FR2960559A1 - Installation for producing hydrogen that is useful to synthesize chemical products, comprises hydrogen production modules comprising electrolysis cells, power supplies, fluid treatment unit, sensor, pilot, driver, and hydrogen storage tank - Google Patents

Abstract

The installation comprises hydrogen production modules comprising electrolysis cells, power supplies that are connected to the module and control current for the production of hydrogen by water electrolysis, a unit for treating fluids obtained from the electrolysis, sensors arranged to send available data indicative of operating state of element in the group comprising cells, modules and treating unit, a pilot arranged to receive the data indicative of a state of operation and to draw records of current control for the power supplies, a driver, and a hydrogen storage tank. The installation comprises hydrogen production modules comprising electrolysis cells, power supplies that are connected to the module and control current for the production of hydrogen by water electrolysis, a unit for treating fluids obtained from the electrolysis, sensors arranged to send available data indicative of operating state of element in the group comprising cells, modules and treating unit, a pilot arranged to receive the data indicative of a state of operation and to draw records of current control for the power supplies, a driver, a hydrogen storage tank, an oxygen storage tank, valves having programmable individual flow installed between the tanks, and reserve modules. The current control ((100(1+1/(M-1)))%) is calibrated for a nominal current, which corresponds to a desired nominal hydrogen flow. The pilot is further arranged to receive record data of hydrogen flow, to calculate a corresponding record of control current for modules, to calculate a record lower than the nominal current for modules, and to transmit an extinction signal of the modules. The modules comprise short-circuit relay for each cell. The driver emits activation signal from the short circuit relay associated with the cells, and calculates a record for the modules concerned to compensate the deactivation of their groups of cells. Each cell comprises: specific bipolar plates having high electrical conductance equipped with two diametrically or diagonally opposite protruding connections; a T-shaped base of an intermediate part having high electrical conductance attached to each protruding connections; and pins having high electrical conductance adapted to be inserted in gaps for automatically or manually constituting the short circuit relay. The calculation of a current control record greater than 200% of the nominal current generates data indicating a failure for the concerned module. The pilot is arranged: in response to available data indicating the failure to reduce the record of hydrogen flow and to calculate a current control corresponding to each of the modules; and to control valves to draw a flow of hydrogen and/or oxygen from the tanks to compensate the decrease of the hydrogen flow record. The pilot determines that the available data indicates a fault when voltage between electrodes of a cell designated by the data is greater than a given threshold or when a temperature of a liquid and gas mixture of the module is greater than a threshold data.

Description

The invention relates to water electrolysis equipment, generators of hydrogen and oxygen, for many industrial applications. Hydrogen applications include the feeding of chemical synthesizers, the filling of fuel tanks for motor vehicles, the doping of natural gas, the storage of energy for intermittent electric generators and the cooling of large generators. Oxygen is usually a by-product. To satisfy some of these applications, these devices must have high power, great flexibility and high reliability. A large power (typically 100 Nm3 / h) required for such equipment requires them to have several hundred electrolysis cells. High flexibility means the ability to quickly meet any production requirement of their user system. And, high reliability means that they are able to function for a very long time (several weeks in a row) in an autonomous way, managing any problem presented by each of their cells. A cell of electrolysis of water produces two gases, hydrogen and oxygen, evacuated in two mixtures liquid + gas. This production is made in response to a large continuous electric current, flowing between two vertical flat electrodes, in an alkaline or acidic electrolyte. An alkaline electrolyte is a liquid, a suitable diaphragm separating the electrodes. In the case of an acid electrolyte, it is generally a proton exchange membrane (PEM), sandwiched between the electrodes. In this case also, this electrolyte may also be an acidic liquid, a suitable thin ceramic separating the electrodes, In all cases, the electrolysis cells are formed between two bipolar plates allowing them to be placed in series and the electrodes, anode and cathode , are circular or rectangular. In industrial equipment, objects of the present invention, the unit area of these electrodes is generally a few tens of square decimetres. In the electrolysis cells of the water, on both sides of the internal separations (diaphragm, ceramic or membrane), two narrow contiguous compartments, generally occupied by grids, are in this way arranged between two bipolar plates, with outer walls of flexible insulating material forming seals. In the case of cells with liquid electrolyte, the grids are insulating and the two electrodes are also the bipolar plates. In the case of PEM membrane cells, the architecture is different, the electrodes are permeable and directly applied to the membrane, conductive grids immersed in the water ensuring the electrical connection of the electrodes and bipolar plates. In alkaline electrolyte cells, the electrodes are generally mild steel and in those with acid electrolyte, they are made of titanium. In PEM membrane cells, the bipolar plates, grids and electrodes are made of titanium and, more specifically, of sintered titanium for the electrodes. A fine catalytic deposition (usually platinum for an acidic electrolyte and nickel for an alkaline) is performed on the electrodes or on the PEM membrane of the cells. Each of the two compartments of a cell has a low inlet for the liquid concerned and a high output for the liquid + gas product mixture, both inlet and outlet being provided in the insulating outer walls.

An electrolysis module is a tight stack of several tens of cells mounted in series. In this stack, one or more liquid distributor ducts and one or more collection ducts liquid + gas mixtures, produced in parallel by each cell, are provided sealed, through the bipolar plates and the flexible outer walls of the two compartments of all module cells. This or these conduits are connected to one or more inputs of each compartment. Each module is associated with a strong DC power generator (hundreds of amps), a pure water tank and a fluid treatment unit comprising two separation chambers for the two liquid + gas mixtures respectively produced in the compartments. cathode and anode. The two separation chambers operate by gravity and they each have a high inlet and two outlets, high for the gas and low for the residual liquid. The residual liquid present at the bottom of each separation chamber finally returns to the compartment which fed it. The high outlets of the separation chambers are connected to the networks for using the two gases produced, H2 and 02. An adjustable opening valve, placed at the outlet of the chamber producing H2, determines the extraction pressure of this gas.

