Hydrogen production installation and method for controlling the hydrogen production installation to supply an installation using said hydrogen.

Abstract

The present invention relates to the field of industrial hydrogen production and more particularly to a hydrogen (H2) production plant intended to supply a hydrogen-using installation and a method for controlling said installation. Figure 1

Description

Title of the invention: Dihydrogen production installation and method for controlling the dihydrogen production installation to supply an installation using said dihydrogen.

[0001] The present invention relates to the field of industrial hydrogen production and more particularly to a hydrogen (H2) production plant intended to supply one or more installations using hydrogen, such as industrial plants that use hydrogen to operate, hydrogen distribution plants as a fuel, in particular service stations. The invention also relates to a method for controlling said production plant. State of the art

[0002] In the context of an industrial installation using dihydrogen, it is advantageous to provide a hydrogen supply to said installation using a dihydrogen production installation which may include at least one electrochemical device enabling the transformation, by means of an electric current, of water - more precisely in the form of water vapor (H2O) - into dihydrogen (H2) and dioxygen (O2), such as a high-temperature solid oxide electrolyzer.

[0003] It is indeed known to carry out high-temperature electrolysis using an electrochemical device forming a reaction zone designed to convert water vapor into dihydrogen. The electrochemical device thus performs vapor-phase electrolysis with water vapor at a temperature that can range from 100°C to 850°C. Such a device is a conventional electrolyzer formed by stacks of cells, each having an anode, a cathode, and an electrolyte. High-temperature electrolysis decomposes the water vapor to form, at the cathode of the cells, a flow of a fluid containing dihydrogen.

[0004] The dihydrogen (H2) which is produced is generally conveyed to a storage unit before being delivered to the installation using said dihydrogen.

[0005] In JP-A-2002129372, the dihydrogen produced in the production unit is sent to a storage unit where it is kept before being transported to the industrial installation where it is used. In order to supply dihydrogen in a stable and regular manner from the storage unit to the installation that consumes it, the pressure in the storage unit must be maintained at a pressure specified or above. In order to maintain the pressure in the storage unit at or above this predetermined pressure, and thus maintain a supply to the industrial plant using this hydrogen, the operation of the hydrogen production unit is controlled according to the pressure in the storage unit. The storage pressure is kept constant by continuously adjusting the intensity of the electrical current (which is directly proportional to the production rate). One drawback is that the electrolyzer is subject to all fluctuations in consumption, resulting in an inability to manage peaks, a risk of cell damage, suboptimal operating conditions, and the venting of some of the production. Furthermore, the electrolyzer described is a proton exchange membrane type, not a less flexible solid oxide type.Such a process is not optimal in terms of continuity of supply and energy costs.

[0006] There is a need to improve the efficiency of hydrogen production facilities and, in particular, to reduce their energy consumption while ensuring a satisfactory supply to the installation using hydrogen. Indeed, if the gap between continuous production and fluctuating consumption is not managed, hydrogen losses may occur. In the event of excess production and low consumption, the excess hydrogen produced must be disposed of, resulting in an economic loss. Description of the invention

[0007] The invention therefore aims to provide a hydrogen production installation to supply one or more installations to be supplied with hydrogen, in which the production of hydrogen is stabilized and optimized with respect to a variable consumption of the installation or installations supplied with hydrogen.

[0008] To this end, the present invention relates to a dihydrogen production installation comprising: - a production unit comprising an electrochemical device configured to produce dioxygen and dihydrogen from water vapor, - a storage unit for the produced dihydrogen, and - delivery means configured to fluidly connect the storage unit to a hydrogen supply installation, characterized in that said installation further comprises: - a flow control valve for the dihydrogen flow in the delivery means - a control unit for the installation, including in particular: • control means for the regulating valve configured to regulate the flow rate of the dihydrogen stream in the delivery means, based on a so-called delivery pressure, measured downstream of said regulating valve, and a so-called storage pressure measured in the storage unit, in order to maintain the delivery pressure in said delivery means equal to a setpoint delivery pressure, and • control means of the production unit configured to regulate the production of dihydrogen, according to the so-called storage pressure measured in the storage unit, so that said storage pressure is greater than the delivery setpoint pressure, to be compatible with the regulation of the flow rate of the dihydrogen flow in the delivery means.

