Fuel system and vehicle

Abstract

The present disclosure relates to a fuel system and a vehicle, the fuel system comprising a fuel tank, a carbon canister, and a carbon canister isolation valve, a first inlet of the carbon canister being connected to a fuel vapor outlet of the fuel tank, a first outlet of the carbon canister being in communication with an external atmosphere through the carbon canister isolation valve, wherein the carbon canister isolation valve is configured to be controllably opened or closed, and is configured to be automatically opened when a pressure difference between a pressure in the carbon canister and a pressure of the external atmosphere is greater than or equal to a preset pressure relief pressure of the carbon canister and less than or equal to a preset pressure compensation pressure of the carbon canister. The carbon canister of the present disclosure can store fuel vapor as a pressure container, thereby improving the capacity of the fuel system to store fuel vapor, and reducing the cost of the vehicle and the space occupied by the fuel system in the vehicle while meeting the low emission requirements of the fuel system. In addition, the carbon canister isolation valve can be automatically opened when the pressure is too high or too low, thereby improving the efficiency of the carbon canister exhaust and air compensation while ensuring the safety and service life of the carbon canister.

Description

Technical Field

[0001] This disclosure relates to the field of vehicle technology, and more specifically, to a fuel system and a vehicle. Background Technology

[0002] Fuel vapor emissions are a major source of hydrocarbon pollutants from automobiles, and their control directly impacts compliance with emission regulations and environmental protection. In related technologies, carbon rods are added to the fuel system to reduce fuel vapor emissions and meet regulatory requirements, thereby increasing vehicle costs and the space occupied by the fuel system within the vehicle. Summary of the Invention

[0003] The purpose of this disclosure is to provide a fuel system and vehicle that can use a charcoal canister as a pressure vessel for storing fuel vapor, thereby at least partially solving the aforementioned technical problems.

[0004] To achieve the above objectives, a first aspect of this disclosure provides a fuel system comprising: a fuel tank; a charcoal canister, wherein a first inlet of the charcoal canister is connected to a fuel vapor outlet of the fuel tank; and a charcoal canister isolation valve, wherein a first outlet of the charcoal canister is connected to the outside atmosphere via the charcoal canister isolation valve; wherein the charcoal canister isolation valve is configured to be controllably opened or closed, and to automatically open when the pressure difference between the pressure inside the charcoal canister and the pressure of the outside atmosphere is greater than or equal to a preset pressure relief pressure of the charcoal canister and less than or equal to a preset air replenishment pressure of the charcoal canister.

[0005] Optionally, the fuel system further includes a fuel tank isolation valve, wherein the fuel vapor outlet of the fuel tank is connected to the first inlet of the charcoal canister through the fuel tank isolation valve; wherein the fuel tank isolation valve is configured to be controllably opened or closed, and can automatically open when the pressure difference between the pressure in the fuel tank and the pressure in the charcoal canister is greater than or equal to the preset pressure relief pressure of the fuel tank and less than or equal to the preset air replenishment pressure of the fuel tank.

[0006] Optionally, the fuel system further includes a controller and a fuel tank pressure sensor. The fuel tank pressure sensor is used to detect the pressure inside the fuel tank. The controller is electrically connected to the fuel tank pressure sensor and the fuel tank isolation valve. The fuel tank's preset pressure relief is set to be less than or equal to the upper limit of the fuel tank's safe pressure. The controller is used to control the opening of the charcoal canister isolation valve or the fuel tank isolation valve when the pressure inside the fuel tank is greater than or equal to the upper limit of the fuel tank's safe pressure. And / or, the fuel tank's preset air replenishment pressure is greater than or equal to the lower limit of the fuel tank's safe pressure. The controller is used to control the opening of the charcoal canister isolation valve or the fuel tank isolation valve when the pressure inside the fuel tank is less than or equal to the lower limit of the fuel tank's safe pressure.

[0007] Optionally, the preset pressure relief pressure of the charcoal canister is less than the upper limit of the safe pressure of the oil tank; and / or, the preset pressure replenishment pressure of the charcoal canister is greater than the lower limit of the safe pressure of the oil tank.

[0008] Optionally, the fuel system further includes a controller, a fuel tank pressure sensor, and a charcoal canister pressure sensor. The fuel tank pressure sensor detects the pressure inside the fuel tank, and the charcoal canister pressure sensor detects the pressure inside the charcoal canister. The fuel tank pressure sensor, the charcoal canister pressure sensor, the fuel tank isolation valve, and the charcoal canister isolation valve are all electrically connected to the controller. The fuel tank's preset pressure relief is set to be less than or equal to the upper limit of the fuel tank's safe pressure, and the charcoal canister's preset pressure relief is set to be greater than the upper limit of the fuel tank's safe pressure. The controller is used to ensure that the pressure inside the fuel tank is greater than or equal to the upper limit of the fuel tank's safe pressure. When the pressure in the charcoal canister is greater than or equal to the upper limit of the full pressure and the pressure inside the charcoal canister is greater than or equal to the upper limit of the safe pressure of the oil tank, the controller controls the opening of the charcoal canister isolation valve or controls the opening of both the charcoal canister isolation valve and the oil tank isolation valve; and / or, when the preset air supply pressure of the oil tank is greater than or equal to the lower limit of the safe pressure of the oil tank and the preset air supply pressure of the charcoal canister is less than the lower limit of the safe pressure of the oil tank, the controller controls the opening of the charcoal canister isolation valve or controls the opening of both the charcoal canister isolation valve and the oil tank isolation valve when the pressure inside the oil tank is less than or equal to the lower limit of the safe pressure of the oil tank and the pressure inside the charcoal canister is less than the lower limit of the safe pressure of the oil tank.

[0009] Optionally, the preset air supply pressure of the charcoal canister is the same as the pressure of the external atmosphere.

[0010] Optionally, the fuel system includes a positive pressure check valve disposed on the fuel tank, the pressure relief outlet of the fuel tank being connected to the outside atmosphere through the positive pressure check valve, the opening pressure of the positive pressure check valve being less than or equal to the upper limit of the safe pressure of the fuel tank and greater than or equal to the preset pressure relief pressure of the fuel tank; and / or, the fuel system includes a negative pressure check valve disposed on the fuel tank, the air replenishment inlet of the fuel tank being connected to the outside atmosphere through the negative pressure check valve, the opening pressure of the negative pressure check valve being greater than or equal to the lower limit of the safe pressure of the fuel tank and less than or equal to the preset air replenishment pressure of the fuel tank.