A water electrolysis cell is an active electrical circuit, having an internal resistance and a bias voltage. This voltage is 1.48 V at 25 ° C is the enthalpy voltage of electrolysis of liquid water. Several parameters are involved in the electrical circuit formed by an electrolysis cell, and in particular the temperature which slightly increases the polarization voltage and appreciably promotes the electrochemical reaction while slightly increasing the resistivity of the metal components (bipolar plates, electrodes). Under these conditions, to produce a given flow rate of H2 corresponding to a specific current density (A / cm 2 of electrodes), if the temperature increases within its allowed range, the cell needs a slightly lower supply voltage. and therefore a lower electric power. Which is beneficial. The hydrogen flow rate of an electrolysis module is proportional to the active surface of the cells, the number of cells that it contains and the intensity of the direct current flowing through them. To produce a given flow, an autopilot calculates the optimal value of this intensity. Each cell has a current / voltage curve that depends on the temperature and the state of its catalytic deposit (density and purity, effective area). In an acid electrolyte cell, the water is oxidized at the anode according to the following half reaction: [H2 O => 1/2 O2 + 2 H + + 2 e-]. The water is thus dissociated, it is in the anode compartment that the water level decreases. The protons migrate through the PEM membrane or electrode separation ceramic, under the effect of the electric field and they are reduced to the cathode, according to the following half reaction: [2 H + + 2 e- => H2]. It should be noted that the protons that migrate through the PEM membrane are generally solvated and, as a result, a transfer of water, called the electroosmotic flow, is established from the anode to the cathode. As for the level of liquid in the anode compartment, it decreases for two reasons: (1) the dissociation of the water and therefore its "consumption" and (2) the flow of the water molecules carried by the protons, in the case of PEM membranes. As a result, only the liquid mixture separation chamber + 02 receives the pure feed water from the apparatus and then the address, mixed with its residual liquid, to the anode compartment. For its part, the residual liquid of the separation chamber of the liquid mixture + H2 returns to the cathode compartment. A solenoid valve, controlled by the autopilot, placed between the two separation chambers, makes it possible to transfer liquid from the cathode chamber to the anode chamber. In the case of an alkaline electrolyte cell, the water is oxidized at the cathode according to the following half reaction: [2 H2O + 2 e- => H2 + 2 OH-]. As the water is thus dissociated, it is in the cathode compartment that the water level decreases. The hydroxides (OH-) migrate from the cathode to the anode under the effect of the electric field and are reduced to the anode according to the half reaction [2 OH->> 1/2 02 + H2O + 2 e-] . Under these conditions, water is consumed at the cathode and, conversely, water is produced at the anode. As a result, the liquid level in the cathode compartment decreases and that of the anode compartment increases. A solenoid valve, placed between the two separation chambers of liquid + gas mixtures, can compensate for this evolution in the opposite direction. The efficiency of an electrolysis cell (typically 80%) is limited due to losses related to electrochemical reactions and ohmic drops. This leads to a continuous increase in temperature. In modules producing less than 1 Nm3 / h, natural convection is sufficient to maintain the temperature around 70 ° C. In systems with larger capacity, it is imperative to regulate the temperature, since this must not exceed 90 ° C, otherwise certain components (seals, membranes, etc.) will be destroyed. Since an average temperature close to 70 ° C. is considered almost optimal, the temperature of the liquid supplying the liquid distributor duct of the anode and cathode compartments of the cells of a module is regulated and maintained in a considerably lower range than this optimal value, by a simple binary control (calorie withdrawal) or double (withdrawal and calorie supply) in regions with large thermal differences.

In any electrolysis equipment, to be sure that everything is working properly, it is necessary that the water used has a minimum purity, that the flow of this water is in agreement with the production of hydrogen required, that the electric generator provides a direct current adapted to this production and that the extraction pressure of the two gases produced is consistent with those desired by the user. These different requirements in fact concern parameters outside the cells that influence their operating mode, their performances and their lifetime. Several known devices have been developed to best ensure these different functions. When these different external parameters have their setpoints, the alkaline or acidic electrolysis cells have ranges of values determined for their internal parameters: bias voltage (electrolysis start), nominal operating voltage, maximum allowed voltage , and densities of the electrolysis current. For acid or alkaline electrolyte cells, these ranges are as follows: bias voltage (1.48 volts), extreme current densities (10 mA / cm 2 and 3 A / cm 2 of electrodes), nominal operating voltage (about 2 Volts), maximum possible voltage (3 Volts) and set temperature, generally relatively low and between 65 and 80 ° C. In practice, however, the optimum conditions of operation of an electrolysis equipment formed by modules of a few tens of electrolysis cells, in principle perfectly supplied with pure water and with good electrical voltage and current, do not last as long as would like the builder. And, the electrical voltages at the cell terminals and / or the temperatures of the two liquid + gas mixtures produced, come out of their target ranges. Indeed, each of the external and internal parameters referred to above can, at a given time and for various reasons, no longer be consistent with its set point. This always leads to local operating deficiencies of one or more cells of the equipment. In some cases, the electric current lines flowing in the cells are no longer homogeneous, short circuits and / or localized circuit interruptions occurring in the electrodes and / or in the electrolyte. This may be due to hidden manufacturing defects of the alkaline or acidic electrolyte used or sediments, insulators or conductors, produced in the long run and accumulated in the liquid present in a compartment of the cell. In the case where several cells of a module have an insufficient operating state or if one of these cells goes into a serious state of malfunction, the production of hydrogen decreases and can reach an alert rating , which the user generally detects quite easily, thanks to a measurement of the intensity of the direct current flowing in the module. This must cause the immediate shutdown of the electrolysis module. The larger the number of cells in an electrolyser equipment, the more difficult it is to build stand-alone equipment capable of producing very high hydrogen flows (up to a few hundred Nm3 / h) with very high reliability. Moreover, in case of deficiency of a few cells or a few modules, the flow of hydrogen from the electrolyser equipment decreases. This can lead to very troublesome situations in the case where the user system of the hydrogen produced by this equipment requires a constant flow.

The first object of the invention is to construct water electrolysis equipment, hydrogen and oxygen generators operating under the control of an autopilot, adapted to continue to operate autonomously, despite the deficiencies of a few components. . The second object of the invention is to construct water electrolysis equipment, hydrogen and oxygen generators operating under the control of an autopilot, adapted to continue to operate independently, combining if necessary strong power and high reliability, despite the deficiencies of a small number of its electrolysis cells.

According to the invention, a water electrolysis equipment, of alkaline or acidic type, operating under the control of an autopilot, for producing hydrogen and oxygen, is characterized in that: - it comprises M modules of N electrolytic cells, their M power supplies and a fluid treatment unit; it comprises means for recording data representative of the functional state of each of these cells and / or of each of these modules; the pilot is programmed to manage these readings, to analyze the collected data and to detect their possible deficiencies and then to elaborate instructions so that this equipment can automatically compensate for the deficiencies of these cells and / or these modules, and thus keep the flow constant. global gas product. According to a complementary feature of the preceding ones, the instructions developed by the autopilot to overcome the deficiencies of a cell and / or a module are control signals: (a) to functionally remove this cell and / or this module deficient of this equipment; (b) to decrease the hydrogen flow rate of the deficient module; (c) and, in either case, to compensate for this shrinkage or decrease by increasing the individual hydrogen flow rates of the other cells and / or other modules of the equipment. Thanks to these arrangements, according to the invention, the detection of a defect or a deficiency of an electrolysis cell and / or a module leads to leaving in its present state of the cell and / or this module (in fact, to circumvent it) but to remove it functionally from the equipment (by removing its power supply) or to reduce this power supply, without having to use any particular means to physically repair this cell and / or module. This withdrawal is automatic in most cases. This distinguishes the invention from any other prior solution, described in several patents, which consists in detecting a particular defect and in physically repairing it by human intervention (in particular by means of mechanical means) in order to restore a particular defect. more or less normal state the cell or module concerned.