[0009] Thus advantageously, this installation makes it possible to produce dihydrogen and to regulate the flow rate of the dihydrogen flow between the storage unit and the installation supplied with H2 so as to have a flow rate of this flow that meets the demand of said installation while maintaining the filling level in the storage unit at an equilibrium between the flow in the storage unit and the flow out of said storage unit to the installation supplied with H2.

[0010] The control of the hydrogen flow regulating valve in the delivery means is thus advantageously determined based on the pressure measured in the H2 delivery means downstream of the regulating valve, in order to maintain, in the delivery means, a so-called delivery pressure equal to a predefined setpoint pressure, thereby maintaining the balance between the hydrogen supply and the variable consumption of the industrial installation using this hydrogen. The valve regulation thus prevents this delivery pressure from deviating too far from the setpoint pressure.

[0011] As soon as a deviation from the setpoint pressure is measured, however small, the control signal to the regulating valve is adjusted: thus, a small adjustment if the deviation is small, a large adjustment (up to complete opening or closing) if the deviation is large or prolonged. In practice, there are therefore always small fluctuations, but reduced to a minimum.

[0012] The valve control is also determined based on the pressure measured within the storage unit, called the storage pressure. This storage pressure is measured and compared to the delivery setpoint pressure to determine whether this storage pressure is compatible with regulating the flow rate of the dihydrogen, which helps control the regulating valve to maintain the delivery pressure equal to the delivery setpoint pressure.

[0013] Said storage pressure is also measured and compared to different storage setpoint pressures indicating a level of filling of the storage unit, also allowing the production of dihydrogen to be regulated according to the storage setpoint pressures.

[0014] Depending on the storage pressure measured in the storage unit, the control unit is configured to select an operating mode of the production plant, which is either a so-called "delivery pressure regulation" mode, in which the control valve is controlled to regulate the flow rate of the dihydrogen in the delivery means when the storage pressure is greater than the delivery setpoint pressure and a storage setpoint pressure, or a so-called "storage pressure regulation" mode in which the control valve is controlled to close when the pressure in the storage unit is less than a storage setpoint pressure, and is no longer compatible with the delivery of dihydrogen to the plant to be supplied with dihydrogen.

[0015] The installation according to the invention therefore includes means for measuring the delivery pressure in the delivery means, downstream of the regulating valve, configured to send the measurements taken to the control unit configured to compare them to at least one setpoint delivery pressure to the installation to be supplied with dihydrogen.

[0016] Furthermore, said installation includes means for measuring the storage pressure in the storage unit, configured to send the measurements taken to the control unit configured to compare them to the delivery setpoint pressure and to at least one storage setpoint pressure indicating a filling level of the storage unit and to control the dihydrogen production unit.

[0017] The control unit thus regulates the production of dihydrogen in order in particular to produce more or less dihydrogen depending on this measured pressure so that the pressure in the storage unit is at a pressure compatible with the regulation of the flow rate of the dihydrogen flow in the delivery means.

[0018] Preferably, the installation according to the invention comprises a compression unit, means for measuring the pressure of the dihydrogen flow upstream of said compression unit, means for comparing the measured pressure to at least one setpoint pressure, venting means provided downstream of the production unit and upstream of said compression unit, means for regulating the flow of the compression unit and means for controlling said venting means as a function of the measured pressure and at least one setpoint pressure.

[0019] Regulation can be implemented in particular by recycling, by speed variation, or by mechanical adjustment of the compressor capacity.

[0020] The control means may thus include a recycling loop configured to take at least part of the dihydrogen flow downstream of the compression unit and reinject it upstream of the compression unit.

[0021] Optionally, the installation also includes a purification unit, means for measuring the pressure of the dihydrogen flow downstream of said purification unit and upstream of the storage unit, means for comparing said measured pressure to at least one setpoint pressure, a dihydrogen flow control valve between said pressure measurement means and the storage unit, venting means upstream of said control valve and means for controlling the venting means and said control valve as a function of the measured pressure and at least one setpoint pressure.

[0022] Advantageously, the electrochemical device comprises a solid oxide electrolyzer, preferably at high temperature.

[0023] Advantageously, the control unit is configured to trigger the command of emergency hydrogen delivery means to the installation to be supplied with hydrogen in the event of closure of the regulating valve of the flow rate of hydrogen in the delivery means.