[0011] Optionally, the fuel system further includes a pressure relief valve, which includes a first pipeline, a second pipeline, a sealing element, and a resilient element. A first end of the first pipeline is connected to the fuel tank, and a second end of the first pipeline is connected to the outside atmosphere. The second pipeline is connected in parallel to the first pipeline. The resilient element is disposed in the first pipeline and connected to the sealing element. The sealing element can move toward the second end under the pressure of the fuel tank to expose the connection between the first pipeline and the second pipeline, and can also move toward the first end under the action of the resilient element to seal the connection between the first pipeline and the second pipeline.

[0012] Optionally, the fuel system further includes a controller and an engine, and the second outlet of the charcoal canister is connected to the intake manifold of the engine via a charcoal canister solenoid valve; the fuel tank isolation valve, the charcoal canister isolation valve, and the charcoal canister solenoid valve are all electrically connected to the controller; when the fuel system is in desorption mode, the controller controls the fuel tank isolation valve, the charcoal canister isolation valve, and the charcoal canister solenoid valve to open.

[0013] A second aspect of this disclosure provides a vehicle including the aforementioned fuel system.

[0014] Through the above technical solution, the charcoal canister isolation valve of the fuel system disclosed herein can be opened in a controlled manner. Thus, when the charcoal canister isolation valve is closed in a controlled manner, it can isolate the charcoal canister from the outside atmosphere. In this way, even if the activated carbon in the charcoal canister is saturated, the charcoal canister can still act as a pressure vessel to store fuel vapor, thereby improving the fuel system's ability to store fuel vapor and enabling the fuel system to meet the low emission requirements of near-zero desorption or even zero desorption. There is no need to add a charcoal rod to the fuel system, thereby meeting the low emission requirements of the fuel system while reducing the cost of the vehicle and the space occupied by the fuel system in the vehicle.

[0015] Furthermore, the charcoal canister isolation valve automatically opens when the pressure difference between the charcoal canister and the outside atmosphere is greater than or equal to the preset pressure relief pressure of the charcoal canister and less than or equal to the preset gas replenishment pressure of the charcoal canister. That is, when the pressure inside the charcoal canister reaches the preset pressure relief pressure, the charcoal canister isolation valve can automatically open to connect the charcoal canister with the outside atmosphere, thereby venting the gas in the charcoal canister. And when the pressure inside the charcoal canister is lower than the preset gas replenishment pressure, the charcoal canister isolation valve can also automatically open to connect the charcoal canister with the outside atmosphere, thereby replenishing the gas in the charcoal canister. There is no need for the controller to open the charcoal canister isolation valve, thus improving the efficiency of charcoal canister venting and gas replenishment while ensuring the safety and service life of the charcoal canister.

[0016] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of a first embodiment of the fuel system provided in this disclosure; Figure 2 This is a schematic diagram of a second embodiment of the fuel system provided in this disclosure; Figure 3 This is a schematic diagram of a third embodiment of the fuel system provided in this disclosure; Figure 4 This is a schematic diagram of a fourth embodiment of the fuel system provided in this disclosure; Figure 5 This is a schematic diagram of a fifth embodiment of the fuel system provided in this disclosure; Figure 6 This is a schematic diagram of the internal structure of the pressure relief valve of the fuel system provided in the embodiments of this disclosure.

[0018] Explanation of reference numerals in the attached figures 1-Fuel tank; 2-Charcoal canister; 3-Charcoal canister isolation valve; 4-Fuel tank isolation valve; 5-Controller; 6-Fuel tank pressure sensor; 7-Charcoal canister pressure sensor; 8-Positive pressure check valve; 9-Negative pressure check valve; 10-Pressure relief valve; 1001-First pipeline; 1002-Second pipeline; 1003-Sealing component; 1004-Elastic component; 11-Engine; 12-Charcoal canister solenoid valve; 13-Ash filter. Detailed Implementation

[0019] The specific embodiments of this disclosure 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 this disclosure.

[0020] In this disclosure, unless otherwise stated, directional terms such as "inner" and "outer" refer to "inner" and "outer" relative to the contour of the corresponding component itself. Furthermore, the terms "first," "second," etc., used in this disclosure are for distinguishing one element from another and do not imply sequentiality or importance. Additionally, in the following description, when referring to the accompanying drawings, unless otherwise explained, the same reference numerals in different drawings denote the same or similar elements. The above definitions are for explanation and illustration only and should not be construed as limiting this disclosure.

[0021] The fuel system and vehicle in the exemplary embodiments of this disclosure will now be described with reference to the accompanying drawings.

[0022] refer to Figures 1 to 6As shown, in a first aspect, this disclosure provides a fuel system including a fuel tank 1, a charcoal canister 2, and a charcoal canister isolation valve 3. The first inlet of the charcoal canister 2 is connected to the fuel vapor outlet of the fuel tank 1. The first outlet of the charcoal canister 2 is connected to the outside atmosphere through the charcoal canister isolation valve 3. The charcoal canister isolation valve 3 is configured to be controllably opened or closed, and to automatically open when the pressure difference between the pressure inside the charcoal canister 2 and the pressure of the outside atmosphere is greater than or equal to the preset pressure relief pressure of the charcoal canister and less than or equal to the preset air replenishment pressure of the charcoal canister.

[0023] The charcoal canister isolation valve 3 can be kept closed for a long time under the control of, for example, the controller 5. Fuel vapors volatilized in the fuel tank 1 can enter the charcoal canister 2 through the first inlet of the charcoal canister 2. The activated carbon and carbon powder in the charcoal canister 2 will adsorb the fuel vapors. When the activated carbon and carbon powder are saturated, the fuel vapors entering the charcoal canister 2 from the fuel tank 1 can be stored in the charcoal canister 2 because the charcoal canister isolation valve 3 is closed. That is, the charcoal canister 2 can be used as a pressure vessel for storing fuel vapors. This improves the fuel system's ability to store fuel vapors and enables the fuel system to meet the low emission requirements of near-zero desorption or even zero desorption. There is no need to add carbon rods to the fuel system. This reduces the cost of the vehicle while meeting the low emission requirements of the fuel system and reduces the space occupied by the fuel system in the vehicle, thus reducing the difficulty of the vehicle chassis space layout.

