Aircraft and fuel supply method

Patent metadata

Field	Value
Publication number	US-2026028131-A1
Application number	US-202519348817-A
Country	US
Kind code	A1
Filing date	Oct 3, 2025
Priority date	Apr 6, 2023
Publication date	Jan 29, 2026
Grant date	—

Abstract

An aircraft includes a first tank and a second tank each storing low-temperature liquid fuel; a pump that receives supply of the low-temperature liquid fuel from the first tank and the second tank; and a controller. Each of the first tank and the second tank is switched between a fuel supply phase of supplying the low-temperature liquid fuel to the pump and a temperature restoring phase of cooling the low-temperature liquid fuel in each of the first tank and the second tank. The controller switches between a first mode where the first tank is in the fuel supply phase and the second tank is in the temperature restoring phase, and a second mode where the first tank is in the temperature restoring phase and the second tank is in the fuel supply phase.

First claim

1 . An aircraft that adopts low-temperature liquid fuel as an energy source, comprising:
a first tank and a second tank, each of which stores the low-temperature liquid fuel; a pump that receives supply of the low-temperature liquid fuel from the first tank and the second tank; and a controller, wherein each of the first tank and the second tank is switched between a fuel supply phase of supplying the low-temperature liquid fuel to the pump and a temperature restoring phase of cooling the low-temperature liquid fuel in each of the first tank and the second tank, and the controller switches between a first mode where the first tank is in the fuel supply phase and the second tank is in the temperature restoring phase, and a second mode where the first tank is in the temperature restoring phase and the second tank is in the fuel supply phase.

2 . The aircraft according to claim 1 , wherein the controller is configured to:
increase a pressure in the first tank in advance to switch the first tank from the temperature restoring phase to the fuel supply phase before the switching to the fuel supply phase; and increase a pressure in the second tank in advance to switch the second tank from the temperature restoring phase to the fuel supply phase before the switching to the fuel supply phase.

3 . The aircraft according to claim 1 , wherein each of the first tank and the second tank includes:
a return line that returns the low-temperature liquid fuel sent out of the first tank or the second tank to the first tank or the second tank; and a pressure-increase vaporizer that heats and vaporizes the low-temperature liquid fuel in the return line, wherein a pressure in each of the first tank and the second tank is increased by returning vaporized fuel resulting from the vaporization to each of the first tank and the second tank via the return line.

4 . The aircraft according to claim 1 , further comprising a temperature sensor that measures a temperature of the low-temperature liquid fuel in the first tank and a temperature sensor that measures a temperature of the low-temperature liquid fuel in the second tank, wherein
the controller switches between the first mode and the second mode on the basis of the temperature of the low-temperature liquid fuel in the first tank and the temperature of the low-temperature liquid fuel in the second tank, the temperatures being measured respectively by the temperature sensors.

5 . The aircraft according to claim 4 , wherein the controller switches to the second mode when the temperature of the low-temperature liquid fuel in the first tank is a predetermined first threshold or higher, and switches to the first mode when the temperature of the low-temperature liquid fuel in the second tank is the first threshold or higher.

6 . The aircraft according to claim 1 , wherein the cooling in the first tank is executed by reducing a pressure in the first tank and the cooling in the second tank is executed by reducing a pressure in the second tank.

7 . The aircraft according to claim 6 , further comprising:
a vent line connected to the first tank and a vent line connected to the second tank; and a pressure regulating valve located on the vent line for the first tank and a pressure regulating valve located on the vent line for the second tank, wherein the controller is configured to open the pressure regulating valve for the first tank to reduce the pressure in the first tank, and is configured to open the pressure regulating valve for the second tank to reduce the pressure in the second tank.

8 . The aircraft according to claim 1 , further comprising:
vent lines connected to the first tank and vent lines connected to the second tank; pressure regulating valves located respectively on the vent lines; and one or more switch valves located between the first and second tanks and the pump, wherein the cooling in the first tank is executed by opening the pressure regulating valves connected to the first tank and the cooling in the second tank is executed by opening the pressure regulating valves connected to the second tank, and the controller switches between the first mode and the second mode by controlling the pressure regulating valves and the one or more switch valves.

9 . The aircraft according to claim 1 , further comprising:
an ejector that communicates with an outlet of the pump via a pipe; a vaporizer that vaporizes the low-temperature liquid fuel flowing in the pipe; and a vent line that connects the first tank and the ejector to each other and a vent line that connects the second tank and the ejector to each other, wherein vaporized gas of the low-temperature liquid fuel generated in each of the first tank and the second tank is supplied to the ejector via each of the vent lines.

10 . The aircraft according to claim 9 , further comprising:
a sub-buffer tank located on each of the vent lines to store the vaporized gas of the low-temperature liquid fuel; and an on-off valve located between the sub-buffer tank and the ejector on each of the vent lines.

11 . The aircraft according to claim 10 , further comprising at least one of an accumulator connected to the pipe connecting the pump and the vaporizer to each other, or a buffer tank located on the pipe connecting the vaporizer and the ejector to each other.

12 . A fuel supply method of supplying low-temperature liquid fuel stored in a first tank and a second tank to a pump connected to the first tank and the second tank, the fuel supply method comprising:
allowing each of the first tank and the second tank to be switched between a fuel supply phase of supplying the low-temperature liquid fuel to the pump, and a temperature restoring phase of cooling the low-temperature liquid fuel in each of the first tank and the second tank; and supplying the low-temperature liquid fuel to the pump by switching between a first mode where the first tank is in the fuel supply phase and the second tank is in the temperature restoring phase, and a second mode where the first tank is in the temperature restoring phase and the second tank is in the fuel supply phase.

13 . The aircraft according to claim 2 , wherein each of the first tank and the second tank includes:
a return line that returns the low-temperature liquid fuel sent out of the first tank or the second tank to the first tank or the second tank; and a pressure-increase vaporizer that heats and vaporizes the low-temperature liquid fuel in the return line, wherein a pressure in each of the first tank and the second tank is increased by returning vaporized fuel resulting from the vaporization to each of the first tank and the second tank via the return line.

14 . The aircraft according to claim 2 , further comprising a temperature sensor that measures a temperature of the low-temperature liquid fuel in the first tank and a temperature sensor that measures a temperature of the low-temperature liquid fuel in the second tank, wherein
the controller switches between the first mode and the second mode on the basis of the temperature of the low-temperature liquid fuel in the first tank and the temperature of the low-temperature liquid fuel in the second tank, the temperatures being measured respectively by the temperature sensors.

15 . The aircraft according to claim 3 , further comprising a temperature sensor that measures a temperature of the low-temperature liquid fuel in the first tank and a temperature sensor that measures a temperature of the low-temperature liquid fuel in the second tank, wherein
the controller switches between the first mode and the second

Assignees

• Kawasaki Heavy Ind Ltd

Inventors

• Tsuru Kazunari
• Iwasaki Hidekazu
• Sasaki Koichi
• Yajima Ayako
• Shimizu Kazuko
• Ichikawa Shingo
• Nodo Ryo
• Kuyama Hiroki
• Tanaka Shota

Classifications

• B64D37/30 Primary

  Fuel systems for specific fuels · CPC title

• B64D37/02

  Tanks (tanks constructed integrally with aircraft wings B64C3/34) · CPC title

• B64D37/005

  Accessories not provided for in the groups B64D37/02 - B64D37/28 · CPC title

• B64D37/34 Primary

  Conditioning fuel, e.g. heating (during filling B64D37/18) · CPC title