A fuel storage device including means for managing gas from a tank

Abstract

The present invention relates to a fuel storage device (1) for a motor vehicle, comprising: - a fuel tank (2); - a canister (10) fluidly connected to the fuel tank (2) and configured to receive a mixture of air and hydrocarbon vapors from the fuel tank (2); - at least one separation unit (14) fluidly connected to the canister (10) and the fuel tank (2), the separation unit (14) being configured to receive the mixture of air and hydrocarbon vapors from the canister (10) and separate the mixture into a hydrocarbon-rich portion and a hydrocarbon-lean portion, the hydrocarbon-rich portion being conveyed to the fuel tank (2); - a return device (18) for returning the hydrocarbon-lean portion to the canister (10); - an evacuation pump (16) arranged between the canister (10) and the separation unit (14) for evacuating the canister (10); - at least one solenoid valve (24) configured to selectively convey the mixture of air and hydrocarbon vapors either to the separation unit (14) or to the fuel tank (2).

Description

Technical Field

[0001] The present invention relates to a device for storing fuel for a motor vehicle, and more particularly to a device for managing a mixture of air and hydrocarbon vapors from such a fuel storage device. The present invention also relates to a method for managing a mixture of air and hydrocarbon vapors from a fuel storage device according to the present invention. Background Art

[0002] Figure 1 A fuel storage device according to the prior art is shown.

[0003] Fuel can be stored in a fuel tank 2. The fuel tank includes a fuel pump 4, a fuel filling limiting device 6, and a ventilation device 8. These elements are known and will not be described in detail in the present application.

[0004] A canister 10 containing a filter is fluidly connected to the fuel tank 2 and collects hydrocarbon vapors from the fuel tank 2. The filter includes, for example, activated carbon that captures these hydrocarbon vapors. The canister 10 also includes an air passage 12 that allows air to enter or leave the canister 10.

[0005] The canister 10 must be emptied regularly. For this purpose, a separation unit 14 for separating a mixture of air and hydrocarbon vapors can be used. An emptying pump 16 for the canister 10 is arranged on the fluid connection between the canister 10 and the separation unit 14. The separation unit 14 is also fluidly connected to the fuel tank 2. A return line 18 fluidly connects the separation unit 14 to the canister 10 through a different fluid connection from that carrying the emptying pump 16. A vacuum pump 20 is arranged on the fluid connection between the separation unit 14 and the fuel tank 2.

[0006] The above-described device operates as follows: When the canister 10 must be emptied, the emptying pump 16 is activated and allows an air and hydrocarbon vapor mixture (the vapor is collected by the activated carbon of the canister 10) to be extracted from the canister 10 to direct it to the separation unit 14. The separation unit 14 separates the received mixture into two parts: a hydrocarbon-rich part and a part lacking hydrocarbon vapors. The hydrocarbon-rich part is sent to the fuel tank 2. The vacuum pump 20 arranged on the fluid connection connecting the separation unit 14 to the fuel tank 2 is capable of creating a pressure difference between upstream and downstream of the separation unit 14. The part lacking hydrocarbon vapors is sent to the canister 10 through the return line 18.

[0007] In parallel with this emptying mechanism of the tank, a diagnostic pump 22 is connected to the reservoir to enable on-board diagnostics (i.e., "On Board Diagnostics", OBD) of the tightness of the fuel reservoir 2. This diagnostic pump 22 is capable of increasing the pressure inside the fuel reservoir 2 when needed. The evolution of this pressure is controlled to verify the absence of leaks at the fuel reservoir 2.

[0008] Due to a non-negligible number of pumps and systems dedicated to a single application being integrated, the above architecture has drawbacks in terms of complexity.

[0009] Document DE 10317583 A1 discloses a device for storing motor vehicle fuel, which includes a fuel reservoir, a tank connected to the fuel reservoir, an emptying pump for emptying the tank, and a group of separation units. The solenoid valve can direct the air and hydrocarbon vapor mixture from the tank to one or the other separation unit according to the concentration of hydrocarbon vapor in the mixture extracted from the tank. Summary of the Invention

[0010] The object of the present invention is in particular to provide a fuel storage device that is less complex and requires fewer components compared to the prior art.