[0024] When the pressure difference between the inside of the charcoal canister 2 and the outside atmospheric pressure is greater than or equal to the preset pressure relief pressure of the charcoal canister, the charcoal canister isolation valve 3 can automatically open to discharge the gas inside the charcoal canister 2, thereby preventing the charcoal canister 2 from being damaged due to excessive internal pressure. When the pressure difference between the inside of the charcoal canister 2 and the outside atmospheric pressure is less than or equal to the preset gas replenishment pressure of the charcoal canister, the charcoal canister isolation valve 3 can also automatically open to draw in gas from the outside atmosphere, thereby preventing the charcoal canister 2 from being damaged due to excessive internal pressure. Thus, while ensuring the safety and service life of the charcoal canister 2, the efficiency of venting and replenishing gas in the charcoal canister 2 is improved.

[0025] The automatic opening of the charcoal canister isolation valve 3 means that the charcoal canister isolation valve 3 can be opened without the control of the controller 5.

[0026] In addition, to ensure that the charcoal canister 2 can store more fuel vapor, the charcoal canister 2 can be a high-pressure charcoal canister.

[0027] In embodiments of this disclosure, such as Figures 1 to 6As shown, the fuel system may also include a fuel tank isolation valve 4, and the fuel vapor outlet of the fuel tank 1 is connected to the first inlet of the charcoal canister 2 through the fuel tank isolation valve 4; wherein, the fuel tank isolation valve 4 is configured to be able to be opened or closed in a controlled manner, and can be automatically opened when the pressure difference between the pressure in the fuel tank 1 and the pressure in the charcoal canister 2 is greater than or equal to the preset pressure relief pressure of the fuel tank and less than or equal to the preset air replenishment pressure of the fuel tank.

[0028] The fuel tank isolation valve 4 can be closed under the control of, for example, the controller 5. This allows the fuel tank 1 to also function as a pressure vessel capable of storing fuel vapor, thereby further improving the fuel system's ability to store fuel vapor. In addition, the isolation between the fuel tank 1 and the charcoal canister 2 can prevent fuel vapor in the fuel tank 1 from continuously entering the charcoal canister 2 and being adsorbed by activated carbon and charcoal powder, thus improving the problem of easy aging of activated carbon and charcoal powder.

[0029] When the pressure difference between the fuel tank 1 and the charcoal canister 2 is greater than or equal to the fuel tank's preset pressure relief pressure, the fuel tank isolation valve 4 can automatically open to release the gas in the fuel tank 1, thereby preventing the fuel tank 1 from being damaged due to excessive internal pressure. When the pressure difference between the fuel tank 1 and the charcoal canister 2 is less than or equal to the fuel tank's preset air replenishment pressure, the fuel tank isolation valve 4 can also automatically open to draw in the gas in the charcoal canister 2, thereby preventing the fuel tank 1 from being damaged due to excessive internal pressure. Thus, while ensuring the safety and service life of the fuel tank 1, the efficiency of venting and replenishing the fuel tank 1 is improved.

[0030] The automatic opening of the fuel tank isolation valve 4 means that the fuel tank isolation valve 4 can be opened without the control of the controller 5.

[0031] It should be noted that pressure changes in fuel tank 1 and / or charcoal canister 2 may be caused by changes in external temperature; the preset pressure relief pressure of the fuel tank and the preset pressure relief pressure of the charcoal canister are both positive pressures relative to atmospheric pressure, and the preset air replenishment pressure of the fuel tank and the preset air replenishment pressure of the charcoal canister are both negative pressures relative to atmospheric pressure; the upper limit of the safe pressure of fuel tank 1 may be slightly less than the upper limit of the pressure of fuel tank 1, and the lower limit of the safe pressure of fuel tank 1 may be slightly greater than the lower limit of the pressure of fuel tank 1.

[0032] Among them, the charcoal canister isolation valve 3 and the oil tank isolation valve 4 can be combination valves that integrate the functions of a solenoid valve, a positive pressure mechanical valve, and a negative pressure mechanical valve.

[0033] The combined valve can be connected to the controller 5. The combined valve can have a first elastic sealing element and a second elastic sealing element. The combined valve has a passage. The first elastic sealing element and the second elastic sealing element can jointly block the passage under the action of their respective elastic elements.

[0034] Taking the charcoal canister isolation valve 3 as an example, when the pressure difference between the charcoal canister 2 and the external atmospheric pressure is greater than or equal to the preset pressure relief pressure of the charcoal canister, the pressure inside the charcoal canister 2 will cause the first elastic sealing element to move in the first direction to open the passage. When the pressure difference between the charcoal canister 2 and the external atmospheric pressure is less than the preset pressure relief pressure of the charcoal canister, the first elastic sealing element will re-seal the passage under the elastic force of its first elastic element, such as a spring. When the pressure difference between the charcoal canister 2 and the external atmospheric pressure is less than or equal to the preset air replenishment pressure of the charcoal canister, the pressure of the external atmospheric pressure will cause the second elastic sealing element to move in the second direction opposite to the first direction to open the passage. When the pressure difference between the charcoal canister 2 and the external atmospheric pressure is greater than the preset air replenishment pressure of the charcoal canister, the second elastic sealing element will re-seal the passage under the elastic force of its second elastic element, such as a spring. When the controller 5 controls the charcoal canister isolation valve 3 to open, the controller 5 can drive the first elastic sealing element or the second elastic sealing element to move to open the passage through electromagnetic drive.

[0035] This combination valve belongs to the common valve body category in the valve body field. This disclosure only provides an exemplary description of its operating principle, and does not specifically limit its internal structure.

[0036] Alternatively, in some other possible implementations, the combination valve may have three passages, each equipped with a solenoid valve, a positive pressure mechanical valve, and a negative pressure mechanical valve.

