Five-Component Refrigerant Mixture for Non-Flammable Low-GWP Cooling

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Solution Overview

Problem

The refrigeration industry faces challenges in finding replacements for ozone-depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) that are non-flammable, have low global warming potential (GWP), and maintain performance equivalent to HFCs like R-22, R-410A, R-407A, R-407C, and R-407F, which are being phased out due to environmental regulations.

Innovation Solution

Compositions comprising difluoromethane, pentafluoroethane, tetrafluoroethane, tetrafluoropropene, and carbon dioxide are developed, which are non-ozone depleting, have reduced direct global warming potential, and are non-flammable, allowing them to serve as environmentally sustainable alternatives for R-22, R-410A, R-407A, R-407C, and R-407F in refrigeration and air conditioning systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If HFC refrigerants (R-22, R-410A, R-407A, R-407C, R-407F) are used to replace CFCs and HCFCs, then ozone depletion potential is reduced to zero, but global warming potential increases and flammability becomes a concern

Engineering Contradiction:
Improveozone depletion potentialVSAvoidglobal warming potential and flammability
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by using difluoromethane (HFC-32) as the primary component with specific weight percentages (40-70%), combined with HFC-125, HFO-1234yf, HFC-134a, and CO2 in controlled amounts. This parameter change achieves low GWP (below 150) and non-flammability while maintaining refrigeration performance, resolving the contradiction between ozone protection and climate change mitigation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite refrigerant mixture combining five different components with specific weight ratios. The composite formulation leverages the complementary properties of each component: HFC-32 provides high efficiency, HFC-125 and HFO-1234yf reduce flammability and GWP, HFC-134a enhances safety, and CO2 further reduces GWP. This composite approach resolves the contradiction by achieving low GWP and non-flammability while maintaining performance

Inventive Principle:
Principle #40Composite materials

2Productivity

If difluoromethane content is increased to improve refrigeration performance, then performance equivalent to R-22 and R-410A is achieved, but flammability increases

Engineering Contradiction:
Improverefrigeration performanceVSAvoidflammability
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent uses CO2 as an intermediary component that suppresses the flammability of difluoromethane. CO2 acts as a flame inhibitor and safety enhancer, allowing high concentrations of HFC-32 (40-70%) to be used for optimal refrigeration performance while the CO2 content (2-20%) ensures the mixture remains non-flammable. This intermediary approach resolves the contradiction between performance and safety

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent copies the safety characteristics of non-flammable refrigerants while maintaining the high performance of difluoromethane-based formulations. By incorporating HFC-125, HFO-1234yf, and CO2, the mixture replicates the safety profile of traditional refrigerants but with improved environmental credentials and comparable or superior performance

Inventive Principle:
Principle #26Copying

3Object-generated harmful factors

If refrigerant mixtures are formulated to have low GWP and non-flammability, then environmental sustainability is improved, but performance equivalence to existing refrigerants becomes difficult to achieve

Engineering Contradiction:
Improveglobal warming potential and flammabilityVSAvoidrefrigeration performance
Core Design Contradiction:
Object-generated harmful factorsVSProductivity

Solution Approach 1:

The patent optimizes the weight percentage parameters of each component to achieve the desired balance. HFC-32 is set at 40-70% for high efficiency, HFC-125 at 5-30% and HFO-1234yf at 5-30% for safety and low GWP, HFC-134a at 0-20% for additional safety, and CO2 at 2-20% for flammability suppression and GWP reduction. These parameter changes enable simultaneous achievement of low GWP, non-flammability, and performance equivalence

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent formulates a composite mixture where each component contributes specific properties: HFC-32 provides high refrigeration efficiency, HFC-125 and HFO-1234yf reduce flammability and GWP, HFC-134a enhances safety margins, and CO2 provides flame inhibition and low GWP. The synergistic interaction of these composite components achieves all three goals of low GWP, non-flammability, and performance equivalence to R-22, R-410A, and other referenced refrigerants

Inventive Principle:
Principle #40Composite materials

Data Source

PatentUS11312891B2Refrigerant mixtures comprising difluoromethane, pentafluoroethane, tetrafluoroethane, tetrafluoropropene, and carbon dioxide and uses thereof
Publication Date: 2022.04.26 THE CHEMOURS CO FC LLC

AI summary

In accordance with the present invention refrigerant compositions are disclosed. The compositions comprise HFC-32, HFC-125, HFO-1234yf, HFC-134a, and CO2. The refrigerant compositions are useful in processes to produce cooling and heating, in methods for replacing refrigerant R-410A or R-22, and in refrigeration, air conditioning or heat pump systems. These inventive compositions are non-flammable and match cooling performance for R-22 and R-410A within ±15%. Additionally, these compositions may serve as replacements for R-404A, R-507, R407A, R407C and/or R-407F in refrigeration, air conditioning or heat pump systems. The compositions as described herein have unexpected flammability properties.