EP1803184A1

EP1803184A1 - Line system for a supplying and/or discharging fluids for a fuel cell

Info

Publication number: EP1803184A1
Application number: EP05810797A
Authority: EP
Inventors: Marielle Marchand; Anna-Maria Morgante; Fahri Keretli
Original assignee: Renault SAS
Current assignee: Renault SAS
Priority date: 2004-10-11
Filing date: 2005-10-07
Publication date: 2007-07-04
Also published as: FR2876499B1; JP2008516386A; JP5100387B2; WO2006040492A1; US20080096071A1; FR2876499A1

Abstract

The invention relates to a line system for supplying and/ or discharging fluids for an assembly of at least two identical fuel cell modules (A, B, C, D), in particular mounted on a motor vehicle, each of which comprises an elementary cell (21) stack and input and output pipes (1, 2, 3, 4, 5,) for different fluids required for operation of the fuel cell, wherein said pipes are arranged on at least one external surface of each module and the supply and/or discharge lines for at least one fluid are connected to the corresponding pipes of the module assembly by means of a single main line (C1) or several successive secondary branches (C2, C3 ) of the symmetric structure of each module, respectively.

Description

Arrangement of supply and / or fluid discharge lines for fuel cells.

The present invention relates to a pipeline arrangement for supplying and / or discharging fluids necessary for the operation of a fuel cell module assembly, such an assembly being particularly suitable for mounting in a motor vehicle.

A fuel cell is capable of producing electricity from hydrogen or a hydrogen - rich gas and oxygen or an oxygen - rich gas, such as air. The hydrogen required for the reaction in the fuel cell can be stored on board a motor vehicle or produced in the motor vehicle itself by means of a reformer device fed with hydrogenated fuel, such as gasoline, diesel, ethanol, etc. This hydrogen or hydrogen-rich gas thus produced is fed through a supply line to the anode-side inlet of the fuel cell. In the same manner, generally compressed air is supplied through a supply line to the cathode side inlet of the fuel cell. In addition, it may be necessary to provide controlled temperature operation of the fuel cell, so that a heat transfer fluid is also circulated within the fuel cell to maintain the operating temperature at a desired temperature. suitable level. A fuel cell used for traction of a motor vehicle generally comprises a plurality of identical modules, each module comprising a stack of elementary cells. The power required to tow a motor vehicle is in fact several tens of kilowatts, which requires a large number of elementary cells to be stacked. get the desired power. For mechanical reasons of stacking as well as to ensure a proper operation, it is preferable, however, to limit the size of each module to a stack of a maximum of one hundred cells. The mounting of several modules whose electrical output is generally connected in series has already been imagined in different ways. Thus, US-A-5,480,738 discloses an arrangement of fuel cell modules in the form of two columns mounted side-by-side. The supply of oxygen is via a main pipe arranged between the two columns and comprising for each column a bypass. As regards the supply of hydrogen, it is done for each column by a single pipe supplying in series the stacks of each of the columns.

US-A-6 1 10 612 describes a support structure for mounting four fuel cell modules as well as the supply and discharge of the various fluids necessary for the operation of all the modules.

However, there are difficulties in operating a set of several identical fuel cell modules arranged as described in the aforementioned documents. Indeed, the modules downstream of the supply, whether in oxygen or hydrogen, or in cooling fluid, are not fed in a manner exactly identical to that of the modules located on the upstream side of the unit. 'food. This results in the appearance of different powers depending on the position of the different modules in the assembly forming the fuel cell.

The safety of operation is not ensured, because of such risks of undernourishment of a module located downstream of the power supply. Such undernourishment may indeed cause a Negative voltage passing of the cells of the module in question, which may lead, after a certain time, to self-heating of the module and to a risk of fire, or even explosion of the module.

The present invention aims to eliminate these difficulties and to allow the realization of a perfectly homogeneous distribution of fluids in a set of identical fuel cell modules, particularly in the case where such a set is mounted in a motor vehicle .

The present invention also aims to improve the operational safety of a set of several identical fuel cell modules.

In one embodiment, the pipe arrangement allows the supply and / or discharge of fluids for a set of at least two identical fuel cell modules, in particular mounted in a motor vehicle. Each module comprises a stack of elementary cells and inlet and outlet pipes for various fluids necessary for the operation of the fuel cell. The inlet and outlet tubings are provided on at least one outer face of each module. The supply and / or discharge lines of at least one of said fluids are connected to the corresponding tubes of the set of modules by a single main pipe and one or more successive secondary branches of symmetrical structure for each respective module. The symmetrical structure of the secondary branches makes it possible to ensure an identical flow rate for all the modules.

