Purge valve with integrated heating function

Abstract

The invention relates to a purge valve (10) for a fuel cell circuit, the valve comprising a body (1) provided with one or more fluid circulation channels (14, 16), the body of the valve further comprising: – a member (6) for opening or closing the channel(s) (14, 16), activation means (4) for activating this member along an axis (XX'), and connection means (24) for connecting these activation means to a power supply; – heating means (8) for heating the valve and connection means (24) for connecting these activation means to a power supply, these heating means being placed between the activation means (4) for activating the member (6) for opening and closing the channel(s) (14, 16) and the channel(s) (14, 16).

Description

[0001] DESCRIPTION

[0002] Title: PURGE VALVE WITH INTEGRATED HEATING FUNCTION

[0003] TECHNICAL FIELD AND PRIOR ART

[0004] The invention relates to the field of purge and drain valves, for example for the water and hydrogen circuit of a fuel cell or, for example, to the field of water valves on thermal vehicles. This valve makes it possible to purge excess hydrogen or water, for example in the circuit associated with a fuel cell, to ensure operation in accordance with demand, both in terms of performance and efficiency.

[0005] With such a valve, we seek to be able to carry out a purge operation over short times (for example of the order of a tenth of a second or more) and according to a cycle which can be quite short (for example 1 s of opening every 5 s to 10 s, depending on use).

[0006] A problem arises in sub-zero temperatures, as solidified water blocks the valve from operating. A heating system is therefore planned.

[0007] Known solutions to the problem of water freezing in this type of system provide heating elements using additional and ancillary components in the supply circuit and / or elements external to the valve, these elements being used as a heat source when powered. However, this type of solution involves a certain amount of space. However, users of this type of valve are increasingly demanding a high level of compactness.

[0008] Furthermore, while frost can form and at least partially block fluid flow channels, it can also form in other areas of the valve where moisture may have previously accumulated.

[0009] One problem is therefore to find a new purge valve system, allowing a certain compactness to be achieved while ensuring efficient operation of the valve. Another problem is to find a new purge valve system, allowing heating of all the parts in which frost can form.

[0010] An objective of the invention is to find a new water / hydrogen purge valve with a heating function allowing operation in many conditions of use of the system, in particular in the case of use at negative temperatures. Indeed, it is common for a water and / or hydrogen purge request to be requested by the system, while the system is subjected to negative temperatures, which can cause the appearance of ice. This ice can prevent the completion of this water and / or hydrogen purge by blocking the movement of the valve. The purge cannot therefore be carried out, degrading the performance of the system. This ice must therefore be melted in order to allow the purge. The water / hydrogen purge valves currently available on the market do not allow this ice melting, which must then be carried out by an additional component.

[0011] Another problem is being impervious to hydrogen molecules, which are thin.

[0012] Another problem is limiting friction to prevent particles from polluting the fuel cell.

[0013] Another problem is to optimize the forces (of the coil, springs) in order to limit the current consumption, the heating of the coil according to the gas disturbances and the pressures useful for the operation of the battery. This therefore aims to limit the performance losses of the solenoid valve.

[0014] STATEMENT OF THE INVENTION

[0015] The invention firstly relates to a valve, for example a purge valve for a circuit of a fuel cell, said valve comprising a body provided with a channel or channels for circulating a fluid, the body of the valve further comprising or containing:

[0016] - a member for opening or closing the channel or said channels, means for activating this member along an axis (XX') and means for connecting these activation means to an electrical supply; - means for heating the valve and means for connecting these activation means to an electrical supply, these heating means being arranged between, on the one hand, the means for activating the member for opening and closing the channel or channels and, on the other hand, the channel or channels themselves.

[0017] A valve according to the invention, for example a water / hydrogen purge valve, with heating function, makes it possible to guarantee optimal operation in all conditions of use of the system, in particular in the case of use at negative temperatures. Indeed, it is common for a circulation of a fluid, for example a purge of water and / or hydrogen from the circuit of a fuel cell, to be requested by the system, while the latter is subjected to negative temperatures, which can cause the appearance of ice. This ice can prevent the circulation of fluids, for example the purge of water and / or hydrogen, from taking place by blocking the actuation of the valve. The valve cannot therefore operate, the purge cannot therefore be carried out in the example of a purge valve, degrading the performance of the system.

