ELECTRICITY GENERATION SYSTEM COMPRISING A FUEL CELL

Abstract

ELECTRICITY GENERATION SYSTEM COMPRISING A FUEL CELL The invention relates to an electricity generation system (200), a fuel cell (206), a condenser (220) with a purge outlet (220e) for liquid water, a supply line (210) connected between a dihydrogen source (202) and a first inlet (220a) of the condenser (220), an inlet line (214) connected between a first outlet (220b) of the condenser (220) and an inlet connection (207a) of the fuel cell (206), a discharge line (212) connected between a discharge connection (207b) of the fuel cell (206) and a second inlet (220c) of the condenser (220), and a first discharge line (216) connected between a second outlet (220d) of the condenser (220) and a dihydrogen treatment system (221). Such an electrical production system thus makes it possible to separate the dihydrogen from the water and the purges can be spaced out and less polluting. Fig.2.

Description

Title of the invention: ELECTRICITY PRODUCTION SYSTEM COMPRISING A FUEL CELL Technical field

[0001] The present invention relates to an electrical production system which comprises a fuel cell and which is intended to be implemented in an aircraft, as well as an aircraft comprising such an electrical production system. STATE OF THE PRIOR ART

[0002] In order to provide an electric current, in particular in an aircraft, it is known to use a fuel cell in which the generation of an electric voltage is achieved by the oxidation on one electrode of a reducing fuel, for example dihydrogen, coupled with the reduction on the other electrode of an oxidant, for example dioxygen from the air.

[0003] In some fuel cells, it is necessary to supply excess hydrogen to the anode in order to ensure a minimum concentration of hydrogen even in the presence of water resulting from oxidation.

[0004] In some installations, water and dihydrogen which is not consumed by the anode are found at the outlet of the anode and they must be discharged to the outside at a purge system which opens at regular intervals. The water and dihydrogen are then expelled, which may not be desirable in certain circumstances. It is therefore desirable to find an arrangement in which the excess dihydrogen is not discharged to the outside while ensuring the evacuation of the water. Statement of the invention

[0005] An object of the present invention is to propose an electrical production system which comprises a fuel cell and which makes it possible to limit the discharge of dihydrogen while ensuring the purging of water.

[0006] For this purpose, an electrical production system is proposed comprising:

[0007] - a fuel cell with an anode and having a first connection arrival and a first departure connection,

[0008] - a condenser comprising a first inlet and a first fluidically outlet connected to each other through said condenser, and a second inlet, a second outlet and a purge outlet fluidly connected to each other through said condenser, wherein said purge outlet provides for the purging of liquid water from said condenser,

[0009] - a supply pipe (210) intended to be fluidically connected between a source of dihydrogen and the first inlet of the condenser,

[0010] - a fluidically connected inlet pipe between the first outlet of the condenser and fuel cell inlet connection,

[0011] - a fluidically connected outlet pipe between the outlet connection of the fuel cell and the second condenser inlet, and

[0012] - a first discharge pipe intended to be fluidically connected between the second condenser outlet and a hydrogen treatment system.

[0013] Such an electrical production system thus makes it possible to separate the dihydrogen from the water and the purges can be spaced out and less polluting.

[0014] According to a particular embodiment, the inlet pipe is fluidically connected to the first discharge pipe through a pressure relief valve.

[0015] According to a particular embodiment, the electrical production system comprises an electrochemical hydrogen pump comprising an inlet, a first outlet and a second outlet, where the inlet is fluidically connected to the first discharge pipe, where the first outlet is fluidically connected to the inlet pipe, and where the second outlet is intended to be fluidically connected to the dihydrogen treatment system.

[0016] The invention also proposes an aircraft comprising a source of dihydrogen and an electrical production system according to one of the preceding variants where one end of the supply pipe is fluidically connected to the source of dihydrogen. Brief description of the drawings

[0017] The above-mentioned features of the invention, as well as others, will appear more clearly on reading the following description of an exemplary embodiment, said description being made in relation to the attached drawings, among which:

[0018] [Fig-1] is a side view of an aircraft having a production system electric according to the invention,

[0019] [Fig.2] is a schematic representation of an electrical production system according to the invention,

[0020] [Fig.3] is a schematic representation of a detail of the electrical production system of [Fig.2], and

[0021] [Fig.4] is a schematic representation of a detail of a variant of the electrical production system of [Fig.2].

