Purge valve with integrated heating function

Abstract

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

Description

Title of the invention: PURGE VALVE WITH INTEGRATED HEATING FUNCTION TECHNICAL FIELD AND PRIOR ART

[0001] 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.

[0002] With such a valve, the aim is 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).

[0003] A problem arises at negative temperatures, as solidified water blocks the valve from operating. A heating system is therefore provided.

[0004] 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 they are supplied. However, this type of solution involves a certain amount of bulk. However, users of this type of valve are increasingly demanding a high level of compactness.

[0005] Furthermore, if frost can form and at least partially block fluid circulation channels, it can also form in other areas of the valve, in which moisture may have previously been deposited.

[0006] A problem is therefore to find a new purge valve system, making it possible to achieve a certain compactness while guaranteeing efficient operation of the valve.

[0007] Another problem is to find a new purge valve system, allowing heating of all the parts in which frost can form. Statement of the invention

[0008] 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 circulation of a fluid, the body of the valve further comprising or containing:

[0009] - a member for opening or closing the channel or said channels, means activating this organ along an axis (XX') and means for connecting these activation means to a current supply;

[0010] - means for heating the valve and means for connecting these means activation to a current supply, these heating means being arranged between on the one hand the activation means of the opening and closing member of the channel or channels and on the other hand the channel or channels themselves.

[0011] 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.

[0012] The 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.

[0013] 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.

[0014] According to one embodiment, the means for activating the opening or closing member of the valve comprise a first coil wound around said axis (XX').

[0015] Means for closing the magnetic circuit of the 1st coil may also be provided; preferably, the wall of the valve body also participates in the magnetic circuit of this 1st coil.

[0016] According to another aspect of the invention, the heating means may comprise a 2nd coil wound around said axis (XX'). Preferably, the 2nd coil 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 1st coil. However, in certain embodiments, the 2nd coil may have an outside diameter greater than that of the first coil.

[0017] A valve according to the invention may comprise means, fixed relative to the valve, for example a stud or a fixed core, and a spring, the latter being arranged between said fixed means and the opening or closing member, allowing maintenance of the latter in a position of closing the channel or channels.

[0018] According to a particularly interesting embodiment, the valve may comprise:

[0019] - a first part, itself comprising the activation means, the member opening or closing of the valve and heating means;

[0020] - a 2nd part comprising the channel or channels, this 2nd part being removable by report to the first part.

[0021] According to another interesting configuration, the means for connecting the activation means and the heating means may 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.

[0022] 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.

[0023] 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.

[0024] The invention also relates to a fuel cell circuit comprising 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.

[0025] The invention also relates to a method for purging a circuit of a fuel cell according to the invention, comprising:

[0026] 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, a circulation of a fluid, for example water and / or hydrogen;

[0027] b) - before, or during or after step a): heating using the heating means.

[0028] 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. Brief description of the drawings

[0029] [Fig. 1] represents an exemplary embodiment of a purge valve according to the invention;

[0030] [Fig.2A] and [Fig.2B] represent 2 embodiments of a lateral electrical connector for a valve according to the invention,

[0031] [Fig.3A] and [Fig.3B] represent an exemplary embodiment of a purge valve

[0032] according to the invention, with a removable lower part;

[0033] [Fig.4] represents a part of a valve according to the invention, with 2 circuits fluid flow.

[0034] [Fig.5] represents a purge circuit comprising a valve according to the invention.

[0035] DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0036] [Fig.l] represents an exemplary embodiment of a water / hydrogen purge valve 10 according to the invention, with integrated heating function.

[0037] It comprises a fixed body 1 which extends along an axis XX'. This fixed body comprises two parts.

[0038] 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.

[0039] The core 6 will therefore be brought, 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.

[0040] The valve can have a purge or drain function and therefore operate in ON / OFF mode. However, the invention can be implemented to produce a proportional valve, for example with several channels, in particular for another application.

[0041] Under this first coil, along the axis XX', there is a second coil 8, which may be smaller than the first, and is separate from the first 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.

[0042] The 2nd coil may be smaller than the first coil (have an outer diameter smaller than that of the first coil), but, alternatively, have an outer diameter equal to that of the first coil, or even larger than that of the first coil (in which case the heating capacity or function is increased)

[0043] 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.

[0044] 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 size and that, in the 3 figures, a lateral space allows the end 12 to be moved between the low position and the high position).

[0045] The electrical power supply of each of the two coils 4, 8 is carried out independently of that of the other coil, via a lateral connector 24 with 4 pins or connection pads 24b 242, 243, 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, that is to say from the purge function of the hydrogen and / or water circuit.

[0046] 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 the circulation of fluid.

[0047] As already explained above and as can be seen in the embodiment illustrated in [Fig.l], 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.

[0048] 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.

[0049] Furthermore, the structure with 2 coils which are aligned around the translation axis of the actuator gives the entire valve a very compact structure.

[0050] Usually, the valve is maintained 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. But, alternatively, the valve is maintained 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 [Fig.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 shown in this figure: as can be understood, a flow channel 14 can be closed while the other flow channel 18 is free.The end 12' of the movable core 6 can be taken by the latter to block one or the other of these 2 channels, one of which (channel 14 in [Fig.4]) can be closed while the flow can be made towards the other channel 18, and vice versa.

[0051] The connection pads 24b 242, 243, 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 the outer wall 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.

[0052] 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. [Fig.3A] shows the valve in which the 2 parts 2, 3 are assembled, the valve then having the same structure as that of [Fig.1]. In [Fig.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.

[0053] 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 of the other components of the valve. We therefore gain in heating efficiency (the ice melts more quickly and / or by consuming less energy) and this for the entire valve.

[0054] Some known systems do not have the capacity 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 2 functions, and therefore to activate or not the heating at any time, in a manner decorrelated from the function of activating the opening or closing of the valve.

[0055] The means which makes it possible to heat a valve according to the invention can be used preventively (in order to avoid the formation of frost) or curatively, after the formation of frost.

[0056] An example of a system in which the present invention can be used is shown schematically in [Fig. 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 shown schematically by reference 40.

Claims

Claims

1. A purge valve (10) for a circuit of a fuel cell comprising, said valve comprising a body (1) 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 a current supply; - means (8) for heating the valve and means (24) for connecting these activation means to a current 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.

2. Valve according to claim 1, the means (4) for activating the opening or closing member of the valve comprising a first coil (4) wound around said axis (XX').

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

4. Valve according to one of claims 2 or 3, the heating means comprising a 2nd coil (8) wound around said axis (XX').

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

6. Valve according to claim 4, the 2nd coil having an outside diameter greater than that of the first coil (4).

7. Valve according to one of claims 1 to 6, 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).

8. Valve according to one of claims 1 to 7, 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 2nd part comprising the channel or channels (14, 16, 18), this 2nd part being removable relative to the first part.

9. Valve according to one of claims 1 to 8, the connection means (24) of the activation means (4) and the heating means (8) comprising 4 pads (24b 242, 243, 244) arranged outside the body of the valve, these pads being distributed in 2 rows parallel to each other or in a single row.

10. Valve according to one of claims 1 to 9, 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.

11. Valve according to one of claims 1 to 10, comprising a fluid inlet channel, and at least 2 flow channels (14, 18) thereof.

12. Valve according to claim 11, one flow channel (14) being able to be closed while the other flow channel (14') is free.

13. Fuel cell circuit comprising a purge valve according to one of claims 1 to 12.

14. Method for purging a circuit of a fuel cell according to claim 13, 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).

15. A method according to the preceding claim, wherein the fluid is water and / or hydrogen.

16. 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.

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