According to a first complementary feature of the preceding, this electrolyser equipment comprises means for raising the electrical voltages between the two electrodes of each of the N cells of each of the M modules. According to a second additional feature of the preceding, this electrolyser equipment comprises means for raising the temperature of one of the liquid + gas mixtures produced by each of the M modules.

According to a particular characteristic of the preceding one, a temperature probe is, on the one hand, immersed in the liquid + gas mixture leaving one of the two exhaust manifolds of the mixtures produced by the module and, on the other hand, connected at the entrance of the autopilot.

According to the invention, this electrolyser equipment is further characterized in that: the (N + 1) bipolar plates of the N cells of each of the M modules are connected to (N + 1) input terminals of a connected multiplexer autopilot; this autopilot comprises a set of programs incorporating: (a) a program (A) for managing the readings, the digitization and the identification of the data; (b) a program (B) for comparing said recorded data with reference data, directly or after appropriate processing, and, where appropriate, diagnosing the presence of a particular defect in a given cell and / or module. In practice, such a multiplexer receives analog data and, driven by the autopilot, produces analog or digital data depending on the location of the analog / digital converter used. This converter can indeed be incorporated into either the multiplexer or the driver. Moreover, the multiplexer may have several groups of (N + 1) inputs and, therefore, be adapted to process the data provided by several modules (two or three for example). Thanks to these arrangements, packets of N variable data, representative at any time of the functional state of each of the N cells of each of the M modules of the electrolyser equipment, are periodically transmitted to the autopilot. For this purpose, the multiplexers intervene one after the other to interrogate one by one each of the N cells of each of the M modules of the equipment. During this cycle, the pilot receives one after the other, each of the M.N data thus recorded. The digital signals finally produced are coded by the coordinates (m, n) of the M.N cells of the equipment and representative of the functional states of each. It is the same for the temperatures of the modules. The pilot program (B) analyzes these data by comparing them with reference data, directly or after prior treatment, and, where appropriate, produces signals indicating the presence of one or more defects or deficiencies, in the one or more of these MN cells and / or in one or more of these M modules. According to additional features of the invention, the driver program (B) produces a major deficiency signal relating to a cell (n, m) of a module when the voltage between the electrodes of this cell is zero or insufficiently greater than its bias voltage (typically 1.5 V); the driver comprises a program (C) for producing: (a) a control signal for stopping the individual flow of the module concerned (m), intended for a voltage variator, incorporated in the power supply of this module; (b) appropriate increase control signals of the individual gas flow rates of the other modules to carry back on these modules the load to maintain the total flow of hydrogen produced at the level imposed by the operator. It will be noted first of all that such a decision of major deficiency, in the case of a too weak voltage between electrodes, is based on the dangerousness of such a situation. Indeed, this situation is due to a quasi-local short circuit, especially because of a local perforation of the PEM membrane or a conductive sediment in its water or in the alkaline or acidic liquid. This can happen in particular due to a manufacturing defect of one of the components or purity of the water used, which requires a longer or shorter electrolysis time to occur. In this case, most of the very strong current (hundreds of Amperes) that passes through this perforation or sediment, non-zero electrical resistance, can cause significant heating of the entire area. Which is dangerous and therefore unacceptable in a medium containing a mixture of hydrogen and oxygen. Thanks to the preceding provisions, the electrolyser equipment reacts autonomously to an urgent situation, in order to functionally eliminate the deficient module from the installation and to compensate for this elimination by rapidly transferring the charge of the hydrogen flow to the modules in question. good condition.

According to complementary features, the pilot program (B) also produces a minor deficiency signal relating to a particular module (m), (a) when the voltage between the electrodes of a cell (n) of this module ( m), reaches a given maximum value, set by the manufacturer (typically 2.5 V); (b) or when the temperature of a liquid + gas mixture of a module (m) reaches a given maximum value, set by the manufacturer (typically 80 ° C); the pilot comprises a program (D) for producing, in response to such a minor deficiency signal: (a) an appropriate decrease control signal of the individual hydrogen flow rate of the module concerned, intended for a voltage converter incorporated in the power supply of this module; (b) for the other modules of the equipment, control signals for the appropriate increase of their individual hydrogen flow rates, intended for the variable-voltage drives of these other modules, to defer to these modules the burden of maintaining the total flow of hydrogen produced, at the level imposed by the operator. Thanks to these provisions, a minor deficiency of a cell and / or a module of the electrolyser equipment is immediately corrected, by an appropriate significant decrease in the hydrogen flow rate of the module concerned and by a slight increase in the flows of the others. . According to complementary features of the above, the pilot comprises a program (E): (a) to allow the functional steps defined above, to be repeated as long as the individual hydrogen flow rates, requested to the modules concerned, remain included in the range defined by the individual extreme flow rates, minimum and maximum, set by the manufacturer, these two rates corresponding to extreme densities of electric current, typically equal to 10 mA / cm2 and 3 A / cm2. (b) to control the decreases in the individual hydrogen flow rates of the minor deficiency modules, preferably in standard increments, each step typically corresponding to a current density of 0.1 A / cm 2, (c) to consider this minor deficiency as a major deficiency and control the shutdown of the power supply of the module concerned, in case the reduction of the individual hydrogen flow rate of this module would lower this flow rate below the minimum imposed flow. Thanks to all these provisions, an electrolyser equipment, improved according to the invention, keeps constant the total flow of H2 required by the user system, by working each module as long as possible and under the best conditions: individual flows reduced for some and increased for others, so as to increase the reliability of the equipment. Indeed, with a very high reliability, that is to say with a probable rate of unavailability particularly low (typically <0.1% over one year), such electro-lysing equipment, comprising a sufficient number of modules , is constantly able to provide the very high total hydrogen flow rate (typically 100 to 200 Nm3 / h), which can be requested by the user system. And this state of affairs remains as long as the M modules of this equipment are not divided into two groups in extreme situations, namely a group of modules each operating at an individual flow rate close to the maximum flow rate set by the manufacturer and a group of modules at full stop. According to the invention, such electrolyser equipment, hydrogen generator, is further characterized in that: - a hydrogen storage tank, of suitable capacity, is associated with it to overcome any temporary lack of production; - solenoid valves with programmable individual flow rates are installed between this tank and the user system concerned; - The pilot program (E) also has the following functions: (a) to significantly lower (typically 20%) the individual hydrogen flow rate of each of these modules in working order, when all these modules operate at close individual flows (typically 5%) of the maximum allowed flow; (b) simultaneously controlling these solenoid valves and connecting this hydrogen reservoir to the user system, in order to keep constant the flow of hydrogen feeding this system; (c) to report this new situation on the pilot's screen. Thanks to these provisions, in an electrolyser equipment at the edge of saturation, its associated hydrogen storage tank comes into play, so that any new detection of a deficient module can not bring one or more of the other modules of the equipment to operate beyond the limits imposed by the manufacturer. This particular situation is indicated on the pilot screen. And the engineers and technicians of the manufacturer, maintenance service representatives of the equipment, are then invited to replace all the defunct modules stopped by modules in perfect condition.

