A hybrid vehicle high pressure tank fuel vapor emission control system and method

Abstract

This invention discloses a high-pressure fuel tank fuel evaporative emission control system and method for hybrid electric vehicles, including a high-pressure fuel tank, an engine, a charcoal canister, an evaporative emission controller, a hybrid vehicle controller, and a high-temperature desorption system. The high-pressure fuel tank stores gasoline vapors. When the fuel tank pressure reaches a threshold or before refueling, the evaporative emission controller controls the isolation valve to open, allowing the vapors in the fuel tank to flow to the charcoal canister through a pressure relief pipeline. By calculating the current charcoal canister load and communicating with the hybrid vehicle controller to obtain the hybrid vehicle's operating status, the evaporative emission controller adopts corresponding control strategies based on the charcoal canister load and the hybrid vehicle's operating status. During charcoal canister desorption, the high-temperature desorption system controlled by the evaporative emission controller can significantly improve desorption efficiency. This effectively solves the problems of low desorption efficiency and full charcoal canister load caused by the short engine operating time in hybrid electric vehicles equipped with high-pressure fuel tanks.

Description

Technical Field

[0001] This invention belongs to the field of hybrid vehicle technology, specifically relating to a control system and method for fuel evaporation emission from a high-pressure fuel tank in a hybrid vehicle. Background Technology

[0002] Hydrocarbon emissions from automobiles are a significant source of volatile organic compound (VOC) emissions into the atmosphere. In 2021, China's automobile hydrocarbon emissions reached 2.002 million tons. Hybrid electric vehicles (HEVs), as a key development path for new energy vehicles, have significantly reduced exhaust emissions while maintaining driving range. However, compared to exhaust emissions, fuel evaporation emissions from HEVs are a more prominent issue. HEVs often operate in pure electric mode, with the engine not running, making it difficult for the charcoal canister to desorb fuel in time, resulting in substantial evaporative emissions. Currently, most HEVs employ high-pressure fuel tank technology, where fuel vapors are only expelled from the tank when the pressure reaches a certain level, which reduces evaporative emissions to some extent. However, issues such as untimely charcoal canister desorption and canister overload still exist. Therefore, efficiently controlling evaporative emissions from the high-pressure fuel tank of HEVs remains a major challenge.

[0003] Existing patent CN105802492B proposes a dual-canister method for hybrid vehicles. The first activated carbon canister adsorbs fuel vapors generated during refueling, while the second adsorbs fuel vapors generated during other processes. When the engine starts, the first activated carbon canister is desorbed preferentially. When the hydrocarbon concentration sensor at the desorption port detects a hydrocarbon concentration below a limit, the second activated carbon canister desorbs. This method only increases the total adsorption capacity of the canisters and does not solve the problem of canister load monitoring. Patent CN104929819B proposes a method for controlling evaporative emissions in hybrid vehicles by recording the engine start-up interval and measuring the hydrocarbon content in the canisters. If the start-up time exceeds a preset threshold and the hydrocarbon content in the activated carbon canister gas exceeds a preset threshold, the user is prompted to start the engine. However, the hydrocarbon content in the canisters is difficult to measure.

[0004] Currently, there is no complete evaporative emission control system or corresponding control method for high-pressure fuel tank evaporative emissions in hybrid vehicles. Therefore, proposing new and efficient control technologies is of great significance for reducing vehicle evaporative emissions. Summary of the Invention

[0005] Purpose of the invention: This invention provides a control system and method for fuel evaporation emission from a high-pressure fuel tank in hybrid electric vehicles, which effectively solves the problems of low desorption efficiency and full charcoal canister due to the short engine running time in hybrid electric vehicles.

[0006] Technical solution: A high-pressure fuel tank fuel evaporation emission control system for hybrid electric vehicles, comprising a fuel tank assembly, a charcoal canister assembly, an engine assembly, and a controller. The fuel tank assembly is connected to the charcoal canister assembly and the engine assembly via a pressure relief pipe and a fuel supply pipe, respectively. The controller is signal-connected to the fuel tank assembly, the charcoal canister assembly, and the engine assembly.

