Vapor Absorption Chiller for Adiabatic CAES Heat Recovery

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Solution Overview

Problem

Existing power generation systems face inefficiencies in meeting varying demand levels, particularly during peak and off-peak hours, as they struggle to effectively store and utilize energy generated during non-peak hours.

Innovation Solution

The implementation of a modified adiabatic compressed air energy storage system that captures and stores heat energy typically lost between compressors, using an air handling unit, vapor absorption chiller, and energy storage unit to enhance efficiency by approximately 8-10% through improved heat management and energy utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If heat energy is lost between compressors in a conventional CAES system, then the system structure remains simple, but energy efficiency decreases significantly

Engineering Contradiction:
Improveheat energy lossVSAvoidsystem complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent converts the harmful heat energy loss between compressors into a beneficial resource by capturing it in a thermal energy storage unit. The heat from the first compressor exhaust and second compressor exhaust is recovered and stored, then utilized during power generation to preheat air or provide thermal energy, thereby converting waste heat into useful energy and improving overall system efficiency.

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

Solution Approach 2:

The patent implements heat recovery by capturing thermal energy that would otherwise be discarded. Thermal energy storage units are positioned to recover heat from compressor exhaust streams, and this recovered energy is later utilized during the power generation phase, preventing energy waste and improving the energy efficiency ratio.

Inventive Principle:
Principle #34Discarding and recovering

2Productivity

If compressed air is stored in a cavern without heat recovery, then the storage system is simple, but energy efficiency during peak demand hours decreases

Engineering Contradiction:
Improvepower generation efficiencyVSAvoidenergy utilization during peak demand
Core Design Contradiction:
ProductivityVSUse of energy by stationary object

Solution Approach 1:

The patent performs preliminary actions by storing thermal energy during off-peak hours when compressors are operating. The thermal energy storage units capture and store heat energy in advance, so that when peak demand occurs and compressed air is released from the cavern, the thermal energy is already available to provide heat to the expanding air, improving efficiency during the critical power generation phase.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements a feedback mechanism where the thermal energy stored during compression is fed back into the system during expansion. The stored thermal energy is transferred to the compressed air during the power generation phase, creating a closed-loop energy system that improves overall efficiency by utilizing both mechanical and thermal energy stores.

Inventive Principle:
Principle #23Feedback

3Reliability

If moisture is not removed from air during compression, then the compression process is simpler, but system reliability decreases due to water damage

Engineering Contradiction:
Improvesystem reliabilityVSAvoidmoisture removal system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts moisture from the compressed air stream using a moisture removal system positioned in the compression pathway. This extraction of water prevents condensation and damage to equipment, thereby improving system reliability while adding a specialized component to handle the moisture separation function.

Inventive Principle:
Principle #2Taking out (Extraction)

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 allows for a significant improvement in overall operating efficiency by recovering heat energy, enabling better energy storage and release during peak demand hours, thus effectively addressing the inefficiencies in existing systems.

Implementation Method 1

a vapor absorption chiller connected to the first compressor and configured to transfer heat energy between a plurality of mediums and to cool the first compressed, heated air flow

Methodology Applied
Scientific EffectHeat transfer: Heat Exchanger

Implementation Method 2

an energy storage unit connected to the second compressor and configured to store heat energy from the second compressed, heated air flow

Methodology Applied
Scientific EffectThermal energy storage: Thermal Energy Storage

Implementation Method 3

air is taken into an axial compressor 4 and compressed during which the air is put under pressure and undergoes an increase in temperature

Methodology Applied
Scientific EffectAdiabatic compression: Adiabatic Heating

Implementation Method 4

any water that is generated by the cooling process is drained off

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP2447505B1Inlet air cooling and moisture removal methods and devices in advanced adiabatic compressed air energy storage systems
Publication Date: 2019.11.27 NUOVO PIGNONE SPA
  • EP2447505B1 patent drawingFigure 1
  • EP2447505B1 patent drawingFigure 2
  • EP2447505B1 patent drawingFigure 3

AI summary

Systems and methods provide for cooling air in a power generation system. The system includes: an air handling unit configured to receive air, to cool the air and to remove moisture from the air; a first compressor fluidly connected to the air handling unit and configured to receive the air from the air handling unit and to exhaust a first compressed, heated air flow; a vapor absorption chiller connected to the first compressor and configured to transfer heat energy between a plurality of mediums and to cool the first compressed, heated air flow; and a second compressor connected to the vapor absorption chiller and configured to receive the cooled first compressed, heated air flow and to exhaust a second compressed, heated air flow.