[0011] To this end, the subject of the present invention is a fuel storage device for a motor vehicle, which includes:

[0012] - a fuel reservoir;

[0013] - a tank, which is fluidly connected to the fuel reservoir and is configured to receive a mixture of air and hydrocarbon vapor from the fuel reservoir;

[0014] - at least one separation unit, which is fluidly connected to the tank and the fuel reservoir, and is configured to receive the mixture of air and hydrocarbon vapor from the tank and separate the mixture into a hydrocarbon-rich part and a hydrocarbon-poor (lacking) part, and the hydrocarbon-rich part is transported to the fuel reservoir;

[0015] - a return device for returning the hydrocarbon-poor part to the tank;

[0016] - an emptying pump arranged between the tank and the separation unit for emptying the tank;

[0017] - at least one solenoid valve, which is arranged between the emptying pump and the separation unit, and the at least one solenoid valve is configured to selectively transport the mixture of air and hydrocarbon vapor to the separation unit or directly to the fuel reservoir.

[0018] Thus, as described above, using at least one solenoid valve, in the case of emptying the tank, the mixture of air and hydrocarbon vapors is directed towards the separation unit, or in the case of diagnosing the tightness of the fuel tank, the mixture of air and hydrocarbon vapors is directly directed towards the fuel tank. Thus, a single pump, here the emptying pump, is sufficient to simultaneously achieve both emptying the tank and diagnosing the tightness of the tank. Thus, it is possible to remove the diagnostic pump and the fluid connection pipeline dedicated to on-vehicle diagnosis of the fuel tank. A simplified architecture with fewer components than the prior art is thus obtained.

[0019] Optional other features that can be adopted individually or in combination in the fuel storage device according to the present invention:

[0020] - The separation unit can be a membrane separation unit. This involves using a type of separation unit proven to be useful for emptying (purifying) the tank;

[0021] - The emptying pump can also form a compressor for the mixture of air and hydrocarbon vapors from the tank. Thus, it is possible to remove the vacuum pump used in the prior art. The presence of the compressor can ensure the pressure difference between upstream and downstream of the separation unit (the upstream pressure is higher than the downstream pressure) to promote the diffusion of the mixture of air and hydrocarbon vapors (mainly hydrocarbon vapors) through the separation unit;

[0022] - The at least one solenoid valve can be a three-way solenoid valve. Thus, an architecture with a single valve for directing the mixture of air and hydrocarbon vapors is obtained;

[0023] - The at least one solenoid valve can include two solenoid valves: a first solenoid valve connecting the emptying pump to the fuel tank, and a second solenoid valve connecting the emptying pump to the separation unit. This involves an alternative architecture for managing the mixture of air and hydrocarbon vapors from the tank;

[0024] - The emptying pump can have a nominal flow rate of 5 to 25 liters per minute. This enables the pump to ensure the above different functions;

[0025] - The fuel storage device can include an electronic control unit for controlling the operating state of the emptying pump and the opening configuration of the at least one solenoid valve. This ensures the combined management of the emptying pump and the solenoid valve according to different requirements for emptying the tank or diagnosing the tightness of the fuel tank;

[0026] - The fuel storage device may include a plurality of separation units installed in series. The first separation unit is configured to receive a mixture of air and hydrocarbon vapor from the tank. At least one second separation unit is configured to receive a first hydrocarbon-lean portion from another separation unit and separate the hydrocarbon-lean portion into a second hydrocarbon-rich portion and a second hydrocarbon-lean portion. The hydrocarbon-rich portion is conveyed towards the fuel tank. This involves optimizing the filtration of the mixture of air and hydrocarbon vapor by only conveying the portion that contains as little hydrocarbon vapor as possible to the fuel tank and conveying the portion that is richest in hydrocarbon vapor to the fuel tank;

[0027] - The fuel storage device may include a plurality of separation units installed in parallel. Each separation unit is configured to receive a portion of the mixture of air and hydrocarbon vapor from the tank and separate the said portion of the mixture of air and hydrocarbon vapor into a hydrocarbon-rich portion and a hydrocarbon-lean portion. The hydrocarbon-rich portion is conveyed towards the fuel tank, and the hydrocarbon-lean portion is conveyed towards the tank. This allows for the simultaneous treatment of a larger volume of the mixture of air and hydrocarbon vapor; and

[0028] - The storage device may include a third solenoid valve arranged on the fluid connection between the fuel tank and the tank. This allows for blocking the fluid connection between the fuel tank and the tank when diagnosing the tightness of the fuel tank.