During the time interval between the detection of this new deficiency and the arrival of these specialists on the site, the flow of the storage tank compensates the general decrease of the total flow of H2 imposed on the equipment. Throughout the duration (typically a few hours) of the intervention of these specialists, the electrolyser equipment is at the total stop (or, if the installation allows it, only the deficient module) and the storage tank provides the totality the flow rate of H2 requested by the user system. When the replacement of the modules in the state of major deficiency is completed, the operator instructs the autopilot to restart the electrolyser equipment and to disconnect the storage tank from the user system concerned. The standard driver program (not specified here) is used to execute these instructions. During the first period of this restart, the equipment operates at a higher total rate, the surplus being used to replenish the storage tank, which is then an appendix of the user system. As soon as this tank is filled again with H2, a second period begins, during which each of the modules of the electrolyser equipment operates at a nominal flow rate to provide the user system with the total flow demanded. At this time, we find the initial conditions for starting up the improved electrolysis equipment according to the invention. And, we can see that, since this first start, despite the minor or major deficiencies of several modules, successively corrected, the user system of the hydrogen produced by this equipment, has been constantly properly powered, in accordance with the objectives of the invention. According to a complementary characteristic of the invention, an oxygen storage tank, equipped with solenoid valves with programmable individual flow rates, is also associated with the water electrolysis equipment; the pilot includes a program for controlling these solenoid valves in order to adjust the additional oxygen flow that might be required. Thanks to this arrangement, it is possible to satisfy, with the greatest reliability, the double requirement of certain particular user systems, operating continuously. This is particularly the case in industrial units carrying out the synthesis or destruction of certain chemicals and in continuous electricity production systems, operating from all intermittent generators, in particular wind turbines and / or photovoltaic panels. In such systems, the complementary storage of oxygen, produced by the water electrolyzer equipment according to the invention, significantly improves the efficiency of fuel cells, powered by the hydrogen produced by this equipment. Moreover, with regard to these intermittent generators of electricity, it will be noted that in the isolated regions, powered by these only sources of energy, it is easy to adapt the number of modules in operation of an electrolyser equipment, at the average electric power, provided at a given moment by these wind turbines and these photovoltaic panels. According to additional general features of the invention, the pilot comprises a program (F), (a) for distributing the number M of modules of this electrolyser equipment into two functional groups of modules, a first group of modules operating at individual rates. nominals and a second, at zero individual rates, the initial number of modules in the second group being typically five to ten times lower than that of the first group; (b) for assigning to the first group an appropriate number of modules, and to address to each of them, in response to an instruction from the operator, an individual rate command typically corresponding to a current density close to 0.5 A / cm2, to produce the total hydrogen flow demanded by the user system; (c) for transmitting, at relatively long regular time intervals (typically each week), a control signal requiring each module in perfect condition of the second group to take the place of a module in perfect condition of the first group and simultaneously , to this one to replace that one. According to additional particular characteristics of the preceding, the pilot comprises a program (G), intervening when a major deficiency affects a module of the first group: (a) to command the module concerned to go off; (b) for controlling a module of the second group to replace in the first group that module stopped and transferred to the second; (d) to control all the modules of the first group thus reconstituted, to adjust their different individual rates so that they are as uniform as possible. Thanks to these new arrangements, a maximized reliability is expected of the equipment according to the invention, because the M modules it comprises experiencing relatively long periodic breaks and therefore fatigue less. This obviously minimizes the probability of deficiencies of all these modules because the total flow required to the equipment is advantageously provided in successive steps. Indeed, the ordinary normal operating time of the equipment is increased, thanks to the functional distribution of the total number M of modules into two groups. Under these conditions, the modules of the second group (their number is typically 10 to 20% of the number M, itself generally between 5 and 30), act as backup modules, ready to automatically replace a defective module to the shutdown, functionally removed from the first group. Thanks to this distribution, the modifications in more or less of the individual flows of the modules are made in stages with reduced levels since the functional elimination of a module is, in most cases of major deficiency, preceded by at least one intermediate stage of minor impairment. In addition, since each module of the second group is periodically transferred into the first group instead of a module in good condition of this group, this periodic switching (typically every week) avoids a degradation in time of its ability to produce the large individual flow that may be required. According to the invention, such electrolyser equipment is further characterized in that: the number M of the modules of the equipment can be any, in particular of 1, each N cell module is composed of P small groups of Q cells ( typically from 3 to 10 for Q, with N = PQ), each group being identified by its coordinates (p, m) and separated from the contiguous groups by specific bipolar plates; each of the P groups of cells comprises a short circuit relay, manual or automatic, between its specific bipolar plates; the autopilot comprises a program (H): (a) to assign to one of the P groups of cells composing a module the voltages detected between the electrodes of one or other of its Q cells; (b) to identify by its coordinates (p, m) any group comprising a cell 20 having a deficiency; (c) for controlling the stopping of at least the module (m) concerned and for signaling this new situation on the screen of the driver of the equipment, when the short-circuit relays of the P groups of the M modules are manual ; (d) to control the short-circuit relay of the group of coordinate cells (p, 25 m), when the P short-circuit relays of the P groups of the M modules are automatic; (e) controlling the voltage converter concerned to increase the voltage supplied by the module's electrical generator (m), to compensate for the functional elimination of the one or more groups of cells including a defective cell; (f) for controlling the shutdown of a particular module, when the percentage of groups of cells shorted, reaches a threshold determined by the manufacturer. According to particular characteristics complementary to the preceding ones, the (P + 1) specific bipolar plates of the P groups of cells of the M modules are discs or rectangles with high electrical conductance, provided with two protruding connectors, diametrically or diagonally opposite; - The foot of a T-shaped intermediate part, with high electrical conductance, is attached to each of these flowing connections, the bars of these T are aligned and a gap is arranged between the ends of the bars of two adjacent intermediate parts; - Two pins with high electrical conductance are adapted to be automatically or manually inserted into these gaps to form a short circuit relay. Thanks to these provisions, the autopilot programmed by the manufacturer detects the deficient state of any group (p) of cells of the module (m). When the short-circuit relays of these groups are manual, this state of affairs appears on the screen of this driver. Then the pilot intervenes to stop the power supply of the module, to ensure the safety of the operator and to prevent the production of any dangerous spark at the time of the short circuit made by him. The module is stopped the time required for the operator to insert the dowel in the space concerned, using any appropriate handling means. During this downtime, the hydrogen storage tank is automatically connected to mitigate the consequences.

