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EP-4438493-B1 - HYDROGEN SUPPLY UNIT FOR AN AIRCRAFT, METHOD OF SUPPLYING LIQUID HYDROGEN IN AN AIRCRAFT, AND AIRCRAFT

EP4438493B1EP 4438493 B1EP4438493 B1EP 4438493B1EP-4438493-B1

Inventors

  • Schulze-Reimann, Kai

Dates

Publication Date
20260506
Application Date
20230331

Claims (9)

  1. Hydrogen supply unit (10, 30) for use in an aircraft, comprising a tank (11) configured to store in its interior (12) liquid hydrogen (LH2), an extraction chamber (13; 23, 24, 25, 26) comprising one or more openings (15) for extracting the liquid hydrogen (LH2) from the tank (11) through the extraction chamber (13; 23, 24, 25, 26), at least one line (16; 27a, 27b, 28a, 28b) connected to the extraction chamber (13; 23, 24, 25, 26) and configured for supplying the liquid hydrogen (LH2) to a consumer unit (54) of the aircraft, and at least one pump (31, 32) connected to the line (16; 27a, 27b, 28a, 28b); characterized in that the extraction chamber (13; 23, 24, 25, 26) is provided in the interior (12) of the tank (11) and mounted on or near the bottom (17) of the tank (11), wherein the openings (15) are provided in the bottom (29) of the extraction chamber (13; 23, 24, 25, 26) close to the bottom (17) of the tank (11).
  2. Hydrogen supply unit according to claim 1, characterized in that two or more such extraction chambers (13; 23, 24, 25, 26) are provided, wherein each extraction chamber (13; 23, 24, 25, 26) is connected to an assigned valve (41, 42, 43, 44), each valve (41, 42, 43, 44) being connected to a control unit (45) configured for opening and closing the valves (41, 42, 43, 44) depending on attitudes and accelerations data of an aircraft when the hydrogen supply unit (10, 30) is operated therein.
  3. Hydrogen supply unit according to one of the preceding claims, characterized in that 3.1. at least one extraction chamber (23, 25) is located in a rear section (33) of the tank (11), and at least one extraction chamber (24, 26) is located in a front section (34) of the tank (11); and/or 3.2. at least one extraction chamber (25, 26) is mounted at or near the ceiling (47) of the tank (11); and/or 3.3. at least a pair of extraction chambers (25, 26) is mounted at or near the ceiling (47) of the tank (11), one of them (25) being located in a rear section (33) of the tank (11) and one of them (26) being located in a front section (34) of the tank (11).
  4. Hydrogen supply unit according to one of the preceding claims, characterized in that the one or more lines (16; 27a, 27b, 28a, 28b) extend from the one or more extraction chambers (13; 23, 24, 25, 26) 4.1. through an aft outlet (51) provided in a rear section (33) or end of the tank (11) and/or through a forward outlet (52) provided in a front section (34) or end of the tank (11); and or 4.2. exclusively through an aft outlet (51) provided in a rear section (33) or end of the tank (11); and/or 4.3. exclusively through a forward outlet (52) provided in a front section (34) or end of the tank (11).
  5. Hydrogen supply unit according to claim 4, characterized in that the one or more pumps (31, 32) are configured for being positioned in the aircraft 5.1. below and/or behind the aft outlet (51) of the tank (11); and/or 5.2. below and/or in front of the forward outlet (52) of the tank (11).
  6. Aircraft, characterized by a hydrogen supply unit (10; 30) according to one of claims 1 to 5.
  7. Method of supplying liquid hydrogen in an aircraft, comprising the steps: a) extracting liquid hydrogen (LH2) from the interior (12) of a tank (11) of an aircraft through at least one extraction chamber (13; 23, 24, 25, 26), and b) supplying the liquid hydrogen (LH2) from the extraction chamber (13; 23, 24, 25, 26) to a consumer unit (54) of the aircraft; characterized in that the extraction chamber (13; 23, 24, 25, 26) is provided in the interior (12) of the tank (11) and mounted on or near the bottom (17) of the tank (11), and comprising one or more openings (15) provided in the bottom (29) of the extraction chamber (13; 23, 24, 25, 26) close to the bottom (17) of the tank (11).
  8. Method according to claim 7, characterized in that two or more such extraction chambers (13; 23, 24, 25, 26) are provided in the tank (11), wherein the liquid hydrogen (LH2) is extracted at different extracting positions where the extraction chambers (13, 23, 24, 25, 26) are located, which extracting positions are selected depending on current attitudes and accelerations of the aircraft.
  9. Method according to claim 7 or 8, characterized in that the hydrogen supply unit (10; 30) according to one of claims 1 to 5 is used.

