Staged Cryogenic Storage for Supercritical Compressed Air Energy

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Solution Overview

Problem

Current compressed air energy storage systems face challenges with insufficient cryogenic energy recovery, high costs, safety concerns due to flammable chemicals, and limitations in scalability and reliability.

Innovation Solution

A staged cryogenic storage subsystem with intermediate cooling cryogenic energy cycles, using air, nitrogen, argon, or helium as working mediums, and incorporating a cryogenic energy compensation system and heat storage heat exchange for autonomous energy recovery without external inputs, enhancing efficiency and safety.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional compressed air energy storage uses large-scale caverns and fossil fuel combustion, then large-scale energy storage is achieved with low cost and long life, but construction site is limited and pollution is caused

Engineering Contradiction:
Improveenergy storage capacityVSAvoidpollution from fossil fuel combustion
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent changes the thermodynamic parameters of the compressed air storage system by implementing staged cryogenic storage, transitioning from conventional single-stage storage to multi-stage temperature and pressure control. This enables the system to store compressed air at extremely low temperatures (cryogenic conditions) in staged containers, achieving high-density energy storage without fossil fuel combustion, thus eliminating pollution while maintaining large-scale storage capacity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite insulation structures for the cryogenic storage containers, combining multiple insulation materials and design layers to maintain extremely low temperatures while preventing heat ingress. This composite approach enables the system to achieve cryogenic storage conditions necessary for high-density energy storage without requiring fossil fuel-based heating systems, thereby eliminating pollution

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If thermal storage type compressed air energy storage recovers compression heat for reheat in turbine stages, then high efficiency and environmental friendliness are achieved, but application is limited to topography condition of gas storage cavern

Engineering Contradiction:
Improvecompression heat recovery efficiencyVSAvoidtopography condition limitation
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The patent extracts the energy storage function from geography-dependent caverns and relocates it to mobile or modular cryogenic storage containers. By taking out the storage medium (compressed air) and placing it in transportable containers with staged cryogenic insulation, the system achieves high efficiency through compression heat recovery while eliminating topography constraints, enabling deployment in diverse locations

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent changes the storage temperature parameter to cryogenic levels with staged temperature control, enabling the system to achieve extremely high energy density in compact containers. This parameter change allows the system to recover compression heat efficiently through staged reheat processes while making the storage units mobile and adaptable to various locations, removing topography limitations

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If large-scale high-pressure resistance container pipes replace gas storage caverns, then topography condition limitation is removed and wide application is enabled, but container cost increases and ratio of container cost to total cost increases with storage time

Engineering Contradiction:
Improveconstruction site flexibilityVSAvoidcontainer cost
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements nested staged storage containers where smaller storage units are placed within larger insulated containers, creating a hierarchical multi-stage cryogenic storage system. This nesting approach reduces the total volume and material required for insulation and structural support compared to single large containers, thereby reducing container cost while maintaining the ability to store large quantities of compressed air with high adaptability to various sites

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent segments the energy storage system into multiple staged containers operating at different temperature and pressure levels, rather than using a single large high-pressure container. This segmentation reduces the wall thickness and material requirements for each individual container, lowering manufacturing costs while maintaining overall storage capacity and providing flexibility in deployment configurations

Inventive Principle:
Principle #1Segmentation

4Quantity of substance

If liquid air technology stores working medium in liquid form at atmospheric or low pressure, then energy storage density increases and construction cost and floor space are reduced, but cryogenic energy recovery is not considered and electricity generation efficiency is very low

Engineering Contradiction:
Improveenergy storage densityVSAvoidelectricity generation efficiency
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent implements a feedback mechanism where the cryogenic energy naturally released during liquid air evaporation is captured and fed back into the system. The staged cryogenic storage containers recover this escape cold energy and use it to pre-cool incoming air before compression or to support the liquefaction process, thereby converting what would be a loss into a useful resource and significantly improving electricity generation efficiency while maintaining high energy storage density

Inventive Principle:
Principle #23Feedback

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 improves cryogenic energy recovery efficiency, reduces compressor outlet pressure, and enables large-scale, cost-effective, and safe energy storage, independent of geographical constraints.

Implementation Method 1

storing and/or releasing cryogenic energy in a staged cryogenic storage subsystem when the gaseous air or the liquid air is converted

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

incorporating a cryogenic energy compensation system and heat storage heat exchange for autonomous energy recovery

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 3

the supercritical air in the compressor outlet absorbs cryogenic energy to be cooled down

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 4

the liquid air boosted by a cryopump absorbs heat and recovers the cryogenic energy, then it is gasified and reheated

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3640449B1Staged cold energy storage type supercritical compressed air energy storage system and method
Publication Date: 2024.04.03 INST OF ENGINEERING THERMOPHYSICS - CHINESE ACAD OF SCI
  • EP3640449B1 patent drawingFigure 1
  • EP3640449B1 patent drawingFigure 2
  • EP3640449B1 patent drawingFigure 3

AI summary

The present disclosure provides a supercritical compressed air energy storage system. The supercritical compressed air energy storage system includes a supercritical liquefaction subsystem, an evaporation and expansion subsystem, a staged cryogenic storage subsystem, a heat storage and heat exchange subsystem, and a cryogenic energy compensation subsystem, the staged cryogenic storage subsystem being used for implementing the staged storage and release of cryogenic energy, improving efficiency of recovering cryogenic energy during energy release and energy storage, and thereby improving cycle efficiency of the system. The present disclosure does not need to provide any inputs of additional cryogenic energy and heat energy input externally, and has the advantages of high cycle efficiency, low cost, independent operation, environmental friendliness, and no limitation on terrain conditions, and it is suitable for large-scale commercial applications.