Hydraulic Accumulator Energy Buffering for Variable Power Conversion

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Solution Overview

Problem

Current energy conversion and storage systems face inefficiencies, high costs, and limitations in flexibility, weight, packaging, and manufacturability, particularly in handling variable energy inputs and outputs, and in integrating renewable energy sources.

Innovation Solution

An Integrated Energy Conversion, Transfer, and Storage System that combines double-sided hydraulic units with double-sided hydro-mechanical accumulator units and directional control valves to capture, store, and release energy efficiently, integrating mechanical, hydraulic, and thermal energy sources for multiple mechanical and electrical outputs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If internal combustion engines operate under variable power conditions to meet different energy needs, then adaptability is improved, but energy efficiency deteriorates due to transient operating conditions and increased consumption

Engineering Contradiction:
Improveadaptability to variable energy needsVSAvoidenergy consumption
Core Design Contradiction:
Adaptability or versatilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts the engine operating speed to match the load requirements, allowing the engine to operate at optimal efficiency points while meeting variable energy demands. The hydraulic accumulator and control system enable continuous adjustment of power delivery without changing engine speed, resolving the contradiction between adaptability and energy efficiency.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

A hydraulic accumulator acts as an intermediary energy storage device between the engine and the load. It absorbs excess energy when the engine produces more power than needed and releases energy when demand exceeds generation, allowing the engine to operate at constant optimal speed while meeting variable load requirements efficiently.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If conventional brake energy recovery systems are implemented, then some kinetic energy is recovered, but efficiency is limited due to additional mass and restricted usage scenarios

Engineering Contradiction:
Improvekinetic energy recoveryVSAvoidsystem mass and complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The energy recovery system is merged with the existing hydraulic power steering and brake systems. The hydraulic accumulator serves dual purposes: storing energy for power assist during normal operation and recovering kinetic energy during deceleration. This integration eliminates the need for separate recovery system components, reducing overall mass and complexity while improving energy recovery efficiency.

Inventive Principle:
Principle #5Merging (Combining)

3Adaptability or versatility

If renewable energy sources like wind, wave, and solar are integrated, then energy sustainability is improved, but system flexibility deteriorates due to large fluctuations in availability

Engineering Contradiction:
Improveenergy sustainabilityVSAvoidenergy availability stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

Hydraulic accumulators serve as intermediary energy storage devices that buffer the fluctuations between renewable energy sources and the load. They absorb excess energy when generation exceeds demand and release energy when demand exceeds generation, stabilizing the system and enabling reliable operation despite variable renewable input.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the physical state and pressure parameters of the hydraulic fluid in the accumulators to match varying energy demands. By adjusting pressure and volume parameters dynamically, the system can store and release energy efficiently, accommodating the variable nature of renewable sources while maintaining stable output.

Inventive Principle:
Principle #35Parameter changes

4Loss of energy

If waste heat recovery systems are implemented, then energy efficiency is improved, but practical application is limited by lack of cost-effective conversion solutions

Engineering Contradiction:
Improvewaste heat energyVSAvoidcost-effectiveness of conversion system
Core Design Contradiction:
Loss of energyVSEase of manufacture

Solution Approach 1:

The system uses hydraulic fluid as the working medium for heat transfer and energy conversion. By utilizing the hydraulic fluid circulation already present in the system, waste heat from the engine and brakes can be recovered and converted to useful work through the hydraulic accumulator, avoiding the need for complex and expensive thermal-to-mechanical conversion equipment.

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

This system enhances energy generation and consumption efficiency by providing intermediate storage capacity and flexible power conversion, enabling constant operation conditions and higher efficiency in vehicles and renewable energy applications.

Implementation Method 1

an elastic component positioned within the first open chamber

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

double-sided hydraulic units integrated with double-sided hydro-mechanical accumulator units

Methodology Applied
Scientific EffectHydraulic Accumulator: Hydraulic Accumulator

Implementation Method 3

double-sided hydraulic units integrated with double-sided hydro-mechanical accumulator units

Methodology Applied
Scientific EffectHydraulic Press: Hydraulic Press

Implementation Method 4

integrating mechanical, hydraulic, and thermal energy sources

Methodology Applied
Scientific EffectHeat Exchanger: Heat Exchanger

Data Source

PatentEP3558766B1Integrated energy conversion, transfer and storage system
Publication Date: 2023.11.29 A&A INTERNATIONAL LLC
  • EP3558766B1 patent drawingFigure 1
  • EP3558766B1 patent drawingFigure 2A~2B
  • EP3558766B1 patent drawingFigure 3

AI summary

An integrated hybrid energy recovery and storage system for recovering and storing energy from multiple energy sources is disclosed. The system includes an accumulator unit having a high pressure accumulator and a low pressure accumulator. At least one piston is mounted for reciprocation in the high pressure accumulator. The accumulator unit is configured to receive, store, and transfer energy from the hydraulic fluid to the energy storage media. The system further includes two or more rotational directional control valves, in which at least one rotational directional control valve is positioned on each side of the accumulator unit. Each rotational directional control valve includes multiple ports. The system also includes two or more variable displacement hydraulic rotational units. At least one variable displacement hydraulic rotational unit is positioned adjacent each of the rotational directional control valves.