Low-Pressure Liquid Hydrogen Storage With Two-Stage Pressure Building

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Solution Overview

Problem

Existing hydrogen storage and delivery systems for vehicles face challenges in maintaining low pressure for storage while meeting high pressure requirements of power systems, leading to inefficiencies and reliability issues such as cavitation and vapor lock, and are bulky and heavy, limiting the range and economy of hydrogen fuel cell vehicles.

Innovation Solution

A multi-stage pressure building system with a hydrogen storage tank having a first portion for vapor and a second portion for liquid, using a first pump submerged in the liquid to boost pressure, a second pump outside the tank to achieve high pressure, and a heat exchanger to manage pressure and temperature, reducing heat leakage and system size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If a single high-pressure pump is used to deliver hydrogen from storage to power systems, then high pressure delivery is achieved, but cavitation and vapor lock occur due to pressure fluctuations

Engineering Contradiction:
Improvedelivery pressureVSAvoidpump reliability
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The single high-pressure pump is divided into two separate pumps: a first pump that delivers hydrogen from storage to an intermediate pressure, and a second pump that delivers from intermediate pressure to the final high pressure required by power systems. This segmentation prevents cavitation and vapor lock by distributing the pressure increase across two stages, each operating within reliable parameters.

Inventive Principle:
Principle #1Segmentation

2Quantity of substance

If liquid hydrogen is stored at high pressure, then sufficient hydrogen levels are maintained for long-term operation, but the system becomes bulky and heavy

Engineering Contradiction:
Improvehydrogen storage capacityVSAvoidsystem weight
Core Design Contradiction:
Quantity of substanceVSWeight of moving object

Solution Approach 1:

The system changes the pressure parameter of stored liquid hydrogen from high pressure to low pressure (near atmospheric pressure). This parameter change allows for a smaller, lighter storage tank while maintaining sufficient hydrogen storage capacity through the two-stage pressure building system that delivers hydrogen at required high pressures to power systems.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If a thermal device is added to maintain storage tank pressure, then pressure stability is improved, but heat leakage into the liquid hydrogen increases

Engineering Contradiction:
Improvestorage pressure stabilityVSAvoidthermal energy loss
Core Design Contradiction:
Stability of the object's compositionVSLoss of energy

Solution Approach 1:

A thermal device is introduced as an intermediary element positioned within the vapor space of the storage tank, thermally coupled to the tank wall but isolated from direct contact with liquid hydrogen. This intermediary approach allows the thermal device to heat vapor and maintain pressure stability while preventing direct heat transfer to the liquid hydrogen, thereby reducing energy loss and boil-off.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

The system optimizes efficiency, reduces size and weight, enhances operational range, and prevents cavitation and vapor lock, enabling reliable high-pressure hydrogen delivery to power systems while maintaining low pressure storage.

Implementation Method 1

The first pump is to receive liquid hydrogen from the second portion of the inner volume when liquid hydrogen is stored in the hydrogen storage tank and to pump the liquid hydrogen out of the hydrogen storage tank to produce a low pressure flow of liquid hydrogen

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 2

The second pump is to receive the low pressure flow of liquid hydrogen from the first pump and to produce a high pressure flow of liquid hydrogen

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 3

The heat exchanger is to receive the high pressure flow of liquid hydrogen from the second pump and to provide a flow of hydrogen gas to a hydrogen-powered energy producing system

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

The thermal device can be to produce thermal energy operable to heat gaseous hydrogen contained in the first portion of the inner volume of the hydrogen storage tank to maintain a pressure within the inner volume above a predetermined pressure value

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP4667811A1Systems and methods for building pressure when using low pressure liquid hydrogen storage
Publication Date: 2025.12.24 CUMMINS INC
  • EP4667811A1 patent drawingFigure 1
  • EP4667811A1 patent drawingFigure 2
  • EP4667811A1 patent drawingFigure 3

AI summary

A system and method for hydrogen storage, and delivery. The system includes a hydrogen storage tank, a first pump disposed within the hydrogen storage tank, and a second pump disposed outside of the hydrogen storage tank. The hydrogen storage tank is to store gaseous hydrogen and liquid hydrogen. The first pump is to pump out liquid hydrogen out of the storage tank, producing a low pressure flow. The second pump is to receive this low pressure flow and produces a high pressure flow of liquid hydrogen. The system can also include a thermal device disposed within the hydrogen storage tank to heat gaseous hydrogen when a pressure within the hydrogen storage tank drops below a predetermined minimum pressure. The system can also include a heat exchanger to receive the high pressure flow of liquid hydrogen from the second pump.