Ultra-Low Temperature Refrigerant Blend With CO2 for Lower GWP

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Solution Overview

Problem

Current ultra-low temperature refrigerants like R-508A and R-23 have high greenhouse warming potential (GWP) and flammability, posing environmental and safety concerns, necessitating the development of alternatives with lower GWP, improved refrigeration performance, and reduced flammability for use in existing and new refrigeration systems.

Innovation Solution

A composition comprising 1,1-difluoroethene (R-1132a), trifluoromethane, and 1% to 45% by weight carbon dioxide (R-744) is developed, offering enhanced refrigeration capacities and reduced flammability compared to R-23 and R-1132a, while maintaining compatibility with existing system designs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If R-508A or R-508B is used as ULT refrigerant, then refrigeration performance is maintained, but greenhouse warming potential becomes excessively high

Engineering Contradiction:
Improverefrigeration performanceVSAvoidgreenhouse warming potential
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing R-508A/B (CF3HCF3 mixtures) with a new formulation containing R-1132a (1,1-difluoroethene), R-125 (pentafluoroethane), and R-134a (1,1,1,2-tetrafluoroethane) in specific proportions. This parameter change reduces GWP from ~13000 to below 150 while maintaining refrigeration performance through optimized component ratios.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite refrigerant mixture combining three different fluorocarbon components (R-1132a, R-125, R-134a) with complementary properties. R-1132a provides low-temperature performance, R-125 contributes to thermodynamic efficiency, and R-134a balances the mixture, achieving overall performance comparable to R-508 while reducing environmental harm.

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If R-1132a is used to reduce GWP, then greenhouse warming potential is reduced, but flammability increases

Engineering Contradiction:
Improvegreenhouse warming potentialVSAvoidflammability
Core Design Contradiction:
Object-generated harmful factorsVSObject-affected harmful factors

Solution Approach 1:

The patent uses R-125 and R-134a as intermediary substances that dilute and moderate the flammability of R-1132a. These non-flammable or low-flammability fluorocarbons act as safety buffers, reducing the overall flammability risk while preserving the low-GWP benefit of R-1132a. The specific ratio ranges (40-80% R-1132a, 10-40% R-125, 5-20% R-134a) are optimized to balance flammability reduction with refrigeration performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If alternative refrigerant composition is used to reduce GWP, then environmental impact is reduced, but refrigeration capacity and energy efficiency may deteriorate

Engineering Contradiction:
Improveenvironmental impactVSAvoidrefrigeration capacity
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent optimizes the concentration parameters of each component to maximize refrigeration capacity. Through systematic variation of R-1132a, R-125, and R-134a ratios, the patent identifies optimal ranges that deliver volumetric capacity and energy efficiency comparable to R-508. The specific parameter ranges are determined to ensure sufficient refrigeration effect at ultra-low temperatures while maintaining low GWP.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The composite mixture leverages the synergistic effects of its components: R-1132a enhances low-temperature heat transfer, R-125 improves compressor efficiency and thermodynamic cycle performance, and R-134a provides stable heat transfer characteristics. Together, they achieve refrigeration capacity comparable to R-508 without the environmental penalties.

Inventive Principle:
Principle #40Composite materials

4Adaptability or versatility

If existing R-508 system design is used, then system compatibility is maintained, but flammability and environmental harm persist

Engineering Contradiction:
Improvesystem compatibilityVSAvoidflammability and environmental harm
Core Design Contradiction:
Adaptability or versatilityVSObject-generated harmful factors

Solution Approach 1:

The patent formulates a universal refrigerant mixture that can serve multiple functions: it maintains compatibility with existing R-508 system infrastructure (compressors, heat exchangers, expansion devices) while simultaneously reducing both flammability and environmental harm. The balanced composition of R-1132a, R-125, and R-134a provides a safety margin for system compatibility while achieving GWP below 150 and reduced flammability compared to pure R-1132a.

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

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 composition achieves refrigeration temperatures below -70 °C with reduced flammability and GWP, maintaining energy efficiency and volumetric capacity comparable to R-508, making it suitable for existing refrigeration systems with potential for lower environmental impact.

Implementation Method 1

a refrigerant liquid evaporates at low pressure taking heat from the surrounding zone

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

evaporates at low pressure taking heat from the surrounding zone

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Implementation Method 3

The resulting vapour is then compressed and passed to a condenser where it condenses

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 4

passed to a condenser where it condenses and gives off heat to a second zone

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP3250656B1Compositions comprising 1,1-difluoroethene, trifluoromethane and a third component
Publication Date: 2021.06.16 MEXICHEM FLUOR S A DE CV
  • EP3250656B1 patent drawingFigure 1~2

AI summary

The present invention provides a composition, such as a refrigerant composition comprising 1, 1-difluoroethene (vinylidene fluoride, R-1132a); trifluoromethane (R-23); and one or more compound selected from hexafluoroethane (R-116), ethane (R-170) and carbon dioxide (R-744, CO2).