Liquid fuel recovery system and vehicle having same

Abstract

The application provides a liquid fuel recovery system and a vehicle with the same, which comprises: a fuel tank, a refueling limiting valve and a gravity valve are arranged in the fuel tank, the gravity valve is provided with a first exhaust port, and the gravity valve is arranged in communication with a fuel storage space of the fuel tank; a primary oil-gas separator is arranged in the fuel tank, a first air inlet of the primary oil-gas separator is arranged in communication with the refueling limiting valve, and the primary oil-gas separator is provided with a second exhaust port; a secondary oil-gas separator is arranged in the fuel tank, the secondary oil-gas separator is provided with a second air inlet, a third air inlet and a third exhaust port, the second air inlet is in communication with the second exhaust port, the third air inlet is in communication with the first exhaust port, the third exhaust port is in communication with an activated carbon tank, and the second exhaust port and the second air inlet are arranged with a height difference in the height direction of the fuel tank. The oil-gas separators are arranged in the fuel tank, fuel leakage is avoided, liquid fuel in the primary oil-gas separator is subjected to secondary oil-gas separation after entering the secondary oil-gas separator, and the liquid fuel is prevented from entering the activated carbon tank.

Description

Technical Field

[0001] This invention relates to the field of vehicle fuel technology, and more specifically, to a liquid fuel recovery system and a vehicle having the same. Background Technology

[0002] To reduce the pollution of the atmosphere by harmful vehicle emissions, fuel vapors must not be directly released into the atmosphere but instead flow into an activated carbon canister. The activated carbon in the canister effectively adsorbs the fuel vapors, significantly reducing evaporative emissions. The most significant factor causing a decrease in the canister's effectiveness is the entry of liquid fuel. Liquid fuel entering the canister causes an irreversible decline in the activated carbon's working capacity. If a large amount of liquid fuel enters the canister, and the canister's capacity decreases by more than 10%, the vehicle's evaporative emissions will exceed standards. Simultaneously, the risk of fuel vapor leakage and fire increases. Furthermore, if a large amount of liquid fuel enters the canister, it may enter the engine, causing unstable engine operation or even stalling.

[0003] Currently, fuel tanks typically use two types of valves: a filler volume control valve (FLVV valve) and a gravity valve (GVV valve). The FLVV valve is a normally open valve that closes when the filler volume reaches the rated capacity, effectively controlling the filler volume. The GVV valve is a pressure-opening valve, closing higher than the FLVV valve. This ensures the fuel tank can breathe normally even when the FLVV valve is closed. There are four methods to prevent liquid fuel from entering the activated carbon canister:

[0004] The first type only has FLVV valves and GVV valves in the fuel tank. Due to the lack of an oil-gas separator structure, there is a high risk that liquid fuel generated by dynamic leakage of the valves will enter the activated carbon canister.

[0005] The second type uses a valve-mounted oil-gas separator structure inside the fuel tank, that is, a top-mounted oil-gas separator structure is integrated on the FLVV valve. It uses a single-stage oil-gas separator, which is not thorough. When there is a lot of fuel in the fuel tank and the refueling limit valve (FLVV valve) is closed, the liquid fuel in the oil-gas separator cannot flow back to the fuel tank, and there is a risk of flowing into the activated carbon canister.

[0006] The third type uses a built-in separate oil-gas separator structure inside the fuel tank. Due to space limitations, the position is usually low, which may cause the liquid fuel entering the oil-gas separator to be unable to flow back. Moreover, the separation effect of this separate oil-gas separator structure is usually not ideal.

[0007] The fourth type is to use an external oil-gas separator structure, which is placed on the fuel tank or near the refueling pipe. The external oil-gas separator structure is usually placed at a higher position, and the liquid fuel return effect is better. However, since the oil-gas separator is external, it is more difficult to arrange in space. At the same time, the external placement of the oil-gas separator will increase the evaporation emissions, which can easily lead to the evaporation emission values ​​exceeding the standard.

