, the appearance varies greatly, resulting in a large change in the original hydrocarbon emissions during the refueling process of the fuel tank. The activated carbon canister needs to be repeatedly tested and designed to meet the requirements of the National VI emission standards. The currently commonly used test method is the closed chamber method. The general large-scale closed chamber equipment used is complex to operate, the test cost is high, and the test cycle is long, which greatly increases the development cost of the on-board refueling gas recovery device. Summary of the invention

[0004] The purpose of the present invention is to provide a testing device for the original hydrocarbon emissions during refueling of a vehicle tank, in order to address the defects of the existing large-scale closed chamber equipment in the prior art, such as complex operation, high test cost and long test cycle. The device can quickly measure the original hydrocarbon emissions during refueling, and provide data support for the design and development of the vehicle-mounted refueling oil and gas recovery system, especially the design of the activated carbon canister.

[0005] Another object of the present invention is to provide a method for measuring and calculating the original hydrocarbon emissions of a fuel tank of an automobile, which is simple to test, easy to operate, has a short test period and low test cost;

[0006] Another object of the present invention is to provide a verification device for the adsorption capacity of an activated carbon canister, by adding a detachable activated carbon canister to the test device.

[0007] Another object of the present invention is to provide a verification method for the verification device, by measuring and calculating the hydrocarbon leakage before and after the activated carbon canister is assembled, thereby judging whether the adsorption capacity of the activated carbon canister meets the requirements.

[0008] The technical solution adopted to achieve the purpose of the present invention is:

[0009] A device for testing the original hydrocarbon emissions of a car tank after refueling, comprising a constant temperature oil storage tank, a test oil tank and a data acquisition controller; a constant flow metering pump is arranged on the connecting pipe between the constant temperature oil storage tank and the test oil tank;

[0010] The air outlet of the test oil tank is connected to an air outlet pipe, on which are installed an air outlet pressure sensor, a gas flow meter and a hydrocarbon concentration detector which are communicatively connected to the data acquisition controller; and inside the test oil tank are installed an oil tank temperature sensor and an oil tank thermostat which are communicatively connected to the data acquisition controller.

[0011] In the above technical solution, the data acquisition controller is provided with an ambient temperature sensor and an ambient pressure sensor, the analog signal input interface of the data acquisition controller is communicatively connected with the measurement signal output ports of the outlet pressure sensor, the fuel tank temperature sensor, the gas flow meter, the ambient temperature sensor and the ambient pressure sensor, the COM interface of the data acquisition controller is communicatively connected with the output port of the hydrocarbon concentration detector, and the analog signal output interface of the data acquisition controller is communicatively connected with the control signal input interface of the fuel tank thermostat.

[0012] In the above technical solution, the constant temperature oil storage tank is connected to the test oil tank through an oil return pipe, and an oil return pump is provided on the oil return pipe.

[0013] In another aspect of the present invention, the method for measuring the initial hydrocarbon emissions of a fuel tank of a vehicle comprises the following steps:

[0014] Step 1: Use the data acquisition controller to adjust the temperature of the constant temperature fuel tank so that the fuel temperature reaches the test required temperature T refuel , adjust the fuel tank thermostat to make the fuel temperature in the test tank reach the test required temperature T tank ;

[0015] Step 2: Initialize the data acquisition controller and set the constant flow metering pump refueling rate V refuel and refueling volume V gasoline , turn on the constant flow metering pump, start refueling, and the data acquisition controller measures the refueling time t refuel , measure the fuel temperature T in the test tank during refueling tank , outlet pressure P out , Gas flow rate at the outlet V mix and hydrocarbon concentration C HC The curves of the four changing with time; t refuel The unit is s, P out The unit is Pa, Vmix The unit is m 3 / s,C HC The unit is %;

[0016] Step 3: The data acquisition controller Calculate the original carbon and hydrogen emissions, where m HC is the original carbon and hydrogen emission during refueling, in g, R is the gas constant, in J / mol·K, M HC is the molecular weight of gasoline vapor, in g / mol.

[0017] Another aspect of the present invention further includes a verification device for the adsorption capacity of the activated carbon canister based on the testing device, and also includes an activated carbon canister that is detachably mounted on the outlet pipe and located between the pressure sensor and the gas flow meter.

[0018] In another aspect of the present invention, the verification method of the verification device comprises the following steps:

[0019] Step 1: Without installing the activated carbon canister, measure the original hydrocarbon emissions during refueling according to the measurement method m HC ;

[0020] Step 2: Based on the m obtained in step 1 HC Determine the target value m of the carbon and hydrogen adsorption capacity of the activated carbon canister in the vehicle refueling oil and gas emission recovery device target , where: m target =m HC / adsorption efficiency η, adsorption efficiency η = 93% to 97%, preferably 95%;

[0021] Step 3: Install an activated carbon canister with the target adsorption capacity on the outlet pipe, and measure m again according to the measurement method. HC ;

[0022] If the m obtained in step 3 HC Greater than or equal to m target *2%, it means that the activated carbon tank does not meet the demand;

[0023] If the m obtained in step 3 HC Less than m target *2%, it means that the activated carbon canister meets the demand.

