INSTALLATION AND METHOD FOR SUPPLYING A FUEL CELL WITH HYDROGEN

Abstract

An installation for supplying a fuel cell with hydrogen comprising a fuel cell, a liquefied hydrogen storage facility and a supply circuit that includes at least one upstream end connected to the storage facility and one downstream end connected to a fuel inlet of the fuel cell, the supply circuit including at least one system for heating hydrogen by heat exchange with a heat source and a set of control valves, the liquefied hydrogen storage facility being configured to keep the liquefied hydrogen in equilibrium with a gaseous phase at a determined nominal storage pressure of between 1.5 and 4.5 bar, the supply circuit including a buffer tank for pressurized gaseous hydrogen which is configured to store the hydrogen withdrawn from the storage facility and heated by the heating system, the set of valves being configured to accumulate pressurized gas in the buffer tank at a determined storage pressure of between 4 and 100 bar, for example between 6 and 8 bar.

Claims

1. An installation for supplying a fuel cell with hydrogen, the installation comprising a fuel cell, a liquefied hydrogen storage facility and a supply circuit comprising at least one upstream end connected to the storage facility and one downstream end connected to a fuel inlet of the fuel cell, the supply circuit comprising at least one system for heating hydrogen by heat exchange with a heat source and a set of control valves, the liquefied hydrogen storage facility being configured to keep the liquefied hydrogen in equilibrium with a gaseous phase at a determined nominal storage pressure of between 1.5 and 4.5 bar, wherein the supply circuit further comprises a liquid withdrawal pipe and a buffer tank for pressurized gaseous hydrogen that is configured to store the hydrogen withdrawn from the storage facility and heated by the heating system, the set of valves being configured to accumulate pressurized gas in the buffer tank at a determined storage pressure of between 4 and 100 bar, the liquid withdrawal pipe connecting a lower portion of the storage facility to the fuel inlet of the fuel cell, the liquid withdrawal pipe comprising, arranged in series, a first heating heat exchanger and a first pressure- and/or flow rate-regulating valve, said first pressure- and/or flow rate-regulating valve being configured to feed the fuel inlet of the fuel cell at a determined operating pressure of between 1 and 3 bar.

2. The installation of claim 1, wherein the circuit further comprises a gas withdrawal pipe connecting an upper portion of the storage facility to an inlet of the buffer tank.

3. The installation of claim 2, wherein the gas withdrawal pipe comprises, arranged in series, a heat exchanger for heating gaseous hydrogen and a second pressure- and/or flow rate-regulating valve, said second pressure- and/or flow rate-regulating valve being configured to transfer gas at the storage pressure into the buffer tank.

4. The installation of claim 3, wherein the second pressure- and/or flow rate-regulating valve is configured to automatically transfer gas from the storage facility to the buffer tank only when the pressure in the storage facility exceeds a determined pressure threshold.

5. The installation of claim 1, wherein the circuit further comprises a gas filling pipe having an upstream end connected to an outlet of the first heating heat exchanger and a downstream end connected to an inlet of the buffer tank, the gas filling pipe comprising a third pressure- and/or flow rate-regulating valve, said third pressure and/or flow rate regulator being configured to transfer gas at the storage pressure into the buffer tank.

6. The installation of claim 1, wherein the circuit further comprises a liquid removal pipe having an upstream end connected to the lower portion of the storage facility and a downstream end connected to an inlet of the buffer tank.

7. The installation of claim 2, wherein the circuit further comprises a set of isolation valves arranged at the inlet and the outlet of the buffer storage facility, the hydrogen heating system comprising an exchange of heat between the fluid contained in the buffer storage facility and a heat source such as the atmosphere for vaporizing and increasing the pressure of the fluid in the buffer tank when the isolation valves are closed, the circuit furthermore comprising an element for limiting the pressure in said buffer storage facility such as a discharge valve which opens above a determined pressure threshold.

8. The installation of claim 7, wherein the heat source is the atmosphere.

9. The installation of claim 1, wherein the supply circuit further comprises a backup feed pipe connecting an outlet of the buffer tank to the fuel inlet of the fuel cell, the backup feed pipe comprising at least one fourth pressure- and/or flow rate-regulating valve configured to provide gas at a determined pressure to the cell.

