Compressed Gas Storage System Pressure Gradient Energy

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Solution Overview

Problem

Current methods for storing electrical energy from renewable sources, such as pumped storage power plants and compressed air energy systems, are inefficient and require significant energy for conditioning and have geographical limitations, while existing compressed gas storage facilities are not optimized for energy storage.

Innovation Solution

A compressed gas storage system with at least two gas storage volumes connected to a gas transport network, utilizing a compressor and engine to create a pressure gradient for energy storage and retrieval, allowing for efficient use of existing gas storage volumes without altering the stored gas quantity, and using a heat accumulator to manage temperature differences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If compressed air energy systems use pressure difference between storage tank and atmosphere, then energy storage is achieved, but heat management becomes complex and dehumidification effort increases

Engineering Contradiction:
Improvestored energyVSAvoidheat management and dehumidification
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent changes the pressure parameter from atmospheric pressure to high pressure (70-200 bar) for storage, and uses a reference pressure (10-50 bar) for comparison. This parameter change allows the system to store energy in the pressure difference between two high-pressure states, avoiding the need for atmospheric pressure differential and the associated heat management and dehumidification complexities.

Inventive Principle:
Principle #35Parameter changes

2Quantity of substance

If pumped storage power plants use height difference between basins, then large energy storage capacity is achieved, but geographical limitations and large storage volume requirements arise

Engineering Contradiction:
Improvestored energyVSAvoidgeographical adaptability
Core Design Contradiction:
Quantity of substanceVSAdaptability or versatility

Solution Approach 1:

The patent replaces the gravitational mechanical system (height difference between basins) with a pressurized gas system. Instead of using gravity and mass of water to store energy, the system uses compressed gas at high pressure (70-200 bar) stored in underground caverns or tanks, eliminating the need for height differences and enabling deployment in various geographical locations.

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

3Quantity of substance

If compressed air is stored at high pressure, then energy density increases, but temperature differences require significant heating or cooling energy

Engineering Contradiction:
Improveenergy densityVSAvoidheating or cooling energy
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent applies preliminary cooling to the gas before compression to a high pressure (70-200 bar). By pre-cooling the gas, the system reduces the temperature rise during compression, thereby minimizing the subsequent heating energy required when the gas is expanded. This preliminary action addresses the temperature management issue proactively rather than reactively.

Inventive Principle:
Principle #10Preliminary 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

This solution enables efficient storage and retrieval of electrical energy using existing compressed gas storage facilities, reducing energy requirements for heating or cooling and allowing for flexible operation akin to pumped storage power plants, while maintaining reasonable temperature differences.

Implementation Method 1

a compressor (4) disposed between the second manifold (6) and the first manifold (3)... the compressor... generating a pressure gradient

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

at least one engine and at least one generator, the engine disposed between the second manifold and the first manifold... the engine... utilizing a pressure gradient... generating electrical energy

Methodology Applied
Scientific EffectExpansion:

Implementation Method 3

using a heat accumulator to manage temperature differences

Methodology Applied
Scientific EffectThermal energy storage: Thermal Energy Storage

Data Source

PatentEP2803841B1Pressurised gas storage device
Publication Date: 2016.09.14 INNOGY NETZE DEUTSCHLAND GMBH
  • EP2803841B1 patent drawingFigure 1
  • EP2803841B1 patent drawingFigure 2~2b
  • EP2803841B1 patent drawingFigure 3

AI summary

A pressurized gas storage facility is preferably designed as a gas storage power plant and comprises two gas storage volumes which are connected to a gas transport network (7), wherein the gas storage volumes communicate with each other via at least a first collecting line (3) and are connected to the gas transport network via at least a second collecting line (6).The compressed gas storage device further comprises at least one compressor (4) arranged between the second manifold (6) and the first manifold (3), and at least one expansion turbine (11) with generator (12) arranged between the second manifold (6) and the first manifold (3), wherein the compressor (4) and the expansion turbine (11) are connected in parallel between the second manifold (6) and the first manifold (3), and wherein the compressor (4) and the expansion turbine (11) are connected in such a way that gas can be transferred between the gas storage volumes by utilizing a pressure differential when the generator (12) is operating or by generating a pressure differential when the compressor (4) is operating.