Polyol Ester Lubricant Prevents Phase Separation in Refrigerants
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Solution Overview
Problem
Current refrigeration systems face issues with phase separation between refrigerants and lubricating oils across a wide temperature range, leading to reduced service life and efficiency, especially when using refrigerants with low global warming potential like unsaturated fluorinated hydrocarbons in car air conditioner systems.
Innovation Solution
A lubricating oil composition featuring a polyol ester compound as the base oil, specifically formulated to maintain compatibility with unsaturated fluorinated hydrocarbon refrigerants, with properties such as low acid and hydroxyl values, high flash point, and kinematic viscosity, along with additives like extreme pressure agents and antioxidants, is used in combination with engineered sliding members and coatings to prevent phase separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional lubricating oils are used with unsaturated fluorinated hydrocarbon refrigerants, then the system can operate with low global warming potential refrigerants, but phase separation occurs between the refrigerant and lubricating oil across a wide temperature range
Solution Approach 1:
The patent changes the chemical parameters of the lubricating oil by using specific polyol esters with controlled molecular weights, hydroxyl values, and acid values. These parameter adjustments ensure compatibility with unsaturated fluorinated hydrocarbon refrigerants across a wide temperature range, preventing phase separation while maintaining low global warming potential.
Solution Approach 2:
The patent employs composite lubricating oil formulations combining polyol esters with specific additives including antioxidants and extreme pressure agents. This composite approach creates a stable mixture that prevents phase separation between the refrigerant and lubricating oil, resolving the contradiction between using environmentally friendly refrigerants and maintaining system stability.
2Stability of the object's composition
If the lubricating oil composition is formulated for compatibility with unsaturated fluorinated hydrocarbon refrigerants, then phase separation is prevented, but the formulation complexity increases
Solution Approach 1:
The patent applies local quality by specifying particular properties for different components of the lubricating oil: polyol esters with specific molecular weights for base compatibility, antioxidants for stability, and extreme pressure agents for lubrication. This targeted approach to component specification achieves phase separation prevention without excessive overall formulation complexity.
3Reliability
If polyol ester compounds with specific properties are used as base oil, then excellent compatibility and sealing properties are achieved, but manufacturing precision requirements increase
Solution Approach 1:
The patent specifies precise parameter ranges for the polyol ester base oil, including acid values of 0.02 mgKOH/g or less and hydroxyl values of 5 mgKOH/g or less. These controlled parameters ensure excellent compatibility with unsaturated fluorinated hydrocarbon refrigerants and reliable sealing properties, with the manufacturing precision requirements being offset by the performance benefits.
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 lubricating oil composition ensures excellent compatibility, sealing properties, and low friction for sliding members, while maintaining stability and extending the service life of refrigeration systems by preventing phase separation and enhancing lubricity.
Implementation Method 1
capability of imparting a low coefficient of friction to sliding members
Implementation Method 2
excellent compatibility, good sealing properties, capability of imparting a low coefficient of friction to sliding members
Implementation Method 3
excellent stability
Implementation Method 4
excellent compatibility
Implementation Method 5
prevent phase separation
Data Source
AI summary
A lubricating oil composition for refrigerators comprising a base oil which comprises as a main component a polyol ester compound obtained from a polyhydric alcohol selected from among pentaerythritol, dipentaerythritol, trimethylolpropane, and neopentyl glycol and a C4 to C20 aliphatic monocarboxylic acid and which has an acid value of 0.02 mgKOH/g or less and a hydroxyl value of 5 mgKOH/g or less. A compressor using the lubricating composition. The lubricating oil composition is applicable to such refrigerators that use a refrigerant having a specific structure, such as an unsaturated fluorinated hydrocarbon compound, and being usable in current car air conditioner systems, and has excellent compatibility with the refrigerant, good sealing properties, capability of imparting a low coefficient of friction to sliding members and, yet, excellent stability. The compressor uses the lubricating composition.