[0024] The present invention also relates to a method for controlling a dihydrogen production plant to supply a plant using said dihydrogen according to the invention, the method comprising: - the control of the regulating valve to regulate the flow rate of the dihydrogen in the delivery means, according to a so-called delivery pressure measured in said delivery means and a so-called storage pressure measured in the storage unit, in order to maintain the delivery pressure in said delivery means at a set delivery pressure, and - the control of the production unit to regulate the production of dihydrogen, according to the storage pressure measured in the storage unit so that the storage pressure of the storage unit is greater than the delivery setpoint pressure, to be compatible with the control of the regulating valve to regulate the flow rate of the dihydrogen flow in the delivery means.

[0025] Advantageously, the pressure of the hydrogen flow in the delivery means is measured downstream of the hydrogen flow control valve in the delivery means configured to fluidly connect the storage unit to the industrial installation, and compared to a delivery setpoint pressure defining a constant supply of hydrogen flow to the hydrogen-supplied installation. Furthermore, the pressure is measured inside the storage unit, i.e., upstream of the control valve. From these two pressures measured upstream and downstream of the control valve, a control signal is determined. of said regulating valve so that the pressure downstream of said valve is equal to the set delivery pressure.

[0026] The storage pressure is also measured and compared to at least one storage setpoint pressure indicating a filling level of the storage unit. This storage pressure measured in the storage unit is thus compared to at least one storage setpoint pressure indicating a filling level of the storage unit, in order to control the production of the production unit and thus indicate whether this storage pressure is compatible with the control valve command.

[0027] Advantageously, at least one storage setpoint pressure PCO is defined indicating an "empty" filling level of the storage unit, incompatible with the control of the regulating valve.

[0028] Storage setpoint pressures are further defined, indicating respectively a filling level of the storage unit to which the storage pressure is compared such that: - PCI corresponding to a minimum storage setpoint pressure indicating a "low" fill level, - PC2 corresponding to a maximum storage setpoint pressure indicating a "full" fill level.

[0029] Advantageously, depending on the value of the storage pressure measured in the storage unit, an operating mode of the installation is selected, which is either a so-called "delivery pressure regulation" mode in which the regulating valve is controlled to regulate the flow rate of the dihydrogen stream in the delivery means when the storage pressure is greater than the delivery setpoint pressure and the storage setpoint pressure indicating an "empty" filling level of the storage unit, or a so-called "storage pressure regulation" mode in which the regulating valve is controlled to close when the storage pressure is at a pressure lower than the storage setpoint pressure indicating an "empty" filling level of the storage unit, incompatible with the control of the regulating valve to regulate the flow rate of the dihydrogen stream in the delivery means.

[0030] If the pressure measured in the storage unit is equal to or less than the setpoint pressure PCO, the so-called "storage pressure regulation" mode is selected, the regulating valve in the delivery means is closed, the storage pressure of the storage unit being incompatible with the control valve command to regulate the flow rate of the dihydrogen in the delivery means, and the dihydrogen production unit is commanded for maximum dihydrogen production until the storage pressure measured in the unit storage is at least equal to the storage setpoint pressure PCO indicating an "empty" fill level of the storage unit.

[0031] The stopping or limitation of the flow of dihydrogen to the installation to be supplied with dihydrogen is thus controlled by the total or partial closure of the regulating valve, the filling level of the storage unit no longer allowing the pressure in the delivery means to be maintained equal to the set pressure plus or minus a predefined deviation.

[0032] The valve position is therefore adjusted according to the deviation from the setpoint pressure. The larger or more prolonged this deviation (measured continuously) is, the more the control valve is closed. If the deviation does not disappear, the valve eventually closes completely. However, at equilibrium, the control valve is open just enough to maintain the storage pressure at the setpoint pressure PCO; at this point, since the pressure is stable, the delivery flow rate is equal to the production flow rate.

[0033] The method according to the invention may further include the control of a backup dihydrogen delivery unit to the installation to be supplied with dihydrogen to compensate for the stoppage of delivery by the production installation when the control of the dihydrogen flow regulation valve is ordered to close.