[0008] The arrangement of valves and oil-gas separators in the aforementioned fuel tank poses a risk of liquid fuel flowing into the activated carbon canister or fuel vapor leakage. Summary of the Invention

[0009] The main objective of this invention is to provide a liquid fuel recovery system and a vehicle having the same, in order to solve the technical problem in the prior art where the arrangement of valves and oil-gas separators in the fuel tank results in liquid fuel flowing into the activated carbon canister or fuel vapor leakage.

[0010] To achieve the above objectives, according to one aspect of the present invention, a liquid fuel recovery system is provided, comprising: a fuel tank, wherein a refueling limit valve and a gravity valve are disposed within the fuel tank, the gravity valve having a first vent and communicating with the fuel storage space of the fuel tank; a primary oil-gas separator, located within the fuel tank, wherein a first air inlet of the primary oil-gas separator is communicating with the refueling limit valve and a second vent; and a secondary oil-gas separator, located within the fuel tank, wherein a second air inlet, a third air inlet, and a third vent are provided, wherein the second air inlet is communicating with the second vent, the third air inlet is communicating with the first vent, the third vent is communicating with an activated carbon canister, and the second vent and the second air inlet are disposed with a height difference in the height direction of the fuel tank.

[0011] Furthermore, at least a portion of the liquid fuel flowing into the secondary oil-gas separator flows back to the fuel tank under gravity or negative pressure.

[0012] Furthermore, in the height direction of the fuel tank, the height of the second exhaust port is lower than the height of the second air inlet, and the liquid fuel flowing into the secondary oil-gas separator flows back to the fuel tank through the second exhaust port.

[0013] Furthermore, the third air inlet is located at the bottom of the secondary oil-gas separator. The third air inlet has a vertically downward extending pipe that is connected to the first exhaust port. The liquid fuel in the secondary oil-gas separator flows back to the fuel tank through the first exhaust port and the gravity valve in sequence.

[0014] Furthermore, a one-way valve is provided at the bottom of the secondary oil-gas separator, through which liquid fuel flowing into the secondary oil-gas separator flows back to the fuel tank.

[0015] Furthermore, the check valve has at least two valves, which are arranged in series along the height direction of the oil tank.

[0016] Furthermore, the cavity of the first-stage oil-gas separator is provided with multiple first baffles, and a gap is left between the first baffles and the inner top wall of the first-stage oil-gas separator. At least one of the multiple first baffles is arranged around the second exhaust port.

[0017] Furthermore, the cavity of the secondary oil-gas separator is provided with multiple second baffles, and there is a gap between the second baffles and the inner top wall of the secondary oil-gas separator. At least one of the multiple second baffles is arranged around the third exhaust port.

[0018] Furthermore, the height difference between the closed position of the refueling limit valve and the lower edge of the second exhaust port in the height direction of the oil tank is greater than 30mm.

[0019] According to another aspect of the present invention, a vehicle is provided, including a liquid fuel recovery system, wherein the liquid fuel recovery system is the liquid fuel recovery system described above.

[0020] By applying the technical solution of this invention, a two-stage oil-gas separator is installed inside the fuel tank. Fuel vapor from the first-stage oil-gas separator and gravity valve enters the activated carbon canister after passing through the second-stage oil-gas separator, preventing fuel leakage. When liquid fuel in the first-stage oil-gas separator enters the second-stage oil-gas separator along with the fuel vapor, the second-stage separator performs secondary oil-gas separation, causing the liquid fuel to remain in the second-stage separator or flow back into the fuel tank, preventing liquid fuel from entering the activated carbon canister and reducing its working capacity. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 A schematic diagram of a first embodiment of the liquid fuel recovery system according to the present invention is shown;

[0023] Figure 2 A schematic diagram of a second embodiment of the liquid fuel recovery system according to the present invention is shown;

[0024] Figure 3 A schematic diagram of the one-way valve in this invention is shown;

[0025] Figure 4 A schematic diagram of the internal structure of the primary oil-gas separator in this invention is shown.