In the case where the short-circuit relays of the groups of cells of the modules are in automatic operation, the pilot controls the short-circuiting of any group he has diagnosed having a defective cell. In addition, it can shut down the entire module, when a given number of cell group deficiency indicators are reached in a module. The automatic short circuit of one or a few groups of cells does not modify the hydrogen production of the module concerned. According to all the preceding features, an electrolyzer equipment formed by M modules operating in parallel, each module comprising N cells with acid electrolyte, is characterized in that it comprises a fluid treatment unit comprising: - means treatment to produce pure water, especially from city water, and a storage tank of this pure water; M pairs of separation chambers of the liquid + H2 and liquid + 02 mixtures, each chamber having a high inlet connected by a pipe to the collecting duct of the appropriate liquid + gas mixture of each of the M modules, and an upper outlet connected to to the appropriate general collector of one of the two gases, H2 and O2, produced by these M pairs of chambers; two liquid level sensors, mounted on the M pairs of separation chambers for the liquid + gas mixtures, connected to the autopilot; - M separation chambers liquid + 02 each having a low inlet connected to the pure water tank, through M solenoid valves and automatic control lift pumps, depending on the liquid level in each of these M rooms; - M separation chambers liquid + H2 mixtures each having a low output connected, through an electrically controlled solenoid valve, to a second low input of the M separation chambers liquid + 02 mixtures, to ensure a certain level of uniformity of water in these M pairs of separation chambers; M pairs of separation chambers of the liquid + 02 and liquid + H2 mixtures, each having a low output for the residual liquid, and these M pairs of low outputs are connected to liquid distributor conduits of the M modules, through M pairs of circulating pumps, with automatic controls, according to the individual flow rates respectively requested to the M modules; - M temperature controllers, with automatic controls, installed upstream of the M liquid distribution conduit entries, connected to the M anode compartments of the cells of the M modules: - the driver includes a program (K) to control at the appropriate time these solenoid valves, these pumps and these temperature regulators. Thanks to these arrangements, this fluid treatment unit of an electrolyzer equipment, generator of hydrogen and oxygen, operates continuously in accordance with the individual flow rates of hydrogen, respectively imposed by the autopilot at each of its M modules. . In fact, if the liquid levels in the M pairs of liquid / gas separation chambers are maintained at average levels, the liquid flow rates in the distributor ducts of the M modules are determined by the individual hydrogen flow rates requested from these modules. . Other features and advantages of the invention will emerge more clearly on reading the following description, taken from examples given for illustrative and non-limiting purposes, taken from the drawings in which: FIG. 1 represents an electrolysis cell with PEM membrane; FIG. 2 schematically represents the groups of cells of a module, their short-circuit relays, the power supply of this module, a multiplexer and an autopilot; FIG. 3 represents a specific bipolar plate of the invention; FIG. 4 schematically represents an autonomous electrolyser equipment comprising several modules, formed of cells with an acid electrolyte, according to the invention; - Figure 5 shows some programs incorporated in the autopilot. The drawings and the description below contain, for the most part, elements of a certain character. They can therefore not only serve to better understand the present invention, but also contribute to its definition, if any.

Figure 1 is a schematic representation of a PEM membrane water electrolysis cell. This cell 10 is sandwiched between two flat bipolar plates 12-14 made of titanium, installed vertically spaced about 6 mm, having a thickness of 1 mm and a surface of a few tens of square decimetres. This cell 10 is constituted by a thin polymer membrane PEM 16, provided on both sides with a fine catalytic deposit (typically a platinum micron), sandwiched between an anode 18 and a cathode 20, both constituted by a disk or a permeable sintered titanium rectangle, approximately 1 mm thick. The spaces between these electrodes 18-20 and the plates 12-14 constitute two compartments: 22 that of anode A and 24 that of cathode C, each occupied by a titanium grid 26 or 28, 2 mm thick. The cell 10 has a flexible outer wall 30, about 20 mm thick. In the upper and lower parts of this wall 30 and the two bipolar plates 12-14 of the cell 10 (and all the cells 10, stacked tightly in an electrolysis module), two pairs of rectilinear ducts are provided. 2 to 3 mm in diameter: at the bottom, a pair 32-34 of water dispensers and, at the top, a pair 36-38 of collectors of water + gas mixtures produced by the cell. The low ducts 32-34 are connected to the compartments 22-24, by two passages 40-42 and the high ducts 36-38, connected to these same compartments by two other passages 44-46. It will be noted that the cells with liquid electrolyte, acid or alkaline, have an architecture more or less similar to that of the PEM membrane cell of FIG. 1: the electrodes and the bipolar plates are merged and not separated, the catalytic deposits are on the electrodes and not on the diaphragm, a diaphragm or a thin ceramic replaces the PEM membrane, insulating grids replace the titanium grids, but the liquid-distributing conduits and the collecting conduits for liquid + gas mixtures are identical. FIG. 2 is a simplified representation of an improved electrolyser module 48, comprising, by way of example, fifteen (N) PEM membrane electrolysis cells 10, divided into three (P) groups 501.3 of five (Q) cells . In each group, each cell is connected to its neighbor by an inner bipolar plate 521.4, the three 501.3 groups of cells having four specific bipolar plates 541.4. Two clamps 561.2 provide the assembly of these cells and these groups and two electrical terminals 581.2 allow the power supply of the module 48. An electric generator 60, powered by the sector, having a voltage variator 62 and a current transducer 63, is connected to the terminals 581.2, by two conductors 641.2, with a large section. Each of the sixteen internal, 52 and specific bipolar plates 54, of the fifteen cells 10, is connected by one of the sixteen conductors 551.16 to one of the sixteen inputs of a multiplexer 66. The two analog output pins of this multiplexer 66 are connected by a double conductor 68 to the input of an autopilot 70, comprising (not shown) a programmed microprocessor, a sequential interrogator and an A / D converter. The frequency of reading of the voltages between electrodes is of the order of the kilohertz. The four specific bipolar plates 541.4 can be connected to their immediate neighbor by three short-circuit relays 721.3. The driver 70 is adapted to emit selective control signals for these short-circuit relays 72 and the voltage converter 62. The links 741.3 and 761.2 are provided for this purpose.