[0037] When the fuel system is in refueling mode, the controller 5 will control the fuel tank isolation valve 4 and the charcoal canister isolation valve 3 to open, thereby ensuring that the internal air passage of the fuel system is unobstructed, so that the fuel system can be in a stable and safe pressure environment.

[0038] Since the opening condition of the oil tank isolation valve 4 is mainly determined by the pressure difference between the oil tank 1 and the charcoal canister 2, in actual working conditions, there may be a situation where the pressure in the oil tank 1 reaches the upper limit of the safe pressure of the oil tank 1, and the pressure in the charcoal canister 2 is positive. As a result, the pressure difference between the oil tank 1 and the charcoal canister 2 may be less than the preset pressure relief pressure of the oil tank, that is, the value of the pressure in the oil tank 1 minus the pressure in the charcoal canister 2 is less than the preset pressure relief pressure of the oil tank, causing the oil tank isolation valve 4 to fail to open automatically and release pressure normally. Alternatively, there may be a situation where the pressure in the oil tank 1 reaches the lower limit of the safe pressure of the oil tank 1, and the pressure in the charcoal canister 2 is negative. As a result, the pressure difference between the oil tank 1 and the charcoal canister 2 may be greater than the preset air replenishment pressure of the oil tank, that is, the value of the pressure in the oil tank 1 minus the pressure in the charcoal canister 2 is greater than the preset pressure relief pressure of the oil tank, causing the oil tank isolation valve 4 to fail to open automatically and replenish air normally.

[0039] Therefore, in the embodiments of this disclosure, such as Figures 1 to 6As shown, the fuel system may also include a controller 5 and a fuel tank pressure sensor 6. The fuel tank pressure sensor 6 is used to detect the pressure inside the fuel tank 1. The controller 5 is electrically connected to the fuel tank pressure sensor 6 and the fuel tank isolation valve 4. The fuel tank preset pressure relief is set to be less than or equal to the upper limit of the safe pressure of the fuel tank 1. The controller 5 is used to control the opening of the charcoal canister isolation valve 3 or the fuel tank isolation valve 4 when the pressure inside the fuel tank 1 is greater than or equal to the upper limit of the safe pressure of the fuel tank 1.

[0040] When the oil tank pressure sensor 6 detects that the pressure inside oil tank 1 has reached the upper limit of the safe pressure of oil tank 1, it indicates that the oil tank isolation valve 4 has not opened automatically. At this time, the controller 5 can control the charcoal canister isolation valve 3 to open, thereby connecting the charcoal canister 2 to the outside atmosphere. The charcoal canister isolation valve 3 can remain open for an extended period until the pressure inside the charcoal canister 2 matches the pressure of the outside atmosphere. This converts the pressure difference between the oil tank 1 and the charcoal canister 2 into a pressure difference between the oil tank 1 and the outside atmosphere. Since the upper limit of the safe pressure of oil tank 1 is greater than or equal to the preset pressure relief pressure, the pressure difference between the oil tank 1 and the outside atmosphere will be greater than or equal to the preset pressure relief pressure, thus causing the oil tank isolation valve 4 to open automatically.

[0041] Alternatively, when the pressure inside the charcoal canister 2 is lower than the pressure inside the fuel tank 1, the controller 5 can directly control the fuel tank isolation valve 4 to open. In this way, the gas in the fuel tank 1 will be directly discharged into the charcoal canister 2, thereby reducing the pressure in the fuel tank 1. This method can also reduce the amount of fuel vapor discharged into the outside atmosphere, thereby reducing pollution and protecting the environment.

[0042] In some possible implementations, the preset air replenishment pressure of the fuel tank can be greater than or equal to the lower limit of the safe pressure of the fuel tank 1. The controller 5 is used to control the opening of the charcoal canister isolation valve 3 or the fuel tank isolation valve 4 when the pressure in the fuel tank 1 is less than or equal to the lower limit of the safe pressure of the fuel tank 1.

[0043] When the fuel tank pressure sensor 6 detects that the pressure inside fuel tank 1 is lower than the safety lower limit of fuel tank 1, it indicates that the fuel tank isolation valve 4 has not opened automatically. At this time, the controller 5 can control the charcoal canister isolation valve 3 to open, thereby connecting the charcoal canister 2 to the outside atmosphere. The charcoal canister isolation valve 3 can remain open for an extended period until the pressure inside the charcoal canister 2 matches the pressure of the outside atmosphere. This converts the pressure difference between fuel tank 1 and charcoal canister 2 into a pressure difference between fuel tank 1 and the outside atmosphere. Since the safety lower limit of fuel tank 1 is less than or equal to the preset pressure relief pressure, the pressure difference between fuel tank 1 and the outside atmosphere will be less than or equal to the preset pressure relief pressure, thus causing the fuel tank isolation valve 4 to open automatically.

[0044] Alternatively, when the pressure inside the charcoal canister 2 is greater than the pressure inside the oil tank 1, the controller 5 can control the oil tank isolation valve 4 to open, so that the gas in the charcoal canister 2 will be replenished into the oil tank 1.

[0045] The aforementioned automatic depressurization and automatic air replenishment of fuel tank 1 achieved by controlling the opening and closing of the charcoal canister isolation valve 3 or the fuel tank isolation valve 4 can coexist within the same fuel system. Furthermore, the methods and processes of automatic depressurization and automatic air replenishment of fuel tank 1 are as described above, and for the sake of brevity, will not be repeated here.

[0046] In some other possible implementations, the preset pressure relief pressure of the charcoal canister can be less than the upper limit of the safe pressure of the fuel tank 1. That is, when the pressure in the fuel tank 1 is greater than or equal to the upper limit of the safe pressure of the fuel tank 1, it can be ensured that the pressure in the charcoal canister 2 is less than the pressure in the fuel tank 1. Thus, the controller 5 can directly open the fuel tank isolation valve 4 to connect the fuel tank 1 and the charcoal canister 2. After the two are connected, the gas in the fuel tank 1 will flow into the charcoal canister 2. If the activated carbon and charcoal powder in the charcoal canister 2 are not in an adsorption saturated state, the charcoal canister 2 can adsorb the newly entered fuel vapor. If the activated carbon and charcoal powder in the charcoal canister 2 are already in an adsorption saturated state, the fuel vapor will be stored in the charcoal canister 2 until the pressure difference between the pressure in the charcoal canister 2 and the external atmospheric pressure is greater than the preset pressure relief pressure of the charcoal canister. At this time, the charcoal canister isolation valve 3 will automatically open to discharge the gas in the charcoal canister 2.