[0026] Figure 5 A schematic diagram of the internal structure of the two-stage oil-gas separator in this invention is shown;

[0027] Figure 6A schematic diagram showing the integration relationship between the primary oil-gas separator and the refueling limit valve in this invention is shown.

[0028] The above figures include the following reference numerals:

[0029] 10. Fuel tank;

[0030] 20. Filling limit valve; 21. Guide post; 22. Snap-fit ​​boss; 23. Snap-fit ​​groove; 24. Float; 25. Oil inlet window; 26. Sealing ring; 27. Air outlet; 28. Valve inner shell; 29. ​​Valve outer shell; 210. Sealing cap;

[0031] 30. Gravity valve; 31. First exhaust port;

[0032] 40. First-stage oil-gas separator; 41. Second exhaust port; 42. First baffle; 43. First air inlet;

[0033] 50. Secondary oil-gas separator; 51. Second air inlet; 52. Third air inlet; 53. Third exhaust port; 54. Extension pipe; 55. Second baffle;

[0034] 60. Activated carbon canister; 61. Adsorption port; 62. Atmospheric port; 63. Desorption port;

[0035] 70. Check valve; 71. First-stage check valve; 72. Second-stage check valve; 73. First-stage baffle; 74. Second-stage baffle;

[0036] 80. Full oil level;

[0037] 90. First pipeline; 91. Second pipeline; 92. Third pipeline. Detailed Implementation

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0042] Combination Figures 1 to 6 As shown, according to a specific embodiment of this application, a liquid fuel recovery system is provided.

[0043] Specifically, the liquid fuel recovery system includes: a fuel tank 10, a primary fuel-gas separator 40, and a secondary fuel-gas separator 50. The fuel tank 10 is equipped with a refueling limit valve 20 and a gravity valve 30. The gravity valve 30 has a first exhaust port 31 and is connected to the fuel storage space of the fuel tank 10. The primary fuel-gas separator 40 is located inside the fuel tank 10. Its first air inlet 43 is connected to the refueling limit valve 20, and it has a second exhaust port 41. The secondary fuel-gas separator 50 is located inside the fuel tank 10. It has a second air inlet 51, a third air inlet 52, and a third exhaust port 53. The second air inlet 51 is connected to the second exhaust port 41, the third air inlet 52 is connected to the first exhaust port 31, and the third exhaust port 53 is connected to the activated carbon canister 60. The second exhaust port 41 and the second air inlet 51 are positioned with a height difference in the height direction of the fuel tank 10.

[0044] It should be noted that the refueling limit valve 20 is a normally open valve. When the refueling volume reaches the rated capacity, the valve closes, which can effectively control the refueling volume. The gravity valve 30 is a pressure-opening valve, and its closing height is higher than that of the refueling limit valve 20. That is, there is a height difference between the gravity valve 30 and the full oil level 80, so as to ensure the normal breathing of the oil tank 10 when the refueling limit valve 20 is closed.

[0045] In the embodiments of this application, a two-stage fuel vapor separator is installed inside the fuel tank 10. Fuel vapor in the first-stage fuel vapor separator 40 and gravity valve 30 enters the activated carbon canister after passing through the second-stage fuel vapor separator 50, preventing fuel leakage. When liquid fuel in the first-stage fuel vapor separator 40 enters the second-stage fuel vapor separator 50 along with the fuel vapor, the second-stage fuel vapor separator 50 performs secondary fuel vapor separation, causing the liquid fuel to remain in the second-stage fuel vapor separator 50 or flow back into the fuel tank 10, preventing liquid fuel from entering the activated carbon canister 60 and causing a decrease in its working capacity.

[0046] In one exemplary embodiment of this application, the secondary oil-gas separator 50 is located between the primary oil-gas separator 40 and the gravity valve 30 to facilitate the arrangement of connecting pipelines. Specifically, the second exhaust port 41 of the primary oil-gas separator 40 is connected to the second air inlet 51 of the secondary separator via a first pipeline 90, the first exhaust port 31 of the gravity valve 30 is connected to the third air inlet 52 of the secondary oil-gas separator 50 via a second pipeline 91, and the third exhaust port 53 of the secondary oil-gas separator 50 is connected to the activated carbon canister 60 via a third pipeline 92.