FIGS. 3a and 3b show the high electrical conductance specific bipolar plates 541.4 of the cell groups of the module 48. FIG. 3a is a front view of a specific circular bipolar plate 54, of a few tens of square decimetres, comprising two connectors. overflowing 801.2, diametrically opposed. These connectors 80 are adapted to allow a short circuit to be made between two adjacent specific bipolar plates, by means of a relay 72 (see FIG. 2), while maintaining a satisfactory distribution of the electric currents in these plates. These specific bipolar plates have the shape of the PEM membranes used, and when these membranes are rectangular, the flowing connections are diagonally opposite. FIG. 3b represents two groups 501.2 of five cells 10, equipped with two electric relay lines 821.2, with automatic or manual control. These two relay lines 821.2 are constituted by small intermediate pieces, T-shaped (with a bar of approximately 30 mm), with a high electrical conductance, transversely fixed to the overhanging connectors 801.2, by their feet provided with an appropriate connector of the trade. In this way, the bars of these T form two rectilinear alignments, perpendicular to the bipolar plates, regularly interrupted by gaps with slightly oblique walls, having an average width of a few millimeters, When a relay 72 performs a short circuit, such The gap is occupied by a dowel 841_ 2 with appropriate oblique edges, with high electrical conductance. In the case of a relay 72 in open circuit, the pins 851.2 are released. When the relays 72 are manually controlled, these pins 84-85 are provided with appropriate handling means (not shown). When these relays 72 are automatically controlled, each of these pins 84-85 are associated (not shown) a return spring and a common electromechanical means, adapted to make it undergo a translation or a tilting. FIG. 4 is a schematic representation of electrolyzer equipment 86, a hydrogen generator with high flow and high reliability, according to the invention. In order not to overload the figure, only the elements of the equipment concerned by the invention are represented. Notably in this figure 4 are the usual visual control, safety, ventilation, purge and pressurizing devices of a hydrogen generating electrolyser.

By way of example, the equipment 86 comprises twenty (M) standard modules each comprising sixty (N) PEM membrane cells, the modules 88 (M1) and 90 (M20) being represented alone. Each module 88-90 is connected to the autopilot 70 by a conductor 68. A conductor 92 connects to the pilot 70 a temperature probe 94 immersed in the collector duct 36 (see fig.1) of the anode compartments of the cells of each module . These twenty 88-90 modules are divided into two functional groups, a first group of seventeen modules and a second group of three modules. According to FIG. 4, in the fluid treatment unit 85, associated with the twenty modules 88-90 of the equipment 86, a water purification device 96, fed by the town water, is connected to a reservoir of water. pure water 98 connected output, through a pump pump lift 100, intermittent automatic operation, and two solenoid valves 102, with automatic control, at the low inputs 104 of the two chambers 106 of separation water + 02, respectively associated with the modules 88- 90. Each of these chambers 106 has a first low output 108 connected, through a conductivity probe 107, a liquid flow sensor 109, a circulation pump 110, a thermal regulator 112, to the water dispensing conduit 32 (see FIG. .1), feeding all the anode compartments 22 of the N cells 10 of the 88-90 modules. Each of the water separation chambers 106 + 02 is equipped with a sensor 114 adapted to evaluate the water level (too high, normal, too low), connected to the pilot 70. The conduits 36-38 water mixing manifolds + 02 and water + H2 (see fig.1) produced by the modules 88-90 are respectively connected by the two insulated pipes 87-89 to the upper inlet 116 of each of the chambers 106 for separating the water mixture + 02 and at the upper entrance 118 of each of the chambers 120 for separating the water + H2 mixture. Each of these chambers 120 has a first low outlet 122 connected, through a flow sensor 123, a circulation pump 124 and a heat-insulated pipe 84, to the water dispensing duct 34 (see FIG. 1) of all the compartments of FIG. cathode 24 of N cells 10 88-90 modules. The separation chambers 120 each have a second low output 128, connected to a second low input 126 of the chambers 106, through a solenoid valve 130, with automatic control, to ensure a certain uniformity of water levels. To do this, a level sensor 132 (connected to the driver 70) is associated with each separation chamber 120. The M pairs of separation chambers 106-120 of the water + gas mixtures each have a high output 133-134 and these M pairs of outputs are respectively connected to the M inputs of a general collector 136 of 02 and the M inputs of a general collector 138 of H2. The outputs of these general collectors lead to the equipment for operating these gases. The oxygen collectors 136 and the hydrogen collector 138 are associated on the one hand with oxygen storage tanks 137a and their associated solenoid valves 137b and on the other hand with hydrogen reservoirs 139a and their associated solenoid valves 139b. . Each of the M modules of the electrolyser system 88-90 is equipped with a power supply unit 60, with automatic control, equipped with a voltage variator 62 and a current transducer 63 (see FIG. According to FIG. 5, the autopilot 70 comprises: a program (A) for surveying, digitizing and identifying, by their coordinates (n, m), the data relating to the M.N cells of the equipment; a program (B) for comparing these data (voltages and temperatures) with reference data and, if necessary, diagnosing a major or minor deficiency of a module (m); a program (C) for stopping a rank module (m) and for increasing the flow rate of the other 5, in case of major deficiency of this module; - a program (D) to reduce the gas flow of a rank module (m) and increase the flow rates of others to maintain constant the total flow, in case of minor deficiency; a program (E) for monitoring the implementation of these programs (A, B, C, D), in order to compare the current density, controlled at one module, at the two thresholds, minimum and maximum, imposed on this density by the manufacturer, and to cause: (a) the shutdown of a module (m) in case the low threshold is crossed; (b) a general decrease of the flow rates of all the modules, in case all the current densities are very close to the maximum permitted threshold, (c) a connection to the user system of the hydrogen storage tank and a setting of its associated solenoid valves, at the same time as this decrease. Thanks to these provisions, the exploitation of an autonomous industrial electrolysis equipment, hydrogen generator with very high flow and very high reliability, becomes easy. In fact, despite the significant probability of defection of one or the other of the electrolytic cells of such equipment, it has the possibility of self-management and to continue its operation, without modifying the flow rate. H2 programmed, fixed by the operator. Since the electrolyser equipment 86, formed by the aforementioned PEM membrane cell modules 60, is in working order, the operator enters his instructions for the individual flow rates of each of the equipment modules 88-90. , depending on the total flow demanded: 150 Nm3 / h, for example. These first individual flows will be nominal flows, corresponding to a current density of 0.5 A / cm 2, of 8.80 Nm 3 / h for example for each of the 17 modules of the first main group and they will be zero for the 3 modules of the second group. As soon as these different flows are produced, by automatic adjustments of the voltage regulators 62, the current transducers 63 provide signals, representative of the different electrical currents and individual hydrogen flow rates of the modules. From these signals, graphical representations of these individual rates appear on the pilot screen 70. This allows the operator to continuously monitor the behavior of each of them. When the autopilot 70 detects that a module of the first group is in a state of major deficiency, in the sense defined above, it delivers three signals: (a) a stop control signal of this module, and (b) a a control signal of the individual flow rate of one of the three modules of the second group, which causes it to produce either the flow rate previously achieved by the stationary module or its initial nominal flow rate with appropriate rebalancing of the flow rates of the other modules. This process can be repeated until the three modules of the second initial group have replaced three deficient modules of the first initial group. Then, as soon as a new module is deficient for a major reason, this module is stopped and joins the second group while the other active modules are required to increase their individual rates. This can be repeated as long as this individual flow rate remains below the maximum permitted flow rate.

