Electrochemical installation equipped with a dilution device

Abstract

Installation (1) comprising a thermal enclosure (2) housing an electrochemical device (3) of the high-temperature electrolyzer or high-temperature fuel cell type. The installation (1) comprises a dilution device (4) configured to introduce into the enclosure (2) a purge fluid such as ambient air, so as to reduce the risk of explosion associated with hydrogen and oxygen leaks. Corresponding method.

Description

Electrochemical installation equipped with a dilution device

[0001] The invention relates to the field of electrochemical installations.

[0002] The invention is of particular interest, but not limiting, for installations comprising at least one solid oxide device forming a high-temperature electrolyzer or a high-temperature fuel cell. State of the art

[0003] High-temperature electrolyzers and high-temperature fuel cells known in the prior art are susceptible to generating gas leaks, particularly of dihydrogen and dioxygen, leading to a risk of explosion.

[0004] There is a need to reduce this risk.

[0005] To this end, the invention relates to an installation comprising an enclosure and an electrochemical device disposed in the enclosure so as to form a fluidic space which is delimited by the enclosure and which extends outside the electrochemical device, the electrochemical device being configured to form or to receive one or more first fluids, preferably including a fluid which includes dihydrogen and a fluid which includes dioxygen, the installation comprising a dilution device configured to introduce into said fluidic space a second fluid in order to reduce in the fluidic space the concentration of first fluids which have leaked from the electrochemical device.

[0006] The invention thus makes it possible to reduce the concentration of first fluids within the enclosure by dilution with the second fluid.

[0007] The invention thus makes it possible to reduce the risk of explosion while maintaining the overall efficiency of the installation.

[0008] In one embodiment, the dilution device includes one or more circulation components such as fans.

[0009] According to a first variant, one or more of said circulation organs are configured to push the second fluid towards the fluidic space so as to increase the pressure within the fluidic space.

[0010] According to a second variant, one or more of said circulation organs are configured to introduce the second fluid into the fluidic space under the action of an extraction of one or more fluids present in the fluidic space.

[0011] Such extraction reduces the risk of dihydrogen leaking outside the enclosure and, therefore, reduces the risk of creating an explosive atmosphere around and within the enclosure.

[0012] In one embodiment, the dilution device includes an analysis element configured to determine the composition of one or more of said fluids present in the fluidic space.

[0013] In one embodiment, the dilution device includes a control element configured to control one or more of said circulation elements according to the composition of one or more of said fluids present in the fluidic space, this composition being able to be determined by the aforementioned analysis element.

[0014] In one embodiment, the dilution device is configured to introduce the second fluid into the fluidic space by natural convection.

[0015] In this embodiment, the dilution device may lack one or more of the aforementioned circulation elements. At least, when the dilution device includes one or more circulation elements, these may not be used to move the second fluid when it is introduced into the fluidic space by natural convection.

[0016] As is known, natural convection can be promoted by introducing the second fluid at a vertically lower part of the enclosure.

[0017] Natural convection helps to reduce the energy consumption of the installation.

[0018] In one embodiment, the dilution device is configured to form an output flow from one or more fluids present in the fluidic space.

[0019] In one embodiment, the dilution device includes a heat exchanger configured to transfer heat from the outlet stream to an inlet stream formed by the second fluid.

[0020] Such an exchanger improves the thermal efficiency of the installation.

[0021] Alternatively, the dilution device can be configured to introduce into the fluidic space the second fluid not heated by the outlet flow.

[0022] In the latter case, the dilution device may be without a heat exchanger.

[0023] The absence of heat transfer from the outlet flow to the inlet flow typically reduces fluid pressure drops as well as the cost of the installation.

[0024] In one embodiment, the dilution device is configured so that the second fluid comprises ambient air and / or a gas such as compressed air stored in one or more first tanks and / or an inert gas such as nitrogen stored in one or more second tanks.

[0025] In one embodiment, the electrochemical device is a solid oxide device.

[0026] In one embodiment, the electrochemical device forms a high-temperature electrolyzer or a high-temperature fuel cell.

[0027] According to another aspect, the invention relates to a method for implementing an installation as described above.

[0028] The method of the invention preferably includes a control of the installation so as to introduce into said fluidic space a second fluid in order to reduce in the fluidic space the concentration of first fluids which have leaked from the electrochemical device.

[0029] Depending on the features implemented in the installation, the process may include, but is not limited to: circulating the inlet and / or outlet flow using the aforementioned circulation devices, and / or determining the composition of one or more fluids present in the fluid space using the aforementioned analysis device, and / or, where the installation includes one or more of said circulation devices, controlling one or more of these circulation devices, preferably based on the composition of one or more fluids present in the fluid space and / or an outlet flow formed by such fluids, this composition being able to be determined using the aforementioned analysis device, and / or transferring heat from the outlet flow to the inlet flow using the aforementioned heat exchanger, and / or selectively forming the inlet flow from one or more fluid sources.for example, from ambient air and / or a gas such as compressed air stored in one or more primary tanks and / or an inert gas such as nitrogen stored in one or more secondary tanks.