[0047] Furthermore, the activated carbon canister is equipped with an adsorption port 61, an atmospheric port 62, and a desorption port 63. The third exhaust port 53 of the secondary oil-gas separator 50 is connected to the adsorption port 61 of the activated carbon canister 60 via a third pipe 92. When the engine is running, fuel vapor adsorbed in the activated carbon canister flows into the engine through the desorption port 63 to participate in combustion. Fresh air flows into the activated carbon canister through the atmospheric port 62 for pressure compensation to ensure pressure balance within the canister. The desorbed activated carbon canister can continue to adsorb fuel vapor, and this process is repeated.

[0048] In one exemplary embodiment of this application, liquid fuel entering the secondary oil-gas separator 50 after passing through the primary oil-gas separator 40 can be retained within the secondary oil-gas separator 50.

[0049] In another exemplary embodiment of this application, at least a portion of the liquid fuel flowing into the secondary oil-gas separator 50 flows back to the fuel tank 10 under gravity or negative pressure. This backflow of liquid fuel to the fuel tank 10 prevents it from accumulating beyond the third exhaust port 53 of the secondary oil-gas separator 50, or from splashing out of the third exhaust port 53 due to vehicle movement, ultimately leading to liquid fuel entering the activated carbon canister 60.

[0050] In one specific exemplary embodiment of this application, such as Figure 1 As shown, the height of the second exhaust port 41 in the height direction of the fuel tank 10 is lower than the height of the second air inlet 51. Liquid fuel flowing into the secondary oil-gas separator 50 flows back to the fuel tank 10 through the second exhaust port 41. Under the action of gravity, some of the liquid fuel entering the first pipeline 90 can flow back to the first oil-gas separator, reducing the amount of liquid fuel entering the secondary oil-gas separator 50 and allowing more separation space to be reserved in the secondary oil-gas separator 50. Due to the height difference and gravity, the liquid fuel entering the secondary oil-gas separator 50 can flow back to the primary oil-gas separator 40 through the second air inlet 51 and the first pipeline 90. During vehicle operation, the consumption of liquid fuel causes the outlet 27 of the refueling limit valve 20 to open, and the liquid fuel in the first oil-gas separator flows back to the fuel tank 10 through the refueling limit valve 20.

[0051] It should be noted that the space inside the fuel tank 10 is relatively large. In the height direction of the fuel tank 10, the position of the secondary oil-gas separator 50 is higher than that of the primary oil-gas separator 40. Therefore, it can meet the design requirement that the height of the second exhaust port 41 is lower than that of the second air inlet 51 in the height direction of the fuel tank 10.

[0052] In another specific exemplary embodiment of this application, such as Figure 2 As shown, the third air inlet 52 is located at the bottom of the secondary oil-gas separator 50. The third air inlet 52 has a vertically downward extending pipe 54, which is connected to the first exhaust port 31. Liquid fuel in the secondary oil-gas separator 50 flows back to the fuel tank 10 sequentially through the first exhaust port 31 and the gravity valve 30. The diameter of the extending pipe 54 and the second pipeline 91 is no greater than 5mm to ensure that even a small amount of liquid fuel in the secondary oil-gas separator 50 will fill the extending pipe 54. After the extending pipe 54 is filled, under negative pressure, the liquid fuel is gradually forced into the second pipeline 91. Because the diameter of the second pipeline 91 is small, the liquid fuel remains continuous in the second pipeline 91. Since the gravity valve 30 is always connected to the fuel storage space of the fuel tank 10, the liquid fuel in the second pipeline 91 flows back to the fuel tank 10 through the gravity valve 30.

