Absorption Chiller Thermal Storage for Stable Vehicle Exhaust Cooling

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Solution Overview

Problem

Existing air conditioning systems in vehicles with internal combustion engines face challenges in providing stable cold production due to the discontinuous and variable nature of exhaust gas heat sources, leading to increased fuel consumption and pollution.

Innovation Solution

A system incorporating a refrigerant storage module connected to the fluid circulation circuit of an absorption machine, allowing for the regulation of refrigerant flow to store or release thermal energy, ensuring stable cold production by managing the variable heat source from exhaust gases.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an absorption chiller is used to produce cold from exhaust gases, then cooling function is provided, but cold production becomes unstable due to discontinuous and variable exhaust gas flow

Engineering Contradiction:
Improvecold production stabilityVSAvoidadaptability to variable exhaust gas flow
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The storage module stores thermal energy in advance when exhaust gas flow is high, so that cooling can be maintained when exhaust gas flow decreases or stops. This preliminary energy storage action resolves the contradiction by preparing resources ahead of time to ensure reliable cold production despite variable exhaust gas conditions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system changes the operational parameters by introducing a storage module that decouples the direct dependency between exhaust gas flow rate and cooling output. The storage module buffers thermal energy, allowing the system to maintain stable cooling performance regardless of variations in exhaust gas parameters, thus resolving the contradiction between reliability and adaptability.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If air conditioning is used in vehicles with internal combustion engines, then cooling is provided, but fuel consumption increases substantially

Engineering Contradiction:
Improvecooling functionVSAvoidfuel consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system converts the harmful waste heat from exhaust gases into useful cooling energy for the vehicle cabin. By using the absorption chiller driven by exhaust heat, the system transforms what would otherwise be wasted energy into a beneficial cooling function, thereby providing reliable air conditioning while avoiding additional fuel consumption.

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

Solution Approach 2:

The air conditioning system serves itself by using the vehicle's own exhaust heat as the energy source for cooling. This self-service approach eliminates the need for additional fuel consumption that would be required by conventional vapor-compression air conditioning systems, resolving the contradiction between providing cooling and minimizing fuel use.

Inventive Principle:
Principle #25Self-service

3Productivity

If exhaust gas heat is used directly to drive the absorption chiller, then cooling is produced, but cooling capacity varies with engine operating mode

Engineering Contradiction:
Improvecooling capacityVSAvoidcooling capacity stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The storage module acts as an intermediary between the variable exhaust gas heat source and the absorption chiller. It buffers thermal energy during high-exhaust-flow conditions and releases it during low-exhaust-flow conditions, thereby mediating the variability and providing stable cooling capacity regardless of engine operating mode.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The storage module utilizes phase transition materials that change state (e.g., solid-liquid transition) at specific temperatures to store and release thermal energy. This phase transition mechanism enables the system to maintain stable cooling capacity by automatically absorbing excess heat when available and releasing it when needed, independent of engine operating variations.

Inventive Principle:
Principle #36Phase transitions

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

The system achieves stable cold power production and optimizes air conditioning performance by regulating refrigeration energy, reducing fuel consumption and pollution, and enhancing mechanical strength of the exhaust system.

Implementation Method 1

an absorption machine for the production of cold from the waste heat of exhaust gas

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 2

a module for storing thermal energy in advance

Methodology Applied
Scientific EffectThermal energy storage: Thermal Energy Storage

Implementation Method 3

the production of cold from the waste heat of exhaust gas... by the evaporator

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

fluidic circulation circuit... between the downstream of the condenser and the upstream of the evaporator

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3584518B1System comprising an absorption machine for refrigeration from the waste heat of exhaust gases of a vehicle comprising a module for storing thermal energy and a method and use of such a system
Publication Date: 2022.03.16 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3584518B1 patent drawingFigure 1
  • EP3584518B1 patent drawingFigure 2~3
  • EP3584518B1 patent drawingFigure 4~5

AI summary

The invention relates to a system comprising a gas exhaust line (300) of a vehicle internal combustion engine and an air conditioning device comprising an absorption chiller for producing cold from exhaust gas characterized in that it comprises at least one storage module suitable for receiving a storage fluid arranged between the upstream of the generator (105) between said generator (105) and the gas exhaust line (300) and the downstream of the evaporator (108) between said evaporator and the secondary heat source, and a control module for the storage module configured to regulate the storage and release of the storage fluid in the storage module so as to provide the generator (105) with a setpoint heat source power and/or that a target cooling energy is produced by the evaporator (108).It is found to be particularly advantageous for vehicles with an internal combustion engine that releases exhaust gases.