[0007] The oil tank assembly includes a high-pressure oil tank, a pressure sensor installed on the top of the high-pressure oil tank, and an isolation valve installed in the pressure relief pipeline;

[0008] The engine assembly includes an engine and an intake manifold connected to the engine intake port;

[0009] The charcoal canister assembly includes a charcoal canister, a desorption flow meter, and a charcoal canister solenoid valve. The charcoal canister is connected to the intake manifold via a desorption pipeline. The desorption flow meter is installed in the desorption pipeline near the desorption port of the charcoal canister, and the charcoal canister solenoid valve is installed in the desorption pipeline near the intake manifold.

[0010] This invention calculates the current load of the carbon canister by calculating the pressure relief of the high-pressure oil tank, the total desorption flow of the carbon canister, and the load of the carbon canister in the previous cycle. The results are accurate, effectively improving the desorption efficiency of the carbon canister and avoiding large amounts of evaporation emissions due to untimely desorption of the carbon canister.

[0011] Preferably, the charcoal canister assembly further includes a high-temperature desorption system, which specifically includes: an air duct connected to the charcoal canister, an air filter, a temperature sensor and an air heater arranged sequentially in the air intake direction in the air duct, and a charcoal canister preheating heater arranged on the outside of the charcoal canister.

[0012] By installing a preheating heater on the outside of the carbon canister, the carbon canister is preheated first. Then, air heated below the target temperature is sent into the carbon canister for mixing through an air heater installed in the air duct, thereby improving the desorption efficiency.

[0013] Preferably, the controller includes an evaporative emission controller and a hybrid vehicle controller, wherein the evaporative emission controller is signal-connected to the hybrid vehicle controller.

[0014] An independent evaporative emission controller can be set up to effectively calculate the total pressure relief of the high-pressure tank and the total desorption of the charcoal canister at fixed cycles. Based on the charcoal canister load, total pressure relief, and total desorption of the previous cycle, the current charcoal canister load is calculated. The controller can also obtain the operating status of the hybrid vehicle by communicating with the hybrid vehicle controller. The evaporative emission controller can then adopt corresponding control strategies based on the charcoal canister load and the operating status of the hybrid vehicle.

[0015] Preferably, the fuel tank assembly further includes a fuel lock system, which specifically includes a fuel lock and a fuel information sensor located at the fuel filler port of the high-pressure fuel tank. The fuel information sensor and the fuel lock are connected to the hybrid vehicle controller.

[0016] By setting up a refueling lock and a refueling information sensor, the pressure inside the high-pressure fuel tank can be effectively controlled during refueling, and pressure can be released in a timely manner to avoid affecting the vehicle's refueling and preventing a large amount of oil vapor from overflowing from the refueling port during refueling.

[0017] Preferably, the pressure relief pipeline is provided with a pressure relief branch, and a mechanical valve connected in parallel with the isolation valve is provided in the pressure relief branch.

[0018] By setting up branch circuits and mechanical valves, it is possible to prevent the isolation valve from failing and causing excessive pressure in the high-pressure oil tank.

[0019] A method for controlling fuel evaporation emissions from a high-pressure fuel tank in a hybrid electric vehicle, specifically including the following steps:

[0020] S1. Calculate the current load of the charcoal canister: The evaporative emission controller calculates the current load of the charcoal canister and the total pressure relief of the high-pressure oil tank based on the previous cycle's charcoal canister load and the total pressure relief of the high-pressure oil tank. Total desorption amount of charcoal canister Calculate the current canister load;

[0021] S2, Desorption Strategy: Divide the current load of the carbon canister into three stages and adopt corresponding control strategies based on the operating status of the hybrid vehicle;

[0022] S3, Charcoal Canister Preheating: When the strategy in S2 determines that desorption is required, the evaporative emission controller controls the air heater and charcoal canister preheating heater to heat the incoming air and charcoal canister respectively, so that the oil and gas molecules in the charcoal canister are in a free state.

[0023] S4. High-temperature desorption: When the engine is running, the evaporative emission controller controls the charcoal canister solenoid valve to open for high-temperature desorption.