Preferably, the lengths, the internal sections or diameters and the radii of curvature of the successive secondary branches are each equal for each respective module. Thus the speed and the pressure drops are equal each time and one obtains an identical supply and / or identical evacuation of all the modules regardless of the flow that flows. The distribution of the fluids in all the identical modules of the set of modules can be perfectly homogeneous, guaranteeing optimal operation of the assembly. The safety of the operation of the assembly is also improved since the underfeeding risks of a specific module are discarded.

The electrical power delivered by each module can be identical, which simplifies the operation control.

In one embodiment, the tubes connected to the different secondary branches are arranged on corresponding faces facing each other of the module assembly.

In another embodiment, the tubings connected to the different secondary branches are arranged on opposite corresponding faces of the set of modules.

Preferably, at least the fluid supply pipes on the cathode and anode compartments of the modules are connected to the corresponding pipes of the set of modules by a single main pipe and one or more successive secondary branches of symmetrical structure for each respective module. .

In an advantageous embodiment, the pipes for supplying and / or discharging the heat transfer fluid ensuring the maintenance of the operating temperature of the modules are connected to the corresponding pipes of the set of modules by a single main pipe and one or several successive secondary branches of symmetrical structure for each respective module. The identical modules may be arranged in different ways to form the aforementioned set of modules. In a preferred embodiment, particularly adapted to an installation under the floor of a motor vehicle, the identical modules are arranged in a substantially horizontal plane. The faces of the modules carrying the pipes are then advantageously in substantially vertical planes, each single main pipe and its associated successive secondary branches being disposed substantially in a horizontal plane. The invention will be better understood in the study of some particular embodiments made as non-limiting examples and illustrated by the appended drawings, in which:

FIG. 1 is a perspective view of a fuel cell module comprising a stack of several elementary cells;

FIGS. 2 to 5 schematically illustrate different arrangements of supply and / or discharge lines for a particular fluid in the case of a set of four identical fuel cell modules and in different configurations; FIG. 6 is a schematic view similar to FIGS. 2 to 5 in the case of a configuration comprising eight identical fuel cell modules in an exemplary arrangement;

FIG. 7 is a perspective view schematically showing the layout of the arrangement of the different feed and / or discharge lines of a particular module forming part of a set of four fuel cell modules;

FIG 8 is a perspective view showing a practical embodiment of an arrangement of supply lines and / or evacuation of all the fluids necessary for operation a set of four identical fuel cell modules for a motor vehicle; and

FIG 9 is a view similar to Figure 8 showing another arrangement in which the arrangement of symmetrical conduits is provided only for a portion of the fluids necessary for the operation of the set of four identical fuel cell modules.

As illustrated in FIG. 1, the fuel cell module referenced as a whole comprises a stack of a plurality of elementary cells 21 (in practice, one hundred: only a portion has been shown in the figure). . The stack constituting the module 20 has a front face 22 and an opposite face or rear face 23. Various inlet and outlet pipes, referenced 24, can be arranged on the faces 22 and 23. In the example illustrated in FIG. figure, each of the faces 22, 23 has three inlet and / or outlet pipes 24. It will of course be understood that the number of inlet and / or outlet pipes on each face 22, 23 depends on the internal architecture of the module 20. It is the same for the arrangement of the tubes 24 on the faces 22 and 23. For the operation of a fuel cell module, such as the module 20 illustrated in FIG. 1, it is necessary to provide a circulation of hydrogen-rich gas on the anode compartment, a circulation of oxygen-rich gas, such as air, on the cathode compartment and, in order to maintain the operating temperature at a suitable level, a circulation of one caloporte fluid ur for cooling the module. It is therefore necessary to provide six tubings 24, respectively:

for the entry of hydrogen on the anode, for the exit of the unconsumed hydrogen from the anode, for the entry of air on the cathode, for the outlet of the non - consumed air from the cathode,

- for the inlet of the cooling fluid, and for the outlet of the cooling fluid.

The outlet tubings make it possible to recover excess anode and cathodic fluids which have not reacted in the module. As indicated above, it is necessary to associate several identical modules, such as the module 20, in the form of an assembly to obtain the necessary power, for example for the traction of a motor vehicle.

FIGS. 2 to 5 illustrate examples of arrangement of supply and / or discharge lines for one of the fluids, in the case of a set of four identical modules to the module 20 of FIG.

