Liquid Hydrogen Pump Control for Stable Engine Supply Pressure

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Solution Overview

Problem

Hydrogen engine vehicles face limitations in travel distance due to insufficient hydrogen gas storage capacity and pressure variations in hydrogen supply, which conventional methods struggle to control effectively.

Innovation Solution

A hydrogen engine vehicle system adjusts the discharge flow rate of a liquid hydrogen pump based on both the flow rate and actual pressure in the pressure chamber, using a pump control unit to match the target pressure, thereby reducing pressure variations and ensuring stable hydrogen supply to the engine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If liquid hydrogen is stored in a liquid hydrogen tank and evaporated to supply hydrogen gas to a hydrogen engine, then the storage capacity is improved, but the pressure variation of hydrogen gas to be supplied to the hydrogen engine increases

Engineering Contradiction:
Improvestorage capacityVSAvoidpressure variation
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The pump control unit adjusts the discharge flow rate of the liquid hydrogen pump based on feedback from both the flow rate of hydrogen gas and the actual pressure in the pressure chamber. This dual-feedback mechanism enables dynamic regulation of the pump operation to maintain stable pressure while supplying sufficient hydrogen gas to the engine.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system transitions from static pressure control to dynamic flow rate adjustment. The discharge flow rate of the liquid hydrogen pump is continuously adjusted based on real-time measurements of hydrogen flow rate and pressure chamber pressure, enabling the system to adapt to varying engine demands while maintaining pressure stability.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the flow rate of hydrogen gas supplied to the hydrogen engine varies greatly, then the adaptability to different driving conditions is improved, but the pressure variation in the pressure chamber increases

Engineering Contradiction:
Improveadaptability to driving conditionsVSAvoidpressure variation
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The pump control unit utilizes dual feedback signals (hydrogen flow rate and pressure chamber pressure) to dynamically adjust the pump discharge flow rate. This enables the system to adapt to varying driving conditions while maintaining stable pressure through continuous regulation based on real-time system state.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the operating parameters of the liquid hydrogen pump (discharge flow rate) based on measured system conditions. By adjusting the pump flow rate in response to variations in hydrogen consumption and pressure chamber pressure, the system maintains pressure stability across different driving conditions.

Inventive Principle:
Principle #35Parameter changes

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 effectively suppresses pressure variations in the hydrogen supply, ensuring consistent hydrogen delivery to the engine, enhancing the vehicle's operational stability and range.

Implementation Method 1

liquid hydrogen stored in the liquid hydrogen tank is pressurized by the hydrogen pump

Methodology Applied
Scientific EffectPumping: Pump

Implementation Method 2

the pressurized liquid hydrogen is evaporated in the evaporator to store hydrogen gas

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

liquid hydrogen is evaporated by a heat exchanger which uses helium gas

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 4

the high-pressure hydrogen gas is减压ed to supply pressure by the pressure reducing valve

Methodology Applied
Scientific EffectPressure reduction: Depressurisation

Implementation Method 5

the discharge flow rate of the liquid hydrogen pump is adjusted based on both the flow rate of hydrogen to be supplied to the hydrogen engine and the actual pressure in the pressure chamber

Methodology Applied
Scientific EffectFlow rate control: Pump

Data Source

PatentEP4303426B1Hydrogen supplying device and hydrogen engine vehicle
Publication Date: 2026.01.21 TOYOTA JIDOSHA KK
  • EP4303426B1 patent drawingFigure 1
  • EP4303426B1 patent drawingFigure 2
  • EP4303426B1 patent drawingFigure 3

AI summary

A hydrogen supplying device (30) includes a liquid hydrogen pump (32), an evaporator (37), a pressure chamber (45) configured to be filled with hydrogen gas flowing therein from the evaporator (37) and to supply the filled hydrogen gas to a hydrogen engine (10), and a pump control unit (80) configured to adjust a discharge flow rate of the liquid hydrogen pump (32) based on both a flow rate of hydrogen to be supplied to the hydrogen engine (10) and an actual pressure in the pressure chamber (45).