[0024] Preferably, S1 specifically comprises:

[0025] The total pressure relief of the high-pressure oil tank It is the threshold pressure relief amount of the isolation valve. Pressure relief before refueling Pressure relief during refueling The sum,

[0026]

[0027] In the formula This represents the total pressure relief capacity of the high-pressure oil tank. For the threshold pressure relief of the high-pressure oil tank isolation valve, The amount of pressure released before refueling, This refers to the amount of pressure released during the refueling process;

[0028] The amount of pressure released in a single instance is:

[0029]

[0030] In the formula, t is the pressure relief time. Gasoline diffusion molar flux Oil and gas mass transfer area;

[0031] The desorption time corresponding to each desorption rate in the current cycle of the carbon canister is calculated by the evaporation emission controller based on the cumulative data from the desorption flow meter. The desorption efficiency at different desorption rates is obtained by querying the calibrated MAP, and the total desorption amount is obtained by interval integration. ;

[0032] The current load on the charcoal canister is calculated based on the fuel vapor loading and desorption rate within the charcoal canister during the current cycle, i.e.:

[0033] when

[0034] when hour,

[0035] In the formula This represents the total pressure relief capacity of the high-pressure oil tank. Total desorption capacity of the charcoal canister Current load of the charcoal canister For the previous cycle's carbon canister load, .

[0036] Preferably, the pressure relief strategy for the high-pressure oil tank is as follows:

[0037] When the refueling switch is pressed in the cab, the refueling information sensor receives the refueling information, and the evaporative emission controller controls the isolation valve to open and release pressure. The discharged fuel vapor is absorbed by the charcoal canister, and the refueling lock remains locked during the process.

[0038] When the pressure sensor in the high-pressure oil tank is less than 2 kPa, the refueling lock opens and refueling can be performed. During the refueling process, the isolation valve 13 remains open until the refueling is completed and the evaporative emission controller closes the isolation valve.

[0039] When there is no refueling information, the evaporative emission controller determines whether the pressure information transmitted by the pressure sensor is greater than the high-pressure fuel tank threshold pressure. If it is less than the threshold pressure, the isolation valve is closed. If it is greater than the threshold pressure, the evaporative emission controller controls the isolation valve to open to release pressure from the high-pressure fuel tank until the pressure in the high-pressure fuel tank is less than 2 kPa, at which point the isolation valve closes.

[0040] Preferably, S2 specifically includes:

[0041] Based on the current load of the charcoal canister calculated by the evaporative emission controller, it is divided into three stages.

[0042] when At 21%, fuel vapor in the carbon adsorption canister is not desorbed;

[0043] when 70% of the time, the evaporative emission controller determines whether the engine should start based on information from the hybrid vehicle controller.

[0044] If the engine is running, the charcoal canister solenoid valve opens, using the vacuum effect of the engine intake manifold for desorption.

[0045] If the engine is not started at this time, the charcoal canister will not desorb;

[0046] when If the vehicle is stationary at this time, the evaporative emission controller sends information to the hybrid vehicle controller, and the vehicle starts the engine first and performs high-temperature desorption in the next running moment;

[0047] If the vehicle is in motion and the engine is running, the evaporative emission controller controls the charcoal canister solenoid valve to open and begin desorption.

[0048] If the vehicle is in motion but the engine is not started, the evaporative emission controller sends a message to the hybrid vehicle controller to immediately start the engine for desorption until the charcoal canister is under current load. Once the power level drops below 70%, resume driving in the original power mode.

[0049] Preferably, S3 specifically includes:

[0050] The evaporative emission controller calculates the preheating temperature based on the current ambient temperature measured by the temperature sensor. and heating temperature size,

[0051] ,

[0052] ,

[0053] In the formula To calibrate the temperature, For air temperature, To calibrate the critical temperature, To calibrate the heating temperature, This is the preheating correction factor. Heating correction factor.

[0054] Beneficial Effects: This invention proposes a novel control system and method for evaporative emissions from high-pressure fuel tanks in hybrid vehicles. An independent evaporative emission controller manages the emissions from the high-pressure fuel tank. This controller calculates the charcoal canister load based on the high-pressure fuel tank pressure relief and the total desorption flow rate of the charcoal canister, and adopts different control modes based on the operating status of the hybrid vehicle. During desorption, the high-temperature desorption system significantly improves desorption efficiency. This effectively solves the problems of low desorption efficiency and full charcoal canister load caused by the short engine operating time in hybrid vehicles equipped with high-pressure fuel tanks, while also reducing the impact of volatile oil vapors on vehicle power, achieving intelligent and efficient evaporative emission control. Attached Figure Description

[0055] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0056] Figure 1 The diagram shown here is a structural diagram of the present invention, omitting signal connections and the controller.