[0018] A valve according to the invention makes it possible to achieve this melting of ice and the opening of the channel or channels with a single component.

[0019] The presence, in the body of the valve, of heating means, in particular arranged between the activation means and the channel or channels, makes it possible to ensure heating, both of the channel or channels themselves and of the parts of the valve located upstream of the channel or channels, and in which frost can also form.

[0020] According to one embodiment, the means for activating the opening or closing member of the valve comprise a l ère coil wound around said axis (XX').

[0021] Means to close the magnetic circuit of the l ère coil may also be provided; preferably, the wall of the valve body also participates in the magnetic circuit of this l ère coil.

[0022] According to various embodiments, the means of connection of the activation means and the heating means are for example and / or preferably:

[0023] - arranged at least partly on or against the outer wall of the valve; - and / or comprise at least 4 studs, for example arranged or distributed in 2 rows parallel to each other or in a single row;

[0024] - and / or are arranged against the valve body, or partly in it, or partly integrated in it.

[0025] The power supply circuit of the l ère coil is for example and advantageously independent of the electrical supply circuit of the 2 eme coil.

[0026] According to another aspect of the invention, the heating means may comprise a 2 eme coil wound around said axis (XX'). Preferably, the 2 emecoil has an outside diameter less than or equal to that of the first coil, it then has less interaction with the opening or closing member than the l ère coil. But, in some embodiments, the 2 eme coil may have a larger outside diameter than the first coil.

[0027] A valve according to the invention may comprise means, fixed relative to the valve, for example a fixed stud or core, and a spring, the latter being arranged between said fixed means and the opening or closing member, allowing the latter to be held in a position for closing the channel or channels.

[0028] According to a particularly interesting embodiment, the valve can comprise:

[0029] - a first part, itself comprising the activation means, the valve opening or closing member and the heating means;

[0030] - a 2 epart comprising the channel or channels, this 2 e part being removable from the first part.

[0031] According to another interesting configuration, the means of connection of the activation means and the heating means can comprise 4 pads arranged outside the body of the valve, these pads being distributed in 2 rows parallel to each other or in a single row.

[0032] It allows to increase the compactness of a system in which it is integrated.

[0033] In a valve according to the invention, the activation means and the heating means of the valve are advantageously aligned along the axis of movement of the opening and closing member.

[0034] According to various achievements, the 2 ème coil can be sized so that: - when part of the valve is frozen, for example at -40°C, thawing is achieved in less than 3 minutes or in less than 2 minutes;

[0035] - and / or for the valve to reach a maximum temperature of 200°C during heating by said 2 ème coil (8).

[0036] Preferably, in a valve according to the invention:

[0037] - a fluid, for example water and / or hydrogen, undergoes a maximum pressure drop of 1 bar between its entry into the valve and its exit from the valve;

[0038] - and / or an outlet flow of a fluid passing through the valve evolves linearly as a function of its pressure at an inlet of the valve.

[0039] According to a particular embodiment of a valve according to the invention, the latter comprises a fluid inlet channel, and at least 2 fluid flow channels. For example, one flow channel can be closed while the other flow channel is free. The invention also relates to a fuel cell circuit comprising and at least one valve, for example a purge valve, according to the invention. Such a circuit comprises for example, in addition to the cell itself, means for supplying the cell with hydrogen. A fuel cell circuit according to the invention may further comprise means for electrically supplying the valve and a circuit for controlling these means.

[0040] The invention also relates to a transport vehicle, for example an airplane, comprising a fuel cell and a fuel cell circuit according to the invention. The invention also relates to a method for purging a circuit of a fuel cell according to the invention, comprising: a) - an opening, respectively a closing, of a channel or channels by actuating the member using the activation means of this member, from a closing, respectively opening, position of a channel or channels to an opening, respectively closing, position of this same channel or these same channels, allowing, respectively preventing, circulation of a fluid, for example water and / or hydrogen; b) - before, or during or after step a): heating using the heating means.Preferably, the heating step allows heating of a portion of the channel or channels and of at least one zone at the interface between the opening or closing member of the valve and the means for activating this member.

[0041] In a method according to the invention:

[0042] - for at least part of the valve frozen, for example at -40°C, before step b), thawing is obtained in less than 3 minutes or in less than 2 minutes;

[0043] - and / or the valve reaches a maximum temperature of 200°C during step b);

[0044] - and / or the fluid undergoes a maximum pressure loss of 1 bar between its entry into the valve and its exit from the valve;

[0045] - and / or an outlet flow of a fluid passing through the valve evolves linearly as a function of its pressure at an inlet of the valve.

