Device for producing water on board of an airplane

Translation of description of equivalent WO 2004040680 A2

Arrangement for generating water on board

aircraft

The invention relates to an arrangement for the generation of water on board an aircraft using one or more fuel cells, a partial or complete integration of a water generating unit in the form of one or more high temperature fuel cell is provided in an aircraft engine such that combustion chambers of aircraft engine completely or are partially replaced with the high temperature fuel cell, and thus supplements the taking place in the combustion chambers conventional process or entirely replaced.

From EP 957 026 A2 a power supply unit on board an aircraft for substituting a main engine, an auxiliary power unit, a ram air turbine or a NiCd battery is known. A fuel cell is used to generate direct current, for supplying air to the fuel cell exhaust air of the aircraft air conditioning system or aircraft external air is used. From the fuel cell exhaust water is produced for the water supply of the aircraft, the fuel cell exhaust air is then discharged to the aircraft environment, which is also true for the exiting from the fuel cell hydrogen. A generation of water by means of a capacitor arranged in Flugzeugauslaß.

In EP 967 676 AI a jet thruster is described having the combustion chambers integrated fuel cell. Here, the fuel cell to the combustion chambers are arranged, in contrast to the subject matter of new models in the annexed main claim, in which the combustion chambers are partially or completely through the high-temperature fuel cell (s) replaced. In the prior art engine of the process of the engine is used only for the operation of the fuel cell.

The invention is therefore based on the object to provide an arrangement of the aforementioned type, in which a fuel cell-gas turbine combined for the exclusive operation with hydrogen and atmospheric oxygen, as an engine and / or as an auxiliary power unit (APU - Auxiliary Power Unit) is provided for water and compressed air supply of the cabin as well as to generate electricity.

The object is achieved in that the high-temperature fuel cells as a type oxide ceramic fuel cell (SOFC - Solid Oxide Fuel Cell) or molten carbonate fuel cell (MCFC - Molten carbonates • te Fuel Cell) are executed or equivalent in performance and temperature level type belong, that the high temperature fuel cell on the anode side pure ner hydrogen and the cathode side air can be supplied to the combustion chambers of a mixture of hydrogen and air is fed to that at least the supply of hydrogen is carried out regulated or switched off completely and that the high-temperature fuel cell, a single or multi-stage turbine is connected downstream of the anode side at least, the thermal energy of the anode exhaust gas is converted into rotational energy.

Embodiments of the invention are described in the dependent claims 2 to 24th

It is contemplated - in this way, but preferably to replace at least a plurality of combustion chambers through one or more high-temperature fuel cells, in contrast to the said object or at least one or more combustion chambers remain for burning a hydrogen-air mixture received. The combustion chambers and high temperature fuel cells are preferably alternately arranged annularly around the shaft or the shafts of the gas turbine.

The combustion chambers are used to start the gas turbine and the high-temperature fuel cells, and a short-term increase of the air throughput of the gas turbine, for example, the time an aircraft. In continuous operation, the thermal energy of high-temperature fuel-cell material for the generation of the air flow is used exclusively. The water production has an anode side, ie hydrogen side in the high-temperature fuel cell instead. This so-called anode exhaust gas is at complete implementation of the registered hydrogen to 100% of water vapor (steam). This superheated steam is passed through a turbine where it is cooled by expansion and hence thermal energy is converted into rotational energy of the turbine shaft. This rotational energy is used in a compressor, to generate the necessary hydrogen sided form for high temperature fuel cell.

In a further process step, the water vapor will eventually condense. This gives pure H₂0, ie distilled water. This water is supplied to the different loads or treated in a salzungseinheit up to drinking water. Attack end gray water is collected in a collection container, as well as of the dehydrating discharged from blackwater water content. The amounts of water to be evaporated in an operated with the waste heat of water condensation process evaporator and fed together with the not required for water extraction vapor fraction from the anode exhaust gas of the high temperature fuel cell before the second turbine stage of the gas turbine. On the air side is drawn in via a so-called fan outside air and / or cabin air. This fan is driven in normal operation by the second turbine stage, during startup by an electric motor. The passed through the fan air is first yorverdichtet in egg-arranged downstream compressor and then compressed in another compressor for the combustion chambers and the air side of the high temperature fuel cell on. The over the combustion chambers and high temperature fuel cells registered thermal energy then drives down the first turbine stage and after the above-described supply of gray water into the hot exhaust stream, the second turbine stage. The -Number of compressor and turbine stages and the number of combustion chambers and high temperature fuel cells can be varied as desired depending on the requirements for different types.