[0022] DETAILED DESCRIPTION OF EMBODIMENTS

[0023] [Fig.l] shows an aircraft 100 which has a fuselage 102 on either side of which a wing 104 is fixed. Under each wing 104 is fixed at least one propulsion system.

[0024] The aircraft 100 comprises a source of dihydrogen 202, a source of dioxygen 204 and an electrical production system 200 according to the invention, one embodiment of which is shown in [Fig.2].

[0025] The invention is more particularly described in the context of an aircraft 100, but it can be applied in other fields, whether in transport or others.

[0026] In the context of the implementation in the aircraft 100, the source of dihydrogen 202 is for example a tank filled with preferably liquid dihydrogen and the source of dioxygen 204 is for example constituted by a scoop arranged at the skin of the aircraft 100 to take outside air.

[0027] In the embodiment of the invention shown in [Fig.l], the hydrogen source 202, the oxygen source 204 and the electrical production system 200 are arranged in the fuselage 102, but a different distribution is possible. For example, the electrical production system 200 and the oxygen source 204 can be located at each propulsion system 106 and the hydrogen source 202 remaining in the fuselage 102.

[0028] In the same way, the electricity produced by the electrical production system 200 can be used either to run the propulsion system 106, for example when it is an electric motor, or to power the various electrical devices of the aircraft 100.

[0029] [Fig. 2] shows the electrical production system 200 which comprises a fuel cell 206 with an anode 206a and a cathode 206b, to which one or more electrical systems 50 are connected. As specified above, an electrical system 50 can be an electric motor such as a propeller motor, or any other electrical device.

[0030] The fuel cell 206 also comprises between the anode 206a and the cathode 206b, an electrolyte 206c. The dihydrogen arrives at the anode 206a and loses its electrons which go towards the electrical system 50 which results in the appearance of hydrogen ions which pass through the electrolyte 206c towards the cathode 206b. The dioxygen which arrives at the cathode 206b combines with the electrons which arrive from the electrical system 50 and forms water at the cathode 206b. By back diffusion through the electrolyte 206c, water is found at the anode 206a.

[0031] At the anode 206a, the fuel cell 206 has a first inlet connection 207a through which the dihydrogen arrives at the anode 206a and a first outlet connection 207b through which excess hydrogen and water leave the anode 206a.

[0032] Similarly, at the cathode 206b, the fuel cell 206 has a second inlet connection 209a through which the oxygen arrives at the cathode 206b and a second outlet connection 209b through which the excess oxygen leaves the cathode 206b.

[0033] On the side of the anode 206a, the electrical production system 200 comprises a condenser 220 comprising a first inlet 220a and a first outlet 220b fluidically connected to each other through said condenser 220 here by means of an internal pipe 211.

[0034] The condenser 220 also includes a second inlet 220c, a second outlet 220d and a purge outlet 220e which are fluidically connected to each other through the condenser 220.

[0035] As explained below, the purge outlet 220e ensures the purge of liquid water from the condenser 220 and where the purge outlet 220e is in the lower part to ensure the purge by gravity.

[0036] The electrical production system 200 also comprises a supply line 210 which is fluidically connected between the dihydrogen source 202 and the first inlet 220a of the condenser 220. Thus, the low temperature dihydrogen which comes from the dihydrogen source 202 serves to cool another fluid inside the condenser 220 in order to liquefy the water vapor molecules and the liquid water can thus be separated from the dihydrogen and discharged through the purge outlet 220e.

[0037] The electrical production system 200 comprises an inlet pipe 214 fluidly connected between the first outlet 220b of the condenser 220 and the inlet connection 207a of the fuel cell 206, in order to bring the dihydrogen which comes from the dihydrogen source 202 to the anode 206a.

[0038] The electrical production system 200 also comprises a departure pipe 212 fluidly connected between the departure connection 207b of the fuel cell 206 and the second inlet 220c of the condenser 220. This departure pipe 212 then transports the excess dihydrogen and the water to the condenser 220. In the condenser 220, in contact with the internal pipe 211, the water vapor then condenses into liquid water, which allows a separation between the gaseous dihydrogen and the liquid water which is purged by the purge outlet 220e.

[0039] The electrical production system 200 comprises a first discharge pipe 216 fluidly connected between the second outlet 220d of the condenser 220 and a dihydrogen treatment system 221. Due to the condensation of the water, the first discharge pipe 216 mainly contains dihydrogen which is transported to the hydrogen treatment system 221 to be stored or reprocessed and returned for example to the hydrogen source 202.

