Polyol Ester Refrigeration Oil Composition

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Solution Overview

Problem

Current refrigeration oil compositions for hydrofluorocarbon-based and hydrocarbon-based refrigerants face challenges in achieving suitable solubility and viscosity for various applications, leading to separation issues and reduced lubricity, necessitating the use of multiple oils and complex raw material management.

Innovation Solution

A polyol ester oil composition is developed through the esterification of pentaerythritol and dipentaerythritol with specific fatty acids, such as 2-methylbutanoic, 2-methylpentanoic, 2-ethylhexanoic, and 3,5,5-trimethylhexanoic acids, allowing for adjustable solubility and viscosity to match different refrigerants and applications without the need for multiple oil types.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the kinematic viscosity of polyol ester oil is lowered to increase solubility of hydrofluorocarbon-based refrigerant, then the solubility is improved, but the lubricity decreases

Engineering Contradiction:
Improvesolubility of refrigerantVSAvoidlubricity
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent uses a composite polyol ester oil formulation containing multiple specific fatty acid components (branched-chain fatty acids with 5-9 carbon atoms combined with saturated fatty acids with 10-12 carbon atoms) to achieve both high solubility and high lubricity simultaneously, eliminating the need to trade off between these properties

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the chemical composition parameters of the polyol ester oil by specifying particular fatty acid components and their ratios (e.g., branched-chain fatty acids at 20-80 mol%, saturated fatty acids at 20-80 mol%), which allows the oil to achieve both high refrigerant solubility and high lubricity without lowering viscosity

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the kinematic viscosity of polyol ester oil is heightening to improve lubricity, then the lubricity is improved, but the hydrofluorocarbon-based refrigerant separates out

Engineering Contradiction:
ImprovelubricityVSAvoidsolubility stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent employs a composite polyol ester oil with specific fatty acid composition (combining branched-chain and saturated fatty acids in controlled ratios) that maintains both high lubricity and high refrigerant solubility, preventing separation while preserving lubricating properties

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the chemical composition parameters by specifying fatty acid types and ratios (e.g., 20-80 mol% branched-chain fatty acids, 20-80 mol% saturated fatty acids), enabling the oil to maintain stable solubility and high lubricity simultaneously

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If multiple polyol ester oils are mixed to achieve suitable solubility and viscosity, then the solubility and viscosity requirements are met, but the polyol ester oil that is less soluble gradually separates out during circulation

Engineering Contradiction:
Improvesolubility and viscosity suitabilityVSAvoidcomposition stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent creates a homogeneous single-phase polyol ester oil formulation with specific fatty acid composition that ensures uniform solubility characteristics throughout the oil, preventing gradual separation of less soluble components during refrigeration cycle circulation

Inventive Principle:
Principle #33Homogeneity

Solution Approach 2:

The patent uses a carefully designed composite polyol ester oil containing specific ratios of branched-chain and saturated fatty acids that achieves both suitable solubility/viscosity and long-term composition stability, eliminating the need to mix multiple different oils

Inventive Principle:
Principle #40Composite materials

4Reliability

If the refrigeration oil has high kinematic viscosity to heighten refrigerant-solution viscosity, then the lubricity is improved, but the flowability is impaired and the refrigerant and oil are less apt to mingle

Engineering Contradiction:
ImprovelubricityVSAvoidflowability and mixing
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent optimizes the kinematic viscosity parameter of the polyol ester oil by controlling fatty acid composition (specific ratios of branched-chain and saturated fatty acids), achieving high lubricity while maintaining sufficient flowability and refrigerant mixing capability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent discards the conventional approach of using excessively high viscosity oils and instead recovers optimal performance by using polyol ester oils with controlled, moderate viscosity that balances lubricity and flowability

Inventive Principle:
Principle #34Discarding and recovering

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 composition prevents oil separation, ensures stable lubricity and cooling performance across various refrigerated facilities, and simplifies raw material procurement and production management by using a single formulation adaptable to multiple refrigerants.

Implementation Method 1

a first polyol ester oil which is a product of the esterification of an alcohol ingredient pentaerythritol and dipentaerythritol, and a fatty acid ingredient

Methodology Applied
Scientific EffectEsterification: Chemical Bonding

Data Source

PatentEP2799527B1Refrigerator oil composition
Publication Date: 2022.02.02 JAPAN SUN OIL
  • EP2799527B1 patent drawingFigure 1~2

AI summary

The refrigeration oil composition for HFC-based refrigerants or HC-based refrigerants of the invention includes a product of the esterification of an alcohol ingredient including pentaerythritol and dipentaerythritol and a fatty acid ingredient including at least one of a linear or branched fatty acid having 5 carbon atoms and a linear or branched fatty acid having 6 carbon atoms and at least one of a linear or branched fatty acid having 8 carbon atoms and a linear or branched fatty acid having 9 carbon atoms, wherein at least one of the fatty acid having 5 carbon atoms and the fatty acid having 6 carbon atoms in the fatty acid ingredient accounts for 20 to 100% by mol of the total amount of the fatty acid ingredient, and either the alcohol ingredient or the fatty acid ingredient is a mixture.