Refrigeration Oil Composition for HFO Hydrogen Fluoride Control

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Solution Overview

Problem

Conventional refrigeration systems using hydrofluoroolefin refrigerants suffer from the degradation of components due to the generation of hydrogen fluoride at high temperatures, leading to corrosion and motor insulation deterioration.

Innovation Solution

Employing an ester-based refrigeration oil with unsaturated fatty acids that react with hydrogen fluoride, forming adducts which are circulated within the system, thereby stabilizing and removing hydrogen fluoride and preventing component degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional HFC refrigerants are used, then refrigeration cycle compatibility is achieved, but fluorine ions decompose ester-based refrigeration oil causing corrosion and motor insulation deterioration

Engineering Contradiction:

Improverefrigeration cycle compatibilityVSAvoidcorrosion and motor insulation deterioration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical composition parameters of the refrigeration oil by introducing unsaturated fatty acid esters with specific molecular structures (containing carbon-carbon double bonds) that alter the oil's reactivity toward fluorine ions, thereby maintaining compatibility while reducing degradation

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The unsaturated fatty acid esters act as intermediaries that react with fluorine ions to form stable compounds, preventing the fluorine ions from directly decomposing the refrigeration oil and causing corrosion

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If fluorine ion concentration in refrigeration oil is limited to 1 ppm or less, then ester-based refrigeration oil decomposition is prevented, but hydrogen fluoride generation from refrigerant decomposition cannot be stopped

Engineering Contradiction:

Improverefrigeration oil stabilityVSAvoidhydrogen fluoride generation

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful hydrogen fluoride generated during refrigerant decomposition into a beneficial process by having the unsaturated fatty acid esters react with and neutralize the hydrogen fluoride, transforming the harmful decomposition product into a stable adduct that circulates in the system

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The refrigeration oil system performs self-protection by using its own unsaturated fatty acid content to react with and neutralize hydrogen fluoride, eliminating the need for external additives or separate protection mechanisms

Inventive Principle:

Principle #25Self-service

3Object-affected harmful factors

If hydrofluoroolefin refrigerant is used, then global warming potential is reduced, but hydrogen fluoride decomposition occurs at high temperatures causing component degradation

Engineering Contradiction:

Improveglobal warming potentialVSAvoidcomponent degradation

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the chemical composition of the refrigeration oil by incorporating unsaturated fatty acid esters with specific structural parameters (carbon-carbon double bonds) that enable hydrogen fluoride scavenging, thereby allowing the use of low-GWP hydrofluoroolefin refrigerants without component degradation

Inventive Principle:

Principle #35Parameter changes

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 refrigeration apparatus effectively suppresses the degradation of components by incorporating hydrogen fluoride into the refrigeration oil, maintaining physical properties and preventing corrosion, while minimizing global warming potential through the use of a hydrofluoroolefin and hydrofluorocarbon mixed refrigerant.

Implementation Method 1

Hydrogen fluoride, a decomposition product of the refrigerant, in the system is removed through the reaction with the unsaturated fatty acid residues in the refrigeration oil

Methodology Applied

Scientific EffectChemical reaction: Chemical Bonding

Data Source

PatentUS20120304687A1Refrigeration apparatus

Publication Date: 2012.12.06 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD

AI summary

Use of a double bond-containing hydrofluoroolefin refrigerant causes a problem that it generates hydrogen fluoride by cleavage and decomposition under influence of oxygen, leading to degradation of the materials and the refrigeration oil used in the refrigeration apparatus and causing troubles in the refrigeration apparatus.It is possible to provide a high-reliability longer-lasting refrigeration apparatus by inexpensive method, by using a double bond-containing hydrofluoroolefin refrigerant in a refrigerating cycle having a refrigerant circulation route extending from a compressor 1, via a condenser 2, an expansion mechanism 3, and an evaporator 4, back to the compressor 1 that contains an ester-based refrigeration oil containing an unsaturated fatty acid as a constituent fatty acid.