[0029] The subject matter of the present invention also lies in a method for managing a mixture of air and hydrocarbon vapor from the tank of a fuel storage device according to any one of the above claims. The method includes the following steps:

[0030] - Controlling the open configuration of the at least one solenoid valve so that the mixture of air and hydrocarbon vapor selectively flows directly towards the fuel tank in the case of testing the tightness of the tank or towards the separation unit in the case of emptying the tank;

[0031] - Activating the emptying pump of the tank; and

[0032] - According to the open configuration of the at least one solenoid valve, conveying the mixture of air and hydrocarbon vapor from the tank to the separation unit or directly to the fuel tank.

[0033] This involves the implementation of managing the mixture of air and hydrocarbon vapor by the above fuel storage device.

[0034] Optional other features that can be adopted alone or in combination according to the management method of the present invention:

[0035] - The method may include activating a compressor of an evacuation pump when the at least one solenoid valve is set to convey a mixture of air and hydrocarbon vapor from the tank to a separation unit. This enables the achievement of the above-mentioned pressure difference in the case of evacuating the tank; and

[0036] - The method may include closing a third solenoid valve arranged on a fluid connection between the fuel tank and the tank when the at least one solenoid valve is set to convey a mixture of air and hydrocarbon vapor from the tank to the fuel tank. This step allows for an increase in the pressure within the fuel tank in the case of diagnosing the tightness of the fuel tank.

[0037] The subject matter of the present invention also lies in a management device for managing a mixture of air and hydrocarbon vapor from a tank of a motor vehicle, the management device comprising:

[0038] - At least one separation unit for separating air and hydrocarbon vapor, which is configured to receive a mixture of air and hydrocarbon vapor from the tank and separate the mixture into a hydrocarbon-rich portion and a hydrocarbon-lean portion, and the hydrocarbon-rich portion is conveyed to the fuel tank;

[0039] - An evacuation pump for evacuating (purifying) the tank, which is configured to convey a mixture of air and hydrocarbon vapor from the tank to the separation unit; and

[0040] - At least one solenoid valve arranged between the evacuation pump and the separation unit, the at least one solenoid valve being configured to selectively convey a mixture of air and hydrocarbon vapor to the separation unit or directly to the fuel tank.

[0041] This relates to the part of the fuel storage device of a motor vehicle dedicated to managing a mixture of air and hydrocarbon vapor from the tank. Description of the Drawings

[0042] The present invention will be better understood by reading the following drawings provided by way of example only and made with reference to the accompanying drawings, in which:

[0043] Figure 1 is a diagram of a fuel storage device of a motor vehicle according to the prior art; and

[0044] Figure 2 is a diagram of a fuel storage device of a motor vehicle according to the present invention. Detailed Description

[0045] ​​In this specification, certain elements or parameters may be indexed, for example, a first element or a second element, and a first parameter and a second parameter, or a first criterion and a second criterion, etc. In such a case, this involves a simple indexing for differentiating and naming elements or parameters or criteria that are close but not identical. This indexing does not imply a priority of one element, parameter, or criterion over another element, parameter, or criterion, and such names can be easily interchanged without departing from the scope of this specification.

[0046] Now refer to Figure 2 , which shows an example of a motor vehicle fuel storage device 1 according to the present invention. The reference numerals used in the description Figure 1 are also used in Figure 2 . Finally, Figure 1 and Figure 2 include different arrows appearing on fluid connection pipelines, which indicate the direction of fluid movement in these fluid connection pipelines. To allow gases and gaseous mixtures to flow along the directions of the arrows present in Figure 1 and Figure 2 , a group of anti - reflux units (such as check valves) are arranged at each fluid connection. Such usage is known to those skilled in the art and is not shown in the drawings and will not be described in detail in this application.

[0047] According to this example, the fuel storage device 1 includes a fuel tank 2 similar to those known in the prior art. The fuel tank includes a fuel pump 4, a fuel filling limiting device 6, and a ventilation device 8 installed in series or separately from each other. These elements are known and will not be described in detail in this application.