In Figure 2, the four modules A, B, C and D are disposed substantially in a horizontal plane at the four corners of a square. The fluid considered as an example may be hydrogen or oxygen, or the cooling fluid. In the example illustrated in FIG. 2, a main pipe C ₁ brings the fluid from the front of the motor vehicle considered as the lower part of FIG. 2, towards the rear, and this up to a point M ₁ located substantially at the center of symmetry of the four modules A, B, C and D. At the point M ₁ , the main pipe C ₁ is divided into two secondary branches C ₂ , one directed towards the modules A and B, the other towards the modules C and D, and this substantially equidistant from each other. The two secondary branches C ₂ extend from the branch point M ₁ to one second branch point M ₂ , where they divide again into two secondary branches C ₃ . Each of these branches C ₃ is connected to an inlet pipe of one of the modules A, B, C and D. In this example, the modules A and C are arranged in the same way with their rear face comprising the tubing input for the fluid considered. Both modules B and D were rotated 180 ° with respect to the two modules A and C. Their inlet manifold for the same fluid is thus directed forward. The inlet manifolds of the different modules, for the fluid in question, are therefore facing each other.

The fluid being fed from the front by the main pipe C ₁ , it is understood that it is then distributed perfectly symmetrically to the four modules A, B, C and D. Indeed, the respective lengths of the two secondary branches C ₂ , as well as the four secondary branches C ₃ , are identical to each other. The fluid path for supplying each of the four modules is therefore of identical length.

In order to ensure a perfect homogeneity of the di flibution of the fluid, it is furthermore provided that the internal diameter of the secondary branches C ₂ is half the internal diameter of the main pipe C ₁ . In the same way, the internal diameter of the secondary branches C ₃ is half the internal diameter of the secondary branches C ₂ or, which amounts to the same, one quarter of the internal diameter of the main pipe C ₁ . With this arrangement, it can be seen that the pressure drops in the fluid flow are exactly the same for each of the four identical modules. If the pipes are not of circular section, the same provisions will be adopted by the reports of the sections of the different conduits and secondary branches. It is also preferably taken care to provide identical radii of curvature at the points of connection

Mi and M ₂ , so again to ensure identical flow velocity and pressure drop for feeding each of the four modules A, B, C and D.

Figure 2 also shows in dashed a variant in which the main pipe C, no longer from the front of the motor vehicle, but from the rear. As in the previous variant, the main pipe C ₁ leads to the branch point M, and is subdivided into secondary branches C ₂ and C ₃ for feeding the four identical modules.

Of course, to simplify the figure, there is shown thereon that the supply of one of the fluids, such as hydrogen, oxygen or a cooling fluid. It will be understood that the supply of other fluids and / or the evacuation of all fluids can be designed in an analogous manner.

FIG. 3 illustrates an arrangement of the four identical modules A, B, C and D identical to that of FIG. 2. In this case, however, the evacuation of a fluid has been shown by a pipe also referenced C ₁ and coming from from a central point M ₁ to a branch with two secondary branches C ₂ . Two other branch points M ₂ are at the place where the secondary branches C ₃ coming from the outlet pipes of each of the four modules A, B, C and D meet in the secondary branch C ₂ . In Figure 3, a variant, in which the exhaust pipe C ₁ is directed towards the rear of the vehicle, has also been shown.

FIG. 4 illustrates the case where the inlet tubes of the different modules A, B, C and D for the fluid in question are no longer located opposite each other, but on the contrary on the opposite faces of the different modules. In this case, the main pipe C ₁ , which comes from one side of the vehicle, leads to the branching point M ₁ where it is subdivided into two secondary branches C ₂ which come to two branching points M ₂ respectively located the front and rear side of all four modules A, B, C and D in the axis of symmetry of the assembly. From the branching points M ₂ , the secondary branches C ₃ are connected to the inlet pipes of the four respective modules. It will be noted that the secondary branches have two bends referenced D ₁ and D ₂ , while each of the secondary branches C ₃ has a bend referenced D ₃ .

As previously, in the examples illustrated in FIGS. 2 and 3, the section or the diameter of the secondary branches C ₂ is half of the cross section or the internal diameter of the main pipe C ₁ , while the cross section or the internal diameter of the secondary branches C ₃ is equal to half of the section or internal diameter of the secondary branches C ₂ . The arrangement of the pipes C ₁ , C ₂ , C ₃ is perfectly symmetrical with respect to the main pipe C, as was the case in the embodiments of FIGS. 2 and 3.