The advantages of the arrangement according to the invention consist in a) flexibility for short-term performance requirements, b) high integration of individual process steps, c) high purity of water obtained, d) high efficiency of the system and in a e) weight saving.

The drawing shows an exemplary embodiment of the invention, namely the single FIGURE shows a hydrogen generation system comprising a tank 1 for liquid hydrogen. Thus, an application in a so-called "Cryoplane" is particularly advantageous. As the drawing it can be seen, replaces a high-temperature fuel cell 7 is partially a combustion chamber 7a of an aircraft engine 2. The high temperature fuel cell 7 are anode-side pure hydrogen and the cathode side air supplied while the combustion chamber 7a, a mixture of hydrogen and air is supplied. This is at least the hydrogen supply regulated or switched off completely executed. The high temperature fuel cell on the anode side 7 is at least one single or multi-stage turbine is connected downstream of 16, 35 converts the thermal energy of the anode exhaust gas into rotational energy. It can type fuel oxide ceramic fuel cell (SOFC - Solid Oxide Fuel Cell) - are used by a comparable in power and temperature level or type or molten carbonate fuel cell (molten carbonate fuel cell MCFC). The high temperature fuel cell 7 is a condensation process 18 downstream condensed water from a part of the anode exhaust gas 35 of the fuel cell. 7 Furthermore, the high-temperature fuel cell can be 7 on the other hand applied to both sides of the air or oxygen side on the one hand and on the fuel or hydrogen side with pressure, with identical or different pressures on the anode side and cathode side allowed. The use of liquid or gaseous hydrogen is possible. Liquid hydrogen 1 can be prior to entering the high temperature fuel cell 7 or combustion chamber 7a evaporated, the evaporator 17 can be operated with the process heat of the anode off-gas condenser 18th A particular embodiment of the inventive arrangement is that the evaporator 17 is carried out annularly around the capacitor 18, or arranged in a circle within the condenser 18 and a tube bundle heat exchanger. Also in this case, at least part of the condensation process 18 can be operated with cooling air 19th

It is possible to collect used water as well as unneeded condensate in a container 32nd The heated in the condensation process 18 air 20 is advantageously used to vaporize the gray water in a separate container 33, in which the gray water means

a pump is transported 37, wherein a filter for retaining solid and suspended matter is provided from the gray water. The condensation process 18 is water taken in distilled quality and so distributed, and that the galleys 23, the hand basin 24 and the showers with a 25 by the metering of salt 23 generated drinking water 22 and the toilets 27 and the humidification 26 supplied with distilled water The turbine stages 8, 9, both the compressor stages 5, 6 and the fan 11 operated, the compressor stages 5, 6, both the high-temperature fuel cell 7 and the combustion chamber 7a airside pressurize. The air flow rate of 3 fans 11 can be used either in an engine for propulsion or an APU for pressurizing the air pressure systems and / or air conditioning. For this purpose a fan 11 with a first stage compressor 5 and the second turbine stage a second compressor stage 9, and 6 and the first turbine stage 8 are each coupled together and run into one another on coaxial shafts at different rotational speeds. The number of interlocking current coaxial shafts is carried out arbitrarily.

The waste water is collected in a collecting tank 28, completely or partially dehydrated 30 and the water content thus obtained is supplied to the gray water collection tank 32nd It is particularly advantageous,

- That the arrangement can also be operated without loss of water to a water system,

- That both the combustion chambers, as well as the high temperature fuel cell can be operated separately and in any combination with each other, and

- That in a separate operation of combustion chambers or high temperature fuel cell 7 individual chambers or Hochteraperatur fuel cells can be switched off.