[0024] Another aspect of the present invention is a device for testing the original hydrocarbon emissions of a fuel tank of an automobile, comprising a constant temperature fuel tank, a test fuel tank, and a data acquisition controller;

[0025] A constant flow metering pump is provided on the connecting pipe between the constant temperature oil storage tank and the test oil tank;

[0026] The air outlet of the test oil tank is connected to an air outlet pipe, and the air outlet pipe is equipped with the air outlet pressure sensor which is communicatively connected to the data acquisition controller. The inside of the test oil tank is equipped with an oil tank temperature sensor, an oil tank pressure sensor, an oil level height sensor and an oil tank thermostat which are communicatively connected to the data acquisition controller.

[0027] In the above technical solution, an ambient temperature sensor and an ambient pressure sensor are provided on the data acquisition controller, and the analog signal input interface of the data acquisition controller is communicatively connected with the measurement signal output ports of the outlet pressure sensor, the fuel tank temperature sensor, the fuel tank pressure sensor, the oil level sensor, the ambient temperature sensor and the ambient pressure sensor, and the analog signal output interface of the data acquisition controller is communicatively connected with the control signal input interface of the fuel tank thermostat.

[0028] In the above technical solution, the constant temperature oil storage tank is connected to the test oil tank through an oil return pipe, and an oil return pump is provided on the oil return pipe.

[0029] The measuring method of the test device for the initial hydrocarbon emission of the automobile fuel tank is characterized by comprising the following steps:

[0030] Step 1: Use the data acquisition controller to adjust the temperature of the constant temperature fuel tank so that the fuel temperature reaches the test required temperature T refuel , adjust the fuel tank thermostat to make the fuel temperature in the test tank reach the test required temperature T tank ;

[0031] Step 2: Initialize the data acquisition controller and set the constant flow metering pump refueling rate V refuel and refueling volume V gasoline , turn on the constant flow metering pump and start refueling;

[0032] Step 3: The data acquisition controller measures the temperature T in the test oil tank through the oil tank temperature sensor tank The pressure P in the fuel tank is measured by the fuel tank pressure sensor over time t. tank The oil level sensor measures the oil level H as time t changes. surf As time t changes, the outlet pressure P is measured by the outlet pressure sensor. out As time t changes, when the set refueling volume is reached, refueling stops;

[0033] Step 4: Calculate the original carbon and hydrogen emissions m according to the calculation formula HC The measured values, specifically:

[0034] S1, calculate the change of gas-liquid interface area in the test tank over time:

[0035]

[0036] Among them, H surf is the oil level height, in m, H0 is the oil level height in the test tank before refueling, in m, both are measured by the oil level sensor, S surf It is the gas-liquid interface area in the test tank after refueling is completed, in m 2 , S0 is the gas-liquid interface area in the test tank before refueling, unit is m 2 , conduct test measurements in advance to obtain the corresponding relationship table between oil level height and gas-liquid interface area, and obtain S0 corresponding to H0 by looking up the table;

[0037] S2, calculate the molar concentration C of fuel vapor at the gas-liquid interface in the test tank during refueling surf0 , the average fuel vapor molar concentration C in the oil and gas space vapor0 and the molar concentration C of the oil-gas mixture in the test tank mix

[0038]

[0039]

[0040]

[0041] Among them, P surf To add fuel at T refuel The saturated vapor pressure at temperature,

[0042] P surf =exp((a+bPrv+cPrv 2 )-(d+ePrv+fPrv 2 ) / T refuel )

[0043] Where Prv is the Reid vapor pressure of gasoline, which is 61000Pa. The coefficients a = 20.657; b = 2.0539e-6; c = -4.2736e-11; d = 3532.8; e = -0.012136; f = 4.5591e-8 are from the following literature: Huang Weiqiu, Zhong Qin. Numerical analysis of non-steady-state oil evaporation and application examples. Acta Petrolei Sinica (Petroleum Processing), 2004, 20(1): 52-57.

[0044] ε surf is the saturation of the added fuel, with a value of 0.9-1.0, dimensionless, P vapor The fuel vapor in the test tank is T tank The unit of saturated vapor pressure at temperature is Pa, which is the same as P surf The calculation formula is the same as ε vaporis the saturation of fuel vapor in the test tank, with a value of 0.9-1.0, dimensionless, P tank is the pressure in the test tank, in Pa, R is the gas constant, in J / (mol·K), and Z is the compressibility factor of the gas, which is 0.951 for an ideal gas;

[0045] S3, according to the time-varying diffusion principle, calculate the original hydrocarbon emission m from the outlet during refueling HC

[0046]

[0047] Where m HC is the molecular weight of gasoline vapor, in g / mol, S surf From formula (2), we can get N out From formula (7), we can get

[0048]

[0049] In formula (7), C surf0 From formula (3), we can get C vapor0 From formula (4), we can get

[0050] U surf is the oil level rising speed, obtained from formula (8), the oil level height H surf Measured by the oil level sensor;

[0051]

[0052] x vapor is the mole fraction of fuel vapor in the test tank, obtained by formula (9),