[0057] Figure 2 This is a diagram showing the overall structure of the system of the present invention.

[0058] Figure 3 This is a simplified flowchart of the carbon canister desorption process of the present invention.

[0059] Figure 4 This is a flowchart of the high-pressure oil tank pressure relief strategy of the present invention.

[0060] Figure 5 This is a flowchart of the carbon canister desorption strategy of the present invention. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0063] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0064] like Figure 1 and 2 As shown, a high-pressure fuel tank evaporative emission control system for a hybrid electric vehicle includes a fuel tank assembly 1, a charcoal canister assembly 2, an engine assembly 3, and a controller. The fuel tank assembly 1 is connected to the charcoal canister assembly 2 and the engine assembly 3 via a pressure relief pipe 4 and a fuel supply pipe 5, respectively. The controller is signal-connected to the fuel tank assembly 1, the charcoal canister assembly 2, and the engine assembly 3.

[0065] The oil tank assembly 1 includes a high-pressure oil tank 11, a pressure sensor 12 disposed on the top of the high-pressure oil tank 11, and an isolation valve 13 installed in the pressure relief pipeline 4.

[0066] The engine assembly 3 includes an engine 31 and an intake manifold 32 connected to the intake port of the engine 31.

[0067] The charcoal canister assembly 2 includes a charcoal canister 21, a desorption flow meter 22, and a charcoal canister solenoid valve 23. The charcoal canister 21 is connected to the intake manifold 32 through a desorption pipeline 24. The desorption flow meter 22 is installed in the desorption pipeline 24 near the desorption port of the charcoal canister 21. The charcoal canister solenoid valve 23 is installed in the desorption pipeline 24 near the intake manifold 32.

[0068] The charcoal canister assembly 2 also includes a high-temperature desorption system, which specifically includes an air duct 25 connected to the charcoal canister 21. An air filter 26, a temperature sensor 27, and an air heater 28 are arranged sequentially in the air intake direction in the air duct 25. A charcoal canister preheating heater 29 is arranged on the outside of the charcoal canister 21.

[0069] The controller includes an evaporative emission controller 61 and a hybrid vehicle controller 62, with the evaporative emission controller 61 and the hybrid vehicle controller 62 being signal-connected.

[0070] The fuel tank assembly 1 also includes a fuel lock system, which specifically includes a fuel lock 14 and a fuel information sensor 15 located at the fuel inlet of the high-pressure fuel tank 11. The fuel information sensor 15 and the fuel lock 14 are connected to the hybrid vehicle controller 62 via signals.

[0071] The pressure relief pipeline 4 is provided with a pressure relief branch 41, and a mechanical valve 42 connected in parallel with the isolation valve 13 is provided in the pressure relief branch 41.

[0072] like Figure 3 As shown, a method for controlling fuel evaporation emissions from a high-pressure fuel tank in a hybrid electric vehicle specifically includes the following steps:

[0073] S1. Calculate the current load of the carbon canister 21: The evaporative emission controller 61 calculates the current load of the carbon canister 21 and the total pressure relief of the high-pressure oil tank 11 based on the previous cycle's carbon canister 21 load and the total pressure relief of the high-pressure oil tank 11. Total desorption amount of charcoal canister 21 Calculate the current load of carbon canister 21 and maintain the calculation state throughout the entire cycle until the desorption is completed and the next cycle begins;

[0074] Specifically, S1 is:

[0075] The total pressure relief of the high-pressure oil tank 11 It is the threshold pressure relief amount of isolation valve 13. Pressure relief before refueling Pressure relief during refueling The sum,

[0076]

[0077] In the formula This represents the total pressure relief capacity of high-pressure oil tank 11. For the threshold pressure relief of isolation valve 13 in high-pressure oil tank 11, The amount of pressure released before refueling, This refers to the amount of pressure released during the refueling process;

[0078] The amount of pressure released in a single instance is:

[0079]