[0053] It should be noted that the space inside the fuel tank 10 is limited. In the height direction of the fuel tank 10, the position of the secondary oil-gas separator 50 is lower than that of the primary oil-gas separator 40. In the height direction of the fuel tank 10, it is difficult to ensure that the height of the second air inlet 51 is higher than that of the second exhaust outlet 41.

[0054] Furthermore, in Figure 1 and Figure 2In the illustrated embodiments, a one-way valve 70 can be installed at the bottom of the secondary oil-gas separator 50. Liquid fuel flowing into the secondary oil-gas separator 50 flows back to the fuel tank 10 via the one-way valve 70. The one-way valve 70 increases the return path of liquid fuel and is simple to install.

[0055] Specifically, in Figure 1 In the embodiment shown, a one-way valve 70 is added. When the vehicle tilts or shakes violently, the liquid fuel in the first-stage oil-gas separator 40 may flow into the second-stage oil-gas separator 50 through the first pipeline 90. The liquid fuel flowing into the second-stage oil-gas separator 50 can flow back to the fuel tank 10 through the one-way valve 70.

[0056] It should be noted that, in Figure 2 In the illustrated embodiment, the fuel level 80 is higher than the one-way valve 70, meaning the one-way valve 70 is submerged in liquid fuel. The liquid fuel in the secondary fuel separator 50 cannot flow back to the fuel tank 10 via the one-way valve 70. At this point, the liquid fuel in the secondary fuel separator 50 fills the extension pipe 54. Under negative pressure, the liquid fuel is gradually forced into the second pipe 91, allowing it to flow back to the fuel tank 10 via the gravity valve 30. Here, the fuel level 80 refers to the fuel level in the fuel tank 10 after it is fully filled.

[0057] Furthermore, at least two check valves 70 are provided, and the at least two check valves 70 are arranged in series along the height direction of the oil tank 10. Specifically, as shown below... Figure 3 As shown, the one-way valve 70 includes: a primary one-way valve 71, a secondary one-way valve 72, a primary baffle 73, and a secondary baffle 74. The primary baffle 73 is located directly below the primary one-way valve 71, and the secondary baffle 74 is located directly below the secondary one-way valve 72. The primary baffle 73 and the secondary baffle 74 serve as limiting supports to prevent excessive deformation of the one-way valves from causing poor sealing. Both the primary baffle 73 and the secondary baffle 74 have through holes to ensure that the liquid fuel in the secondary oil-gas separator 50 flows out smoothly. When the fuel tank 10 shakes, the valve core of the one-way valve may tilt. A small amount of liquid fuel entering the secondary oil-gas separator 50 through the secondary one-way valve 72 will be blocked by the primary one-way valve 71. The probability of liquid fuel entering the secondary oil-gas separator 50 through the two-stage one-way valves 70 is extremely low.

[0058] like Figure 4As shown, the cavity of the primary oil-gas separator 40 is provided with multiple first baffles 42. A gap is left between the first baffles 42 and the inner top wall of the primary oil-gas separator 40. At least one of the multiple first baffles 42 is arranged around the second exhaust port 41, and fuel vapor flows out from the second exhaust port 41 through the gap. Specifically, the primary oil-gas separator 40 has a cylindrical structure, and there are four first baffles 42, one of which is a U-shaped structure. This U-shaped first baffle 42 is arranged around the second exhaust port 41, and the remaining three first baffles 42 are arranged around the first air inlet 43 of the primary oil-gas separator 40. An outlet is left between two adjacent first baffles 42, allowing splashed liquid fuel to gradually collide and settle. The first baffles 42 act as a buffer. After the liquid fuel entering the primary oil-gas separator 40 through the first air inlet 43 collides with the first baffles 42, it flows downward along the first baffles 42 to the bottom of the cavity, preventing liquid fuel from splashing out from the second exhaust port 41.

[0059] It should be noted that the shape of the primary oil-gas separator 40 is not limited; it can also be rectangular, polygonal, etc. The shape and number of the first baffle 42 are also not limited, as long as they can serve as a collision buffer.