[0053]

[0054] Among them C mix From formula (5), we can get C vapor0 From formula (4), we get:

[0055] is the turbulent diffusion coefficient, which is obtained from formula (10):

[0056]

[0057] Where Re = ρU surf d / μ,U surf is the oil surface rising speed, which is calculated by formula (8), ρ and μ are the density of the oil-gas mixture, respectively, in kg / m 3 , and dynamic viscosity, in N·s / m 2, which can be obtained by consulting the Handbook of Chemical Calculation (Nicholas P. Chopey. Handbook of Chemical Calculation, China Petrochemical Press, Beijing, 2005); d is the equivalent diameter of the mass transfer interface of the oil tank, in m, d = H surf / L surf , where S surf is the gas-liquid interface area, obtained from formula (2), L surf is the perimeter of the gas-liquid interface, obtained by measuring the perimeter of the cross section at different heights from the bottom plane of the tank, in meters;

[0058] D AB is the laminar diffusion coefficient, is the dimensionless molar average velocity, which can be obtained from formula (11):

[0059]

[0060] where x vapor From formula (9), we can get x surf is the mole fraction of fuel vapor at the oil surface in the test tank, obtained by formula (12),

[0061]

[0062] Among them C mix From formula (5), we can get C surf0 Obtained by formula (3).

[0063] The verification device for the adsorption capacity of the activated carbon canister based on the test device also includes an activated carbon canister detachably mounted on the outlet pipe, and along the gas flow direction, the activated carbon canister is located downstream of the outlet pressure sensor.

[0064] The verification method of the verification device is characterized by comprising the following steps:

[0065] Step 1: Without installing the activated carbon canister, measure the original hydrocarbon emissions during refueling according to the measurement method m HC ;

[0066] Step 2: Based on the m obtained in step 1 HC Determine the target value m of the carbon and hydrogen adsorption capacity of the activated carbon canister in the vehicle refueling oil and gas emission recovery device target , where: m target =m HC / adsorption efficiency η, adsorption efficiency η = 93% to 97%, preferably 95%;

[0067] Step 3: Install an activated carbon canister with the target adsorption capacity on the outlet pipe, and measure m again according to the measurement method. HC ;

[0068] If the m obtained in step 3 HC Greater than or equal to m target *2%, it means that the activated carbon tank does not meet the demand;

[0069] If the m obtained in step 3 HC Less than m target *2%, it means that the activated carbon canister meets the demand.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] 1. The test device has a simple structure and can quickly measure the original hydrocarbon emissions during refueling, with a short test cycle;

[0072] 2. The original hydrocarbon emissions during refueling can be measured without hydrocarbon concentration detector and gas flow meter, and the test cost is low;

[0073] 3. It can conveniently measure the original hydrocarbon emissions during refueling, and provide data support for the design and development of vehicle refueling gas recovery system, especially the design of activated carbon tank;

[0074] 4. The test device for the adsorption capacity of the activated carbon canister is suitable for the determination of the original hydrocarbon emissions of activated carbon canisters of various shapes and specifications. It is possible to determine whether the adsorption capacity of the activated carbon canister meets the requirements without repeated tests and designs. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 The figure shows the structure schematic diagram of the test device for the initial hydrocarbon emission of refueling in the automobile tank in Example 1.

[0076] Figure 2 Shown is a schematic structural diagram of the verification of the adsorption capacity of the activated carbon canister in Example 1.

[0077] Figure 3 The figure shows the structure schematic diagram of the test device for the initial hydrocarbon emission of refueling in the automobile tank in Example 2.

[0078] In the figure: 1-data acquisition controller; 2-ambient temperature sensor; 3-ambient pressure sensor; 4-oil inlet pipe; 5-fuel pipe; 6-constant flow metering pump; 7-constant temperature oil storage tank; 8-return oil pump; 9-return oil pipe; 10-test oil tank; 11-gas flow meter; 12-exhaust pipe; 13-exhaust pressure sensor; 14-hydrocarbon concentration detector; 15-oil tank temperature sensor; 16-oil tank thermostat; 17-oil tank pressure sensor; 18-oil level sensor; 19-oil extraction pipe; 20-activated carbon tank DETAILED DESCRIPTION

[0079] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0080] Example 1

[0081] A testing device for the original hydrocarbon emission of a car tank after refueling, comprising a constant temperature oil storage tank 7, a test oil tank 10 and a data acquisition controller 1; a constant flow metering pump 6 is arranged on the connecting pipe between the constant temperature oil storage tank 7 and the test oil tank 10;

[0082] The gas outlet of the test oil tank 10 is connected to an outlet pipe 12, on which an outlet pressure sensor 13, a gas flow meter 11 and a hydrocarbon concentration detector 14 are installed, and a tank temperature sensor 15 and a tank thermostat 16 are installed inside the test oil tank 10;

[0083] The data acquisition controller 1 is communicatively connected with the gas outlet pressure sensor 13 , the gas flow meter 11 , the hydrocarbon concentration detector 14 , the fuel tank temperature sensor 15 and the fuel tank thermostat 16 , respectively.