[0046] BRIEF DESCRIPTION OF THE DRAWINGS

[0047] [Fig. 1] represents an exemplary embodiment of a purge valve according to the invention;

[0048] [Fig. 2A] and [Fig. 2B] represent 2 embodiments of a lateral electrical connector for a valve according to the invention,

[0049] [Fig. 3A] and [Fig. 3B] represent an exemplary embodiment of a purge valve according to the invention, with a removable lower part;

[0050] [Fig. 4] represents a part of a valve according to the invention, with 2 fluid flow circuits.

[0051] [Fig. 5] represents a purge circuit comprising a valve according to the invention.

[0052] [Fig. 6] represents an outlet flow as a function of the inlet pressure in a valve according to the invention.

[0053] [Fig. 7] - [Fig. 9C] represent various tests or various simulations carried out with or for an example of embodiment of a valve according to the invention.

[0054] DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0055] Figure 1 shows an exemplary embodiment of a water / hydrogen purge valve 10 according to the invention, with integrated heating function. It comprises a fixed body 1 which extends along an axis XX'. This fixed body comprises two parts.

[0056] A first part 2, or upper part, comprises 2 coils 4, 8, centered on the axis XX'. The coil 4 is located in the upper part and operates in the following manner: when it is supplied with current, it generates a magnetic field B which will interact with a mobile core 6, which has magnetic properties to be able to interact with the field generated by the coil 4; it is for example paramagnetic, that is to say that it is weakly attracted by an external magnetic field, or ferromagnetic, that is to say that it retains its magnetization after having been subjected to a magnetic field.

[0057] The core 6 will therefore be caused, depending on the direction of this field, to move along the axis XX'. It can therefore be brought from a low position, in which its end 12 obstructs a channel or channels 14, 16 for fluid circulation, to a high position in which this channel or these channels is / are free for the circulation of a fluid or, conversely, from this same high position to its low position, in which it obstructs said channels. As will be seen below, the end 12 is advantageously conical in shape or comprises at least one part of conical shape. The valve can have a purge or drain function and therefore operate in ON / OFF. However, the invention can be implemented to produce a proportional valve, for example with several channels, in particular for another application.

[0058] Below this first coil, along the axis XX', is a second coil 8, which may be smaller than the l ère, and is separated from the l ère coil, this second coil 8 being dedicated to the heating function: the Joule effect of the current in the coil 8 will heat the environment close to it, thus allowing the melting of any ice formed. This second coil is also centered on the axis XX', but is located downstream of the first coil in the direction of the channel or channels 14, 16.

[0059] The 2 èmecoil may be smaller than the first coil (have an outside diameter smaller than that of the first coil), but, alternatively, have an outside diameter equal to that of the first coil, or even greater than that of the first coil (in which case the heating capacity or function is increased) A part 11, in the form of a washer or plate pierced in its middle to allow the core 6 of the actuator to pass through, allows the magnetic circuit formed by the coil 4, arranged in the upper part, to be closed. This magnetic circuit also passes through the side walls 13, 15 of the valve.

[0060] In the lower part 3 of the valve is the seat of the end 12 (also called "buffer") of the actuator, when the latter is in the low position (closing of the valve), as well as the channel or channels 14, 16 for the passage of the fluid (water or hydrogen) (note that figures 1, 3A and 3B are not representative of the actual dimensions and that, in the 3 figures, a lateral space allows the end 12 to be moved between the low position and the high position).

[0061] The electrical power supply of each of the two coils 4, 8 is carried out independently of that of the other coil (which cannot be seen in the side views of figures 1, 3A or 3B), via a lateral connector 24 with 4 pins or connection pads 24i, 24?, 24s, 244 (figures 2A and 2B), 2 pins being dedicated to each coil. This makes it possible to decouple the operation of each coil from the operation of the other coil, and therefore to actuate the heating function separately from the activation function of the actuator, i.e. from the purge function of the hydrogen and / or water circuit. The connector 24, or the connection pins or pads 24i, 24?, 24a, 244 can be connected to means or one or more electrical power supply sources 17, for example one or more current sources (for example between 0.5A and 7A or 10A) or voltage sources (for example between 5V and 30V or even 32V or 35V).The lateral connector 24 is arranged at least partly against or partly in the body 1 and / or integrated therein while leaving the connection pins or pads accessible from the outside of the valve.