[0060] like Figure 5 As shown, the secondary oil-gas separator 50 has multiple second baffles 55 inside its cavity. A gap exists between the second baffles 55 and the inner top wall of the secondary oil-gas separator 50. At least one of the second baffles 55 is arranged around the third exhaust port 53, through which fuel vapor flows out. Specifically, the secondary oil-gas separator 50 has a rectangular structure, with four second baffles 55. One of these is U-shaped, surrounding the third exhaust port 53. The remaining three second baffles 55 are spaced apart along the length of the secondary oil-gas separator 50, with an outlet between adjacent baffles 55 to allow splashed liquid fuel to gradually collide and settle. The second baffles 55 act as a buffer; after colliding with the second baffles 55, the liquid fuel entering the secondary oil-gas separator 50 flows downwards along the baffles 55 to the bottom of the cavity, preventing liquid fuel from splashing out from the third exhaust port 53.

[0061] It should be noted that the shape of the primary oil-gas separator 40 is not limited; it can also be cylindrical, polygonal, etc. The shape and number of the second baffle 55 are also not limited, as long as they can serve as a collision buffer.

[0062] like Figure 6As shown, the first-stage oil-gas separator 40 is integrated on the top of the refueling limit valve 20, and the first air inlet 43 of the first-stage oil-gas separator 40 is directly opposite the air outlet 27 of the refueling limit valve 20. Specifically, the refueling limit valve 20 includes: a valve housing 29, a valve inner housing 28, a snap-fit ​​boss 22, a guide post 21, a float 24, an oil inlet window 25, a sealing ring 26, an air outlet 27, and a sealing cap 210. The valve housing 29 and the valve inner housing 28 are sleeved and connected to form the cavity of the refueling limit valve 20. The valve housing 29 has an oil inlet window 25, which is connected to the cavity of the refueling limit valve 20. The top of the float 24 is connected to the sealing cap 210, which is used to block the air outlet 27. The primary oil-gas separator 40 has an outwardly extending connecting sleeve with a snap-fit ​​groove 23. The primary oil-gas separator 40 is connected to the valve housing 29 of the refueling limit valve 20 via the connecting sleeve. The valve housing 29 is snapped into place by a snap-fit ​​boss 22 and a snap-fit ​​groove 23. A sealing ring 26 is provided on the outer periphery of the valve inner housing 28. The valve inner housing 28 is sealed to the connecting sleeve of the primary oil-gas separator 40 via the sealing ring 26, which is located above the oil inlet window 25. This top-mounted structure of the primary oil-gas separator 40 allows for real-time backflow of dynamically leaking fuel, more effectively reducing the risk of fuel leakage.

[0063] It should be noted that during the initial refueling process, the float 24 is positioned below the refueling limit valve 20 due to gravity. Fuel vapor in the fuel tank 10 flows sequentially through the inlet window 25, the outlet 27, and the first air inlet 43 into the primary fuel-air separator 40, and then enters the secondary fuel-air separator 50 through the second exhaust port 41. When the refueling level reaches the lower edge of the inlet window 25 of the refueling limit valve 20, liquid fuel flows into the refueling limit valve 20 from the inlet window 25. Under the action of buoyancy, the float 24 rises along the guide post 21. When the sealing cap 210 on top of the float 24 contacts the inner wall of the refueling limit valve 20 and blocks the outlet 27, the fuel vapor in the fuel tank 10 cannot be discharged, the pressure in the fuel tank 10 rises rapidly, liquid fuel cannot be added further, the refueling nozzle shuts off, the refueling process ends, and the liquid level in the fuel tank 10 reaches the full fuel level 80.

[0064] As an alternative implementation, the primary oil-gas separator 40 and the refueling limit valve 20 can be a non-integrated structure. When the refueling limit valve 20 is in the open state, it is sufficient to ensure that the first air inlet 43 of the primary oil-gas separator 40 is connected to the air outlet 27 of the refueling limit valve 20.