[0084] The refueling rate and refueling volume are set by the constant flow metering pump 6 , and the data acquisition controller 1 can also be connected to the constant flow metering pump 6 for communication, so as to set the refueling rate and refueling volume by the data acquisition controller 1 .

[0085] From the side close to the gas outlet, the gas outlet pressure sensor 13, the gas flow meter 11 and the hydrocarbon concentration detector 14 are sequentially installed on the gas outlet pipe 12 to improve the accuracy of the measurement result.

[0086] As a preferred embodiment, the data acquisition controller 1 is provided with an ambient temperature sensor 2 and an ambient pressure sensor 3. The analog signal input interface of the data acquisition controller 1 is communicatively connected with the outlet pressure sensor 13, the fuel tank temperature sensor 15, the gas flow meter 11 and the measurement signal output ports of the ambient temperature sensor 2 and the ambient pressure sensor 3. The COM interface of the data acquisition controller 1 is communicatively connected with the output port of the hydrocarbon concentration detector 14. The analog signal output interface of the data acquisition controller 1 is communicatively connected with the control signal input interface of the fuel tank thermostat 16. The measured value of the hydrocarbon concentration detector 14 is read through the COM interface using the modbus protocol, and the original hydrocarbon emission during the refueling process is calculated by the calculation formula (1) in combination with the refueling time.

[0087] The specific measurement and calculation methods are as follows:

[0088] First, the data acquisition controller controls the temperature thermostat in the test oil tank and the adjustable constant temperature oil storage tank so that the added fuel temperature T refueland the temperature in the oil tank T tank After the state stabilizes, the refueling rate V is set by the adjustable constant flow metering pump. refuel and refueling volume V gasoline , start refueling. During the refueling process, the data acquisition controller records in real time the measurement values ​​of the ambient temperature sensor 2, ambient pressure sensor 3, fuel tank temperature sensor 15, fuel tank pressure sensor 17, oil level sensor 18, gas flow meter 11 and hydrocarbon concentration detector 14 as a function of time t. The measurement value of the ambient pressure sensor 2 is used as the benchmark for other sensors, and the ambient temperature sensor 3 is used to correct the measurement value of the high-sensitivity gas flow meter. Since the temperature inside the fuel tank is between 20-40°C and the absolute pressure is around 1 standard atmosphere, the oil-gas mixture escaping from the fuel tank is in an ideal gas state, which can be calculated using the ideal gas state equation using the refueling time t refuel (Unit: s), flow meter flow data V mix (Unit: m 3 / s), outlet pressure P out (Unit: Pa), oil tank temperature T tank (Unit: K) and hydrocarbon concentration C HC (Unit: %), calculate the original carbon and hydrogen emissions during refueling m HC (Unit: g).

[0089] Calculation formula:

[0090]

[0091] Where R is the gas constant (unit: J / (mol·K)), m HC is the molecular weight of gasoline vapor (unit: g / mol), which is a known quantity. The gas constant R can be found in the following literature: Moran and Shapiro, Fundamentals of Engineering Thermodynamics, Wiley, 4th Ed, 2000. The molecular weight of gasoline vapor M HC It can be found in the following literature: Huang Weiqiu, Zhong Qin. Numerical analysis of non-steady-state oil evaporation and application examples. Acta Petrolei Sinica (Petroleum Processing), 2004, 20(1): 52-57.

[0092] As a preferred embodiment, the constant temperature oil storage tank 7 is connected to the test oil tank 10 via a return oil pipe 9, and a return oil pump 8 is provided on the return oil pipe 9. After the test is completed, the gasoline in the test oil tank is pumped back to the adjustable constant temperature oil storage tank through the return oil pump to facilitate the next test.

[0093] Example 2

[0094] Based on Example 1, verification of the adsorption capacity of the activated carbon canister:

[0095] Step 1: Without installing the activated carbon canister 20, measure the original carbon and hydrogen emissions m during refueling according to Example 1. HC ;

[0096] Step 2: Based on the m obtained in step 1 HC Determine the target value m of the carbon and hydrogen adsorption capacity of the activated carbon canister in the vehicle refueling oil and gas emission recovery device target , where: m target =m HC / adsorption efficiency η, adsorption efficiency η = 93% to 97%, preferably 95%;

[0097] Step 3, such as Figure 2 As shown, the target adsorption capacity m target The activated carbon canister (20) is installed on the outlet pipe (12) and is located between the outlet pressure sensor (13) and the gas flow meter (11). According to Example 1, m is measured again. HC According to the calculation method of Example 1, the hydrocarbon leakage after the activated carbon canister is installed is calculated again by formula (1) and the m is measured again. HC ;

[0098] If the m obtained in step 3 HC Greater than or equal to m target *2%, it means that the activated carbon canister (20) does not meet the demand;

[0099] If the m obtained in step 3 HC Less than m target *2%, it means that the activated carbon canister (20) meets the requirements.

[0100] Example 3

[0101] Compared with Example 2, this embodiment can further reduce the cost of the test device.