[0030] Other advantages and features of the invention will become apparent from the detailed, non-limiting description that follows. Brief description of the figures

[0031] The detailed description that follows refers to the attached drawings in which: a is a schematic view of an installation according to the invention, comprising a chamber, an electrochemical device placed in the chamber, and a dilution device, a showing the electrochemical device in dihydrogen production mode; a is a schematic view of the installation, showing the electrochemical device in energy generation mode; a is a schematic view of an installation as illustrated in Figures 1 and 2, showing a circulation element arranged upstream of the chamber; a is a schematic view of an installation as illustrated in Figures 1 and 2, showing a circulation element arranged downstream of the chamber;This is a schematic view of an installation as illustrated in Figures 1 and 2, showing a circulation element arranged upstream of the enclosure, a fluidic analysis element and a control element for the circulation element based on a fluidic composition determined by the analysis element; this is a schematic view of an installation as illustrated in Figures 1 and 2, showing a circulation element arranged downstream of the enclosure, a fluidic analysis element and a control element for the circulation element based on a fluidic composition determined by the analysis element; this is a schematic view of an installation as illustrated in Figures 1 and 2, showing a heat exchanger configured to transfer heat from a flow exiting the enclosure to a flow entering the enclosure;This is a schematic view of an installation as illustrated in Figures 1 and 2, showing a heat exchanger similar to that of the [unspecified], as well as a fan, an analysis unit and a control unit similar to those of the [unspecified]; this is a schematic view of an installation as illustrated in Figures 1 and 2, showing a heat exchanger similar to that of the [unspecified], as well as a fan, an analysis unit and a control unit similar to those of the [unspecified]; this is a schematic view of an installation as illustrated in Figures 1 and 2, showing a fluidic network comprising three paths suitable for introducing into the enclosure one or more fluids from different sources, in particular one source constituted by the environment of the installation and two sources formed by tanks. Detailed description of implementation methods

[0032] With reference to figures 1 and 2, the invention relates to an installation 1 comprising an enclosure 2, an electrochemical device 3 and a device 4 called a dilution device.

[0033] In this example, the electrochemical device 3 is a reversible solid oxide device.

[0034] In this embodiment, device 3 is used to form a high-temperature electrolyzer, also known by the Anglo-Saxon name "Solid Oxide Electrolysis Cell" (SOEC). Such an electrolyzer 3, as is known per se, allows the formation of a fluid 6 comprising dihydrogen and a fluid 7 comprising dioxygen by gas-phase electrolysis, from a stream 8 of water vapor having a temperature that can typically be between 500°C and 850°C and optionally from a stream 8A of air.

[0035] In this embodiment, device 3 is used to form a high-temperature fuel cell, also known as a Solid Oxide Fuel Cell (SOFC). As is known, such a fuel cell 3 generates a flow of electrons 9 from a fluid 6 containing dihydrogen and a fluid 7 containing dioxygen, these fluids acting as a reducing fuel and an oxidizing agent, respectively. The operating temperature of the fuel cell 3 is typically between 700°C and 1000°C.

[0036] In this description, the fluids 6 and 7 formed by, or introduced into, the electrochemical device 3 are referred to as "first fluids".

[0037] The enclosure 2, commonly referred to by its Anglo-Saxon name "hotbox," helps to maintain the electrochemical device 3 at its operating temperature. Enclosure 2 thus forms a thermal enclosure, or oven, reducing heat loss from the inside to the outside of enclosure 2.

[0038] More specifically, the electrochemical device 3 is for this purpose arranged in the enclosure 2, so as to form a space 11 between the electrochemical device 3 and the enclosure 2.

[0039] Space 11, here called "fluidic space", thus extends outside the electrochemical device 3, in particular around it, and is delimited by enclosure 2.

[0040] In other words, enclosure 2 comprises an internal volume, part of which is occupied by the electrochemical device 3 and another part forms the fluidic space 11.

[0041] The invention relates more specifically to the dilution device 4, which is intended to introduce a fluid into the fluidic space 11. In this document, this fluid is also referred to as the "second fluid" or "sweep fluid".

[0042] The second fluid can typically include a gaseous fluid such as ambient air taken from the environment of installation 1 and / or one or more gaseous fluids taken from one or more storage tanks.

[0043] In general, the dilution device 4 is configured to introduce into space 11 an inlet flow which is formed by said second fluid.

[0044] The introduction of the inlet flow into space 11 can be achieved by any means of channeling 12, such as one or more conduits and / or one or more distributors and / or one or more openings in enclosure 2.