[0047] By setting the preset pressure relief pressure of the charcoal canister in this way, it is not necessary to test the pressure inside the charcoal canister 2, which simplifies the procedure for depressurizing the oil tank 1.

[0048] In some possible implementations, the preset gas replenishment pressure of the charcoal canister can be greater than the lower limit of the safe pressure of the oil tank 1. That is, when the pressure in the oil tank 1 is less than or equal to the lower limit of the safe pressure of the oil tank 1, it can be guaranteed that the pressure in the charcoal canister 2 is always greater than the pressure in the oil tank 1. Therefore, the controller 5 can directly open the oil tank isolation valve 4 to connect the oil tank 1 and the charcoal canister 2. After the two are connected, the gas in the charcoal canister 2 will replenish the oil tank 1, thereby preventing the oil tank 1 from being damaged due to its internal pressure being too low.

[0049] By setting the preset air replenishment pressure of the charcoal canister in this way, it is not necessary to check the pressure inside the charcoal canister 2, which simplifies the steps of replenishing air in the fuel tank 1.

[0050] In the embodiments of this disclosure, in the same fuel system, the preset pressure relief pressure of the charcoal canister can be less than the upper limit of the safe pressure of the fuel tank 1, and the preset air replenishment pressure of the charcoal canister can be greater than the lower limit of the safe pressure of the fuel tank 1. Thus, when the fuel tank 1 needs to be depressurized or replenished, that is, when the pressure in the fuel tank 1 is greater than or equal to the upper limit of the safe pressure of the fuel tank, or less than or equal to the lower limit of the safe pressure of the fuel tank 1, the controller 5 can directly control the fuel tank isolation valve 4 to open, without having to detect the pressure of the charcoal canister 2. Therefore, there is no need to install the charcoal canister pressure sensor 7 in the charcoal canister 2, which reduces the number of devices arranged in the fuel system, lowers the cost of the fuel system, simplifies the steps of depressurizing and replenishing the fuel tank 1, and improves efficiency.

[0051] In some possible implementations, such as Figure 2 As shown, in addition to the controller 5 and the fuel tank pressure sensor 6, the fuel system may also include a charcoal canister pressure sensor 7. The fuel tank pressure sensor 6 detects the pressure inside the fuel tank 1, and the charcoal canister pressure sensor 7 detects the pressure inside the charcoal canister 2. The fuel tank pressure sensor 6, the charcoal canister pressure sensor 7, the fuel tank isolation valve 4, and the charcoal canister isolation valve 3 are all electrically connected to the controller 5. The preset pressure relief of the fuel tank can be set to be less than or equal to the upper limit of the safe pressure of the fuel tank 1, and the preset pressure relief of the charcoal canister can be set to be greater than the upper limit of the safe pressure of the fuel tank 1. The controller 5 controls the opening of the charcoal canister isolation valve 3 or the opening of both the charcoal canister isolation valve 3 and the fuel tank isolation valve 4 when the pressure inside the fuel tank 1 is greater than or equal to the upper limit of the safe pressure of the fuel tank 1, and the pressure inside the charcoal canister 2 is greater than or equal to the upper limit of the safe pressure of the fuel tank 1.

[0052] If the oil tank pressure sensor 6 detects that the pressure in oil tank 1 is greater than or equal to the upper limit of the safe pressure of oil tank 1, it indicates that the oil tank isolation valve 4 has not opened automatically. At this time, since the preset pressure relief pressure of the charcoal canister is set to be greater than the upper limit of the safe pressure of oil tank 1, the pressure in charcoal canister 2 will be greater than the pressure in oil tank 1. Therefore, the charcoal canister pressure sensor 7 can detect the pressure in charcoal canister 2 first when the oil tank pressure sensor 6 detects that the pressure in oil tank 1 is greater than or equal to the upper limit of the safe pressure of oil tank 1. If the pressure in charcoal canister 2 is detected to be greater than or equal to the upper limit of the safe operating pressure of oil tank 1, the controller 5 can control... The charcoal canister isolation valve 3 opens to allow gas in the charcoal canister 2 to be discharged to the outside atmosphere. Specifically, when the charcoal canister pressure sensor 7 detects that the pressure inside the charcoal canister 2 is equal to the pressure of the outside atmosphere, the controller 5 can control the charcoal canister isolation valve 3 to close. In this way, the oil tank isolation valve 4 will automatically open, allowing gas in the oil tank 1 to be discharged to the charcoal canister 2. Alternatively, when the charcoal canister pressure sensor 7 detects that the pressure inside the charcoal canister 2 is less than the pressure in the oil tank 1, the controller 5 controls the charcoal canister isolation valve 3 to close and controls the oil tank isolation valve 4 to open. This also allows gas in the oil tank 1 to be discharged to the charcoal canister 2, thereby completing the pressure relief operation of the oil tank 1.

[0053] In some other possible implementations, the preset air replenishment pressure of the fuel tank can be greater than or equal to the lower limit of the safety pressure of the fuel tank 1, and the preset air replenishment pressure of the charcoal canister is less than the lower limit of the safety pressure of the fuel tank 1. The controller 5 is used to control the charcoal canister isolation valve 3 to open or control the charcoal canister isolation valve 3 and the fuel tank isolation valve 4 to open when the pressure in the fuel tank 1 is less than or equal to the lower limit of the safety pressure of the fuel tank 1 and the pressure in the charcoal canister 2 is less than the lower limit of the safety pressure of the fuel tank 1.