[0102] A test device for the original hydrocarbon emission of a fuel tank of an automobile, comprising a constant temperature fuel tank 7, a test fuel tank 10 and a data acquisition controller 1, wherein the data acquisition controller 1 is connected with an ambient temperature sensor 2 and an ambient pressure sensor 3, and the data acquisition controller 1 receives data from the ambient temperature sensor 2 and the ambient pressure sensor 3 through an analog signal input interface;

[0103] A constant flow metering pump 6 is connected to the pipeline between the constant temperature oil storage tank 7 and the test oil tank 10, and a refueling pipe 5 is provided at the oil outlet of the constant flow metering pump 6, and the refueling pipe 5 is connected to the oil inlet pipe 4 of the test oil tank 10, and an oil extraction pipe 19 is provided at the oil inlet of the constant flow metering pump 6, and the oil extraction pipe 19 is connected to the constant temperature oil storage tank 7; the constant flow metering pump 6 can set the refueling rate V refuel and refueling volume V gasoline ;

[0104] The air outlet of the test oil tank 10 is connected to an air outlet pipe 12, and an air outlet pressure sensor 13 is installed on the air outlet pipe 12. The test oil tank 10 is internally installed with an oil tank temperature sensor 15, an oil tank pressure sensor 17, an oil level sensor 18, and an oil tank thermostat 16;

[0105] The data acquisition controller 1 is provided with an ambient temperature sensor 2 and an ambient pressure sensor 3 (the measurement value of the ambient pressure sensor 2 is used as a reference for other sensors, and the ambient temperature sensor 3 is used to correct the measurement value of a high-sensitivity gas flow meter). The analog signal input interface of the data acquisition controller 1 is communicatively connected with the measurement signal output ports of the outlet pressure sensor 13, the fuel tank temperature sensor 15, the fuel tank pressure sensor 17, the oil level sensor 18, the ambient temperature sensor 2 and the ambient pressure sensor 3. The analog signal output interface of the data acquisition controller 1 is communicatively connected with the control signal input interface of the fuel tank thermostat 16.

[0106] As a preferred embodiment, the constant temperature oil storage tank 7 is connected to the test oil tank 10 via a return oil pipe 9, and a return oil pump 8 is provided on the return oil pipe 9. After the test is completed, the gasoline in the test oil tank 10 is pumped back to the constant temperature oil storage tank 7 via the return oil pump 8 to facilitate the next test.

[0107] The specific measurement and calculation methods are as follows:

[0108] First, the temperature of the controllable constant temperature oil storage tank is adjusted by the data acquisition controller 1 so that the fuel temperature reaches the test required temperature T refuel , such as 30°C. Adjust the fuel tank thermostat 16 so that the fuel temperature in the test tank reaches the test required temperature T tank , such as 35℃. After the temperature stabilizes, initialize the data acquisition controller and set the constant flow metering pump refueling rate V refuel , such as 35L / min, set the refueling volume V gasoline For example, 45L. Turn on the constant flow metering pump 6 and start the refueling operation. The data acquisition controller 1 measures the temperature T in the test oil tank through the oil tank temperature sensor 15. tank The oil tank pressure sensor 17 measures the oil tank pressure P tank The oil level H is measured by the oil level sensor 18.；urf The outlet pressure P is measured by the outlet pressure sensor 13. out , the data acquisition controller 1 can collect T tank , P tank , H surf and P out The four change with time t. When the set refueling volume is reached, refueling stops. The data acquisition controller 1 calculates the original carbon and hydrogen emission m by recording the data according to the calculation formula (2-12) HC measured or predicted value.

[0109] Specifically, (1) calculate the change of the gas-liquid interface area in the test tank with time t

[0110] Since the refueling rate is constant at V refuel (Unit: L / min), oil level height H surf (unit: m), is the oil level rising speed, oil level rising speed and gas-liquid interface area S surf (Unit: m 2 ) have the following relationship

[0111]

[0112] Among them, H0 is the oil level height in the test tank before refueling (unit: m), S0 is the gas-liquid interface area in the test tank before refueling (unit: m) 2 The corresponding relationship table between the oil level height and the gas-liquid interface area is obtained by conducting test measurements in advance, and the S0 corresponding to H0 is obtained by looking up the table.

[0113] (2) Calculate the molar concentration C of the fuel vapor at the gas-liquid interface in the test tank during refueling surf0 (Unit: mol / m 3 ), the average fuel vapor molar concentration C in the oil and gas space vapor0 (Unit: mol / m 3 ) and the molar concentration of the oil-gas mixture in the test tank C mix (Unit: mol / m 3 );

[0114]

[0115]

[0116]

[0117] Among them, P surf To add fuel at T refuel The saturated vapor pressure at temperature,

[0118] Psurf =exp((a+bPrv+cPrv 2 )-(d+ePrv+fPrv 2 ) / T refuel )

[0119] Where Prv is the Reid vapor pressure of gasoline, which is 61000Pa. The coefficients a = 20.657; b = 2.0539e-6; c = -4.2736e-11; d = 3532.8; e = -0.012136; f = 4.5591e-8 are from the following literature: Huang Weiqiu, Zhong Qin. Numerical analysis of non-steady-state oil evaporation and application examples. Acta Petrolei Sinica (Petroleum Processing), 2004, 20(1): 52-57.