[0034] Advantageously, the dihydrogen production unit is also controlled for maximum dihydrogen production until the pressure measured in the storage unit is at least equal to the setpoint pressure PCO, in order to restore the filling level of the storage unit which allows a compliant supply of dihydrogen to the installation to be supplied with dihydrogen.

[0035] Advantageously, if the storage pressure measured in the storage unit is higher than the setpoint pressure PCO but lower than the minimum setpoint pressure PCI, the so-called "delivery pressure regulation" mode is selected, and the regulating valve is opened while simultaneously maintaining maximum hydrogen production at the hydrogen production unit to rapidly replenish the H2 reserve. Thus, between PCO and PCI, the pressure in the delivery means is regulated while replenishing the stock (i.e., maintaining the maximum production setpoint) and ensuring regulation to consumers.

[0036] The appropriate filling level is, in fact, defined by a pressure within the storage unit that is between the set pressure PCI and the set pressure PC2, to ensure a satisfactory supply to the installation supplied with H2.

[0037] If the storage pressure measured in the storage unit is higher than the minimum storage setpoint pressure PCI and lower than the maximum storage setpoint pressure PC2, the system remains in the "delivery pressure regulation" operating mode, and the production unit is activated. of dihydrogen to produce dihydrogen so that the pressure in the storage unit corresponds as closely as possible (within the limits of flexibility of the electrolyzer) to a balance between the inflow of dihydrogen into the storage unit and the outflow of dihydrogen from the storage unit to the installation to be supplied with dihydrogen, the pressure in the storage unit being maintained between the minimum and maximum set pressures.

[0038] If the pressure measured in the storage unit exceeds the maximum storage setpoint pressure PC2, the production unit is commanded to stop or its flow rate is reduced. This results in production being slowed to its minimum capacity or the production unit being shut down.

[0039] Of course, it is possible to specify additional storage setpoint pressures, allowing, in particular, the definition of different levels to more precisely control hydrogen production and favor optimized production regimes. It is also possible to control the transitions between the different regimes continuously rather than based on thresholds.

[0040] Detailed description of the invention

[0041] The invention will be well understood and other aspects and advantages will become clear upon reading the following description, given by way of example with reference to the attached drawing plate which represents:

[0042] [Fig. 1] a dihydrogen production installation for an installation consuming said dihydrogen according to the invention.

[0043] As can be seen in [Fig. 1], the invention provides a dihydrogen production plant. This production plant in the example shown comprises a production unit including an electrochemical device such as a high-temperature solid oxide electrolyzer 1 which allows the transformation, by means of an electric current, of water - more precisely water vapor (H2O) - into dihydrogen (H2) and dioxygen (O2).

[0044] The dihydrogen thus produced is intended to supply, for example an industrial installation 5 which consumes this dihydrogen to operate. This installation to be supplied with dihydrogen can also be a dihydrogen distribution installation, for example as a fuel like a service station.

[0045] Thus, the electrolyzer 1 produces dihydrogen H2 at the cathode and the output is conveyed to a storage unit 4. The dihydrogen stored in the storage unit 4 is then conveyed to the use installation 5. Preferably, the dihydrogen at the output of the electrolyzer 1 first passes through a compression unit 2, and then optionally through a purification unit 3 before being sent to the storage unit 4.

[0046] At the outlet of the storage unit 4, the installation includes delivery means configured to fluidly connect the storage unit 4 to the industrial installation 5 using dihydrogen. These delivery means include, for example, a delivery line 6 from the outlet of the storage unit 4 to the industrial installation 5.

[0047] In order to operate the industrial installation 5 which consumes dihydrogen, the dihydrogen flow is defined to satisfy the operation of said installation and, for this purpose, a setpoint pressure PC4 in the delivery line 6 is defined so as to provide a delivery flow rate of dihydrogen corresponding to the demand of the installation to be supplied with dihydrogen.

[0048] In order to regulate the supply of dihydrogen to the industrial installation 5, a regulating valve 7 for the dihydrogen flow is provided on the delivery line 6, allowing in particular to maintain a supply between the storage unit 4 and the industrial installation 5, adapted to the dihydrogen requirements of the installation 5, i.e. a supply responding to the fluctuations of these requirements according to the operation of the installation 5.