[0045] Installation 1 can also be configured to allow the fluid(s) present in space 11 to exit enclosure 2 in the form of at least one so-called outlet flow, by any means of piping 13, such as one or more conduits and / or one or more collectors and / or one or more openings in enclosure 2.

[0046] The invention makes it possible in particular to reduce, within the fluidic space 11, the concentration of first fluids that have leaked from the electrochemical device 3 and, consequently, to reduce the risks of explosion.

[0047] The dilution device 4 may include various components or parts, including but not limited to those described below, as well as combinations thereof.

[0048] The preceding description applies by analogy to each of the examples described below. Furthermore, the description of any structural or functional characteristic, particularly when made with reference to a given figure, applies by analogy to other figures and embodiments when the embodiment in question incorporates such a characteristic, it being specified that each of the figures schematically represents one or more components or parts in a non-limiting manner.

[0049] The dilution device 4 may include one or more circulation components, such as fans, for example according to the embodiments in Figures 3 and 4.

[0050] In the example shown, the dilution device 4 includes a fan 21 positioned upstream of the enclosure 2 relative to the direction of flow of the inlet. The fan 21 is thus configured to push the second fluid towards the fluidic space 11, thereby tending to increase the pressure within the fluidic space 11.

[0051] In the example shown, the dilution device 4 includes a fan 21 positioned downstream of the enclosure 2 relative to the direction of flow of the outlet. The fan 21 is thus configured to introduce the second fluid into the fluidic space 11 by extracting the fluid(s) present in this space 11.

[0052] In other embodiments, for example that described later below with reference to the dilution device 4 is configured to introduce the second fluid into the fluidic space 11 by natural convection, in other words without recourse to circulation devices such as those described above.

[0053] The dilution device 4 may include an analysis element to determine the composition of the fluid(s) present in the fluidic space 11.

[0054] Without limitation, the dilution device 4 may include a control element configured to control the installation 1, and in particular one or more elements of the dilution device 4, depending on the fluidic composition previously determined by the analysis element and / or depending on other criteria or parameters predetermined or determined by another element (not shown).

[0055] Lamontre gives an example in which the dilution device 4 includes on the one hand an analysis unit 22 configured to determine the composition of a part of the output flow and, on the other hand, a control unit 23 configured to control a circulation unit 21 arranged according to the principle of the, i.e. upstream of the enclosure 2.

[0056] Lamontre gives another example in which the dilution device 4 includes an analysis unit 22 configured to determine the composition of a part of the output flow and a control unit 23 configured to control a circulation unit 21 arranged according to the principle of the, i.e. downstream of the enclosure 2.

[0057] In each of the examples in Figures 5 and 6 and, more generally, in embodiments in which the dilution device 4 includes an analysis element and a control element as described above, the control element 23 can be configured to control one or more elements of the installation 1 according to the fluidic composition determined by the analysis element 22 and / or according to other criteria or parameters.

[0058] In particular, the control unit 23 can be configured to modify one or more parameters of a circulation unit 21, for example a flow rate, proportionally to a concentration of dihydrogen and dioxygen in the part of the outlet flow analyzed by the unit 22.

[0059] Alternatively, one or more circulation devices 21 of the installation 1 can be controlled without parameter adjustment, i.e. independently of the composition of the output flow.

[0060] The dilution device 4 may include a heat exchanger 24, for example as illustrated in the.

[0061] In the example shown, the exchanger 24 is configured to transfer heat from the outlet flow to the inlet flow.

[0062] Of course, the dilution device 4 can be configured without such a heat exchanger. More specifically, the dilution device 4 can be configured to introduce into the fluidic space 11 the second fluid not heated by the outlet flow, as illustrated for example in Figures 5, 6 and 10.

[0063] The different embodiments described above can also be combined, for example in the manner described below with reference to figures 8 to 10. The preceding description applies of course by analogy to the examples that follow, and vice versa.

[0064] In the example of the, the dilution device 4 includes a fan 21, an analysis unit 22, a control unit 23 and a heat exchanger 24, arranged so as to combine the embodiments of figures 5 and 7.

[0065] In the example of the, the dilution device 4 includes a fan 21, an analysis unit 22, a control unit 23 and a heat exchanger 24 arranged to combine the embodiments of figures 6 and 7.

[0066] In the example shown, the dilution device 4 comprises a fluidic network with three ports 31, 32, and 33, each equipped with a valve 36, 37, and 38, respectively. Port 31 is fluidically connected to a space external to the installation 1, in order to introduce ambient air into the network. Ports 32 and 33 are fluidically connected to reservoirs 41 and 42, respectively, in order to introduce the respective fluids stored in them into the network.