The supply of fluid through these supply lines, as illustrated in Figure 4, is perfectly homogeneous. Again, as in the previous embodiment, the radii of curvature of the different secondary branches are each time identical to maintain the symmetry and thus the homogeneity of the distribution of the fluid.

FIG. 4 also shows an arrangement in which the main pipe C ₁ instead of coming from the left of FIG. 4 comes from the line of FIG. 4. FIG. 5 illustrates an arrangement identical to that of FIG. 4, in which the pipe shown is an evacuation pipe, the fluid outlet tubes considered on the opposite external faces of the different modules A, B, C and D. Figure 6 illustrates an assembly comprising eight identical fuel cell modules. Four modules A, B, C and D, arranged as was the case in the embodiments of the preceding figures, are arranged in the same horizontal plane and next to four identical modules E, F, G and H arranged in the same manner as the modules A, B, C and D. In this example, which corresponds substantially to that of Figure 2, there is shown a supply line arrangement in the case where the inlet tubes of the corresponding fluid are located on the opposite faces of the different modules. The main pipe C ₁ brings the fluid considered from the front of the vehicle to the point M ₁ where it separates into two secondary branches C ₂ which, after a bend D ₁ , reaches a second branch point M ₂ which is located substantially at the respective centers of the two groups of four modules A, B, C, D on the one hand, and E, F, G, H on the other hand. From there, we find a similar arrangement to that of Figure 2, with two secondary branches C ₃ to the point of branching M ₃ from which two secondary branches C ₄ , which are each connected to a tubing of input of one of the eight modules A to H.

As was the case previously, the arrangement of the feed pipe for the fluid in question is perfectly symmetrical with respect to the main pipe C ₁ , the lengths of each of the secondary branches being each time equal to the point of branching. next. The same rule of decreasing the cross-section or internal diameter of the pipes is also applied, the secondary branch C ₂ being of a section or a diameter half of the main pipe C ₁ , the secondary branch C ₃ being of one section or of an internal diameter half of the secondary branch C ₂ and the secondary branch C ₄ being of a diameter half of the secondary branch C ₃ . The radii of curvature are also maintained preferably identical to each curve.

In this way, as in the previous embodiments, a perfectly homogeneous fluid distribution is obtained on the eight identical fuel cell modules.

Figure 6 shows in dashed a supply C ₁ made from the rear of the vehicle.

FIG. 7 more precisely illustrates an arrangement of all supply and discharge lines for a fuel cell module such as module A of a set of four identical modules arranged substantially in a horizontal plane at the four corners. of a square.

In FIG. 7, only the axis of the various supply and evacuation ducts for the module A is shown. It will of course be understood that similar ducts are provided for the other identical modules B, C and D.

In the illustrated example, the module A comprises, on its front face 22, an outlet pipe 2a for hydrogen not consumed in the anode part and an outlet pipe 4a for air not consumed at the cathode.

The rear face 23 of the module A has four tubes, namely a tube 1a for the entry of hydrogen into the anode compartment, a tube 3a for the entry of air into the tube. cathodic compartment, a pipe 5a for the inlet of the cooling fluid and a pipe 6a for the outlet of the cooling fluid.

In the illustrated example, the pipes 2a and 3a located respectively on the faces 22 and 23 are both located in an upper horizontal plane, noted P ₃ . The two tubul ures 5a, 6a on the face 23 are located in an intermediate horizontal plane, noted P ₂ . Finally, the two pipes 1a and 4a located respectively on the faces 23 and 22 are located in a lower horizontal plane, noted P ₁ .

If we first consider tubing 1a for the entry of hydrogen into the anodic part, the hydrogen is supplied by a main line C _{1 1} to the point of branching M ₁ , from which a secondary branch C ₂ j goes to a point of branching M _{2 j} from which part in particular a secondary branch C ₃ ,. It thus appears that the inlet tube 1a of the module A is supplied with hydrogen by the successive pipes C ₁ , C _{2 1} and C ₃ , the sections or diameters of which are in each case divided by two as explained above. Also shown in the figure, shown in fine lines, the tubes I b, 3b, 5b and 6b of the module B facing the corresponding tubes of the module A. The tubing Ib is fed by a secondary branch C _{3 1} directed towards the module B from the point of branching M ₂ ,. In the same way, the modules C and D can be powered by a secondary branch C _2. , Which starts from the branch point M _M.

If we now consider the outlet pipe 2a of the module A, it appears that it is connected to the main pipe C _{1 2} which comes from the left of the set of modules, which is divided into two secondary branches C _{2 2 of} which one goes around both sides of the module A to arrive at the point of branching M _{2 2} from which a secondary branch C _{3 2} is connected to the outlet pipe 2a.