[0040] With this installation, the water vapor is extracted from the anode and the purge frequency can be reduced and the dihydrogen is no longer expelled to the outside. In addition, the condensation of the water causes a depression inside the condenser 220 which makes it possible to attract the dihydrogen and the water present at the anode 206a.

[0041] In the embodiment of the invention presented here, solenoid valves are arranged on certain pipes to modulate the flows circulating in said pipes.

[0042] There is thus a solenoid valve 20a on the supply pipe 210 to regulate the quantity of dihydrogen circulating from the dihydrogen source 202.

[0043] There is a solenoid valve 20b on the first discharge pipe 216 to regulate the amount of hydrogen reaching the hydrogen treatment system 221.

[0044] There is a solenoid valve 20c, here a valve with pressure limiter, on the inlet pipe 214 to limit the quantity of dihydrogen arriving at the anode 206a.

[0045] At the purge outlet 220e, a purge line 222 is fluidically connected between the purge outlet 220e and a water treatment system 224 that can treat the water for reuse on board the aircraft 100 or discharge it externally. A solenoid valve 20d is provided on the purge line 222 to control the transfer of water to the water treatment system 224.

[0046] Of course, it is possible to modify the positions of the solenoid valves 20a-d to obtain similar controls.

[0047] [Fig.3] shows the detail of the condenser 220 and its connections.

[0048] On the side of the cathode 206b, the electrical production system 200 comprises a humidifier 240 which comprises a first inlet 240a, a first outlet 240b, a second inlet 240c and a second outlet 240d.

[0049] The humidifier 240 also has a membrane 239 that separates the humidifier 240 into two paths, where the first inlet 240a and the first outlet 240b are fluidically connected to each other through a first path, and where the second inlet 240c and the second outlet 240d are fluidically connected to each other through a second path.

[0050] The membrane 239 is a breathable membrane, that is to say that it only allows water vapor to pass from one path to the other, and more particularly here from the second path to the first path.

[0051] The electrical production system 200 comprises a first supply line 232a which is fluidically connected between the oxygen source 204 and the first inlet 240a of the humidifier 240, and a second supply line 232b which is fluidically connected between the first outlet 240b of the humidifier 240 and the second inlet connection 209a of the fuel cell 206. Here a solenoid valve 20g is placed on the second supply pipe 232b.

[0052] The oxygen thus passes from the oxygen source 204 to the cathode 206b by crossing the first path of the humidifier 240.

[0053] The electrical production system 200 also comprises a gas / liquid separator 234 with an inlet 234a, a first outlet 234b and a second outlet 234c. Conventionally, the gas / liquid separator 234 operates by gravity to separate the gases upwards (here the first outlet 234b), and the liquid downwards (here the second outlet 234c).

[0054] The inlet 234a is intended to receive a gas / liquid mixture, here a mixture of oxygen / water, the first outlet 234b allows the evacuation of oxygen and the second outlet 234c allows the evacuation of water.

[0055] The electrical production system 200 also comprises a first return pipe 236a which is fluidically connected between the second starting connection 209b of the fuel cell 206 and the second inlet 240c of the humidifier 240 and a second return pipe 236b which is fluidically connected between the second outlet 240d of the humidifier 240 and the inlet 234a of the gas / liquid separator 234. Here a solenoid valve 20h is placed on the first return pipe 236a.

[0056] The excess oxygen and water which exit at the cathode 206b thus pass from the cathode 206b to the gas / liquid separator 234 by crossing the second path of the humidifier 240.

[0057] When passing through the humidifier 240, the humidity present in the second path, i.e. that coming from the fuel cell 206, passes into the first path, i.e. that which goes towards the fuel cell 106.

[0058] The electrical production system 200 also comprises an evacuation pipe 238 which is fluidically connected between the first outlet 234b of the gas / liquid separator 234 and the oxygen source 204. The oxygen, which has therefore been dried by passing through the humidifier 240 and the gas / liquid separator 234, returns to the oxygen source 204 which may be outside the aircraft 100.

[0059] The electrical production system 200 comprises a second discharge pipeline 240 which is fluidically connected to the second outlet 234c of the gas / liquid separator 234 and to the water treatment system 224.

[0060] In the embodiment of the invention shown here, the electrical generation system 200 includes a bypass line 242 that is fluidically connected between the first return line 236a and the second return line 236b bypassing the humidifier 240 to control the relative humidity. oxygen entering the cathode 206b by reducing the moisture supply. Here, the bypass pipe 242 is connected to the solenoid valve 20h which is three-way.