[0067] By way of non-limiting example, tank 41 stores compressed air and tank 42 stores an inert gas such as nitrogen.

[0068] The dilution device 4 of the installation 1 includes an unshown control element for valves 36, 37 and 38, allowing the selective introduction of one or more of the aforementioned fluids, in this case ambient air and / or compressed air stored in tank 41 and / or nitrogen stored in tank 42.

[0069] As an example, a control procedure such as the one described below can be implemented: in nominal operation, opening valve 36 and closing valves 37 and 38 to introduce ambient air into fluid space 11 via passage 31 by natural convection; when the temperature in enclosure 2 is below a predetermined threshold, for example 150°C, and / or when conditions do not allow the introduction of ambient air into fluid space 11 via passage 31 by natural convection, opening valve 37 and closing valves 36 and 38 to introduce compressed air from reservoir 41 into fluid space 11; when a risk of explosion is identified, for example by analyzing the composition of the outlet flow, opening valve 38 and closing valves 36 and 37 to introduce compressed air into fluid space 11. nitrogen from tank 42.

[0070] The aforementioned valves can also be configured and controlled to form said second fluid from several fluids from several respective sources, for example by mixing ambient air and nitrogen, or compressed air and nitrogen.

[0071] More generally, the dilution device 4 can be configured to form the second fluid, selectively according to one or more parameters and / or an operating phase of the installation 1, or alternatively permanently, by mixing fluids from multiple sources which may be different in number and type compared with the sources described above with reference to the.

[0072] It is understood that the enclosure of the installation of the invention can receive several electrochemical devices and more generally that the installation of the invention can comprise one or more enclosures each receiving one or more electrochemical devices and / or each forming one or more fluidic spaces supplied with a second fluid by one or more dilution devices according to any of the embodiments described above.

[0073] In particular, the installation of the invention may include a dilution device common to several enclosures and / or several dilution devices each dedicated to a respective enclosure of the installation.

[0074] Furthermore, the fact that a device or component is not shown in a given figure does not mean that the installation shown in that figure lacks that device or component. Thus, for example, Figures 1, 2, 3, and 10 do not specifically depict means for the fluid(s) present in space 11 to exit enclosure 2, despite the fact that installation 1 shown in these figures may include such means. As another, non-limiting example, installation 1 may be equipped with a device for analyzing the composition of the outlet flow.

Claims

Installation (1) comprising an enclosure (2) and an electrochemical device (3) disposed in the enclosure (2) so as to form a fluidic space (11) which is delimited by the enclosure (2) and which extends outside the electrochemical device (3), the electrochemical device (3) being configured to form or to receive one or more first fluids, preferably including a fluid which includes dihydrogen and a fluid which includes dioxygen, the installation (1) comprising a dilution device (4) configured to introduce into said fluidic space (11) a second fluid in order to reduce in the fluidic space (11) the concentration of first fluids which have leaked from the electrochemical device (3). Installation (1) according to claim 1, wherein the dilution device (4) comprises one or more circulation elements (21) such as fans, one or more of said circulation elements (21) being able to be configured to: push the second fluid towards the fluidic space (11) so as to increase the pressure within the fluidic space (11), or introduce the second fluid into the fluidic space (11) under the action of an extraction of one or more fluids present in the fluidic space (11). Installation (1) according to claim 2, wherein the dilution device (4) comprises an analysis element (22) configured to determine a composition of one or more of said fluids present in the fluidic space (11) and a control element (23) configured to control one or more of said circulation elements (21) according to the composition thus determined. Installation (1) according to claim 1, wherein the dilution device (4) is configured to introduce the second fluid into the fluidic space (11) by natural convection. Installation (1) according to any one of claims 1 to 4, wherein the dilution device (4) is configured to form an outlet flow from one or more fluids present in the fluidic space (11). Installation (1) according to claim 5, wherein the dilution device (4) includes a heat exchanger (24) configured to transfer heat from the outlet stream to an inlet stream formed by the second fluid. Installation (1) according to claim 5, wherein the dilution device (4) is configured to introduce into the fluidic space (11) the second fluid not heated by the outlet flow. Installation (1) according to any one of claims 1 to 7, wherein the dilution device (4) is configured so that the second fluid comprises ambient air and / or a gas such as compressed air stored in one or more first tanks (41) and / or an inert gas such as nitrogen stored in one or more second tanks (42). Installation (1) according to any one of claims 1 to 8, wherein the electrochemical device (3) is a solid oxide device, preferably forming a high-temperature electrolyzer or a high-temperature fuel cell. Method of implementing an installation (1) according to any one of claims 1 to 9, comprising a control of the installation (1) so as to introduce into said fluidic space (11) a second fluid in order to reduce in the fluidic space (11) the concentration of first fluids which have leaked from the electrochemical device (3).

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