[0049] For this purpose, the production installation includes valve control means 7 configured to regulate the flow rate of the dihydrogen flow in order to maintain this flow rate adapted to the needs of the industrial installation 5. The installation according to the invention further includes a control unit comprising valve control means 7 configured to regulate the production of dihydrogen.

[0050] The production installation therefore includes means 61 for measuring the pressure P4, referred to as the delivery pressure, in the delivery line 6 at the outlet of said storage unit 4, and downstream of the control valve 7, i.e., on the industrial installation side 5, as well as means for comparing said delivery pressure P4 with a setpoint pressure PC4. The measuring means 61 are configured to send the measurements taken to the control unit of the production installation, which includes comparison means configured to compare them to at least one setpoint pressure.

[0051] The production installation also includes means 41 for measuring the so-called storage pressure P3 in the storage unit 4, as well as means for comparing the storage pressure P3 measured in the storage unit 4 to setpoint pressures PC0, PCI and PC2 representing different filling levels of the storage unit 4. The means 41 for measuring the storage pressure P3 in the storage unit 4 are configured to send the measurements taken to the control unit, which includes the comparison means configured to compare said measurements to at least one storage setpoint pressure indicating a filling level of the storage unit.

[0052] Thus, the set pressure PCO indicates an "empty" filling level of the storage unit 4, the minimum storage set pressure PCI indicates a "low" filling level of the storage unit 4 and the maximum storage set pressure PC2 indicates a "full" filling level of the storage unit 4, the storage pressure P3 in the storage unit 4 advantageously being between PCI and PC2 to satisfy an appropriate supply to the industrial installation 5.

[0053] The control means of the regulating valve 7 are then configured to regulate the flow rate of the dihydrogen flow in the delivery line 6, as a function of the delivery pressure P4 measured downstream of said regulating valve 7 and the pressure P3 measured in the storage unit 4. These control means act on the regulating valve 7.

[0054] This regulating valve 7 is therefore controlled both according to the delivery pressure P4 and the storage pressure P3 measured within the storage unit 4, the pressure P3 having to be greater than the delivery setpoint pressure PC4. This storage pressure P3 measured in the storage unit 4 makes it possible to verify the filling level of said storage unit 4, which makes it possible to regulate both the flow rate of dihydrogen at the outlet of the storage unit 4 to the use installation 5 and the flow rate of H2 at the inlet, i.e. the production of H2.

[0055] Thus, when the storage pressure P3 is measured and compared to the setpoint pressures and is determined to be lower than PCO, which corresponds to a setpoint pressure representing an "empty" level of the storage unit 4, the demand of the consuming installation 5 can no longer be met.

[0056] The installation control unit advantageously includes selection means 71, allowing selection of either an installation operating mode called "storage pressure regulation P3", or an operating mode called "delivery pressure regulation P4".

[0057] Thus, when the pressure P3 is less than or equal to PCO, the installation switches to the so-called "P3 storage pressure regulation" mode which, when implemented, controls the regulating valve 7 to close.

[0058] The installation therefore switches to the so-called "P3 storage pressure regulation" mode, because the storage unit 4 can no longer provide a satisfactory flow of dihydrogen from the storage unit 4 to the industrial use installation 5 and a maximum production of dihydrogen is then also commanded at the electrolyzer 1 to restore a filling level of the storage unit 4 adequate for operation.

[0059] Preferably, the control means of the control valve 7 in the delivery line 6 are configured to trigger the control of delivery means emergency hydrogen delivery to the industrial installation 5 in case of closure of the control valve 7. Thus, these control means when the control valve 7 is closed can directly trigger the control of the emergency delivery means or send a message to a control unit of said emergency delivery means in order to start an "emergency" delivery of hydrogen 8, thus allowing the industrial installation 5 using hydrogen to operate while waiting for the production unit to refill the storage unit 4.

[0060] When the pressure P3 is measured to be higher than the setpoint pressure PCO but lower than the LHV pressure, the "delivery pressure regulation P4" mode is selected again, and the control valve 7 is opened while maintaining maximum hydrogen production at the electrolyzer 1 to continue rapidly replenishing the H2 reserve. The closure of the H2 flow at the outlet of the storage unit 4 is no longer commanded.

[0061] The control of the opening of the regulating valve 7 allows a flow of dihydrogen to be restored in the delivery line 6, the pressure of which tends towards the setpoint pressure PC4.