Description

The invention relates to a hydrogen supply unit for use in an aircraft. Further, the invention relates to a method of supplying liquid hydrogen in an aircraft. In addition, the invention relates to an aircraft. In particular, the invention can be applied in aircrafts such as airplanes, helicopters and other objects that can fly. Gas emissions having an impact on the climate have to be reduced. Particularly in aviation, a switch from conventional gas turbine engines to propulsion systems based on hydrogen (H2) has been identified as a growing market with a high number of aeroplanes in the next years and decades, in order to achieve zero emission flights. Many research institutes and companies have been searching for viable propulsion architectures to eliminate or reduce aircraft emissions for regional and larger aircrafts. In such aircrafts, the hydrogen is provided as liquid hydrogen (LH2) in a tank within the aircraft and supplied via pipes to the aircraft's propulsion engine and/or other consumer units of the aircraft. US 6,178,991 B1 describes a safety container for storing and transporting environmentally hazardous substances including hydrogen, the container having inlets and outlets and glass wool filling the container, further comprising an inert gas chamber in the container. An aircraft equipped with wing tanks is shown, which are divided into individual tanks which are each filled with a latticework of glass wool. DE 10 2018 215 384 A1 shows a tank device comprising a tank and a valve device. The tank comprises a tank housing in which a tank interior is formed. The tank housing comprises a neck portion with a passage opening, which opens at one end of the neck portion into the tank interior. At the opposite end of the neck portion, the valve device is formed. The valve device and the tank interior are sealed from an environment. US 2008/0023493 A1 discloses a storage system for fuel cell gases. It comprises an outer shell and at least one bladder positioned inside the outer shell. A primary chamber is defined between the outer shell and the bladder, and a secondary chamber is defined interior to the bladder. The primary chamber maintains a first pressure range, and the secondary chamber maintains a second pressure range. US 2006/0014070 A1 describes a storage device including a bladder that contains a hydrogen fuel source and conforms to the volume of the hydrogen fuel source. EP 1 355 107 A2 discloses a pressure tank for holding a pressurized fluid. The tank comprises a receiving chamber comprising a receiving room which is limited by chamber walls. A non-return valve is fixed in a cover portion assigned to the receiving room. EP 3 708 896 A1 shows a gas tank system comprising a gas tight outer shell in which a heat resistant shell is positioned for storing a gas. A channel is formed between the outer and the inner shell, through which hydrogen flows when the tank is filled. The inner shell has an outlet formed by an opening in the inner shell through which the gas flows when the tank is filled and when the gas is taken out. EP 3 176 490 A1 describes a cryogenic tank for storing cryogenic liquids. It has an inner storage volume within a first wall and comprises a plurality of chambers within the inner storage volume. When supplying the LH2 to the aircraft's propulsion or other consumer unit, accidental feeding of the pipes with gaseous H2 (GH2) in the tank needs to be avoided. Further, the amount of unusable LH2 remaining in the tank after a maximum LH2 extraction shall be minimized. Therefore, it is the object of the invention to maximize utilization of the LH2 provided in an LH2 tank of an aircraft, and to prevent ingestion of gaseous hydrogen when liquid hydrogen from the tank is supplied to a consumer unit in the aircraft. According to a first aspect, the invention provides a hydrogen supply unit for use in an aircraft, comprising a tank configured to store in its interior liquid hydrogen, an extraction chamber comprising one or more openings for extracting the liquid hydrogen from the tank through the extraction chamber, at least one line connected to the extraction chamber and configured for supplying the liquid hydrogen to a consumer unit of the aircraft, and at least one pump connected to the line, wherein the extraction chamber is provided in the interior of the tank and mounted on or near the bottom of the tank, wherein the openings are provided in the bottom of the extraction chamber close to the bottom of the tank. Preferably, the extraction chamber is attached to a wall of the tank surrounding the hydrogen. Preferably, two or more such extraction chambers are provided in the tank, wherein each extraction chamber is connected to an assigned valve. Preferably, each valve is connected to a control unit configured for opening and closing the valves depending on attitudes and accelerations of the aircraft. Preferably, the control unit is configured for receiving data from the air data iner