[0048] The canister 10 is fluid - connected to the fuel tank and is configured to receive a mixture of air and hydrocarbon vapors from the fuel tank 2. The filter housed in the canister 10, including, for example, activated carbon, is capable of capturing hydrocarbon vapors from the fuel tank 2. The canister 10 also includes an air inlet 12 that allows air to enter or exit the canister 10 (especially when emptying the canister).

[0049] A separation unit 14 fluid - connected to the canister 10 and the fuel tank 2 is configured to receive a mixture of air and hydrocarbon vapors from the canister 10 and separate the mixture into a hydrocarbon - rich portion (fraction) and a hydrocarbon - poor portion (fraction). The hydrocarbon - rich portion is conveyed towards the fuel tank 2 (note that a diffuser 26 is provided at the end of the fluid connection extending from the separation unit 14 to the fuel tank 2). The hydrocarbon - poor portion is conveyed back to the canister 10 through a return device, such as a return line 18.

[0050] The separation unit 14 may be a membrane separation unit. In one embodiment, the membrane is a hydrocarbon separation membrane using a material that has a high permeability coefficient for fuel vapor but a low permeability coefficient for air. The membrane may include:

[0051] - A non-porous thin film layer that preferably allows fuel vapor to pass through by diffusion and dissolution; and

[0052] - A porous support membrane layer that supports the non-porous thin film layer.

[0053] The thin film layer serves as the main function of the membrane. It is generally composed of a polymer material or an elastomer material based on three-dimensional cross-linked and insoluble silicone, and the polymer material has high selectivity and permeability for hydrocarbons. The thin film layer may have a thickness of about 0.5 μm to 3 μm. On the other hand, for the porous support membrane layer, it is necessary to have high resistance to hydrocarbons. For example, in addition to synthetic resins such as polyimide (PI), polyetherimide (PEI), and polyvinylidene fluoride (PVDF), ceramics are used. The membrane has a structure in the shape of a flat plate, hollow fiber, honeycomb, spiral, etc.

[0054] According to one embodiment of the present invention, the fuel storage device 1 includes a plurality of separation units installed in series:

[0055] - A first separation unit, such as the separation unit 14, which is configured to receive a mixture of air and hydrocarbon vapor from the tank 10;

[0056] - At least one second separation unit (not shown), which is configured to receive a first hydrocarbon-lean portion from another separation unit, such as the separation unit 14, and separate the hydrocarbon-lean portion into a second hydrocarbon-rich portion and a second hydrocarbon-lean portion, and the second hydrocarbon-rich portion is conveyed to the fuel tank 2.

[0057] As described above, this enables the optimization of the treatment of the mixture of air and hydrocarbon vapor to convey only the portion that is very lacking (lean) in hydrocarbon vapor to the tank 10.

[0058] According to another embodiment of the present invention, the fuel storage device 1 includes a plurality of separation units installed in parallel. Each separation unit is configured to receive a portion of the mixture of air and hydrocarbon vapor from the tank 10 and separate the said portion of the mixture of air and hydrocarbon vapor into a hydrocarbon-rich portion and a hydrocarbon-lean portion. The hydrocarbon-rich portion is conveyed to the fuel tank 2, and the hydrocarbon-lean portion is conveyed to the tank 10. Thus, according to this embodiment, there are a plurality of separation units fluidly connected to the evacuation pump 16 of the tank 10. This allows for the simultaneous processing of a larger volume of the mixture of air and hydrocarbon vapor.

[0059] The evacuation pump 16 of the tank 10 is arranged between the tank 10 and the separation unit 14. It allows the extraction of the mixture of air and hydrocarbon vapor from the tank 10 when it is activated due to the need to empty the tank 10 or diagnose the tightness of the fuel tank 2.

[0060] The evacuation pump 16 preferably has a nominal flow rate of 5 to 25 liters per minute. Generally, the nominal flow rate of the evacuation pump 16 is selected such that it can properly direct the mixture of air and hydrocarbon vapor to the separation unit 14 or the fuel tank 2.

[0061] Preferably, the evacuation pump 16 also forms a compressor for the mixture of air and hydrocarbon vapor from the tank 10. As Figure 2 shown, it is thus no longer necessary to arrange a vacuum pump 20 downstream of the separation unit 14. Thereby, the pressure difference across the separation unit 14 is obtained by an overpressure (high pressure) upstream of the separation unit 14, rather than an underpressure (low pressure) downstream of it. In one example, the overpressure and underpressure are relative to the atmospheric pressure.