[0062] In addition to the movable core 6, which moves longitudinally along the axis XX', under the action of the coil 4, the valve may further comprise a fixed core or stud 20, a spring 22 being arranged in compression, along the axis XX', between the latter and the movable core 6. This spring makes it possible to maintain the actuator 6 in a position which closes the valve, the latter only opening under the action of the coil 4, the magnetic field which it generates then interacting with the actuator 6 in order to free the channels 14, 16 for fluid circulation.

[0063] As already explained above and as can be seen in the embodiment illustrated in figure 1, the 2 coils are aligned on the axis XX' along which the actuator can be set in motion by the action of the coil 4.

[0064] Thus, the heating coil 8 is optimally arranged between, on the one hand, the fluid inlets / outlets which may be at least partially obstructed by ice, and on the other hand the upper part of the device, since, here too, moisture may have condensed and give rise to the formation of frost, in particular between the fixed core 20 and the movable core 6 and / or around the latter. Consequently, the coil 8 has a heating function in both directions (as illustrated by the references 26 and 30), towards the top and towards the bottom of the device.

[0065] In addition, the structure with 2 coils that are aligned around the actuator translation axis gives the entire valve a very compact structure.

[0066] Typically, the valve is held in a closed state, the actuator being in a low position using the spring 22 arranged between the movable core 6 and the fixed core 20. However, as a variant, the valve is held in an open state, the actuator being for example again in a low position using the spring 22, but an outlet 14' for the flow of fluid towards a conduit 18 being arranged above this low position, as illustrated in FIG. 4. Depending on the applications and depending on the position of the element or the buffer 12', the fluid can thus be redirected into different conduits 14, 18. The element or the buffer 12' can then have a shape allowing it to close the orifice 14i which opens towards the conduit 14 or the orifice 142 which allows the fluid to flow towards the conduit 18.This figure 4 also shows that a valve according to the invention can be combined with for example several flow channels 14, 18, 2 flow channels being represented in this figure: as understood, one flow channel 14 can be closed while the other flow channel 18 is free. The end 12' of the movable core 6 can be carried by the latter to block one or the other of these 2 channels, one of them (the channel 14 in figure 4) being able to be closed while the flow can take place towards the other channel 18, and vice versa.

[0067] The connection pads 24i, 242, 24s, 244 of the connector 24 can be arranged in 2 superimposed rows of 2, as illustrated in FIG. 2A, or can be all 4 aligned, as illustrated in FIG. 2B. The configuration of FIG. 2A makes it possible to occupy less space on or against the outer wall 13, 15 of the valve. However, as already indicated above, this outer wall is used for looping the magnetic circuit of the activation coil 4. Consequently, the configuration of FIG. 2A, with 2 superimposed rows of each 2 pads, allows better activation of the actuator.

[0068] According to one embodiment, explained in connection with Figures 3A and 3B, the lower part 3 of the valve is removable; it is for example made of a plastic material, while the upper part is made of a metallic material, allowing the circulation of the magnetic flux. By changing this lower part, the dimensions of the channels can therefore be varied according to requirements. Figure 3A shows the valve in which the 2 parts 2, 3 are assembled, the valve then having the same structure as that of Figure 1. In Figure 3B, the 2 parts 2, 3 are separated, and part 3 can be replaced by another part comprising pipes 14, 16 having diameters different from those of part 3 which has been removed. Such a structure therefore offers a lot of flexibility to a user.

[0069] The connection pins or pads 24 of a valve according to the invention, in particular according to the embodiments of FIGS. 3A and 3B, may be connected to means or an electrical power source such as the source 17 of FIG. 1 (for example a current or voltage source). The means 17 may be controlled by an electronic circuit 19 (FIG. 1), for example a processor or CPU (or FCCU communication protocol), the configuration of this circuit and / or the control mode defining whether a current source or a voltage source is retained for the means 17.

