Air conditioning system comprising an absorption machine and a mechanical compression machine

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Solution Overview

Problem

Absorption machines using waste heat from internal combustion engines struggle to produce sufficient cold, especially during urban driving or high ambient temperatures, and existing hybrid solutions with R124 refrigerant face environmental concerns and durability issues with NH3-based systems.

Innovation Solution

An air conditioning system combining an absorption machine and a mechanical compression machine, where the refrigerant and working solution are separate, with the absorption machine's working solution serving as a heat source for the compression machine, using environmentally friendly hydrofluoro-olefin refrigerants like R-1234yf and an NH3/H2O mixture, and employing tri-fluid heat exchangers for efficient heat transfer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If an absorption machine uses waste heat from an internal combustion engine for cold production, then it can utilize available thermal energy, but it cannot produce sufficient cold power under certain conditions such as urban driving or high ambient temperatures

Engineering Contradiction:
Improvewaste heat utilizationVSAvoidcold production power
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The patent combines an absorption machine and a mechanical compression machine into a hybrid air conditioning system. The absorption machine handles base cooling using waste heat, while the mechanical compression machine supplements cooling capacity when needed, achieving both waste heat utilization and sufficient cold power production.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The hybrid system serves multiple functions: the absorption machine provides eco-friendly operation using waste heat, while the mechanical compression machine ensures adequate cooling capacity under high-demand conditions. The system adapts to different operating scenarios (urban driving, highway driving, high ambient temperatures) by adjusting the contribution of each machine.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Device complexity

If a hybrid system uses R124 refrigerant, then it simplifies the system architecture with a common refrigerant, but it has strong environmental impact and risks being banned

Engineering Contradiction:
Improvesystem architectureVSAvoidenvironmental impact
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the refrigerant parameter from R124 (HCFC with high environmental impact) to R1234yf (hydrofluoro-olefin with low environmental impact). This parameter change maintains system functionality while eliminating the environmental harm, and the separate circuit design accommodates the different refrigerant properties.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent extracts the harmful element (R124 refrigerant) from the system and replaces it with an environmentally friendly alternative (R1234yf). By separating the refrigerant circuits, the harmful substance is completely removed while maintaining the hybrid architecture benefits.

Inventive Principle:
Principle #2Taking out (Extraction)

3Object-affected harmful factors

If an NH3-based system is used, then it provides environmentally friendly refrigeration, but it reduces the durability of the compressor oil due to oxidation caused by water entrainment

Engineering Contradiction:
Improveenvironmental friendlinessVSAvoidcompressor oil durability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent extracts the NH3 refrigerant from the compression machine circuit and places it only in the absorption machine circuit. This eliminates the harmful interaction between NH3-water mixtures and compressor oil, while preserving the environmental benefits of NH3 in the absorption cycle where it does not contact oil.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent segments the refrigerant circuits into separate absorption and compression loops. The absorption machine uses NH3/H2O working solution while the compression machine uses a different refrigerant that is compatible with compressor oil, preventing oxidation and durability issues while maintaining eco-friendly operation overall.

Inventive Principle:
Principle #1Segmentation

4Reliability

If separate refrigerant circuits are used for the absorption and compression machines, then it prevents contamination and maintains reliability, but it increases the number of system components

Engineering Contradiction:
Improvesystem reliabilityVSAvoidnumber of system components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the absorption machine and mechanical compression machine into a unified hybrid system with shared components (condenser, evaporator, control system). This reduces the overall number of components compared to two completely separate systems, while maintaining separate refrigerant circuits for reliability.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances cold production by leveraging waste heat effectively, reduces environmental impact, and maintains thermomechanical resistance, allowing for compact and reliable operation in vehicles, including during conditions where absorption machines alone cannot meet cooling demands.

Implementation Method 1

The evaporator of the absorption machine is coupled to the evaporator of the compression machine so that the working solution at the level of the evaporator of the absorption machine constitutes at least partially a source of heat intended to exchange with the refrigerant in the evaporator of the compression machine

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Implementation Method 2

The condenser of the absorption machine is coupled to the condenser of the compression machine so that the working solution at the condenser of the absorption machine constitutes at least partially a source of heat intended to be exchanged with the refrigerant fluid in the condenser of the compression machine

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 3

Absorption machines allow calories to be taken from a hot source to produce cold temperatures

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 4

the compressor draws in the refrigerant in the gaseous state, advantageously at low pressure and at low temperature, to raise its pressure and its temperature

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 5

the expansion valve partially vaporizes the refrigerant in the liquid state to lower its temperature

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP3627074B1Air conditioning system comprising an absorption machine and a mechanical compression machine
Publication Date: 2021.11.17 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP3627074B1 patent drawingFigure 1~2

AI summary

The invention relates to an air conditioning system comprising: an absorption chiller for the production of cold comprising an absorber (105), a generator (107), a condenser (102), an evaporator (104) and an absorption fluid circuit (100) adapted to receive a working solution comprising a refrigerant and an absorbent, and a mechanical compression chiller for the production of cold comprising a mechanical compressor (203), a condenser (202), an expansion valve (201), an evaporator (204) and a compression fluid circuit (200) adapted to receive a refrigerant, characterized in that the refrigerant is separate from the working solution,The absorption fluid circulation circuit (100) and the compression fluid circulation circuit (200) are separate closed circuits, and the evaporator (104) of the absorption machine is coupled to the evaporator (204) of the compression machine, and the condenser (102) of the absorption machine is coupled to the condenser (202) of the compression machine, such that the working solution of the absorption machine constitutes, at least partially, a heat source for exchange with the refrigerant of the compression machine. It finds a particularly advantageous application in applications using an internal combustion engine, whether for stationary or unstationary uses.