Quaternary HFC Refrigerant Mixture for Low-GWP R-404A Replacement

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

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, energy efficient, and compatible with existing systems, due to tightening environmental regulations.

Innovation Solution

A non-flammable refrigerant mixture comprising 23-25.5 weight percent HFO-1234yf, 22-24.5 weight percent HFC-32, 24.5-27 weight percent HFC-125, and 25.5-28 weight percent HFC-134a, optionally with HFO-1234ze, which offers low GWP and azeotropic properties, allowing for use as replacements in refrigeration systems without requiring significant equipment modifications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If HFC refrigerants (R-404A, R-507) are used to replace CFCs and HCFCs, then ozone depletion potential is eliminated, but global warming potential increases

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 using a quaternary mixture of HFO-1234yf, HFC-32, HFC-125, and HFC-134a with specific weight percentages. This composition achieves low GWP (less than 150) while maintaining refrigeration performance, thereby changing the environmental impact parameters from high GWP to low GWP

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite refrigerant mixture combining four different hydrofluorocarbon compounds (HFO-1234yf, HFC-32, HFC-125, HFC-134a) in specific proportions. This composite approach allows optimization of multiple properties simultaneously: low GWP, non-flammability, and adequate refrigeration performance

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If natural refrigerants (hydrocarbons like butane or propane) are used as replacements, then global warming potential is reduced, but flammability and toxicity increase

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

Solution Approach 1:

The patent changes the chemical composition from pure hydrocarbons to a quaternary HFC mixture containing HFO-1234yf (20-30 wt%), HFC-32 (20-30 wt%), HFC-125 (20-35 wt%), and HFC-134a (15-30 wt%). This composition achieves non-flammability (ASHRAE safety class A1) while maintaining low GWP

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses HFO-1234yf as an intermediary component that bridges between the low GWP of hydrocarbons and the non-flammability of traditional HFCs. HFO-1234yf has very low GWP and when combined with other HFCs in specific proportions, the mixture achieves both low GWP and non-flammability

Inventive Principle:
Principle #24Intermediary (Mediator)

3Object-generated harmful factors

If replacement refrigerants are selected to meet low GWP requirements, then environmental regulations are satisfied, but system compatibility and energy efficiency deteriorate

Engineering Contradiction:
Improveglobal warming potentialVSAvoidsystem compatibility
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent optimizes the composition parameters of the quaternary mixture to achieve a balance between low GWP and system compatibility. The specific weight percentages of HFO-1234yf (20-30%), HFC-32 (20-30%), HFC-125 (20-35%), and HFC-134a (15-30%) are tuned to provide adequate refrigeration performance and compatibility with existing equipment

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a universal refrigerant mixture that can serve multiple functions: low GWP (environmental compliance), non-flammability (safety), and adequate refrigeration performance (system compatibility). The quaternary composition is designed to work in various refrigeration applications including commercial refrigeration and air conditioning systems

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 proposed refrigerant mixture provides comparable cooling performance and energy efficiency to existing systems, while reducing GWP and eliminating flammability risks, making it suitable for retrofitting or new applications in medium and low-temperature refrigeration.

Implementation Method 1

The refrigeration industry has been working for the past few decades to find replacement refrigerants for the ozone depleting chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) being phased out

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

Certain compositions comprising tetrafluoropropene, difluoromethane, pentafluoroethane and tetrafluoroethane have been found to possess suitable properties to allow their use as replacements of higher GWP refrigerants currently in use

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Data Source

PatentEP3425018B1Refrigerant mixtures comprising tetrafluoropropene, difluoromethane, pentafluoroethane, and tetrafluoroethane and uses thereof
Publication Date: 2019.12.25 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, or consists essentially of (a) from 23 weight percent to 25.5 weight percent HFO-1234yf, (b) from 22 weight percent to 24.5 weight percent HFC-32, (c) from 24.5 weight percent to 27 weight percent HFC-125, and (d) from 25.5 weight percent to 28 weight percent HFC-134a. 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.