[0062] An electromagnetic valve 24 is arranged between the evacuation pump 16 and the separation unit 14. The electromagnetic valve 24 is configured to selectively convey the mixture of air and hydrocarbon vapor to the separation unit 14 or to the fuel tank 2. This selective conveyance depends on whether it is specifically necessary to empty the tank 10 or to verify the tightness of the fuel tank 2.

[0063] The electromagnetic valve 24 can convey the mixture of air and hydrocarbon vapor directly back to the fuel tank 2. "Directly back" means that the mixture of air and hydrocarbon vapor returns to the fuel tank 2 without passing through an intermediate structure. In other words, with respect to conveying the mixture of air and hydrocarbon vapor back to the fuel tank 2, the electromagnetic valve 24 is only connected to this fuel tank through a fluid connection pipeline.

[0064] As in Figure 2As can be seen, the solenoid valve 24 can be a three-way solenoid valve. Thus, this three-way solenoid valve is fluidly connected to the tank 10, the separation unit 14, and the fuel tank 2. Alternatively to using a three-way solenoid valve, two solenoid valves can be used, with a first solenoid valve connecting the emptying pump 16 to the fuel tank 2 and a second solenoid valve connecting the emptying pump 16 to the separation unit 14. For example, a component including two solenoid valves installed in parallel can be considered, which includes a common input, and each solenoid valve includes respective outputs connected to the fuel tank 2 or to the separation unit 14. Of course, depending on the architecture of the component, more specifically, depending on the number of separation units to be connected to the emptying pump 16, the number of solenoid valves used can be varied.

[0065] A fourth channel can be provided on the solenoid valve 24 to connect it to the fluid communication for collecting the hydrocarbon-rich portion from the separation unit 14, so as to be able to use the existing fluid communication between the solenoid valve 24 and the fuel tank 2 to convey this hydrocarbon-rich portion to the fuel tank 2.

[0066] Thus, the solenoid valve 24 includes four channels (leading to). It is fluidly connected to the tank 10 (to receive a mixture of air and hydrocarbon vapors), twice connected to the separation unit 14 (to convey a mixture of air and hydrocarbon vapors to it and receive the hydrocarbon-rich portion), and also connected to the fuel tank 2 (to convey a mixture of air and hydrocarbon vapors to it in the case of testing the tightness of the fuel tank 2, or to convey the hydrocarbon-rich portion to it in the case of emptying the tank 10). The solenoid valve 24 can be a four-way solenoid valve. It can also involve multiple solenoid valves. Thus, the operation of the solenoid valve 24 can be programmed such that the open configuration of the solenoid valve corresponds to the desired routing.

[0067] The assembly consisting of the separation unit 14, the emptying pump 16, and the solenoid valve 24 forms a device for managing the mixture of air and hydrocarbon vapors from the tank 10 of a motor vehicle.

[0068] An electronically controllable unit 28 can be provided for controlling the operating state of the emptying pump 16 and the open configuration of the solenoid valve 24. Thus, the operation of the emptying pump 16 and the solenoid valve 24 can be controlled by the same electronically controllable unit 28 to activate the emptying pump 16 and bring the solenoid valve 24 into a suitable open configuration when it is necessary to empty the tank 10 or to verify the tightness of the fuel tank 2. In order to ensure the continuous performance of the separation unit 14, the pressure difference across the separation unit 14 must be kept constant, and for this purpose it is sufficient to keep the pressure upstream of the separation unit 14 constant. In one example, the electronically controllable unit 28 controls the emptying pump 16 to keep the pressure upstream of the separation unit 14 constant, for example at three bar. Thus, the electronically controllable unit 28 includes a predetermined control program stored in a non-volatile memory and a processor for controlling the emptying pump 16 and the solenoid valve 24 based on the predetermined control program. It is also possible for the electronically controllable unit 28 to monitor the evolution of the pressure in the fuel tank 2 after the mixture of air and hydrocarbon vapours has been channelled from the tank 10 to the fuel tank 2 by interacting with an internal pressure sensor (not shown) of the fuel tank 2.