[0054] If the oil tank pressure sensor 6 detects that the pressure in oil tank 1 is less than or equal to the lower safety pressure limit of oil tank 1, it indicates that the oil tank isolation valve 4 has not opened automatically. At this time, because the preset replenishment pressure of the charcoal canister is set to be less than the lower safety pressure limit of oil tank 1, the pressure in charcoal canister 2 will be less than the pressure in oil tank 1. Therefore, the charcoal canister pressure sensor 7 can detect the pressure in charcoal canister 2 first when the oil tank pressure sensor 6 detects that the pressure in the oil tank is less than or equal to the lower safety pressure limit of oil tank 1. If the pressure in charcoal canister 2 is detected to be less than or equal to the lower safety operating limit of oil tank 1, the controller 5 can control the charcoal canister 2. The canister isolation valve 3 is opened to allow outside air to enter the charcoal canister 2. When the charcoal canister pressure sensor 7 detects that the pressure inside the charcoal canister 2 is equal to the pressure of the outside air, the controller 5 can control the charcoal canister isolation valve 3 to close. In this way, the fuel tank isolation valve 4 will automatically open, allowing the gas in the charcoal canister 2 to enter the fuel tank 1. Alternatively, when the charcoal canister pressure sensor 7 detects that the pressure inside the charcoal canister 2 is greater than the pressure in the fuel tank 1, the controller 5 controls the charcoal canister isolation valve 3 to close and controls the fuel tank isolation valve 4 to open. This also allows the gas in the charcoal canister 2 to enter the fuel tank 1, thus completing the gas replenishment operation of the fuel tank 1.

[0055] In the embodiments of this disclosure, the scheme of determining the opening mode of the charcoal canister isolation valve 3 and the fuel tank isolation valve 4 based on the specific pressure detected by the charcoal canister pressure sensor 7 can be applied to the same fuel system. The depressurization operation and air replenishment operation of the fuel tank 1 are as described above, and will not be repeated here for the sake of brevity.

[0056] In some implementations, the preset air replenishment pressure of the charcoal canister can be the same as the pressure of the outside atmosphere. This setting ensures that there will be no negative pressure inside the charcoal canister 2, thereby ensuring that the pressure difference between the oil tank 1 and the charcoal canister 2 is less than or equal to the preset air replenishment pressure of the oil tank. That is, when it is necessary to replenish the oil tank 1, the oil tank isolation valve 4 can open automatically without failing to open.

[0057] Using this method, when replenishing fuel tank 1, there is no need to detect the pressure inside the charcoal canister 2 or to control the opening of the fuel tank isolation valve 4 through the controller 5, thereby simplifying the steps of replenishing fuel tank 1 and improving the efficiency of replenishing fuel tank 1.

[0058] This method can be applied to the fuel system in any of the above embodiments.

[0059] In other possible implementations, such as Figure 3 As shown, the fuel system may include a positive pressure check valve 8 installed on the fuel tank 1. The pressure relief outlet of the fuel tank 1 is connected to the outside atmosphere through the positive pressure check valve 8. The opening pressure of the positive pressure check valve 8 is less than or equal to the upper limit of the safe pressure of the fuel tank 1 and greater than or equal to the preset pressure relief pressure of the fuel tank.

[0060] In this way, when the pressure inside the oil tank 1 is greater than or equal to the upper limit of the safe pressure of the oil tank 1 because the oil tank isolation valve 4 is not open, the positive pressure check valve 8 will open, thereby venting the gas in the oil tank 1 into the outside atmosphere and completing the depressurization operation of the oil tank 1.

[0061] In some possible implementations, such as Figure 4 As shown, the fuel system includes a negative pressure check valve 9 installed on the fuel tank. The air inlet of the fuel tank 1 is connected to the outside atmosphere through the negative pressure check valve 9. The opening pressure of the negative pressure check valve 9 is greater than or equal to the lower limit of the safe pressure of the fuel tank 1 and less than or equal to the preset air inlet pressure of the fuel tank.

[0062] In this way, when the pressure inside the oil tank 1 is less than or equal to the lower limit of the safe pressure of the oil tank 1 because the oil tank isolation valve 4 is not open, the negative pressure check valve 9 will open, thereby replenishing the outside atmosphere into the oil tank 1 and completing the air replenishment operation of the oil tank 1.

[0063] It should be noted that the fuel system can be equipped with both a positive pressure check valve 8 and a negative pressure check valve 9, or the positive pressure check valve 8 and the negative pressure check valve 9 can be used individually in any of the above embodiments. The method of venting gas through the positive pressure check valve 8 and the method of replenishing gas through the negative pressure check valve 9 in the fuel system are as described above. For the sake of brevity, this disclosure will not repeat them here.

[0064] For example, when the fuel tank 1 of the fuel system is depressurized, it can be done by positive pressure check valve 8, and when the fuel tank 1 is replenished with air, it can be done by opening fuel tank isolation valve 4 and / or charcoal canister isolation valve 3; or, when the fuel tank of the fuel system is replenished with air, it can be done by negative pressure check valve 9, and when the fuel tank 1 is depressurized, it can be done by opening fuel tank isolation valve 4 and / or charcoal canister isolation valve 3.

[0065] In embodiments of this disclosure, such as Figure 5 and Figure 6As shown, the fuel system may also include a pressure relief valve 10. The pressure relief valve 10 includes a first pipeline 1001, a second pipeline 1002, a sealing element 1003, and an elastic element 1004. The first end of the first pipeline 1001 is connected to the fuel tank 1, and the second end of the first pipeline 1001 is connected to the outside atmosphere. The second pipeline 1002 is connected to the first pipeline 1001. The elastic element 1004 is disposed in the first pipeline 1001 and connected to the sealing element 1003. The sealing element 1003 can move toward the second end under the pressure of the fuel tank 1 to expose the connection between the first pipeline 1001 and the second pipeline 1002, and can move toward the first end under the action of the elastic element 1004 to seal the connection between the first pipeline 1001 and the second pipeline 1002.

[0066] The preset pressure relief pressure of the oil tank is set to be less than or equal to the upper limit of the safe pressure of the oil tank 1. The pressure in the oil tank 1 that can push the sealing member 1003 to overcome the elastic member 1004 and move towards the second end is less than or equal to the upper limit of the safe pressure of the oil tank 1 and greater than or equal to the preset pressure relief pressure of the oil tank. Thus, when the pressure in the oil tank 1 is greater than or equal to the upper limit of the safe pressure of the oil tank 1 because the oil tank isolation valve 4 is not opened, the pressure inside the oil tank 1 will cause the sealing member 1003 to overcome the elastic force of the elastic member 1004, such as a spring, and move towards the second end. As a result, the sealing member 1003 will be exposed at the junction of the first pipeline 1001 and the second pipeline 1002, so that the gas in the oil tank 1 can enter the carbon canister 2. After a certain amount of gas is discharged from the oil tank 1, the pressure applied to the sealing member 1003 inside the oil tank 1 will make the sealing member 1003 unable to overcome the elastic force of the elastic member 1004. As a result, the sealing member 1003 will re-seal the connection between the first pipeline 1001 and the second pipeline 1002.