[0062] When the measured pressure P3 is between the setpoint pressure PCI and the setpoint pressure PC2, which is higher than PCI, the situation is "normal," in which the storage unit fully fulfills its role as a buffer between the production and consumption functions. The production of H2 by the electrolyzer 1 is not constrained by the storage tank's fill level. At the operator's discretion, the production flow rate can be controlled under optimal efficiency conditions, or at a flow rate close to the delivery flow rate to stabilize the pressure P3, or conversely, at a higher or lower flow rate depending on anticipated deliveries to the industrial plant 5.

[0063] The control means of the production unit are configured to control and regulate the production of dihydrogen in the electrolyzer 1, as a function of the storage pressure P3 measured in the storage unit 4 so that the pressure in the storage unit 4 is at a storage pressure P3 allowing a delivery pressure P4 in the delivery line 6, equal to the setpoint pressure PC4, with plus or minus a predefined deviation.

[0064] Thus, in an example embodiment, it is possible to define the following setpoint pressures: PCO: 250,000 Pa, PCI: 500,000 Pa, PC2: 800,000 Pa, PC4: 150,000 Pa.

[0065] These setpoint pressure values, given as an example, can be adjusted at any time, depending on the constraints related to the type of installation to be supplied, depending on the needs of the installation to be supplied and the different stations of the production installation itself.

[0066] Advantageously, the setpoint pressures are defined relative to each other in the following manner PC4 <PCO<PC1<PC2.

[0067] Thus, in summary, if the measured storage pressure P3 is less than or equal to PC0, an "empty" level is detected in the storage unit 4. In this case, the H2 flow at the outlet of the storage unit 4 is limited (control valve 7 is closed), and the system switches to "storage pressure regulation P3" mode, commanding maximum H2 production at the electrolyzer 1. When the storage pressure P3 is greater than the setpoint pressure PC0 but less than the setpoint pressure PCI, the storage unit 4 is considered to be filling, but the minimum filling level of the storage unit 4, represented by the setpoint pressure PCI, has not yet been reached. Therefore, H2 production by the electrolyzer is still commanded to be maximum, but the storage pressure P3 no longer interferes with the control valve 7 for the purpose of closing it. We then switch back to "P4 delivery pressure regulation" mode.Once the storage pressure P3 is greater than PCI and less than PC2, the filling of storage unit 4 is free to fluctuate.

[0068] If the storage pressure P3 is measured to be higher than the setpoint pressure PC2, then the production of H2 is stopped or reduced.

[0069] The table below summarizes these different modes of regulation.

[0070] [Tables 1] P3 < PC0 PC0 < P3 < PCI PCI < P3 < PC2 P3 > PC2 Empty storage Storage to be replenished Storage near equilibrium Storage almost full Control valve "Storage pressure regulation" mode "Delivery pressure regulation" mode Electrolyzer production Max Max delivery flow, or no setpoint Stop or reduce

[0071] The pressure P3 is therefore greater than PC0 in the so-called "delivery pressure regulation" mode and than the delivery setpoint pressure PC4.

[0072] Preferably, between the electrolyzer 1 and the storage unit 4 there are a compression unit 2 and a purification unit 3. The process according to the invention also provides for measuring the pressure PI of the dihydrogen flow at the outlet of the electrolyzer 1.

[0073] Means are provided for measuring the pressure PI of the dihydrogen flow upstream of said compression unit 2, as well as means for comparing the measured pressure PI to at least one setpoint pressure PCP1. Venting means 10 are provided downstream of the production unit 1 and upstream of said compression unit 2. Similarly, a recycling loop 9 is provided as a means for regulating the flow rate of the compression unit, configured to draw at least a portion of the dihydrogen flow downstream of the compression unit 2 and reinject it upstream of the compression unit 2, and control means 21 for said venting means 10 and said recycling loop 9 as a function of the measured pressure PI and the setpoint pressure PCP1.

[0074] Depending on the pressure PI measured relative to the setpoint pressure PCP1, the parameters of the compression unit 2 are adjusted accordingly (recirculation valve 9a, speed variation) and if the pressure PI measured is greater than PCP1, the vent means 10 are opened.

