Hydrogen Recirculation Compressor for Regenerative Braking Energy Absorption

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Solution Overview

Problem

Heavy-duty vehicles with fuel cell systems face challenges in managing excessive energy generated during braking, as conventional methods like battery storage or resistor dissipation are inefficient or impractical, leading to compromised braking performance and energy efficiency.

Innovation Solution

A system with an electrically powered compressor in the hydrogen fuel storage and recirculation system, which pressurizes hydrogen fuel in response to energy dissipation needs, leveraging the hydrogen fuel storage system to absorb and reuse electrical energy generated during braking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If regenerative braking is used to generate electrical energy during braking, then kinetic energy is converted to electrical energy for storage, but excessive energy cannot be stored when batteries are fully charged, leading to energy loss

Engineering Contradiction:

Improveenergy utilizationVSAvoidexcessive energy dissipation

Core Design Contradiction:

Use of energy by moving objectVSLoss of energy

Solution Approach 1:

The patent converts the harmful excessive electrical energy that cannot be stored into beneficial compressed hydrogen fuel. The electrical energy powers a compressor that pressurizes hydrogen from the storage system through a recirculation loop, transforming waste energy into useful fuel compression that can be reused by the fuel cell system.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Reliability

If brake resistors are used to dissipate excessive energy, then thermal management is required, but cooling capacity constraints limit braking performance during extended downhill operation

Engineering Contradiction:

Improvebraking capacityVSAvoidcooling system load

Core Design Contradiction:

ReliabilityVSTemperature

Solution Approach 1:

The patent replaces the thermal management-based brake resistor system with an electrical-to-mechanical energy conversion system. Instead of converting excessive electrical energy to heat that requires cooling, the system converts it to mechanical compression work on hydrogen gas, eliminating the thermal management bottleneck and enabling sustained braking capacity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Loss of energy

If hydrogen fuel is recirculated through compression, then excess electrical energy is absorbed and reused, but additional system components and control complexity are required

Engineering Contradiction:

Improveenergy waste reductionVSAvoidsystem complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements a multi-functional recirculation system where the compressor serves dual purposes: compressing hydrogen for fuel cell supply and absorbing excess electrical energy from regenerative braking. The recirculation loop integrates energy management, fuel supply, and pressure regulation functions into a single system architecture, reducing overall system complexity despite the added energy dissipation capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

Enhances energy management efficiency by dynamically adjusting compressor operation to dissipate excess energy, improving braking capacity and overall energy utilization while reducing waste, and optimizing hydrogen fuel storage and supply.

Implementation Method 1

an electrically powered compressor disposed in the recirculation hydrogen fuel system, wherein the electrically powered compressor is controllable to pressurize hydrogen fuel

Methodology Applied

Scientific EffectElectrical energy to mechanical energy conversion:

Implementation Method 2

pressurize hydrogen fuel in the recirculation hydrogen fuel system

Methodology Applied

Scientific EffectCompression: Compression

Data Source

PatentUS20250313100A1System, method of controlling a system, and vehicle comprising a system

Publication Date: 2025.10.09 VOLVO TRUCK CORP

AI summary

A system for a vehicle, the system comprising a hydrogen fuel storage system for storing hydrogen fuel; a recirculation hydrogen fuel system for transporting hydrogen fuel, the recirculation hydrogen fuel system having a fuel inlet configured to be in fluid communication with the hydrogen fuel storage system and further a fuel return line to the hydrogen fuel storage system, wherein the recirculation hydrogen fuel system is configured to be in fluid communication with a hydrogen fuel-consuming power source, the system further comprising an electrically powered compressor disposed in the recirculation hydrogen fuel system; and wherein the electrically powered compressor is controllable to pressurize hydrogen fuel in the recirculation hydrogen fuel system in response to a determined need for dissipating energy.