[0120] ε surf is the saturation of the added fuel, with a value of 0.9-1.0, dimensionless, P vapor The fuel vapor in the test tank is T tank The unit of saturated vapor pressure at temperature is Pa, which is the same as P surf The calculation formula is the same as ε vapor is the saturation of fuel vapor in the test tank, with a value of 0.9-1.0, dimensionless, P tank is the pressure in the test tank, in Pa, R is the gas constant, in J / (mol·K), and Z is the compressibility factor of the gas, which is 0.951 for an ideal gas;

[0121] Since the pressure P in the test tank is tank and T tank Changes occur in real time, thus affecting the actual vapor pressure and molar concentration of fuel vapor at the gas-liquid interface and in the oil-gas space;

[0122] (3) According to the time-varying diffusion principle, calculate the original hydrocarbon emission m from the outlet during refueling. HC

[0123]

[0124] Where m HC is the molecular weight of gasoline vapor (can be found in the following literature: Huang Weiqiu, Zhong Qin. Numerical analysis of non-steady-state oil evaporation and its application examples. Acta Petrolei Sinica (Petroleum Processing), 2004, 20(1): 52-57.), unit is g / mol, S surf From formula (2), we can get N out From formula (7), we can get

[0125]

[0126] In formula (7), Csurf0 From formula (3), we can get C vapor0 From formula (4), we can get

[0127] U surf is the oil level rising speed, obtained from formula (8):

[0128]

[0129] x vapor is the mole fraction of fuel vapor in the test tank, obtained by formula (9),

[0130]

[0131] Among them C mix From formula (5), we can get C vapor0 Obtained by formula (4).

[0132] is the turbulent diffusion coefficient, which is obtained from formula (10):

[0133]

[0134] Where Re = ρU surf d / μ,U surf is the oil surface rising speed, which is calculated by formula (8), ρ and μ are the density of the oil-gas mixture, respectively, in kg / m 3 , and dynamic viscosity, in N·s / m 2 , which can be obtained by consulting the Handbook of Chemical Calculation (Nicholas P. Chopey. Handbook of Chemical Calculation, China Petrochemical Press, Beijing, 2005); d is the equivalent diameter of the mass transfer interface of the oil tank, in m, d = S surf / L surf , where S surf is the gas-liquid interface area, obtained from formula (2), L surf D is the perimeter of the gas-liquid interface, obtained by measuring the perimeter of the cross section at different heights from the bottom plane of the tank, in meters. AB is the laminar diffusion coefficient, which can be obtained by looking up the Handbook of Chemical Engineering Calculation (Nicholas P. Chopey. Handbook of Chemical Engineering Calculation, China Petrochemical Press, Beijing, 2005).

[0135] is the dimensionless molar average velocity, which can be obtained from formula (11):

[0136]

[0137] where x vapor From formula (9), we can get x surfis the mole fraction of fuel vapor at the oil surface in the test tank, obtained by formula (12),

[0138]

[0139] Among them C mix From formula (5), we can get C surf0 Obtained by formula (3).

[0140] Example 4

[0141] This example is based on Example 3, and verifies the adsorption capacity of the activated carbon canister:

[0142] Step 1: Without installing the activated carbon canister 20, measure the original carbon and hydrogen emissions m during refueling according to Example 3. HC ;

[0143] Step 2: Based on the m obtained in step 1 HC Determine the target value m of the carbon and hydrogen adsorption capacity of the activated carbon canister in the vehicle refueling oil and gas emission recovery device target , where: m target =m HC / adsorption efficiency η, adsorption efficiency η = 93% to 97%, preferably 95%;

[0144] Step 3, such as Figure 2 As shown, an activated carbon canister (20) having the target adsorption capacity is installed on the outlet pipe (12) and is located between the outlet pressure sensor (13) and the gas flow meter (11). According to Example 3, m is measured again. HC According to the calculation method of Example 3, the hydrocarbon leakage after the activated carbon canister is installed is calculated again by formula (1), and m is measured again. HC ;

[0145] If the m obtained in step 3 HC Greater than or equal to m target *2%, it means that the activated carbon canister (20) does not meet the demand;

[0146] If the m obtained in step 3 HC Less than m target *2%, it means that the activated carbon canister (20) meets the requirements

[0147] The sensors in the above embodiments may adopt the models listed in Table 1 below, or other models that can implement the technical solutions of the present invention.