When the autopilot 70 detects that a particular module of the first group has a minor deficiency, as defined above, it produces the following signals: (a) a decrease control signal of 20% for example of the individual rate of this module, which reduces this initial flow rate to 7 Nm3 / h, and (b) a control signal for increasing the individual flow rates of the other 16 modules of the first group, which increase to 9 Nm3 / h to maintain the total flow rate of the equipment at 150 Nm3 / h. This process is repeated by lowering, preferably in standard steps of current density (for example 0.1 A / cm 2), the individual flow rates of the first deficient modules and increasing the individual flow rates of the other modules. This continues (with the shutdown of the modules with major deficiency or individual expected rate lower than the minimum threshold and the replacement of each one of them by one of the three modules of the second initial group with a rebalancing of the respective flows of the modules of the first group as well as reconstituted) until the individual flow rate requested at each of the last modules of this first group reaches the maximum allowed individual flow (5 modules at 30 Nm3 / h, corresponding to a maximum current density of 2 A / cm 2, for example ).

In anticipation of such a situation of saturation of the equipment, the operator can provide a fallback position of reducing the total flow required and solicit the hydrogen storage tank to mitigate this decrease. In this case, all the steps of the process described above are repeated identically, but with a total production objective markedly reduced for the equipment itself, for example, up to 120 Nm3 / h, and 24 Nm3 / h of maximum permissible flow for each of the five modules remaining in play. The graphical representation of these individual flows allows the operator to follow in real time the evolution of the behavior of the equipment and thus to make any decision appropriate for the follow-up to be given to any particular case. The set of these successive modifications of individual flow rates of the modules has for sole objective, the automatic maintenance of the total flow of hydrogen required to the equipment. Variations of this process in several stages are of course possible as long as this objective is ensured. In response to an instruction from the operator increasing, for example by 10%, the total hydrogen flow demanded from the electrolyser equipment 86, digital control signals are sent to the M power supply blocks 60 of the modules 88. 90 of the equipment as well as its 2M circulation pumps 110-124: all these components increase their production by 10%. The hydrogen flow rate of each module is followed by the display of the intensity of its feed current, measured by the current transducer 63. Under these conditions, the volumes of water + gas mixtures produced by all the cells of the the equipment also increases and the uniformity of the normal levels that previously existed in all the separation chambers 106-120 of the M modules can be destroyed. If the level in the separation chambers of the water + H2 mixtures is too high, the solenoid valves 130 are opened until the previous uniformity is restored. In the case where the temperature of the + 02 water mixture, measured by the thermocouple 94 of a particular module, exceeds a threshold imposed in response to this increase in flow rate of H2, the thermal controller 112 of this module would correct this excess by lowering the temperature water injected into the conduit 32 water dispenser of this module. The autopilot 70 ensures the proper functioning of the fluid treatment unit 85. For this purpose, in response to the level sensors 114-132, the solenoid valves 102 and 130 are controlled for the average levels of the water in the chambers. 106-120 separation of water + gas mixtures are within an allowed range. The conductivity probes 107 of the water supplied by the separation chambers 106 to the modules 88-90 produce signals analyzed by the pilot 70. This pilot can use these water conductivity signals to correct the voltages measured between the electrodes. cells, before comparing them to reference values. More generally, it uses them to stop the module concerned in case the measured conductivity is greater than a determined threshold. The signals supplied by the liquid flow sensors 109-123 are likewise analyzed and in the case where the measured flow rate is lower than a variable threshold, set according to the hydrogen flow rate requested from the module concerned, the module is stopped by the pilot. The temperature regulators 112 of the water returned to the anode compartments of the cells are governed by the pilot 70. The same is true for the pumps 110-124, assigned to the streams of water entering the two compartments of the cells. The invention is not limited to the equipment 86 described in FIG.

The modules 88-90 of the improved electrolyser equipment 86 are of the standard type but they could have complied with the module 48 according to FIG. 2 and comprise P groups of cells, the autopilot 70 then being adapted to process (as indicated above). ) the different signals available and to produce the appropriate control signals to manually or automatically short-circuit the deficient group. This possibility is particularly advantageous for electrolyser equipment, hydrogen generator with high reliability but limited hydrogen flow, comprising for example one, two or three modules. Furthermore, it will be noted that the architecture of the fluid treatment unit 85 of the water electrolysis equipment 86 described in FIG. 4, in which the separation chambers of the water + gas mixtures are specific to each of the modules. , is not the only architecture possible. It is possible to have two collective chambers for separating the water + gas mixtures, directly or indirectly fed by the M pairs of collector ducts of the two mixtures produced by the modules, with their two low outlets directly or indirectly connected, through 2M pumps. circulation, to the M pairs of water distribution conduits of these modules. In cases where these connections are indirect, one or two intermediate tanks will be used, (1) to collect water + gas mixtures of the same type, produced by the different modules, before sending the whole to the collective chamber of separating and / or (2) for collecting the residual water from these two chambers before sending them to the distributor ducts of the M modules. In practice, the use of such intermediate tanks entails various disadvantages, including a significant increase in the lengths of the pipes, and one of the other two solutions will therefore be generally preferred. The description of the invention was made with reference to electrolysis cells equipped with PEM acid membranes. In hydrogen generating systems, equipped with cells with liquid, alkaline or acid electrolyte, the technological adaptations of the invention to this particular type of cell are within the reach of any specialist in these systems and will therefore not be described here. It appears from the above that the invention relates to a plant for producing hydrogen comprising: - M hydrogen production modules (48-88-90) each comprising at least one electrolysis cell (10), - a a plurality of power supplies (60), each connected to a current controlled module (48-88-90) for the production of hydrogen by electrolysis of water, said current control being calibrated for a nominal current which corresponds to a desired nominal flow rate of hydrogen, characterized in that at least some of the power supplies are dimensioned to be able to provide current control at least equal to (100 (1 + 1 / (M-1))% of the current nominal. This installation may have the following additional features: a. a processing unit (85) for treating fluids from the electrolysis; - a plurality of sensors (55-94) arranged to transmit availability data indicating an operating state of at least one element in the group including some at the least cells (10), at least some of the modules (48-88-90) and the processing unit, and - a driver (70) arranged to receive said data indicative of a state of operation, and to derive therefrom selectively current control commands for said power supplies, some of which may be greater than said rated current. b. the pilot is arranged to receive data of hydrogen flow rate instructions, and to calculate a corresponding current control setpoint for the M modules. c. Installation according to claim 2 or 3, wherein at least some of the modules comprise several cells associated with several groups, these modules comprising short-circuit relays for each cell group they contain, and in which, in response to data indicating a fault and designating one or more groups of cells of one of these modules, said driver (70) emits an activation signal of the short-circuit relay (s) associated with these groups of cells, and calculates a setpoint for the relevant modules provided to compensate for the deactivation of their groups of short-circuited cells. d. each cell group comprises: - specific bipolar plates (54) which are discs or rectangles with high electrical conductance, having two protruding connectors (80), diametrically or diagonally opposite, - a foot of an intermediate piece (82) ), T-shaped, with high electrical conductance, attached to each of these two projecting connectors (80), the bars of these T being aligned and a gap being arranged between the ends of the bars of two adjacent intermediate parts, and - two dowels (84), with high electrical conductance, adapted to be inserted into these gaps, automatically or manually, to constitute the short-circuit relay (72). e. in response to availability data indicating a fault and designating one or more modules, said driver (70) calculates a lower setpoint than the rated current for the designated modules and a setpoint for at least some of the other modules which compensates for the decrease in the setpoint designated modules. f. said setpoint calculation for at least some of the other modules comprises a substantially equal increase in the control setpoint for all these other modules. g- calculating a current control setpoint lower than 67% of the nominal current generates availability data indicating a fault for the module concerned. h. in response to availability data indicating a failure and denoting one or more modules, said driver (70) emits an extinction signal of this or these modules, and calculates a setpoint for the other modules designed to maintain the flow of hydrogen produced by the installation. i. the calculation of a current control setpoint greater than 200% of the nominal current generates availability data indicating a fault for the installation. j. the pilot is arranged, in response to availability data indicating a failure of the installation, to reduce said hydrogen flow set point and to calculate a corresponding current control setpoint for each of the M modules. k. it can furthermore comprise a hydrogen storage tank (139a) and / or an oxygen storage tank (137a), and solenoid valves (137a, 139b), with individual programmable flows, installed between this or these tanks ( 137a, 139a) and respective outputs of hydrogen and oxygen from the installation, in which the pilot is arranged to control the solenoid valves (137b, 139b) to draw a flow of hydrogen and / or oxygen from the reservoirs (137a, 139a) for mitigating the decrease of said hydrogen flow set point. 1. It can further comprise L spare modules, and wherein, in response to availability data indicating a fault and designating one or more modules, the driver is arranged to activate one or more spare modules, and to calculate a current control setpoint for the functional modules intended to maintain the flow of hydrogen produced by the installation. m. the sensors are arranged to measure at least one of the group comprising the electrical voltage between the electrodes of at least some of the cells (10) of the installation, the temperature of one of the liquid + gas mixtures produced by some at less modules ,. not. the pilot determines that availability data indicates a failure when the voltage between the electrodes of a cell designated by these data is greater than a given threshold, or when the temperature of a liquid + gas mixture of a module designated by these data is greater than a given threshold.15