[0069] According to one embodiment (not shown), the emptying pump 16 can be a bi-directional pump capable of delivering the mixture of air and hydrocarbon vapours from the tank 10 to the separation unit 14 and delivering the hydrocarbon-lean portion of the separation unit 14 to the tank 10. Thus, the return line 18 can be omitted. The solenoid valve 24 is controlled to allow this delivery to pass through (its open configuration being the same for the two delivery paths described above). In this case, the electronically controllable unit 28 can effect a specific control of the emptying pump 16. The emptying pump first delivers the mixture of air and hydrocarbon vapours from the tank 10 to the separation unit 14, maintaining the pressure upstream of the separation unit 14 at a higher level than the downstream pressure (in the absence of a vacuum pump downstream thereof), and finally extracts the hydrocarbon-lean portion from the separation unit 14 by reversing the operation of the emptying pump 16 in order to deliver it to the tank 10.

[0070] A third solenoid valve (not shown; supplementing the solenoid valve 24 described above or the two solenoid valves) can be arranged in the fluid connection between the fuel tank 2 and the tank 10. This third solenoid valve can be closed when diagnosing the tightness of the fuel tank (for example controlled by the electronically controllable unit 28) to prevent gas from flowing from this third solenoid valve to the tank 10.

[0071] Regarding the method for managing the mixture of air and hydrocarbon vapours from the tank 10, the method includes the following steps:

[0072] - Control the opening configuration of the solenoid valve 24 (or solenoid valves) to selectively direct a mixture of air and hydrocarbon vapors directly to the fuel tank when testing the tightness of the fuel tank 2, or to the separation unit 14 when emptying the canister 10, which can be implemented by the electronic control unit 28;

[0073] - Activate the emptying pump 16 of the canister 10. This emptying pump will thus extract a mixture of air and hydrocarbon vapors from the canister 10, regardless of its destination; and

[0074] - Depending on the opening configuration of the solenoid valve 24, direct the mixture of air and hydrocarbon vapors from the canister 10 to the separation unit 14 or directly to the fuel tank 2. This allows the mixture of air and hydrocarbon vapors to be processed by one or more separation units or to increase the internal pressure of the fuel tank 2 depending on the opening configuration of the solenoid valve 24 (or solenoid valves).

[0075] In the case of emptying the canister 10 and processing the mixture of air and hydrocarbon vapors with the separation unit 14, the compressor of the emptying pump 16 can be activated (e.g., by the electronic control unit 28) to obtain the pressure difference across the separation unit 14 as described above.

[0076] Furthermore, for the reasons of increasing the internal pressure of the fuel tank 2 as described above, the third solenoid valve arranged on the fluid connection between the fuel tank 2 and the canister 10 can be closed when the solenoid valve 24 is set to allow the mixture of air and hydrocarbon vapors to pass from the canister 10 to the fuel tank 2.

[0077] List of reference numerals

[0078] 1: Fuel storage device

[0079] 2: Fuel tank

[0080] 4: Fuel pump

[0081] 6: Filling limit device

[0082] 8: Ventilation device

[0083] 10: Canister

[0084] 12: Intake port

[0085] 14: Separation unit

[0086] 16: Emptying pump

[0087] 18: Return line

[0088] 20: Vacuum pump

[0089] 22: Diagnostic pump

[0090] 24: Solenoid valve

[0091] 26: Diffuser

[0092] 28: Electronic control unit

Claims

1. A fuel storage device (1) for a motor vehicle, comprising: - a fuel tank (2); - a canister (10) fluidly connected to the fuel tank (2) and configured to receive a mixture of air and hydrocarbon vapors from the fuel tank (2); - at least one separation unit (14) fluidly connected to the canister (10) and the fuel tank (2), the separation unit (14) being configured to receive the mixture of air and hydrocarbon vapors from the canister (10) and separate the mixture into a hydrocarbon-rich portion and a hydrocarbon-lean portion, the hydrocarbon-rich portion being conveyed towards the fuel tank (2); - a return device (18) for returning the hydrocarbon-lean portion to the canister (10); - an evacuation pump (16) of the canister (10) arranged between the canister (10) and the separation unit (14); - at least one solenoid valve (24) arranged between the evacuation pump (16) and the separation unit (14), characterized in that the at least one solenoid valve (24) is configured to selectively convey the mixture of air and hydrocarbon vapors to the separation unit (14) or directly to the fuel tank (2).

2. The fuel storage device (1) according to the previous claim, wherein, The separation unit (14) is a membrane separation unit.