[0080] In the formula, t is the pressure relief time. Gasoline diffusion molar flux Oil and gas mass transfer area;

[0081] The desorption time corresponding to each desorption rate in the current cycle carbon canister 21 is calculated by the evaporation emission controller 61 based on the data from the desorption flow meter 22. The desorption efficiency at different desorption rates is obtained by querying the calibrated MAP, and the total desorption amount is obtained by interval integration. ;

[0082] The current load of charcoal canister 21 is calculated based on the fuel vapor loading and desorption rate within the charcoal canister 21 during the current cycle, i.e.:

[0083] when

[0084] when hour,

[0085] In the formula This represents the total pressure relief capacity of high-pressure oil tank 11. Total desorption capacity of carbon canister 21 The current load of charcoal canister 21 For the previous cycle, the carbon canister 21 was under load. .

[0086] like Figure 4 As shown, the pressure relief strategy of the high-pressure oil tank 11 is as follows:

[0087] When the refueling switch is pressed in the cab, the refueling information sensor 15 receives the refueling information, and the evaporative emission controller 61 controls the isolation valve 13 to open and release pressure. The discharged fuel vapor is absorbed by the charcoal canister 21, and the refueling lock 14 is locked during the process.

[0088] When the pressure of the pressure sensor 12 in the high-pressure oil tank 11 is less than 2 kPa, the refueling lock 14 is opened, and refueling can be carried out. During the refueling process, the isolation valve 13 remains open until the refueling is completed and the evaporative emission controller 61 controls the isolation valve 13 to close.

[0089] When there is no refueling information, the evaporative emission controller 61 determines whether the pressure information transmitted by the pressure sensor 12 is greater than the threshold pressure of the high-pressure oil tank 11. If it is less than the threshold pressure, the isolation valve 13 is closed. If it is greater than the threshold pressure, the evaporative emission controller 61 controls the isolation valve 13 to open to release the pressure of the high-pressure oil tank 11 until the pressure in the high-pressure oil tank 11 is less than 2 kPa, at which point the isolation valve 13 is closed.

[0090] like Figure 5 As shown, S2, desorption strategy: the current load of the carbon canister 21 is divided into three stages, and corresponding control strategies are adopted in combination with the operating status of the hybrid vehicle;

[0091] Specifically, S2 is:

[0092] Based on the current load of the charcoal canister 21 calculated by the evaporation emission controller 61, it is divided into three stages.

[0093] when At 21%, the oil and gas in the carbon adsorption tank 21 are not desorbed;

[0094] when 70%, the evaporative emission controller 61 determines whether the engine 31 should start based on the information from the hybrid vehicle controller 62.

[0095] If the engine 31 is running, the charcoal canister solenoid valve 23 opens, and desorption is performed using the vacuum effect of the intake manifold 32 of the engine 31.

[0096] If the engine 31 is not started at this time, the charcoal canister 21 will not desorb;

[0097] when If the vehicle is stationary at this time, the evaporative emission controller 61 sends information to the hybrid vehicle controller 62, and the vehicle starts the engine 31 first and performs high-temperature desorption in the next running moment.

[0098] If the vehicle is in motion and the engine 31 is running, the evaporative emission controller 61 controls the charcoal canister solenoid valve 23 to open and begin desorption.

[0099] If the vehicle is in motion but the engine 31 is not started, the evaporative emission controller 61 sends a message to the hybrid vehicle controller 62 to immediately start the engine 31 for desorption until the charcoal canister 21 is under its current load. Once the power level drops below 70%, resume driving in the original power mode.

[0100] S3, Charcoal Canister 21 Preheating: When the strategy in S2 determines that desorption is required, the evaporative emission controller 61 controls the air heater 28 and the charcoal canister preheating heater 29 to heat the incoming air and charcoal canister 21 respectively, so that the oil and gas molecules in the charcoal canister 21 are in a free state.

[0101] Specifically, S3 is:

[0102] The evaporative emission controller 61 calculates the preheating temperature based on the current ambient temperature measured by the temperature sensor 27. and heating temperature size,

[0103] ,

[0104] ,

[0105] In the formula To calibrate the temperature, For air temperature, To calibrate the critical temperature, To calibrate the heating temperature, This is the preheating correction factor. Heating correction factor.