[0067] In addition, since the second pipeline 1002 is connected in parallel to the first pipeline 1001, and the plug 1003 can move within the first pipeline 1001, the pressure inside the carbon canister 2 will not affect the movement of the plug 1003.

[0068] To ensure that the gas in the oil tank 1 can enter the charcoal canister 2, the pressure in the charcoal canister 2 should be less than the pressure in the oil tank 1 when the pressure relief valve 10 is open. For example, a charcoal canister pressure sensor 7 can be installed in the charcoal canister 2. When the charcoal canister pressure sensor 7 detects that the pressure in the charcoal canister 2 is greater than the pressure in the oil tank 1, the controller 5 can control the charcoal canister isolation valve 3 to open. Alternatively, the preset pressure relief pressure of the charcoal canister can be less than the upper limit of the safe pressure of the oil tank 1. Thus, it can be ensured that when the pressure in the oil tank 1 is greater than or equal to the upper limit of the safe pressure of the oil tank 1, the pressure in the charcoal canister 2 is less than the pressure in the oil tank 1.

[0069] Furthermore, the pressure relief valve 10 can be applied in any of the above embodiments, and its pressure relief method is as described above. For the sake of brevity, this disclosure will not repeat it here.

[0070] In some possible implementations, the fuel system may further include a controller 5 and an engine 11, with the second outlet of the charcoal canister 2 connected to the intake manifold of the engine 11 via a charcoal canister solenoid valve 12; the fuel tank isolation valve 4, the charcoal canister isolation valve 3, and the charcoal canister solenoid valve 12 are all electrically connected to the controller 5; when the fuel system is in desorption mode, the controller 5 controls the fuel tank isolation valve 4, the charcoal canister isolation valve 3, and the charcoal canister solenoid valve 12 to open.

[0071] When the activated carbon or carbon powder in the charcoal canister 2 is saturated and can no longer adsorb fuel vapor discharged from the fuel tank 1, the fuel system can desorb the fuel vapor in the charcoal canister 2. That is, when the vehicle's engine is running, the controller 5 can control the charcoal canister solenoid valve 12 and the charcoal canister isolation valve 3 to open. In this way, the low pressure in the intake manifold of the engine 11 will generate suction to absorb the fuel vapor stored in the charcoal canister 2 or the fuel adsorbed on the activated carbon or carbon powder, while the outside atmosphere will replenish the charcoal canister 2 with new gas, thereby ensuring that the intake manifold can continuously absorb the fuel vapor and / or fuel in the charcoal canister 2. At the same time, if the fuel tank isolation valve 4 is opened, the gas in the fuel tank 1 can be discharged to the charcoal canister 2 to reduce the pressure in the fuel tank 1. Thus, the risk of the gas pressure inside the fuel tank 1 exceeding the safe upper limit pressure of the fuel tank 1 can be reduced to a certain extent.

[0072] It should be noted that the controller 5 disclosed herein can be an electronic control unit (ECU) in a vehicle.

[0073] In addition, the first outlet of the charcoal canister 2 of the fuel system disclosed herein is also connected to an ash filter 13, which can filter out impurities carried by the outside atmosphere during the replenishment of the charcoal canister 2, thereby ensuring the service life and working efficiency of the charcoal canister 2.

[0074] A second aspect of this disclosure provides a vehicle that includes the aforementioned fuel system. It should be noted that the vehicle has all the beneficial effects of the aforementioned fuel system, which will not be elaborated upon here.

[0075] In summary, this disclosure exemplarily illustrates the working principle of a fuel system.

[0076] The fuel tank isolation valve 4 and charcoal canister isolation valve 3 of this disclosed fuel system can treat the fuel tank 1 and charcoal canister 2 as a pressure vessel capable of storing fuel vapor. This enhances the fuel system's ability to store fuel vapor, eliminating the need for additional charcoal rods in the fuel system. This reduces vehicle costs while meeting low emission requirements and minimizes the space occupied by the fuel system within the vehicle, simplifying chassis layout. Furthermore, the fuel tank isolation valve 4 prevents fuel vapor from continuously entering the charcoal canister 2 and being adsorbed by activated carbon and charcoal powder, thus mitigating the problem of activated carbon and charcoal powder aging easily.

[0077] Furthermore, since the oil tank isolation valve 4 and the charcoal canister isolation valve 3 can be opened and closed automatically, both the oil tank 1 and the charcoal canister 2 have the effects of automatic pressure relief and automatic air replenishment, thereby improving the efficiency of exhaust and air replenishment while ensuring their safety and service life.

[0078] When the fuel system of this disclosure is in refueling mode, the controller 5 can control the opening of the fuel tank isolation valve 4 and the charcoal canister isolation valve 3 to ensure that the air passage in the fuel system remains unobstructed, thereby enabling the fuel system to be in a stable and safe pressure environment.

[0079] When the fuel system of this disclosure is in desorption mode, the controller 5 can control the opening of the fuel tank isolation valve 4, the charcoal canister isolation valve 3 and the charcoal canister solenoid valve 12. This can not only perform desorption operations on the charcoal canister 2, but also reduce the risk of the air pressure inside the fuel tank 1 exceeding the safe upper limit pressure of the fuel tank 1 to a certain extent.

[0080] When the pressure of the fuel tank 1 in the fuel system disclosed herein is greater than or equal to the upper limit of the safe pressure of the fuel tank 1, the gas in the fuel tank 1 can be discharged through the positive pressure check valve 8, or the gas in the fuel tank 1 can be discharged through the pressure relief valve 10, or the controller 5 can allow the gas in the fuel tank 1 to enter the charcoal canister 2 by opening the charcoal canister isolation valve 3 and / or the fuel tank isolation valve 4.