The arrangement of the discharge pipe connected to the outlet pipe 4a is substantially identical to that of the pipes connected to the outlet pipe 2a. Indeed, the outlet pipe 4a is connected to the main pipe C _{1 4} via the secondary branch

C _{2 4} and the secondary branch C _{3 4} .

The supply lines of the inlet manifold 3a are arranged substantially in the same manner as the feed lines of the inlet manifold 1a. Indeed, the inlet pipe 3a is connected to the main pipe C _{1 3} to a secondary pipe C _{2 3} , itself connected to a secondary branch C _{3 3} .

The evacuation pipe connected to the outlet pipe 6a comprises a main pipe C _{1 6} which, after the junction point M _{1 6} , divides into two secondary branches C _{2 6} and then into two secondary branches C _{3 6} .

The supply line connected to the inlet pipe 5a also comprises a main pipe C _{1 5} which is subdivided into two secondary branches C _{2 5} and then into two secondary branches C _{3 5} .

It will be noted that the main ducts C, _Λ and C _{1 3} respectively supplying the inlet ducts _1a and 3a are located on the front side of the vehicle, that is to say on the front face 22 of the module A. two pipes are placed between the two modules A and C. They are generally one above the other in a vertical plane, respectively at the height of the planes P ₃ and P ₁ , the main pipe C _{1 3} being above the main pipe C ₁ ,.

The two discharge pipes C _{1 2} and C _{1 4} respectively connected to the outlet pipes 2a and 4a are, for their part, located on the left side of the figure. They are substantially in a vertical plane, the pipe C _{1 2} being above the pipe C _{1 4} respectively at the height of the planes P ₃ and P ₁ , that is to say the same planes as the tubes of exit 2a and 4a. They are also located substantially in an axis between modules A and B.

Finally, the main pipes C, ₅ and C _{1 6} are both located on the rear side, that is to say on the side of the rear face 23 of the module A. They are located substantially in a vertical plane.

It will be noted that the cooling fluid supply pipe C _{1 5} passes from the first upper plane P ₃ to the intermediate plane P ₂ in which the inlet pipe 5a is located. For this purpose, the secondary branch C _{2 5} is inclined to pass from the plane P ₃ to the plane P ₂ .

FIG. 8 illustrates a practical embodiment incorporating the principles of FIG. 7, the arrangement being the same as in FIG.

7.

In FIG. 8, the four identical fuel cell modules A, B, C and D are completely shown, as well as the complete arrangement of the supply and discharge lines of the fluids in the same general arrangement as in FIG. 7. The six main pipes are grouped in pairs, as was the case in Figure 7. The main pipes C _{1 1} for the supply of anode compartments in hydrogen and C _{1 3} for air supply compartments The two cathode conductors are arranged at the rear of the vehicle on the side of the faces 22 of the two modules A and C. These two main ducts C ₁ and C _{1 3} are placed one above the other substantially in a plane. vertical in the interval between the two modules A and C. The two main lines Cj ₅ for the supply of cooling fluid and C _{1 6} for the return of the cooling fluid, open on the opposite side, that is to say on the front side of the vehicle or on the side of the faces 23 the two modules B and D. These two main ducts are arranged substantially in a vertical plane and extend in the interval between the two modules B and D.

Finally, the two main pipes C _{1 2} for the evacuation of hydrogen from the anode compartments, and C _{1 4} for the air outlet coming from the cathode compartments, are arranged on the side of the two modules A and B .

The set of pipes and their associated secondary branches, is designed symmetrically according to the invention. Thus, for example, we see in Figure 8 the arrangement of the two secondary branches C _{2 3} which start from the point of branching M _{1 3} and are connected to the main pipe C _{1 3} for the air supply cathode compartments of the four modules A, B, C and D. It can be seen in FIG. 8 that the diameter of the secondary branches C _{2 3} is half the internal diameter of the main pipe C _{1 3} . At the branching points M _{2 3} , the secondary branches C _{2 3} again separate into two secondary branches C _{3 3} whose internal diameter is half the internal diameter of the secondary branches C _{2 3} .

In this way it is understood that the air supply of the cathode compartments of the four identical modules A, B, C and D is done on the four corresponding inlet tubes 3a, 3b, 3c and 3d, in a perfectly homogeneous and identical manner, since the length of the pipes is exactly the same for the four modules A, B, C and D. In the same way, taking into account the symmetrical reduction of the internal diameters of the different secondary branches, the pressure losses as well as the speed flow of the supply air are the same for the four modules A, B, C and D. In addition, the radii of curvature of each elbow are each identical.