[0106] S4. High-temperature desorption: When the engine 31 is running, the evaporative emission controller 61 controls the charcoal canister solenoid valve 23 to open for high-temperature desorption.

[0107] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0108] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling fuel evaporative emissions from a high-pressure fuel tank in a hybrid electric vehicle, comprising a fuel evaporative emission control system for implementing the method, including a fuel tank assembly (1), a charcoal canister assembly (2), an engine assembly (3), and a controller. The fuel tank assembly (1) is connected to the charcoal canister assembly (2) and the engine assembly (3) via a pressure relief pipe (4) and a fuel supply pipe (5), respectively. The controller is signal-connected to the fuel tank assembly (1), the charcoal canister assembly (2), and the engine assembly (3). The oil tank assembly (1) includes a high-pressure oil tank (11), a pressure sensor (12) installed on the top of the high-pressure oil tank (11), and an isolation valve (13) installed in the pressure relief pipeline (4). The engine assembly (3) includes an engine (31) and an intake manifold (32) connected to the intake port of the engine (31). The canister assembly (2) includes a canister (21), a desorption flow meter (22) and a canister solenoid valve (23). The canister (21) is connected to the intake manifold (32) through a desorption pipeline (24). The desorption flow meter (22) is installed in the desorption pipeline (24) near the desorption port of the canister (21). The canister solenoid valve (23) is installed in the desorption pipeline (24) near the intake manifold (32). Its features are, The control method specifically includes the following steps: S1. Calculate the current load of the carbon canister (21): The evaporative emission controller (61) calculates the current load of the carbon canister (21) and the total pressure relief of the high-pressure oil tank (11) based on the previous cycle. Total desorption amount of charcoal canister (21) Calculate the current load on the carbon canister (21); S2, Desorption Strategy: Divide the current load of the carbon canister (21) into three stages and adopt corresponding control strategies in combination with the operating status of the hybrid vehicle; S3, preheating of charcoal canister (21): When the strategy in S2 determines that desorption is required, the evaporative emission controller (61) controls the air heater (28) and the charcoal canister preheating heater (29) to heat the incoming air and charcoal canister (21) respectively, so that the oil and gas molecules in the charcoal canister (21) are in a free state. S4. High-temperature desorption: When the engine (31) is in the starting state, the evaporative emission controller (61) controls the carbon canister solenoid valve (23) to open for high-temperature desorption.

2. The method for controlling fuel evaporation emissions from the high-pressure fuel tank of a hybrid electric vehicle according to claim 1, characterized in that, The carbon canister assembly (2) also includes a high-temperature desorption system, which specifically includes an air duct (25) connected to the carbon canister (21). An air filter (26), a temperature sensor (27) and an air heater (28) are arranged in sequence in the air intake direction in the air duct (25). A carbon canister preheating heater (29) is arranged on the outside of the carbon canister (21).

3. The method for controlling fuel evaporation emissions from the high-pressure fuel tank of a hybrid electric vehicle according to claim 1, characterized in that, The controller includes an evaporative emission controller (61) and a hybrid vehicle controller (62), with the evaporative emission controller (61) and the hybrid vehicle controller (62) being signal-connected.

4. The method for controlling fuel evaporation emissions from the high-pressure fuel tank of a hybrid electric vehicle according to claim 1, characterized in that: The fuel tank assembly (1) also includes a fuel lock system, which specifically includes a fuel lock (14) and a fuel information sensor (15) located at the fuel inlet of the high-pressure fuel tank (11). The fuel information sensor (15) and the fuel lock (14) are connected to the hybrid vehicle controller (62) via signals.

5. The method for controlling fuel evaporation emissions from the high-pressure fuel tank of a hybrid electric vehicle according to claim 1, characterized in that: The pressure relief pipeline (4) is provided with a pressure relief branch (41), and a mechanical valve (42) connected in parallel with the isolation valve (13) is provided in the pressure relief branch (41).

