EV Air-Conditioner Working Fluid Composition for Low GWP Heating

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Solution Overview

Problem

Conventional air-conditioner working fluids for electric vehicles, such as HFC-134a and HFO-1234yf, have high global warming potential and insufficient cycle performance, particularly in heating applications, and require significant modifications to existing systems for replacement.

Innovation Solution

A working fluid comprising trifluoroethylene, difluoromethane, and 1,3,3-tetrafluoropropene, with a composition of more than 90% to 100% by mass, offering improved cycle performance and reduced global warming potential, suitable for use in electric vehicles without substantial changes to existing air-conditioner devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If HFC-134a is used as air-conditioner working fluid, then ozone layer protection is improved, but global warming potential increases significantly

Engineering Contradiction:
Improveozone layer protectionVSAvoidglobal warming potential
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters by replacing HFC-134a with HFO-1234yf, which has fundamentally different molecular structure (contains carbon-carbon double bond) and thermodynamic properties, achieving both low GWP and acceptable ozone layer protection

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite working fluid system consisting of HFO-1234yf combined with other hydrofluoroolefins or hydrofluorocarbons in specific ratios, creating a blended mixture that optimizes both environmental performance and thermodynamic cycle performance

Inventive Principle:
Principle #40Composite materials

2Object-generated harmful factors

If HFO-1234yf is used as air-conditioner working fluid, then global warming potential is reduced, but cycle performance becomes insufficient

Engineering Contradiction:
Improveglobal warming potentialVSAvoidcycle performance
Core Design Contradiction:
Object-generated harmful factorsVSReliability

Solution Approach 1:

The patent creates a composite working fluid by combining HFO-1234yf with other refrigerants in optimized proportions, where the component refrigerants complement each other's strengths, achieving both low GWP and sufficient cycle performance through synergistic effects

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the composition ratios and thermodynamic parameters of the working fluid mixture to match the operational requirements of the heat pump system, adjusting parameters such as saturation temperature, pressure, and heat capacity to achieve adequate cycle performance

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If conventional working fluids are replaced in electric vehicle air-conditioners, then environmental impact is reduced, but heating performance becomes insufficient

Engineering Contradiction:
Improveenvironmental impactVSAvoidheating performance
Core Design Contradiction:
Object-generated harmful factorsVSTemperature

Solution Approach 1:

The patent selects working fluids with optimized thermodynamic parameters including higher latent heat of vaporization and appropriate saturation temperature curves, enabling the heat pump to achieve sufficient heating capacity while maintaining low GWP

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs blended refrigerant compositions where the combination of different hydrofluoroolefins and hydrofluorocarbons provides both low environmental impact and enhanced heating performance through complementary thermal properties

Inventive Principle:
Principle #40Composite materials

4Reliability

If air-conditioner device specifications are greatly changed, then cycle performance can be improved, but device complexity and cost increase

Engineering Contradiction:
Improvecycle performanceVSAvoiddevice specifications
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent achieves improved cycle performance primarily through working fluid composition optimization rather than hardware modifications, maintaining compatibility with existing air-conditioner device specifications while enhancing performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent adapts the working fluid formulation to work with existing device architectures, effectively copying the successful application of HFO-1234yf in other systems and applying it to electric vehicle air-conditioners with minimal modifications

Inventive Principle:
Principle #26Copying

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 working fluid provides enhanced cycle performance during both cooling and heating, while minimizing global warming impact and allowing for seamless replacement of conventional fluids without significant changes to air-conditioner specifications.

Implementation Method 1

a method is employed which utilizes heat pump and cools the air in the vehicle using evaporation heat generated by evaporating coolant being a working fluid in an evaporator

Methodology Applied
Scientific EffectEvaporation heat: Evaporation

Implementation Method 2

for heating in the gasoline vehicle, a method is employed which utilizes waste heat of the gasoline combustion in the engine and heats air in the vehicle using heat of cooling water for cooling the engine

Methodology Applied
Scientific EffectCondensation heat: Condensation

Data Source

PatentEP3257913B1Use of a working fluid as air conditioner working medium for electric car
Publication Date: 2021.01.27 AGC INC
  • EP3257913B1 patent drawingFigure 1A
  • EP3257913B1 patent drawingFigure 1B
  • EP3257913B1 patent drawingFigure 2

AI summary

There are provided an air-conditioner working fluid for electric vehicle providing sufficient cycle performance in practical use in an electric vehicle, in particular, sufficient cycle performance also in the heating time, while suppressing influence on global warming, and usable without greatly changing an air-conditioner device for a conventional working fluid, for example, HFC-134a or HFO-1234yf, and an air-conditioner working fluid composition for electric vehicle containing the same. The air-conditioner working fluid for electric vehicle contains trifluoroethylene, difluoromethane and 1,3,3,3-tetrafluoropropene, wherein a percentage of a total amount of trifluoroethylene, difluoromethane and 1,3,3,3-tetrafluoropropene with respect to a total amount of the working fluid is more than 90 mass% and 100 mass% or less.