[0061] In the embodiment of the invention shown in [Fig. 1], the inlet pipe 214 is fluidically connected to the first discharge pipe 216 through a pressure relief valve 218. The pressure relief valve 218 allows the passage of dihydrogen from the inlet pipe 214 into the first discharge pipe 216 when the pressure in the inlet pipe 214 exceeds a threshold.

[0062] In the embodiment of the invention shown in [Fig.4], the electrical production system 200 comprises an electrochemical hydrogen pump 402 which has an inlet 402a, a first outlet 402b and a second outlet 402c.

[0063] The electrochemical hydrogen pump 402 has an architecture close to that of the fuel cell 206 with an anode 404a, a cathode 404b and between them an electrolyte 404c which allows the transfer of hydrogen ions from the anode 404a to the cathode 404b.

[0064] The electrochemical hydrogen pump 402 is subjected to an electric current between the anode 404a and the cathode 404b with a generator 406 in order to create an electric field which allows the oxidation of dihydrogen at the anode 404a, the transport of hydrogen ions from the anode 404a to the cathode 404b through the electrolyte 404c and the reduction of the hydrogen ions into dihydrogen at the cathode 404b. With such an electrochemical hydrogen pump 402, only dihydrogen passes through the electrolyte 404c, which allows it to be separated from the other elements present at the second outlet 220d.

[0065] The input 402a and the second output 402c are on the anode side 404a and the first output 402b is on the cathode side 404b.

[0066] The inlet 402a is fluidically connected to a first strand of the first discharge pipe 216 and the second outlet 402c is fluidically connected to the hydrogen treatment system 221 through a second strand of the first discharge pipe 216.

[0067] The first outlet 402b is fluidically connected to the inlet pipe 214 to supply the anode 206a of the fuel cell 206.

[0068] The dihydrogen which leaves the condenser 220 through its second outlet 220d thus enters the electrochemical hydrogen pump 402 through its inlet 402a. The dihydrogen moves through the anode 402a, the electrolyte 402c and the cathode 404b and is discharged to the fuel cell 206 through the first outlet 402b.

[0069] Any traces of dihydrogen and the remaining elements (such as water, nitrogen, etc.) exit the electrochemical hydrogen pump 402 through its second exit 402c to join the dihydrogen treatment system 221 which consists of an evacuation to the outside.

[0070] In this embodiment, the solenoid valve 20c of the inlet pipe 214 is replaced by a solenoid valve 20f on the outlet pipe 212.

Claims

Claims

1. An electrical production system (200) comprising: - a fuel cell (206) with an anode (206a) and having a first inlet connection (207a) and a first outlet connection (207b), - a condenser (220) having a first inlet (220a) and a first outlet (220b) fluidly connected to each other through said condenser (220), and a second inlet (220c), a second outlet (220d) and a purge outlet (220e) fluidly connected to each other through said condenser (220), wherein said purge outlet (220e) ensures the purge of liquid water from said condenser (220), - a supply line (210) intended to be fluidically connected between a source of dihydrogen (202) and the first inlet (220a) of the condenser (220), - a inlet pipe (214) fluidically connected between the first outlet (220b) of the condenser (220) and the inlet connection (207a) of the fuel cell (206),- a departure pipe (212) fluidly connected between the departure connection (207b) of the fuel cell (206) and the second inlet (220c) of the condenser (220), and - a first discharge pipe (216) intended to be fluidically connected between the second outlet (220d) of the condenser (220) and a dihydrogen treatment system (221).,

2. An electrical production system (200) according to claim 1, characterized in that the inlet pipe (214) is fluidically connected to the first discharge pipe (216) through a pressure relief valve (218).

3. Electrical production system (200) according to claim 1, characterized in that it comprises an electrochemical hydrogen pump (402) comprising an inlet (402a), a first outlet (402b) and a second outlet (402c), where the inlet (402a) is fluidically connected to the first discharge pipe (216), where the first outlet (402b) is fluidically connected to the inlet pipe (214), and where the second outlet (402c) is intended to be fluidically connected to the dihydrogen treatment system (221).

4. Aircraft (100) comprising a source of dihydrogen (202) and an electrical production system (200) according to one of the preceding claims where one end of the supply pipe (210) is fluidically connected to the source of dihydrogen (202).

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