[0065] Furthermore, the height difference between the closed position of the refueling limit valve 20 and the lower edge of the second vent 41 in the height direction of the fuel tank 10 is greater than 30mm. Specifically, as shown... Figure 6As shown, the distance between the full oil level 80 and the lower edge of the second exhaust port 41 is H, where H is greater than 30mm. That is, to maintain a sufficient height difference between the full oil level 80 and the second exhaust port 41, reducing the splashing of liquid fuel from the second exhaust port 41.

[0066] According to another specific embodiment of this application, a vehicle is provided, including a liquid fuel recovery system, which is the liquid fuel recovery system in the above embodiment.

[0067] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0068] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0069] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0070] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A liquid fuel recovery system, characterized in that, include: The oil tank (10) is equipped with a refueling limit valve (20) and a gravity valve (30). The gravity valve (30) is provided with a first exhaust port (31). The gravity valve (30) is connected to the oil storage space of the oil tank (10). A primary oil-gas separator (40) is located inside the oil tank (10). The first air inlet (43) of the primary oil-gas separator (40) is connected to the refueling limit valve (20). The primary oil-gas separator (40) is provided with a second exhaust port (41). A secondary oil-gas separator (50) is located inside the oil tank (10). The secondary oil-gas separator (50) is provided with a second air inlet (51), a third air inlet (52) and a third exhaust outlet (53). The second air inlet (51) is connected to the second exhaust outlet (41), the third air inlet (52) is connected to the first exhaust outlet (31), and the third exhaust outlet (53) is connected to the activated carbon canister (60). The second exhaust outlet (41) and the second air inlet (51) are arranged with a height difference in the height direction of the oil tank (10). At least a portion of the liquid fuel flowing into the secondary oil-gas separator (50) is returned to the fuel tank (10) under the action of gravity or negative pressure.

2. The liquid fuel recovery system according to claim 1, characterized in that, The height of the second exhaust port (41) in the height direction of the fuel tank (10) is lower than the height of the second air inlet (51). The liquid fuel flowing into the secondary oil-gas separator (50) flows back to the fuel tank (10) through the second exhaust port (41).

3. The liquid fuel recovery system according to claim 1, characterized in that, The third air inlet (52) is located at the bottom of the secondary oil-gas separator (50). The third air inlet (52) has a vertically downward extending extension pipe (54). The extension pipe (54) is connected to the first exhaust port (31). The liquid fuel in the secondary oil-gas separator (50) flows back to the fuel tank (10) through the first exhaust port (31) and the gravity valve (30) in sequence.

4. The liquid fuel recovery system according to any one of claims 1-3, characterized in that, The bottom of the secondary oil-gas separator (50) is provided with a one-way valve (70), and the liquid fuel flowing into the secondary oil-gas separator (50) flows back to the fuel tank (10) through the one-way valve (70).

5. The liquid fuel recovery system according to claim 4, characterized in that, The check valve (70) has at least two, and the at least two check valves (70) are arranged in series along the height direction of the oil tank (10).

6. The liquid fuel recovery system according to claim 1, characterized in that, The cavity of the primary oil-gas separator (40) is provided with a plurality of first baffles (42), and there is a gap between the first baffles (42) and the inner top wall of the primary oil-gas separator (40). At least one of the plurality of first baffles (42) is arranged around the second exhaust port (41).

7. The liquid fuel recovery system according to claim 1, characterized in that, The cavity of the secondary oil-gas separator (50) is provided with a plurality of second baffles (55), and there is a gap between the second baffles (55) and the inner top wall of the secondary oil-gas separator (50). At least one of the plurality of second baffles (55) is arranged around the third exhaust port (53).

8. The liquid fuel recovery system according to claim 1, characterized in that, The height difference between the closed position of the refueling limit valve (20) and the lower edge of the second exhaust port (41) in the height direction of the oil tank (10) is greater than 30mm.

9. A vehicle comprising a liquid fuel recovery system, characterized in that, The liquid fuel recovery system is the liquid fuel recovery system according to any one of claims 1-8.

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