[0148]

[0149] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to illustrate the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "on" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0150] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0151] The above is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A testing device for the initial hydrocarbon emissions of a vehicle tank after refueling, characterized in that: It comprises a constant temperature oil storage tank (7), a test oil tank (10) and a data acquisition controller (1); a constant flow metering pump (6) is arranged on the connecting pipe between the constant temperature oil storage tank (7) and the test oil tank (10); The gas outlet of the test oil tank (10) is connected to an air outlet pipe (12), and the air outlet pipe (12) is equipped with an air outlet pressure sensor (13), a gas flow meter (11) and a hydrocarbon concentration detector (14) which are communicatively connected to the data acquisition controller (1), and the test oil tank (10) is internally equipped with an oil tank temperature sensor (15) and an oil tank thermostat (16) which are communicatively connected to the data acquisition controller (1); The measuring method of the testing device comprises the following steps: Step 1: adjust the temperature of the constant temperature oil storage tank (7) through the data acquisition controller (1) so that the fuel temperature reaches the test required temperature T refuel , adjust the fuel tank thermostat (16) so that the fuel temperature in the test fuel tank (10) reaches the test required temperature T tank ; Step 2, initialize the data acquisition controller (1) and set the refueling rate V of the constant flow metering pump (6) refuel and refueling volume V gasoline , turn on the constant flow metering pump (6), start refueling, and the data acquisition controller (1) measures the refueling time t refuel , measure the fuel temperature T in the test tank during refueling tank , outlet pressure P out , Gas flow rate at the outlet V mix and hydrocarbon concentration C HC The curves of the four changing with time; t refuel The unit is s, P out The unit is Pa, V mix The unit is m 3 / s,C HC The unit is %; Step 3, the data acquisition controller (1) passes Calculate the original carbon and hydrogen emissions, where m HC is the original carbon and hydrogen emission during refueling, in g, R is the gas constant, in J / mol·K, M HC is the molecular weight of gasoline vapor, in g / mol.

2. The testing device for the initial hydrocarbon emission of a fuel tank of an automobile as claimed in claim 1, characterized in that: The data acquisition controller (1) is provided with an ambient temperature sensor (2) and an ambient pressure sensor (3); the analog signal input interface of the data acquisition controller (1) is communicatively connected to the outlet pressure sensor (13), the fuel tank temperature sensor (15), the gas flow meter (11), the ambient temperature sensor (2) and the measurement signal output ports of the ambient pressure sensor (3); the COM interface of the data acquisition controller (1) is communicatively connected to the output port of the hydrocarbon concentration detector (14); and the analog signal output interface of the data acquisition controller (1) is communicatively connected to the control signal input interface of the fuel tank thermostat (16).

3. A verification device for the adsorption capacity of an activated carbon canister based on the test device according to claim 1 or 2, characterized in that: It also includes an activated carbon canister (20) which is detachably mounted on the gas outlet pipe (12) and is located between the gas outlet pressure sensor (13) and the gas flow meter (11).

4. The verification method of the verification device according to claim 3, characterized in that: The steps include: Step 1: without installing the activated carbon canister (20), measure the original hydrocarbon emissions during refueling m HC ; Step 2: Based on the m obtained in step 1 HC Determine the target value m of the carbon and hydrogen adsorption capacity of the activated carbon canister in the vehicle refueling oil and gas emission recovery device target , where: m target =m HC / adsorption efficiency η, adsorption efficiency η = 93% ~ 97%; Step 3, installing an activated carbon canister (20) having the target adsorption capacity on the outlet pipe (12), and connecting the activated carbon canister (20) to the outlet of the outlet pressure sensor (13), and measuring m again according to the measurement method as claimed in claim 3 HC ; If the m obtained in step 3 HC Greater than or equal to m target *2%, it means that the activated carbon canister (20) does not meet the demand; If the m obtained in step 3 HC Less than m target *2%, it means that the activated carbon canister (20) meets the requirements.