[0075] Means for measuring the pressure P2 of the dihydrogen flow are provided downstream of the purification unit 3 and upstream of the storage unit 4, as well as means for comparing said measured pressure P2 to at least one setpoint pressure PCP2. Venting means 12 are also provided upstream of said pressure P2 measuring means, a regulating valve 11 for the dihydrogen flow between said pressure P2 measuring means and the storage unit 4, as well as means for controlling the venting means 12 and said regulating valve 11 as a function of the measured pressure P2 and the setpoint pressure PCP2.

[0076] A pressure measurement P2 is thus provided between the purification unit 3 and the storage unit 4. This pressure measurement P2 contributes to maintaining a constant pressure in the purification unit 3 and to regulating the sending of H2 to the storage unit 4 by controlling the regulating valve 11. The pressure P2 is measured and compared to the setpoint pressure PCP2 and if it is greater than PCP2, the venting means 12 are then controlled.

[0077] Thus, the production installation and the process for controlling and regulating the production of dihydrogen make it possible to optimize production while taking into account the costs of maintaining the electrolyzer 1 in standby mode, the production costs of H2, the expected consumption, and the energy costs.

Claims

Demands

1. Hydrogen production installation comprising: - a production unit comprising an electrochemical device (1) configured to produce, from steam, dioxygen and dihydrogen, - a storage unit (4) for the dihydrogen produced, and - delivery means configured to fluidly connect the storage unit to an installation (5) to be supplied with dihydrogen, characterized in that said installation further comprises: - a regulating valve (7) for the flow rate of the dihydrogen stream in the delivery means, - a control unit for the installation comprising: • control means for the regulating valve (7) configured to regulate the flow rate of the dihydrogen stream in the delivery means, as a function of a pressure (P4) referred to as the delivery pressure, measured downstream of said regulating valve (7), and a pressure referred to as the storage pressure (P3) measured in the storage unit (4),in order to maintain the delivery pressure (P4) in said delivery means equal to a setpoint delivery pressure (PC4), and • control means of the production unit (1) configured to regulate the production of dihydrogen, as a function of the storage pressure (P3) measured in the storage unit (4), so that said storage pressure is greater than the setpoint delivery pressure (PC4), to be compatible with the regulation of the dihydrogen flow rate in the delivery means.

2. Installation according to claim 1, characterized in that it comprises means for measuring the delivery pressure (P4) in the delivery means, downstream of the control valve (7), configured to send the measurements taken to the control unit configured to compare them to at least one delivery setpoint pressure (PC4).

3. An installation according to claim 1 or 2, characterized in that it comprises means (41) for measuring the storage pressure (P3) in the storage unit (4), configured to send the measurements taken to the control unit configured for comparison at least one storage setpoint pressure (PCO, PCI, PC2) indicating a fill level of the storage unit (4) and control the dihydrogen production unit.

4. Installation according to claim 3, characterized in that, depending on the storage pressure (P3) measured in the storage unit (4), the control unit is configured to select an operating mode of the production installation (1), which is either a so-called "delivery pressure regulation" mode in which the control valve (7) is controlled to regulate the flow rate of the dihydrogen flow in the delivery means when the storage pressure (P3) is greater than the delivery setpoint pressure (PC4) and greater than a storage setpoint pressure (PCO), or a so-called "storage pressure regulation" mode in which the control valve (7) is controlled to close when the storage pressure (P3) in the storage unit (4) is less than a storage setpoint pressure (PCO).

5. Installation according to any one of claims 1 to 4, characterized in that it comprises a compression unit (2), means for measuring the pressure (PI) of the dihydrogen flow upstream of said compression unit (2), means for comparing the pressure (PI) measured to at least one setpoint pressure (PCP1), venting means (10) provided downstream of the production unit (1) and upstream of said compression unit (2), means for regulating the flow of the compression unit and means for controlling said venting means (10) as a function of the pressure (PI) measured and at least one setpoint pressure (PCP1).

6. Installation according to any one of claims 1 to 5, characterized in that it comprises a purification unit (3), means for measuring the pressure (P2) of the dihydrogen flow downstream of said purification unit (3) and upstream of the storage unit (4), means for comparing said pressure (P2) measured to at least one setpoint pressure (PCP2), a regulating valve (11) of the dihydrogen flow between said pressure measuring means (P2) and the storage unit (4), venting means (12) upstream of said regulating valve (11), and means for controlling the venting means (12) and said regulating valve (11) as a function of the measured pressure (P2) and at least one setpoint pressure (PCP2).