[0070] A valve according to the invention allows, by integrating a heating function, a significant gain in size, cost, as well as in control capacity, since there is only one part which ensures the functions of opening / closing the valve but also of heating it. It therefore brings compactness to the purge system of the circuit. In addition, the heating function is located as close as possible to the passage of the fluid, which is not the case when using a separate component, but also other components of the valve. There is therefore a gain in heating efficiency (the ice melts more quickly and / or by consuming less energy) and this for the entire valve.

[0071] Some known systems do not have the ability to separate the actuation function from the heating function: heating can then only be carried out when the valve is in a fixed position. A valve according to the invention makes it possible to decouple the two functions, and therefore to activate or not the heating at any time, in a manner decorrelated from the activation function of the opening or closing of the valve.

[0072] The means for heating a valve according to the invention can be used for prevention (to avoid the formation of frost) or curatively, after frost has formed. Thawing tests for a valve according to the invention are presented below.

[0073] An example of a system in which the present invention can be used is shown schematically in Figure 5: reference 30 designates fuel cell elements, one outlet of which is provided with a valve 10 according to the invention, which is used on the purge part of the circuit of this cell. The cell is supplied by hydrogen supply means 32. It is connected to various elements of a fluid circulation circuit, these elements being represented schematically by reference 40.

[0074] A water / hydrogen purge valve with integrated heating function is particularly useful when operating a fuel cell intended for a transport vehicle, particularly an aircraft, where the circuit of such a cell may be subject to freezing. This valve allows excess hydrogen or water to be purged from the cell system.

[0075] As can be seen in Figures 1, 3A, 3B and 4, the seals 12, 12' have a conical portion. Such a shape can in particular be reused in cooling applications, using oil or gas. Preferably, the seat on which it rests also has a conical or truncated cone shape. This conical shape of the seal has the advantage of:

[0076] Better durability because of fewer cuts on edges and less pinching between two moving components;

[0077] Better sealing because the conical shape makes it possible to compensate for shape defects.

[0078] In addition, this conical shape: improves the proportionality of the solenoid valves because the conical section leads to a more gradual opening of the channel; reduces disturbances because the cone will better “guide” the fluid; helps ensure a good flow of hydrogen.

[0079] A water / hydrogen purge valve according to the invention, with heating function, allows optimal operation in all conditions of use of the system, in particular in the case of use at negative temperature.

[0080] A valve according to the invention, by integrating this heating function, allows a significant gain in size, cost, as well as in control capacity (one part instead of two). In addition, the heating function is located as close as possible to the fluid passage, which is not the case when using a separate component.

[0081] According to one embodiment, the means 24 for connecting the activation means and the heating means comprise, for example, at least 4 pads arranged outside the body 1 of the valve, against this body 1 or partly in it; this makes it possible to increase the compactness of a system in which the valve is integrated.

[0082] According to a practical embodiment, a valve according to the invention may comprise a carcass, for example made of plastic injection, on which the coil is wound. The body 1, for its part, is metallic and contains the moving part, comprising the moving core, and possibly the seal 12, the spring 22.

[0083] Other aspects or properties of a valve according to the invention are presented below in connection with Figures 6-9C. Figure 6 shows the evolution of the outlet hydrogen flow (y-axis on the left) and the pressure drop (y-axis on the right) as a function of the inlet pressure in a valve according to the invention.

[0084] The pressure drop (represented by black triangles) evolves linearly for inlet pressures below 2.5 bar and stabilizes at around 1 bar for inlet pressures above 2.5 bar. The outlet flow, represented by line D, evolves linearly for the entire pressure range, notably between 0 or 0.5 bar and 4 bar or even 5 bar.

[0085] Figure 7 shows the evolution of the current (curve l c ) and tension (curve l t) (y-axis on the left) and the temperature (y-axis on the right) as a function of the operating time of the heating coil of a valve according to the invention for a voltage of 24V and a heating current of 2A. More precisely, the temperature is measured on the valve casing (curve Ia), on the coil (curve IIa) and on the valve body (curve Ilia), curve IVa representing the ambient temperature. This curve shows that a maximum temperature of 200°C is reached (from about 40 min), which ensures safety of the valve (no risk of damage to the valve with such a maximum temperature, and no risk of flammability (in particular hydrogen)). The different temperatures are measured using thermocouples, the ambient temperature being 22.15°C.

