Vehicle Hydrogen Storage Charge Control for Cryogenic Boil-Off

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Solution Overview

Problem

Cryogenic hydrogen storage systems in vehicles suffer from boil-off losses due to heat penetration, leading to increased tank pressure and the need for venting, which is costly and inefficient.

Innovation Solution

A control system that adjusts the state of hydrogen charge by controlling refueling levels and consumption based on predicted stop duration and location to prevent boil-off losses, using software-based methods without additional hardware.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the hydrogen tank is well-insulated to reduce heat penetration, then boil-off losses are reduced, but cost, weight, and storage space increase

Engineering Contradiction:
Improveboil-off lossesVSAvoidtank weight
Core Design Contradiction:
Loss of energyVSWeight of stationary object

Solution Approach 1:

The control system performs preliminary actions by predicting future stop durations and locations, then proactively adjusting the hydrogen charge state before the vehicle arrives at the stop location. This prevents boil-off losses during anticipated long stops without requiring additional insulation hardware, thereby avoiding increased tank weight.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent replaces the mechanical/physical solution of enhanced tank insulation with a control system that uses software algorithms and sensor data to manage hydrogen levels. This substitution avoids adding heavy insulation materials while achieving the same goal of reducing boil-off losses through intelligent charge state management.

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

2Loss of energy

If more insulation is added to the hydrogen tank, then boil-off losses are reduced, but manufacturing cost increases

Engineering Contradiction:
Improveboil-off lossesVSAvoidmanufacturing cost
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The control system replaces expensive additional insulation materials and complex manufacturing processes with a software-based solution that uses existing sensors and processors. This reduces manufacturing costs while effectively preventing boil-off losses through predictive charge state management.

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

Solution Approach 2:

The system uses data copying and information processing rather than physical material addition. By copying and analyzing route information, stop duration data, and current hydrogen levels, the control system creates a virtual model to optimize charge states without adding physical insulation layers that would increase manufacturing complexity and cost.

Inventive Principle:
Principle #26Copying

3Loss of energy

If the hydrogen tank is made more insulated, then boil-off losses are reduced, but storage space decreases

Engineering Contradiction:
Improveboil-off lossesVSAvoidstorage space
Core Design Contradiction:
Loss of energyVSVolume of stationary object

Solution Approach 1:

The control system proactively manages hydrogen charge states based on predicted stop durations and locations before the vehicle reaches those stops. This preliminary action prevents boil-off losses during anticipated long stops without requiring additional insulation that would reduce storage space.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent substitutes physical insulation that would occupy tank space with a control system that manages hydrogen levels using software algorithms. This maintains full storage space availability while preventing boil-off losses through intelligent charge state adjustment based on predicted operating conditions.

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

4Duration of action of stationary object

If the vehicle stops for a long time, then hydrogen pressure increases due to heat penetration, but venting hydrogen causes boil-off losses

Engineering Contradiction:
Improvestop durationVSAvoidboil-off losses
Core Design Contradiction:
Duration of action of stationary objectVSLoss of energy

Solution Approach 1:

The control system performs preliminary actions by predicting long stop durations and locations in advance. When a long stop is anticipated, the system proactively reduces the hydrogen charge state before the stop occurs, ensuring that even with heat penetration during the long stop, the pressure will not reach venting levels, thus preventing boil-off losses.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system applies preliminary anti-action by counteracting the expected pressure increase from heat penetration during long stops. It does this by reducing the hydrogen charge state in advance, creating a buffer that prevents pressure from reaching the venting threshold, thereby preventing the harmful effect of boil-off losses during extended stationary periods.

Inventive Principle:
Principle #9Preliminary anti-action

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

Reduces boil-off losses by maintaining optimal hydrogen levels, avoiding venting, and ensuring efficient hydrogen use without adding weight or reducing storage space.

Implementation Method 1

Heat input from the environment into a cryogenic tank leads to hydrogen evaporating, which increases the pressure

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

Cryogenic hydrogen in a vehicle is stored in an insulated tank. But some heat penetration from ambient always occurs

Methodology Applied
Scientific EffectThermal Insulation: Thermal Insulation

Data Source

PatentEP4585845A1Control system and method for preventing hydrogen boil-off losses
Publication Date: 2025.07.16 VOLVO TRUCK CORP
  • EP4585845A1 patent drawingFigure 1
  • EP4585845A1 patent drawingFigure 2
  • EP4585845A1 patent drawingFigure 3

AI summary

A control system (110) and method for controlling a state of hydrogen charge in a hydrogen storage system (120) comprised in a vehicle (100) to prevent hydrogen boil-off losses are provided. The control system (110) obtains information about a predetermined stop duration and location for the vehicle (100); obtains information on a required hydrogen usage for reaching the predetermined stop location from a current location of the vehicle (100); obtains information on a maximum hydrogen level (121) of the hydrogen storage system (120) to prevent hydrogen boil-off losses when the vehicle (100) reaches the predetermined stop location and the stop duration starts; and generates a control signal for controlling the state of hydrogen charge of the hydrogen storage system (120) based on a current hydrogen level (122) in the hydrogen storage system (120) when the vehicle (100) is at the current location, the required hydrogen usage for reaching the predetermined stop location and the maximum hydrogen level (121) of the hydrogen storage system (120) to prevent hydrogen boil-off losses such that the hydrogen level in the hydrogen storage system (120) when the vehicle reaches the predetermined stop location is equal or less than the maximum hydrogen level (121) in the hydrogen storage system to prevent hydrogen boil-off losses.