Hydrogen Fuel Tank Induction Heating for Pressure Control

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Solution Overview

Problem

Conventional tank pressurization systems for hydrogen fuel tanks in aircraft are ineffective at low temperatures, as inert gases like nitrogen liquefy and mix with hydrogen, and existing systems require tank penetrations that lead to heat loss, leakage, and increased weight.

Innovation Solution

A fuel system using superconducting inductors inside and outside the tank to induce current and heat the hydrogen, maintaining pressure without tank penetrations, with a controller managing heating modes to control heat input.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If conventional tank pressurisation systems use inert gas (nitrogen) to maintain pressure, then pressure can be maintained, but the nitrogen liquefies at low temperatures and mixes with hydrogen fuel

Engineering Contradiction:
Improvetank pressureVSAvoidfuel contamination
Core Design Contradiction:
Stress or pressureVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the mechanical pressurisation system (inert gas injection) with an electromagnetic heating system. Electrical inductors generate electromagnetic fields that induce currents in the hydrogen fuel, heating it directly to maintain pressure without introducing foreign substances into the fuel tank.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces electrical inductors as an intermediary mechanism between the power source and the hydrogen fuel. The inductors transfer energy electromagnetically through the tank wall and fuel without requiring physical penetration or direct contact that would contaminate the fuel.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stress or pressure

If tank penetrations are added for pressurisation, then pressure can be maintained, but heat loss, leakage, and weight increase

Engineering Contradiction:
Improvetank pressureVSAvoidthermal loss
Core Design Contradiction:
Stress or pressureVSLoss of energy

Solution Approach 1:

The patent replaces mechanical penetrations (valves, pipes, fittings) with an electromagnetic field-based heating system. The inductors can be positioned externally or with minimal penetration, using electromagnetic coupling to heat the fuel through the tank wall without requiring extensive openings that would compromise thermal insulation.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes the tank wall itself as a transparent medium for electromagnetic field penetration. The inductors are designed to couple electromagnetically through the tank wall material, allowing energy transfer without compromising the structural integrity or thermal insulation properties of the tank shell.

Inventive Principle:
Principle #30Flexible shells and thin films

3Stress or pressure

If tank penetrations are added for pressurisation, then pressure can be maintained, but weight increases

Engineering Contradiction:
Improvetank pressureVSAvoidsystem weight
Core Design Contradiction:
Stress or pressureVSWeight of moving object

Solution Approach 1:

The patent replaces heavy mechanical pressurisation components (valves, pipes, fittings, support structures) with lightweight electrical inductors and wiring. The electromagnetic heating system requires significantly less structural support and fewer mechanical connections, reducing overall system weight.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts the pressurisation function from the mechanical domain and relocates it to the electromagnetic domain. By removing the need for complex mechanical penetrations and support structures, the system achieves pressure maintenance with minimal weight addition.

Inventive Principle:
Principle #2Taking out (Extraction)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Maintains tank pressure efficiently, reduces weight and thermal losses, and minimizes leakage risks by using superconducting inductors to heat hydrogen, allowing for controlled pressure regulation.

Implementation Method 1

a second inductor provided externally to the tank, and configured to induce a current in the first inductor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

heating of the fuel using electrical induction

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 3

At least one of the first inductor and the second inductor may comprise a superconducting material

Methodology Applied
Scientific EffectSuperconductivity: Superconductivity

Data Source

PatentEP4549715B1Gas turbine engine
Publication Date: 2025.11.19 ROLLS ROYCE PLC
  • EP4549715B1 patent drawingFigure 1
  • EP4549715B1 patent drawingFigure 2
  • EP4549715B1 patent drawingFigure 3

AI summary

A fuel system (200) for a hydrogen fuelled aircraft propulsion system (103) comprises a tank (104) configured to store hydrogen, a first inductor (436a-c) provided within the tank (104) and configured to heat hydrogen fuel within the tank (104), and a second inductor (432a-c) provided externally to the tank (104), and configured to induce a current in the first inductor (436a-c).