Variable Mode Compressed Air Energy Storage System

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Solution Overview

Problem

Traditional compressed air energy storage (CAES) systems lack flexibility in generation modes, relying on a single electrical machine for both compression and generation, which limits their operational efficiency and adaptability to varying power demands.

Innovation Solution

A CAES system with a programmable logic controller (PLC) that manages a compressor train, intercooler, aftercooler, electric motor, generator, and turbine train, allowing for variable flow rates and modes of operation, including low, emergency, and high power generation, by diverting air to a combustor and controlling fuel supply to optimize energy production based on grid demands.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single electrical machine is used for both compression and generation functions, then equipment redundancy is reduced, but operational flexibility and adaptability to varying power demands deteriorate

Engineering Contradiction:
Improveequipment redundancyVSAvoidoperational flexibility
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The system segments the electrical machine functions by using separate motor and generator units with clutch mechanisms, allowing independent control of compression and generation operations. This enables the system to adapt to varying power demands while maintaining equipment efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements dynamic operational modes where the clutch connections can be reconfigured in real-time based on grid demands. The controller adjusts the connection state of clutches to switch between single-generator mode, dual-generator mode, and other operational configurations, providing adaptability without permanent redundancy.

Inventive Principle:
Principle #15Dynamics

2Device complexity

If traditional CAES operation modes are used, then system simplicity is maintained, but response capability to peak and emergency power needs deteriorates

Engineering Contradiction:
Improvesystem simplicityVSAvoidresponse capability
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system implements multiple dynamic operational modes (single-generator mode, dual-generator mode, first emergency mode, second emergency mode) that can be switched based on grid requirements. The controller dynamically adjusts clutch connections and fuel injection rates to optimize response capability for peak and emergency power needs.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters such as fuel injection rate, air flow rate, and clutch connection state to transition between different generation modes. These parameter changes enable rapid response to varying power demands while maintaining a relatively simple physical system configuration.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If fixed generation modes are used, then system reliability is improved, but operational efficiency under varying conditions deteriorates

Engineering Contradiction:
Improvesystem reliabilityVSAvoidoperational efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The controller receives feedback regarding grid power demands and system operational state, then adjusts clutch connections and fuel injection rates accordingly. This feedback mechanism maintains system reliability through controlled transitions while optimizing operational efficiency for current conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically adjusts its operational mode based on real-time conditions, switching between reliable fixed modes (single-generator, dual-generator) and emergency modes as needed. This dynamic adaptation maintains reliability while improving operational efficiency under varying grid demands.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2880274B1Compressed air energy storage system having variable generation modes
Publication Date: 2019.04.10 APEX COMPRESSED AIR ENERGY STORAGE LLC
  • EP2880274B1 patent drawingFigure 1A
  • EP2880274B1 patent drawingFigure 1B
  • EP2880274B1 patent drawingFigure 1C

AI summary

A method of operating a compressed air energy storage (CAES) system (1) includes operating a compressor train (3w,h() of the CAES system, thereby compressing air. The method further includes, while operating the compressor train: inter-cooling a first portion of the compressed air; further compressing the inter-cooled first portion; after- cooling the further compressed first portion; supplying the after- cooled first portion to a storage vessel; supplying a second portion of the compressed air to a combustor; combusting the second portion; and operating a turbine train (9h,w) of the CAES system using the combusted second portion.