7. Installation according to any one of claims 1 to 6, characterized in that the electrochemical device comprises a solid oxide electrolyzer (1), preferably at high temperature.

8. Installation according to any one of claims 1 to 7, characterized in that the control unit is configured to trigger the control of emergency hydrogen delivery means (8) to the installation to be supplied with hydrogen in the event of closure of the regulating valve (7) of the flow rate of hydrogen in the delivery means.

9. A method for controlling a dihydrogen production installation to supply an installation using said dihydrogen according to any one of claims 1 to 8, the method comprising: - controlling the regulating valve (7) to regulate the flow rate of the dihydrogen in the delivery means, as a function of a delivery pressure (P4) measured in said delivery means and a storage pressure (P3) measured in the storage unit (4), in order to maintain the delivery pressure (P4) in said delivery means at a setpoint pressure (PC4), and - controlling the production unit to regulate the production of dihydrogen, as a function of the storage pressure (P3) measured in the storage unit (4) so ​​that the storage pressure (P3) of the storage unit is greater than the delivery setpoint pressure (PC4),to be compatible with the control of the regulating valve (7) for regulating the flow rate of the dihydrogen in the delivery means.

10. A method according to claim 9, characterized in that the storage pressure P3 is measured and compared to at least one storage setpoint pressure indicating a filling level of the storage unit.

11. A method according to claim 10, characterized in that at least one storage setpoint pressure PCO is defined indicating an "empty" fill level of the storage unit.

12. A method according to claim 11, characterized in that storage setpoint pressures are further defined, indicating respectively a filling level of the storage unit (4) to which the storage pressure (P3) is compared such that: - PCI corresponding to a minimum storage setpoint pressure indicating a "low" fill level, - PC2 corresponding to a maximum storage setpoint pressure indicating a "full" fill level.

13. A method according to claims 11 or 12, characterized in that, depending on the value of the storage pressure (P3) measured in the storage unit (4), an operating mode of the installation is selected, which is either a so-called "delivery pressure regulation" mode in which the control valve (7) is controlled to regulate the flow rate of the dihydrogen flow in the delivery means when the storage pressure (P3) is greater than the delivery setpoint pressure (PC4) and the storage setpoint pressure (PCO) indicating an "empty" filling level of the storage unit (4), or a so-called "storage pressure regulation" mode in which the control valve (7) is controlled to close when the storage pressure (P3) is at a pressure lower than the storage setpoint pressure (PCO) indicating an "empty" filling level of the storage unit (4),incompatible with the control of the regulating valve (7) for regulating the flow rate of dihydrogen in the delivery means.

14. A method according to claim 11 or 12, characterized in that, if the pressure measured in the storage unit is equal to or less than the storage setpoint pressure (PCO) indicating an "empty" filling level of the storage unit, the so-called "storage pressure regulation" mode is selected, the control valve (7) in the delivery means is ordered to close, the storage pressure (P3) of the storage unit being incompatible with the control valve (7) to regulate the flow rate of the dihydrogen in the delivery means, and the dihydrogen production unit is ordered to produce maximum dihydrogen until the storage pressure (P3) measured in the storage unit (4) is at least equal to the storage setpoint pressure (PCO) indicating an "empty" filling level of the storage unit (4).

15. A method according to claim 14, characterized in that it further comprises controlling a backup hydrogen delivery unit to the installation (5) to be supplied with hydrogen, during the control for closing the regulating valve (7) of the dihydrogen flow.

16. A method according to claims 12 and 13, characterized in that, if the storage pressure (P3) measured in the storage unit (4) is greater than the storage setpoint pressure (PCO) indicating an "empty" filling level of the storage unit (4) but less than the storage setpoint pressure (PCI), the so-called "delivery pressure regulation (P4)" mode is selected and the opening of the control valve (7) is commanded while always commanding the maximum production of dihydrogen at the level of the dihydrogen production unit to quickly replenish the dihydrogen reserve.

17. A method according to claim 12, characterized in that, if the storage pressure (P3) measured in the storage unit (4) exceeds the storage setpoint pressure (PC2), the production unit (1) is ordered to stop or its flow rate to be reduced.

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