[0081] When the pressure of the fuel tank 1 in the fuel system disclosed herein is less than or equal to the lower limit of the safe pressure of the fuel tank 1, the outside atmosphere can be replenished into the fuel tank 1 through the negative pressure check valve 9, or the controller 5 can replenish the gas in the charcoal canister 2 into the fuel tank 1 by opening the charcoal canister isolation valve 3 and / or the fuel tank isolation valve 4.

[0082] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0083] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0084] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A fuel system, characterized in that, include: tank; A charcoal canister, the first inlet of which is connected to the fuel vapor outlet of the fuel tank; as well as A charcoal canister isolation valve, through which the first outlet of the charcoal canister is connected to the outside atmosphere; The charcoal canister isolation valve is configured to be controllably opened or closed, and to automatically open when the pressure difference between the pressure inside the charcoal canister and the external atmospheric pressure is greater than or equal to the preset pressure relief pressure of the charcoal canister and less than or equal to the preset air replenishment pressure of the charcoal canister.

2. The fuel system according to claim 1, characterized in that, The fuel system also includes a fuel tank isolation valve, through which the fuel vapor outlet of the fuel tank is connected to the first inlet of the charcoal canister; The oil tank isolation valve is configured to be controllably opened or closed, and can be automatically opened when the pressure difference between the pressure in the oil tank and the pressure in the carbon canister is greater than or equal to the preset pressure relief pressure of the oil tank and less than or equal to the preset air replenishment pressure of the oil tank.

3. The fuel system according to claim 2, characterized in that, The fuel system also includes a controller and a fuel tank pressure sensor. The fuel tank pressure sensor is used to detect the pressure inside the fuel tank. The controller is electrically connected to the fuel tank pressure sensor and the fuel tank isolation valve. Wherein, the preset pressure relief pressure of the oil tank is set to be less than or equal to the upper limit of the safe pressure of the oil tank, and the controller is used to control the opening of the charcoal canister isolation valve or the oil tank isolation valve when the pressure in the oil tank is greater than or equal to the upper limit of the safe pressure of the oil tank; and / or, The preset air replenishment pressure of the oil tank is greater than or equal to the lower limit of the safe pressure of the oil tank. The controller is used to control the opening of the charcoal canister isolation valve or the oil tank isolation valve when the pressure in the oil tank is less than or equal to the lower limit of the safe pressure of the oil tank.

4. The fuel system according to claim 3, characterized in that, The preset pressure relief pressure of the charcoal canister is less than the upper limit of the safe pressure of the oil tank; and / or, The preset air replenishment pressure of the charcoal canister is greater than the lower limit of the safe pressure of the oil tank.

5. The fuel system according to claim 2, characterized in that, The fuel system also includes a controller, a fuel tank pressure sensor, and a charcoal canister pressure sensor. The fuel tank pressure sensor is used to detect the pressure inside the fuel tank, and the charcoal canister pressure sensor is used to detect the pressure inside the charcoal canister. The fuel tank pressure sensor, the charcoal canister pressure sensor, the fuel tank isolation valve, and the charcoal canister isolation valve are all electrically connected to the controller. Wherein, the preset pressure relief pressure of the oil tank is set to be less than or equal to the upper limit of the safe pressure of the oil tank, and the preset pressure relief pressure of the charcoal canister is set to be greater than the upper limit of the safe pressure of the oil tank. The controller is used to control the opening of the charcoal canister isolation valve or control the opening of both the charcoal canister isolation valve and the oil tank isolation valve when the pressure in the oil tank is greater than or equal to the upper limit of the safe pressure of the oil tank, and the pressure in the charcoal canister is greater than or equal to the upper limit of the safe pressure of the oil tank; and / or, The preset air supply pressure of the oil tank is greater than or equal to the lower limit of the safe pressure of the oil tank, and the preset air supply pressure of the charcoal canister is less than the lower limit of the safe pressure of the oil tank. The controller is used to control the opening of the charcoal canister isolation valve or control the opening of both the charcoal canister isolation valve and the oil tank isolation valve when the pressure in the oil tank is less than or equal to the lower limit of the safe pressure of the oil tank and the pressure in the charcoal canister is less than the lower limit of the safe pressure of the oil tank.

6. The fuel system according to any one of claims 2-4, characterized in that, The preset air supply pressure of the charcoal canister is the same as the pressure of the outside atmosphere.

7. The fuel system according to any one of claims 2-5, characterized in that, The fuel system includes a positive pressure check valve mounted on the fuel tank. The pressure relief outlet of the fuel tank is connected to the outside atmosphere through the positive pressure check valve. The opening pressure of the positive pressure check valve is less than or equal to the upper limit of the safe pressure of the fuel tank and greater than or equal to the preset pressure relief pressure of the fuel tank; and / or, The fuel system includes a negative pressure check valve installed on the fuel tank. The fuel tank's air inlet is connected to the outside atmosphere through the negative pressure check valve. The opening pressure of the negative pressure check valve is greater than or equal to the lower limit of the fuel tank's safety pressure and less than or equal to the fuel tank's preset air replenishment pressure.

8. The fuel system according to any one of claims 2-5, characterized in that, The fuel system also includes a pressure relief valve, which includes a first pipeline, a second pipeline, a sealing element, and a resilient element. The first end of the first pipeline is connected to the fuel tank, and the second end of the first pipeline is connected to the outside atmosphere. The second pipeline is connected in parallel to the first pipeline. The resilient element is disposed in the first pipeline and connected to the sealing element. The sealing element can move toward the second end under the pressure of the fuel tank to expose the connection between the first pipeline and the second pipeline, and can also move toward the first end under the action of the resilient element to seal the connection between the first pipeline and the second pipeline.

9. The fuel system according to claim 2, characterized in that, The fuel system also includes a controller and an engine. The second outlet of the charcoal canister is connected to the intake manifold of the engine via a charcoal canister solenoid valve. The fuel tank isolation valve, the charcoal canister isolation valve, and the charcoal canister solenoid valve are all electrically connected to the controller. When the fuel system is in desorption mode, the controller controls the opening of the fuel tank isolation valve, the charcoal canister isolation valve, and the charcoal canister solenoid valve.

10. A vehicle, characterized in that, The fuel system comprising any one of claims 1-9.

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