10. The installation of claim 7, wherein the supply circuit further comprises a backup feed pipe connecting an outlet of the buffer tank to the fuel inlet of the fuel cell, the backup feed pipe comprising at least one fourth pressure- and/or flow rate-regulating valve configured to provide gas at a determined pressure to the cell and, arranged in series, a valve shutter, a heating heat exchanger, and a pressure-sensitive safety valve for discharging the gas to the outside of the circuit in the event of pressure above a safety threshold.

11. The installation of claim 9, wherein the backup feed pipe is connected to the fuel inlet of the fuel cell via a connection to a portion of the liquid withdrawal pipe.

12. The installation of claim 1, wherein the set of valves is configured to accumulate pressurized gas in the buffer tank at a determined storage pressure of between 6 and 8 bar

13. A method for supplying a fuel cell with hydrogen using the installation of claim 1, wherein the fuel cell is fed with hydrogen by the storage facility, the method comprising a step of transferring hydrogen from the storage facility to the buffer tank.

14. The method of claim 13, wherein the step of transferring hydrogen from the storage facility to the buffer tank is performed during an interruption to the feeding of the cell with hydrogen by the storage facility, in particular during a shutdown of the fuel cell.

15. The method of claim 13, wherein the step of transferring hydrogen from the storage facility to the buffer tank is performed during a shutdown of the fuel cell.

16. The method of claim 13, further comprising, during the operation of the fuel cell, a step of detecting a fault in the feeding of the fuel cell with hydrogen by the storage facility and, in response, a step of backup feeding in which the fuel cell is fed with hydrogen by the buffer tank.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0031] Other distinctive features and advantages will become apparent on reading the description below, which is made with reference to the figures, in which:

[0032] FIG. 1 represents a diagrammatic and partial view illustrating the structure and the operation of a first implementational example of an installation according to the invention,

[0033] FIG. 2 represents a diagrammatic and partial view illustrating an example of variations in a possible pressure within the cryogenic storage facility of the installation,

[0034] FIG. 3 represents a diagrammatic and partial view illustrating the structure and the operation of a second implementational example of an installation according to the invention,

[0035] FIG. 4 represents a diagrammatic and partial view illustrating the structure and the operation of a third implementational example of an installation according to the invention,

[0036] FIG. 5 represents a diagrammatic and partial view illustrating the structure and the operation of a fourth implementational example of an installation according to the invention,

[0037] FIG. 6 represents a diagrammatic and partial view illustrating the structure and the operation of a fifth implementational example of an installation according to the invention,

[0038] FIG. 7 represents a diagrammatic and partial view illustrating the structure and the operation of a sixth implementational example of an installation according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0039] The installation 1 for supplying a fuel cell with hydrogen comprises a fuel cell 2, a liquefied hydrogen storage facility 3 and a supply circuit 4, 14 comprising at least one upstream end connected to the storage facility 3 and one downstream end connected to a fuel inlet of the fuel cell 2.

[0040] The supply circuit 4, 14 comprises at least one system 5, 15 for heating hydrogen by heat exchange with a heat source and a set of control valves 6, 16, 26.

[0041] The liquefied hydrogen storage facility 3 is configured to keep the liquefied hydrogen in equilibrium with a gaseous phase at a relatively low determined nominal storage pressure of for example between 1.5 and 4.5 bar.

[0042] The supply circuit 4, 14 includes a buffer tank 7 for pressurized gaseous hydrogen which is configured to store the hydrogen withdrawn from the storage facility 3 and heated by the heating system 5, 15. The set of valves is configured to accumulate pressurized gas in the buffer tank 7 at a relatively high determined storage pressure of between 4 and 100 bar, for example between 6 and 8 bar.

[0043] The supply circuit comprises a liquid withdrawal pipe 4 connecting the lower portion of the storage facility 3 to the fuel inlet of the fuel cell 2.

[0044] The liquid withdrawal pipe 4 comprises, arranged in series: a first heating heat exchanger 5 (or evaporator) and a first pressure- and/or flow rate-regulating valve 6. This first pressure- and/or flow rate-regulating valve 6 is configured to feed the fuel inlet of the fuel cell 2 at a determined operating pressure of for example between 1 and 3 bar abs. This feeding with hydrogen from the liquid storage facility 3 constitutes what is called normal operation, when the fuel cell 2 is in an operating state.