[0086] Figure 8A shows the temperature variation over time for a thermocouple placed closest to the heating coil (curve Ib), a thermocouple furthest from the heating coil (curve IVb), and thermocouples placed respectively at the inlet and outlet of the solenoid valve (curves I1b and I1b). Starting from a temperature of -40°C, we see that the solenoid valve can be thawed in less than 3 minutes. Other measurements have shown that, from a temperature of -40°C, the solenoid valve can be thawed in less than 2 minutes (see the tests shown in figures 8A-8E2). For this test:

[0087] - the heating time differs from figure 7, since, in figure 8A, the heating is cut off after 120s; - a thermocouple is installed on the coil, one on the fixed core, one on the inlet hole of the solenoid valve, and one on the outlet hole. For these different tests (the following data are also valid for the tests in figures 8A-8E2): the coil has a resistance of 18.8 Q; the current supply is between 1 A and 3 A; the maximum supply voltage is between 24 V and 32 V.

[0088] Figures 8B1-8E2 show different tests carried out with the different current and voltage pulses; these are shown in Figures 8B1, 8C1, 8D1 and 8E1 respectively. For these different tests, the inlet diameter of the valve (measured where arrow 16 is located in Figure 1) is 2 mm, and its outlet diameter (measured where arrow 14 is located in Figure 1) is 0.68 mm.

[0089] Figures 8B2, 8C2, 8D2 and 8E2 represent the evolution of the different temperatures measured on or against the valve, with a thermocouple located as close as possible to the heating coil (curves Ib, Ic, Id, Ic), with a thermocouple as far as possible from the heating coil (curves IVb, IVc, IVd, IVe), and thermocouples placed respectively at the inlet and outlet of the solenoid valve (curves I Ib, Ile, I Id, Ile and I II b, I1 le, Illd, Illle).

[0090] Figures 9A - 9C show simulations obtained using the Software: ANSYS 2022. R2. The magnetic stainless steel 430F (used for the mobile core and the fixed core which are in contact with hydrogen) is replaced by an HSMn30 steel. In the case of Figure 9A, the main technical data relating to the device are assembled in the following table, where Dep is the distance between the fixed core 20 and the mobile core 6 and DEPC is the distance between the initial positioning (0) of the heating coil 8 and another positioning of this heating coil.

[0091] The force developed by the heating coil along the z axis is then: Fz=0.20637 N.

[0092] In the case of Figure 9B, the heating coil is moved 2 mm from its initial placement (case of Figure 9A). Here again, the main technical data relating to the device are assembled in the following table:

[0093] We then see that the force developed by the heating coil is Fz = 0.11797 N In the case of Figure 9C, the length of the external casing has been reduced. The main technical data relating to the device are assembled in the following table:

[0094] The force developed by the heating coil is then Fz=0.18665 N.

[0095] These results show that the heating coil, even with a long outer casing, does not affect the magnetism of the valve and cannot open or close it. These different tests show that the heating coil (in particular its external diameter and / or its number of turns) and its positioning (preferably as close as possible to the moving core) can be sized without interfering with the core activation coil. Sizing of the heating coil can be carried out on the basis of tests as explained above in order to obtain the desired heating, for example in terms of maximum temperature and / or in terms of thawing time.

[0096] The heating of a valve according to the invention can be controlled by a current of, for example, between 0.5A and 5A or 7A or 10A or a voltage of, for example, between 5V and 30V or 32V or 35V.

Claims

CLAIMS 1. Purge valve (10) for a circuit of a fuel cell comprising, said valve comprising a body (1) comprising an outer wall (13, 15), this body being provided with a channel or channels (14, 16) for circulating a fluid, the body of the valve further comprising: - a member (6, 12, 12') for opening or closing said channel or channels (14, 16, 18), means (4) for activating this member along an axis (XX') and means (24) for connecting these activation means to an electrical power supply, said activation means (4), comprising a ère coil (4) wound around said axis (XX'); - means (8) for heating the valve, these heating means (8) comprising a 2 èmecoil (8) wound around said axis (XX'), and means (24) for connecting these heating means to an electrical power supply, these heating means being arranged between on the one hand the means (4) for activating the member (6) for opening and closing the channel or channels (14, 16, 18) and on the other hand the channel itself or the channels (14, 16, 18) themselves, - the connection means (24) of the activation means (4) and the heating means (8) being arranged at least partly on or against the outer wall (13, 15) of the valve.