6. The method for controlling fuel evaporation emissions from the high-pressure fuel tank of a hybrid electric vehicle according to claim 1, characterized in that, Specifically, S1 is: The total pressure relief of the high-pressure oil tank (11) It is the threshold pressure relief amount of the isolation valve (13). Pressure relief before refueling Pressure relief during refueling The sum, ， In the formula This is the total pressure relief of the high-pressure oil tank (11). For the threshold pressure relief of the isolation valve (13) of the high-pressure oil tank (11), The amount of pressure released before refueling, This refers to the amount of pressure released during the refueling process; The amount of pressure released in a single instance is: ， In the formula, t is the pressure relief time. Gasoline diffusion molar flux Oil and gas mass transfer area; The desorption time corresponding to each desorption rate of the current cycle carbon canister (21) is calculated by the evaporation emission controller (61) based on the data from the desorption flow meter (22). The desorption efficiency at different desorption rates is obtained by querying the calibrated MAP, and the total desorption amount is obtained by interval integration. ; The current load of the charcoal canister (21) is calculated based on the fuel vapor loading and desorption rate in the charcoal canister (21) during the current cycle, i.e.: when , when hour, , In the formula This is the total pressure relief of the high-pressure oil tank (11). Total desorption capacity of charcoal canister (21), The current load of the charcoal canister (21) is as follows: For the previous cycle of carbon canister (21) load, .

7. The method for controlling fuel evaporation emissions from the high-pressure fuel tank of a hybrid electric vehicle according to claim 6, characterized in that, The pressure relief strategy of the high-pressure oil tank (11) is as follows: When the refueling switch is pressed in the cab, the refueling information sensor (15) receives the refueling information, the evaporative emission controller (61) controls the isolation valve (13) to open and release pressure, and the discharged fuel vapor is adsorbed by the charcoal canister (21). During the process, the refueling lock (14) is locked. When the pressure of the pressure sensor (12) in the high-pressure oil tank (11) is less than 2 kPa, the refueling lock (14) is opened, allowing the refueling operation. During the refueling process, the isolation valve (13) remains open until the refueling is completed and the evaporative emission controller (61) controls the isolation valve (13) to close. When there is no refueling information, the evaporative emission controller (61) determines whether the pressure information transmitted by the pressure sensor (12) is greater than the threshold pressure of the high-pressure oil tank (11). If it is less than the threshold pressure, the isolation valve (13) is closed. If it is greater than the threshold pressure, the evaporative emission controller (61) controls the isolation valve (13) to open to release the pressure of the high-pressure oil tank (11) until the pressure in the high-pressure oil tank (11) is less than 2 kPa, and then the isolation valve (13) is closed.

8. The method for controlling fuel evaporation emissions from a high-pressure fuel tank in a hybrid electric vehicle according to claim 7, characterized in that, Specifically, S2 is: Based on the current load of the carbon canister (21) calculated by the evaporative emission controller (61), it is divided into three stages. when At 21%, the oil and gas in the carbon adsorption tank (21) are not desorbed; when 70%, the evaporative emission controller (61) determines whether the engine (31) is started at this time based on the information from the hybrid vehicle controller (62). If the engine (31) is running, the charcoal canister solenoid valve (23) opens, and desorption is carried out using the vacuum effect of the intake manifold (32) of the engine (31); If the engine (31) is not started at this time, the charcoal canister (21) will not detach; when If the vehicle is stopped at this time, the evaporative emission controller (61) sends information to the hybrid vehicle controller (62), and the vehicle starts the engine (31) first and performs high-temperature desorption in the next running moment; If the vehicle is in motion and the engine (31) is running, the evaporative emission controller (61) controls the canister solenoid valve (23) to open and begin desorption. If the vehicle is in motion but the engine (31) is not started, the evaporative emission controller (61) sends a message to the hybrid vehicle controller (62) to immediately start the engine (31) for desorption until the current load of the charcoal canister (21) is reached. Once the power level drops below 70%, resume driving in the original power mode.

9. The method for controlling fuel evaporation emissions from the high-pressure fuel tank of a hybrid electric vehicle according to claim 1, characterized in that, Specifically, S3 is: The evaporative emission controller (61) calculates the preheating temperature based on the current ambient temperature measured by the temperature sensor (27). and heating temperature size, ， ， In the formula To calibrate the temperature, For air temperature, To calibrate the critical temperature, To calibrate the heating temperature, This is the preheating correction factor. Heating correction factor.

Images