[0045] In the embodiment of FIG. 1, the circuit comprises a gas withdrawal pipe 8 connecting the upper portion of the storage facility 3 to an inlet of the buffer tank 7. The gas withdrawal pipe 8 comprises, arranged in series: a second heat exchanger 15 for heating gaseous hydrogen and a second pressure- and/or flow rate-regulating valve 26. The second heat exchanger 15 is for example an atmospheric heater which brings the removed gaseous hydrogen to a temperature of 22 K to 100 K.

[0046] The second pressure- and/or flow rate-regulating valve 26 is for its part configured to transfer gas at the storage pressure, for example between 5 and 8 bar, into the buffer tank 7.

[0047] The second pressure- and/or flow rate-regulating valve 26 (and/or an appropriate valve shutter system (not shown), for example at least one non-return valve) may be configured to automatically transfer pressurized gas from the storage facility 3 to the buffer tank 7, preferably only when the pressure in the storage facility 3 exceeds a determined pressure threshold.

[0048] This is because, in particular in the phases in which the fuel cell 2 is not fed by the storage facility 3 for relatively long periods, the storage facility 3 has a tendency to self-pressurize. Its internal pressure can in particular reach thresholds of greater than 5 bar. This pressure decreases as soon as hydrogen is withdrawn in the gas headspace.

[0049] FIG. 2 illustrates an example of variations in pressure P (in bar) in the storage facility 3 as a function of time t. As illustrated, the pressure can describe rising gradients in the case of self-pressurization, for example, and falling gradients (in the case of withdrawal, for example). The second regulation valve 26 can for example be configured (regulated, dimensioned, calibrated or controlled) so as to open when the upstream pressure is greater than an opening threshold (for example 6 bar) and to close again when the upstream pressure is less than this opening threshold (or another pressure threshold).

[0050] This makes it possible to transfer, preferably automatically, gas from the storage facility 3 to the buffer tank 7, preferably only when the pressure in the storage facility 3 exceeds a determined pressure threshold. In the embodiment of FIG. 3, the circuit comprises a gas filling pipe 9 having an upstream end connected to an outlet of the first heating heat exchanger 5 and a downstream end connected to an inlet of the buffer tank 7. This gas filling pipe 9 comprises a second pressure- and/or flow rate-regulating valve 26, said second pressure- and/or flow rate-regulating valve 26 being configured to transfer gas at the storage pressure into the buffer tank 7 after said gas has passed through the first heating heat exchanger 5.

[0051] In other words, the filling of the buffer tank 7 can be controlled by an expansion device 26 on a diversion line of the liquid withdrawal pipe 4, downstream of the first heating heat exchanger 5.

[0052] This expansion device 26 (or an equivalent valve or valve shutter, cf. below) can be activated in particular when the feeding of hydrogen to the fuel cell 2 is shut off. In this case, the feeding of the fuel cell 2 with gaseous hydrogen can be performed by the buffer tank 7 via a downstream third pressure- and/or flow rate-regulating valve 16 (the outlet of which can be connected to the downstream portion of the liquid withdrawal pipe 4 which is connected to the fuel inlet of the fuel cell 2).

[0053] The embodiment of FIG. 4 differs from that of FIG. 3 in that the expansion device 26 is replaced by a simple valve or valve shutter. It should be noted that, just as in the embodiment of FIG. 3, the inlet of the buffer tank 7 could be connected to the upper portion of the storage facility 3 in order to recover the vaporization gas (instead of the gas obtained from the vaporization of the liquid in the heat exchanger 5).

[0054] The embodiment of FIG. 5 differs from that of FIG. 3 in that the inlet and the outlet of the buffer tank 7 have been combined. The filling of the buffer tank 7 or the withdrawal of gas from the buffer tank 7 are controlled by a second regulation valve or valve shutter connected to the liquid withdrawal pipe 4, for example downstream of the first heating heat exchanger 5 and upstream of the first pressure- and/or flow rate-regulating valve 6.

[0055] The filling of the buffer tank 7 may in particular be controlled by the second valve 26 which can be automatically opened as soon as the pressure in the storage facility 3 is greater than a high threshold. This second valve 26 may also be automatically opened when the normal feeding of the fuel cell 2 with hydrogen is shut off (for example due to a lack of liquid in the storage facility).