The same results are obtained by the same means for the supply of the other fluids as well as their evacuation.

FIG. 9 illustrates a variant in which only a part of the fluids has a perfectly homogeneous distribution according to the invention. Apart from this difference, the structure of the arrangement of the supply and discharge lines is the same and the four identical modules A, B, C and D of the figure are found.

8, arranged in the same way.

The structure and arrangement of the main and secondary branches for the supply and discharge of the coolant are the same as in figure 8. Thus, the arrangement of the two main pipes C _{1 is found. 5} for the supply of the cooling fluid and C _{1 6} for the discharge of the cooling fluid on the front side of the vehicle, that is to say the front faces 23 of the two modules B and D. In the same way, we find the structure and arrangement of the main pipes C _{1 3} for the air supply of the cathode compartments and C ₁ , for the supply of hydrogen to the anode compartments. These main ducts are disposed on the rear side of the vehicle on the rear faces 22 of the two modules A and C, as was the case in FIG. 8. In contrast to FIG. 8, however, the main ducts C _{1 2} for the evacuation of hydrogen not consumed by the anode compartments and C _{1 4} for the air outlet of the cathode compartments, are also arranged on the rear side of the vehicle, so that all the main pipes C _{1 3} , C _{1 2} , C _{1 1} and C _{1 4} are arranged in a vertical plane on the rear side of the vehicle, in the gap left free between the two identical modules A and C. The arrangement of the main lines C _{1 2} and C _{1 4 as} well as their secondary branches, is not totally symmetrical for the four modules A, B, C and D to the detriment of the homogeneity of the flow. This arrangement, however, has the advantage of better integration into the vehicle, given the layout of the various main lines of the rear side of the vehicle. The main pipe C _{1 4} and the main pipe C, ₂ extend rectilinearly in the gap between the modules A and C, then in the gap between the modules B and D. The secondary branches, such as C _{2 4} or C _{2 2} , the diameter of which is equal to half the internal diameter of the corresponding main pipes C _{1 4} and C _{1 2} , allow the flow of air and hydrogen from the four modules from the pipes of respective outputs 2a, 2b, 2c, 2d and 4a, 4b, 4c, 4d of the four modules A, B, C and D. Given the arrangement of the modules, these outlet pipes are on the rear faces 22 of the the rear of the vehicle for modules A and C, and front panels 23 on the front side of the vehicle for modules B and D.

Claims

1 - Arrangement of supply and / or fluid discharge lines for a set of at least two identical fuel cell modules (A, B, C, D), in particular mounted in a motor vehicle, each comprising a stacking of elementary cells (21) and inlet and outlet pipes (1, 2, 3, 4, 5, 6) for different fluids necessary for the operation of the fuel cell, said pipes being arranged on the ground external face of each module, characterized in that the supply and / or discharge lines of at least one of said fluids are connected to the corresponding tubes of the set of modules by a single main pipe (C ₁ ) and one or more successive secondary branches (C ₂ , C ₃ ) of symmetrical structure for each respective module. 2-pipe arrangement according to claim 1, characterized in that the lengths, sections or internal diameters and the radii of curvature of successive secondary branches are each equal for each respective module.

3-pipe arrangement according to claims 1 or 2, characterized in that the pipes connected to the different secondary branches are arranged on corresponding faces facing the set of modules.

4-pipe arrangement according to claims 1 or 2, characterized in that the tubings connected to the different secondary branches are arranged on opposite corresponding faces of the set of modules.

5-pipe arrangement according to any one of the preceding claims, characterized in that at least the supply lines of said fluids on the compartments The cathodes and anodes of the modules are connected to the corresponding tubes of the set of modules by a single main pipe and one or more successive secondary branches of symmetrical structure for each respective module. 6-pipeline arrangement according to claim 5, characterized in that the supply lines and / or heat transfer fluid supply ensuring the maintenance of the operating temperature of the modules are connected to the corresponding tubes of the set of modules by a single main pipe and one or more successive secondary branches of symmetrical structure for each respective module.

7-pipe arrangement according to any one of the preceding claims, characterized in that the identical modules are arranged in a substantially horizontal plane, the faces of the modules carrying the pipes being in substantially vertical planes, each single main pipe and its successive subsidiary branches being arranged substantially in a horizontal plane.