3. The fuel storage device (1) according to any one of claims 1 to 2, wherein, The evacuation pump (16) also forms a compressor for the mixture of air and hydrocarbon vapors from the canister (10).

4. The fuel storage device (1) according to any one of the preceding claims, wherein, The at least one solenoid valve (24) is a three-way solenoid valve.

5. The fuel storage device (1) according to any one of claims 1 to 3, wherein, The at least one solenoid valve (24) comprises two solenoid valves: a first solenoid valve connecting the evacuation pump (16) to the fuel tank (2) and a second solenoid valve connecting the evacuation pump (16) to the separation unit (14).

6. The fuel storage device (1) according to any one of the preceding claims, wherein, The evacuation pump (16) has a nominal flow rate of 5 to 25 liters per minute.

7. The fuel storage device (1) according to any one of the preceding claims, the fuel storage device comprising an electronic control unit (28) for controlling the operating state of the evacuation pump (16) and the open configuration of the at least one solenoid valve (24).

8. The fuel storage device (1) according to any one of the preceding claims, the storage device comprising a plurality of separation units (14) mounted in series, a first separation unit (14) being configured to receive the mixture of air and hydrocarbon vapors from the canister (10), and at least one second separation unit being configured to receive the first hydrocarbon-lean portion from another separation unit and separate the hydrocarbon-lean portion into a second hydrocarbon-rich portion and a second hydrocarbon-lean portion, the hydrocarbon-rich portion being conveyed to the fuel tank (2).

9. The fuel storage device (1) according to any one of claims 1 to 7, said storage device comprising a plurality of separation units (14) installed in parallel, each separation unit (14) being configured to receive a portion of the mixture of air and hydrocarbon vapors from the tank (10) and to separate said portion of the mixture of air and hydrocarbon vapors into a hydrocarbon-rich portion and a hydrocarbon-lean portion, said hydrocarbon-rich portion being conveyed to the fuel tank (2), and said hydrocarbon-lean portion being conveyed to the tank (10).

10. The fuel storage device (1) according to any one of the above claims, said fuel storage device comprising a third solenoid valve arranged in the fluid connection between the fuel tank (2) and the tank (10).

11. A method for managing a mixture of air and hydrocarbon vapors from a tank (10) of a fuel storage device (1) according to any one of the above claims, the method comprising the following steps: - controlling the open configuration of the at least one solenoid valve (24) such that the mixture of air and hydrocarbon vapors selectively flows directly to the fuel tank (2) in the case of testing the tightness of the fuel tank (2), or to the separation unit (14) in the case of emptying the tank (10); - activating the emptying pump (16) of the tank (10); and - conveying the mixture of air and hydrocarbon vapors from the tank (10) to the separation unit (14) or directly to the fuel tank (2) according to the open configuration of the at least one solenoid valve (24).

12. The method for managing a mixture of air and hydrocarbon vapors according to claim 11, which comprises the step of activating the compressor of the emptying pump (16) when the at least one solenoid valve (24) is set to convey the mixture of air and hydrocarbon vapors from the tank (10) to the separation unit (14).

13. The method for managing a mixture of air and hydrocarbon vapors according to any one of claims 11 to 12, which comprises the step of closing a third solenoid valve arranged in the fluid connection between the fuel tank (2) and the tank (10) when the at least one solenoid valve (24) is set to convey the mixture of air and hydrocarbon vapors from the tank (10) to the fuel tank (2).

14. A management device for managing a mixture of air and hydrocarbon vapors from a tank (10) of a motor vehicle, the management device comprising: - at least one separation unit (14) for separating air and hydrocarbon vapors, which is configured to receive a mixture of air and hydrocarbon vapors from the tank (10) and to separate said mixture into a hydrocarbon-rich portion and a hydrocarbon-lean portion, said hydrocarbon-rich portion being conveyed to the fuel tank (2); - An emptying pump (16) for emptying the tank (10), which is configured to convey the mixture of air and hydrocarbon vapor from the tank (10) to the separation unit (14); and - At least one solenoid valve (24) arranged between the emptying pump (16) and the separation unit (14), characterized in that the at least one solenoid valve (24) is configured to selectively convey the mixture of air and hydrocarbon vapor to the separation unit (14), or directly to the fuel tank (2).

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