[0056] In the embodiment of FIG. 6, the circuit comprises a liquid removal pipe 10 having an upstream end connected to the lower portion of the storage facility 3 and a downstream end connected to an inlet of the buffer tank 7. As illustrated, this liquid removal pipe 10 can be a diversion of the upstream portion of the liquid withdrawal pipe 4.

[0057] In this embodiment, the circuit comprises a set of isolation valves 11, 12 arranged at the inlet and at the outlet of the buffer storage facility 7. A possible heating of the hydrogen comprises an exchange of heat between the fluid contained in the buffer storage facility 7 and a heat source such as the atmosphere for vaporizing and increasing the pressure of the fluid in the buffer tank 7 when the isolation valves 11, 12 are closed and trap the fluid in the buffer tank 7. Moreover, the circuit preferably additionally comprises an element 13 for limiting the pressure in said buffer storage facility 7 such as a discharge valve connected to the tank 7 and opening above a determined pressure threshold.

[0058] In this configuration, the buffer tank 7 can thus be filled with cryogenic liquid upstream of the first heating heat exchanger 5 via the opening of the upstream isolation valve 11 (and possibly the downstream isolation valve 12). When the buffer tank 7 is filled and preferably cold (temperature for example of between 25 and 150 K), the isolation valves 11, 12 can be closed. The trapped liquid will evaporate due to the heat inputs (possibly also via active heating); the pressure increases in the buffer tank 7. Any possible overpressure can be discharged via the discharge valve 13 (which can remain closed during filling of the buffer tank 17 at constant pressure). The pressure in the buffer tank 7 is for example brought to a value between 6 and 100 bar and thus constitutes a reserve of pressurized hydrogen for feeding the fuel cell 2 in the event of failure of the normal feed (for example via the opening of the downstream isolation valve 12).

[0059] The embodiment of FIG. 7 differs from that of FIG. 6 in that the inlet of the buffer tank 7 is connected to the upper portion of the storage facility 3 via a gas withdrawal pipe 8.

[0060] The filling of the buffer tank 7 can thus be performed upstream of the first heating heat exchanger 5 by opening the upstream isolation valve 11 and possibly the second isolation valve 12. The buffer tank 7 is filled with cold gas from the storage facility 3. The rest of the process can be identical to that described above in relation with FIG. 6.

[0061] Thus, in the normal configuration the storage facility 3 can be maintained at a relatively low pressure (less than 5 bar for example) and feeds the fuel cell 2 at a pressure of between 1 and 5 bar via evaporation and regulation of pressure. A possible and temporary overpressure in the storage facility 3 can be used to fill the buffer tank 7 at a higher pressure (5 bar or more for example). This pressurized gas reserve 7 is usable for feeding the fuel cell 2 with hydrogen if the normal feed is unavailable. In the configurations of FIG. 6 and FIG. 7, the pressure in the buffer tank 7 can be brought up to more than 200 bar by simple heating of the cold gas/liquid trapped in the tank 7 while the valves 11 and 12 are closed. This makes it possible to continue to feed the fuel cell 2 for example for the time it takes for the pressurization system of the storage facility 3 to re-establish the nominal operating pressure of the hydrogen.

[0062] The installation may thus take advantage of the self-pressurization (inactivated cell) use phases of the storage facility 3 during which the pressure in the storage facility 3 may rise to a pressure greater than 5 bar for filling a buffer tank 7.

[0063] As illustrated in the non-limiting examples, the hydrogen used to fill the buffer tank 7 may be removed directly at the gas headspace (upper portion of the storage facility), upstream and/or downstream of the heating heat exchanger(s) 5, 15.

[0064] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

[0065] The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.

[0066] “Comprising” in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing i.e. anything else may be additionally included and remain within the scope of “comprising.” “Comprising” is defined herein as necessarily encompassing the more limited transitional terms “consisting essentially of” and “consisting of”; “comprising” may therefore be replaced by “consisting essentially of” or “consisting of” and remain within the expressly defined scope of “comprising”.

[0067] “Providing” in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

[0068] Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

[0069] Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

[0070] All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.