2. Valve according to claim 1, further comprising means (11) for closing the magnetic circuit of the ère coil (4).

3. Valve according to claim 1 or 2, the 2 ème coil having an outside diameter less than or equal to that of the first coil (4).

4. Valve according to one of claims 1 to 3, the 2 èmecoil having an outer diameter greater than that of the first coil (4).

5. Valve according to one of claims 1 to 4, the connection means (24) of the activation means (4) and the heating means (8) comprising at least 4 pads (24i, 24?, 24 3 , 24 4 ).

6. Valve according to claim 5, the at least 4 pads being arranged or distributed in 2 rows parallel to each other or in a single row.

7. Valve according to one of claims 1 to 6, the connection means (24) of the activation means (4) and the heating means (8) of the valve being arranged against the body (1) of the valve, or partly in it, or partly integrated in it.

8. Valve according to one of claims 1 to 7, the electrical supply of the l ère coil (4) being independent of that of the 2 eme coil (8).

9. Valve according to one of claims 1 to 8, further comprising means (20) fixed relative to the valve and a spring (22), arranged between said fixed means (20) and the member (6), allowing the latter to be held in a position of closing or opening of the channel or channels (14, 16, 18).

10. Valve according to one of claims 1 to 9, 2 ème coil (8) being sized so that: - when part of a valve is frozen, for example at -40°C, thawing is achieved in less than 3 minutes or in less than 2 minutes; - and / or so that the valve reaches a maximum temperature of 200°C during heating by said 2 ème coil (8).

11. Valve according to one of claims 1 to 10, in which a fluid, for example water and / or hydrogen, undergoes a maximum pressure drop of 1 bar between its entry into the valve and its exit from the valve.

12. Valve according to one of claims 1 to 11, in which an outlet flow of a fluid which passes through the valve evolves linearly as a function of its pressure at an inlet of the valve.

13. Valve according to one of claims 1 to 12, the valve comprising: - a first part, itself comprising the activation means (4), the member (6) for opening or closing the valve and the heating means (8); - a 2 e part comprising the channel or channels (14, 16, 18), this 2 e part being removable from the first part.

14. Valve according to one of claims 1 to 13, the activation means (4) and the means (6) for heating the valve being aligned along an axis (XX') of movement of the opening and closing member.

15. Valve according to one of claims 1 to 14, comprising a fluid inlet channel, and at least 2 flow channels (14, 18) thereof.

16. Valve according to claim 15, one flow channel (14) being able to be closed while the other flow channel (14') is free.

17. Valve according to one of claims 1 to 16, one end (12) of the member (6) for opening and closing the channel or channels (14, 16, 18) being of conical or frustoconical shape comprising at least one part of conical or frustoconical shape.

18. Fuel cell circuit comprising a purge valve according to one of claims 1 to 17.

19. Fuel cell circuit according to claim 18, further comprising means (17) for electrically supplying the valve and a circuit for controlling these means.

20. Transport vehicle, for example airplane, comprising a fuel cell and a fuel cell circuit according to claim 18 or 19.

21. Method for purging a circuit of a fuel cell according to claim 18 or 19, possibly in a vehicle according to claim 20, comprising: a) - opening the channel or channels (14, 16, 18) by actuating the opening or closing member (6) using the activation means (4) of this member, from a closing position, respectively opening, of the channel or channels (14, 16, 18) to an opening position, respectively closing, of this same channel or these same channels, allowing, respectively preventing, circulation of a fluid; b) - before, during or after step a): heating using the heating means (8).

22. Method according to the preceding claim, in which the fluid is water and / or hydrogen.

23. Method according to the preceding claim, in which the heating step allows heating of a part of the channel or channels (14, 16, 18) and of at least one zone at the interface between the member (6) for opening or closing the valve and the means (4) for activating this member.

24. Method according to one of claims 21 to 23, in which at least one part of the valve is frozen, for example at -40°C, before step b), the thawing being obtained in less than 3 minutes or in less than 2 minutes.

25. Method according to one of claims 21 to 24, in which the valve reaches a maximum temperature of 200°C during step b).

26. Method according to one of claims 21 to 25, in which the fluid undergoes a maximum pressure drop of 1 bar between its entry into the valve and its exit from the valve.

27. Method according to one of claims 21 to 26, in which an outlet flow of a fluid which passes through the valve evolves linearly as a function of its pressure at an inlet of the valve.

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