5. A device for testing the initial hydrocarbon emissions of a car's fuel tank, characterized in that: It comprises a constant temperature oil storage tank (7), a test oil tank (10) and a data acquisition controller (1); A constant flow metering pump (6) is provided on the communication pipeline between the constant temperature oil storage tank (7) and the test oil tank (10); The air outlet of the test oil tank (10) is connected to an air outlet pipe (12), and an air outlet pressure sensor (13) is installed on the air outlet pipe (12) and is communicatively connected to the data acquisition controller (1). The test oil tank (10) is internally installed with an oil tank temperature sensor (15), an oil tank pressure sensor (17), an oil level sensor (18), and an oil tank thermostat (16) which are communicatively connected to the data acquisition controller (1); The measuring method of the testing device comprises the following steps: Step 1: Use the data acquisition controller (1) to adjust the temperature of the constant temperature oil storage tank (7) so that the fuel temperature reaches the test required temperature T refuel , adjust the fuel tank thermostat (16) so that the fuel temperature in the test fuel tank (10) reaches the test required temperature T tank ; Step 2: Initialize the data acquisition controller (1) and set the refueling rate V of the constant flow metering pump (6) refuel and refueling volume V gasoline , turn on the constant flow metering pump (6) and start refueling; Step 3: The data acquisition controller (1) measures the temperature T in the test oil tank through the oil tank temperature sensor (15). tank The pressure P in the fuel tank is measured by the fuel tank pressure sensor (17) as time t changes. tank The oil level H is measured by the oil level sensor (18) as time t changes. surf As time t changes, the outlet pressure P is measured by the outlet pressure sensor (13). out As time t changes, when the set refueling volume is reached, refueling stops; Step 4: Calculate the original carbon and hydrogen emissions m according to the calculation formula HC The measured values, specifically: S1, calculate the change of gas-liquid interface area in the test oil tank (10) over time: Among them, H surf is the oil level height, in m, H0 is the oil level height in the test tank before refueling, in m, both are measured by the oil level sensor, S surf It is the gas-liquid interface area in the test tank after refueling is completed, in m 2 , S0 is the gas-liquid interface area in the test tank before refueling, unit is m 2 , conduct test measurements in advance to obtain the corresponding relationship table between oil level height and gas-liquid interface area, and obtain S0 corresponding to H0 by looking up the table; S2, calculate the molar concentration C of fuel vapor at the gas-liquid interface in the test tank during refueling surf0 , the average fuel vapor molar concentration C in the oil and gas space vapor0 and the molar concentration C of the oil-gas mixture in the test tank mix Among them, P surf To add fuel at T refuel The saturated vapor pressure at temperature, P surf =exp((a+bPrv+cPrv 2 )-(d+ePrv+fPrv 2 ) / T refuel ) Where Prv is the Reid vapor pressure of gasoline, which is 61000Pa, coefficients a = 20.657; b = 2.0539e-6; c = -4.2736e-11; d = 3532.8; e = -0.012136; f = 4.5591e-8; ε surf is the saturation of the added fuel, with a value of 0.9-1.0, dimensionless, P vapor The fuel vapor in the test tank is T tank The unit of saturated vapor pressure at temperature is Pa, which is the same as P surf The calculation formula is the same as ε vapor is the saturation of fuel vapor in the test tank, with a value of 0.9-1.0, dimensionless, P tank is the pressure in the test tank, in Pa, R is the gas constant, in J / (mol·K), and Z is the compressibility factor of the gas, which is 0.951 for an ideal gas; S3, according to the time-varying diffusion principle, calculate the original hydrocarbon emission m from the outlet during refueling HC Among them, M HC is the molecular weight of gasoline vapor, in g / mol, S surf From formula (2), we can get N out From formula (7), we can get In formula (7), C surf0 From formula (3), we can get C vapor0 From formula (4), we can get U surf is the oil level rising speed, obtained from formula (8), the oil level height H surf Measured by the oil level sensor; x vapor is the mole fraction of fuel vapor in the test tank, obtained by formula (9), Among them C mix From formula (5), we can get C vapor0 From formula (4), we get: is the turbulent diffusion coefficient, which is obtained from formula (10): Where Re = ρU surf d / μ,U surf is the oil surface rising speed, which is calculated by formula (8), ρ and μ are the density of the oil-gas mixture, respectively, in kg / m 3 , and dynamic viscosity, in N·s / m 2 ; d is the equivalent diameter of the oil tank mass transfer interface, in m, d = S surf / L surf , where S surf is the gas-liquid interface area, obtained from formula (2), L surf is the perimeter of the gas-liquid interface, obtained by measuring the perimeter of the cross section at different heights from the bottom plane of the tank, in meters; D AB is the laminar diffusion coefficient, is the dimensionless molar average velocity, which can be obtained from formula (11): where x vapor From formula (9), we can get x surf is the mole fraction of fuel vapor at the oil surface in the test tank, obtained by formula (12), Among them C mix From formula (5), we can get C surf0 Obtained by formula (3).

6. The testing device for the initial hydrocarbon emission of a fuel tank of an automobile as claimed in claim 5, characterized in that: The data acquisition controller (1) is provided with an ambient temperature sensor (2) and an ambient pressure sensor (3); the analog signal input interface of the data acquisition controller (1) is communicatively connected to the measurement signal output ports of the outlet pressure sensor (13), the fuel tank temperature sensor (15), the fuel tank pressure sensor (17), the fuel level sensor (18), the ambient temperature sensor (2) and the ambient pressure sensor (3); and the analog signal output interface of the data acquisition controller (1) is communicatively connected to the control signal input interface of the fuel tank thermostat (16).

7. A verification device for the adsorption capacity of an activated carbon canister based on the test device as claimed in claim 5, characterized in that: It also includes an activated carbon canister (20) which is detachably mounted on the gas outlet pipe (12), and the activated carbon canister (20) is located downstream of the pressure sensor (13) along the gas flow direction.

8. The verification method based on the verification device of claim 7, characterized in that: The steps include: Step 1: without installing the activated carbon canister (20), measure the original hydrocarbon emissions during refueling m HC ; Step 2: Based on the m obtained in step 1 HC Determine the target value m of the carbon and hydrogen adsorption capacity of the activated carbon canister in the vehicle refueling oil and gas emission recovery device target , where: m target =m HC / adsorption efficiency η, adsorption efficiency η = 93% ~ 97%; Step 3, installing an activated carbon canister (20) having the target adsorption capacity on the outlet pipe (12), and connecting the activated carbon canister (20) to the outlet of the outlet pressure sensor (13), and measuring m again according to the measurement method as claimed in claim 7 HC ; If the m obtained in step 3 HC Greater than or equal to m target *2%, it means that the activated carbon canister (20) does not meet the demand; If the m obtained in step 3 HC Less than m target *2%, it means that the activated carbon canister (20) meets the requirements.

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