Claims (15)

REVENDICATIONS1. Hydrogen production plant comprising: - M hydrogen production modules (48-88-90) each comprising at least one electrolysis cell (10), - a plurality of electrical power supplies (60), each connected to a module (48-88-90) which it controls in current for the production of hydrogen by electrolysis of water, said current control being calibrated for a nominal current which corresponds to a desired nominal flow rate of hydrogen, characterized in at least some of the power supplies are dimensioned to provide current control at least equal to (100 (1 + 1 / (M-1))% of the rated current. 2. Installation according to claim 1, further comprising: - a processing unit (85) for treating the fluids resulting from the electrolysis, - a plurality of sensors (55-94) arranged to transmit availability data indicating a state operating at least one element in the group comprising at least some cells (10), at least some of the modules (48-88-90) and the processing unit, and - a driver (70) arranged to receive said data indicative of a state of operation, and for selectively deriving current control commands for said power supplies, some of which may be greater than said rated current. 3. Installation according to claim 2, wherein the driver is arranged to receive data of hydrogen flow rate instructions, and to calculate a corresponding current control setpoint for the M modules. 4. Installation according to claim 2 or 3, wherein at least some of the modules comprise several cells associated with several groups, these modules comprising short-circuit relays for each group of cells they contain, and in which, in response to data indicating a failure and designating one or more groups of cells of one of these modules, said driver (70) transmits an activation signal of the short-circuit relay (s) associated with these groups of cells, and calculates a setpoint for the relevant modules provided to compensate for the deactivation of their groups of short-circuited cells. 5. Installation according to claim 4, wherein each cell group comprises: specific bipolar plates (54) which are discs or rectangles with high electrical conductance, provided with two protruding connectors (80), diametrically or diagonally opposite, - a foot of an intermediate piece (82), T-shaped, with high electrical conductance, attached to each of these two projecting connectors (80), the bars of these T being aligned and a gap being arranged between the ends of the strips of two adjacent intermediate parts, and - two pins (84), with high electrical conductance, adapted to be inserted into these gaps, automatically or manually, to form the short-circuit relay (72). The plant of claim 2 or 3, wherein, in response to availability data indicating a failure and designating one or more modules, said driver calculates an instruction lower than the rated current for the designated modules and a setpoint for at least some of the other modules that compensates for the decrease in the setpoint of the designated modules. 7. Installation according to one of claims 6, wherein said setpoint calculation for at least some of the other modules comprises a substantially equal increase in the control setpoint for all these other modules. 8. Installation according to one of claims 2 to 7, wherein the calculation of a current control setpoint less than 67% of the nominal current generates availability data indicating a fault for the module concerned. 9. Installation according to one of claims 2 to 8, wherein, in response to availability data indicating a failure and designating one or more modules, said driver (70) emits an extinction signal of this or these modules, and calculates a set point for the other modules designed to maintain the flow of hydrogen produced by the installation. 10. Installation according to one of claims 2 to 9, wherein the calculation of a current control setpoint greater than 200% of the nominal current generates availability data indicating a failure for the installation. 11. Installation according to claim 10, wherein the pilot is arranged, in response to availability data indicating a failure of the installation, to reduce said hydrogen flow set point and to calculate a corresponding current control setpoint for each of the M modules. 12. Installation according to claim 11, further comprising a hydrogen storage tank (139a) and / or an oxygen storage tank (137a), and solenoid valves (137a, 139b) with programmable individual flow rates installed. between this or these reservoirs (137a, 139a) and respective outputs of hydrogen and oxygen of the installation, in which the pilot is arranged to control the solenoid valves (137b, 139b) to draw a flow of hydrogen and / or oxygen reservoir (s) (137a, 139a) to mitigate the decrease of said set point of hydrogen flow. 13. Installation according to one of claims 2 to 12, further comprising L reserve modules, and wherein, in response to availability data indicating a failure and designating one or more modules, the driver is arranged to activate one or several reserve modules, and for calculating a current control setpoint for the functional modules intended to maintain the flow of hydrogen produced by the installation. 14. Installation according to one of claims 2 to 13, wherein the sensors are arranged to measure at least one of the group comprising the voltage between the electrodes of at least some of the cells (10) of the installation, the temperature of one of the liquid + gas mixtures produced by at least some of the modules ,. 15. Installation according to one of claims 2 to 14, wherein the driver determines that availability data indicate a failure when the voltage between the electrodes of a cell designated by these data is greater than a given threshold, or when the The temperature of a liquid + gas mixture of a module designated by these data is greater than a given threshold.