Non-Flammable Refrigerant Blend for Low-GWP R-404A Replacement

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Solution Overview

Problem

The refrigeration industry faces challenges in finding replacements for high global warming potential (GWP) refrigerants like R-404A and R-507 that are non-flammable, have low GWP, and maintain existing system performance, due to regulatory pressures and the need for alternatives to HFCs.

Innovation Solution

A non-flammable refrigerant mixture comprising 20-25.5 weight percent HFO-1234yf, 20-24.5 weight percent HFC-32, 24.5-30 weight percent HFC-125, and 25.5-30 weight percent HFC-134a, with optional 0.0001-10 weight percent HFO-1234ze, which provides azeotropic properties and is suitable for replacing R-404A and R-507 in refrigeration systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If HFC refrigerants (R-404A, R-507) are used to replace ozone-depleting substances, then zero ozone depletion potential is achieved, but global warming potential becomes unacceptably high

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

Solution Approach 1:

The patent changes the chemical composition parameters by transitioning from pure HFC refrigerants to a specific mixture of HFO-1234yf, HFC-32, HFC-125, and HFC-134a in defined proportions. This parameter change achieves both low GWP (<150) and non-flammability, resolving the contradiction between ozone protection and climate protection

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite refrigerant mixture combining four different compounds (HFO-1234yf, HFC-32, HFC-125, HFC-134a) with specific weight percentages. This composite approach leverages the complementary properties of each component to achieve non-flammability, low GWP, and system compatibility simultaneously

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If hydrocarbons (butane, propane) or natural refrigerants (CO2) are used as replacements, then low global warming potential is achieved, but flammability or toxicity issues arise

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

Solution Approach 1:

The patent modifies the composition parameters by incorporating HFO-1234yf (non-flammable) as the primary component (20-25.5 wt%) combined with specific amounts of HFC-32 (20-24.5 wt%) and other HFCs, achieving a non-flammable mixture with low GWP that maintains refrigeration performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent develops a composite refrigerant blend that combines the low-GWP properties of HFO-1234yf with the performance characteristics of HFC-32, HFC-125, and HFC-134a. This composite material achieves both low environmental impact and safety requirements through synergistic composition

Inventive Principle:
Principle #40Composite materials

3Object-generated harmful factors

If existing HFC refrigerant systems are replaced with alternative refrigerants, then environmental compliance is improved, but system performance and compatibility deteriorate

Engineering Contradiction:
Improveenvironmental complianceVSAvoidsystem performance
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent optimizes the compositional parameters of the refrigerant mixture to match the thermodynamic and operational characteristics of R-404A and R-507, ensuring that system performance, cooling capacity, and efficiency are maintained while achieving low GWP and non-flammability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a universal refrigerant mixture that can replace multiple existing HFC refrigerants (R-404A, R-507, and others) across different applications without requiring system modifications. The composite formulation provides multi-functionality by delivering low GWP, non-flammability, and broad system compatibility simultaneously

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

Data Source

PatentUS9523027B2Refrigerant mixtures comprising tetrafluoropropene, difluoromethane, pentafluoroethane, and tetrafluoroethane and uses thereof
Publication Date: 2016.12.20 THE CHEMOURS CO FC LLC

AI summary

A non-flammable refrigerant mixture is disclosed. The non-flammable refrigerant mixture consists essentially of (a) from 20 weight percent to 25.5 weight percent HFO-1234yf, (b) from 20 weight percent to 24.5 weight percent HFC-32, (c) from 24.5 weight percent to 30 weight percent HFC-125 (d) from 25.5 weight percent to 30 weight percent HFC-134a, and (e) from about 0.0001 weight percent to 10 weight percent trans-HFO-1234ze. These refrigerant mixtures are useful as components in compositions also containing non-refrigerant components (e.g. lubricants), in processes to produce cooling, in methods for replacing refrigerant R-404A or R-507, and in refrigeration apparatus.