Refrigerator Oil Composition for HFO Acid Value Suppression
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Solution Overview
Problem
Refrigerator oil compositions face an increase in acid value due to the thermal instability of unsaturated fluorinated hydrocarbon compounds (HFO) used in refrigerants, especially under high-temperature conditions, which are exacerbated by the compactification and increased performance of refrigerators.
Innovation Solution
A refrigerator oil composition containing a specific epoxy compound, along with base oils such as polyalkylene glycol, polyvinyl ether, or polyol ester, is developed to suppress the increase in acid value by capturing fluorine components generated from HFO decomposition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional refrigerant oils (mineral oil, synthetic ester, or PAG) are used in refrigeration systems with HFC-134a or HFC-123ze (E), then the system can operate, but the oil deteriorates due to oxidation and hydrolysis reactions, leading to increased viscosity, sludge formation, and reduced system reliability
Solution Approach 1:
The patent introduces a specific package of additives acting as intermediaries between the refrigerant oil and the degradation environment. These additives (including oxidation inhibitors, hydrolysis inhibitors, and viscosity modifiers) mediate the chemical interactions, preventing direct degradation while maintaining oil performance throughout the refrigeration cycle.
Solution Approach 2:
The invention creates a composite refrigerant oil formulation by combining base oil (mineral oil, synthetic ester, or PAG) with specific additive packages. This composite structure provides multiple functions simultaneously: the base oil ensures lubrication and heat transfer, while the additives provide oxidation resistance, hydrolysis resistance, and viscosity stability.
2Productivity
If refrigerant oil is used in systems with HFC-134a or HFC-123ze (E), then the refrigeration function is achieved, but the oil undergoes oxidation and hydrolysis reactions causing increased viscosity and sludge formation
Solution Approach 1:
The patent converts the harmful effects of oxidation and hydrolysis into beneficial protective mechanisms. By adding specific inhibitors, the degradation reactions are redirected to form protective films on metal surfaces and stabilize the oil structure, transforming what would be destructive chemical reactions into protective ones that prevent further degradation.
Solution Approach 2:
The invention changes the chemical parameters of the refrigerant oil by introducing additives that alter the oil's resistance to oxidation and hydrolysis. This modifies the oil's chemical stability parameters, allowing it to maintain consistent viscosity and performance characteristics even under the thermal and chemical stress of refrigeration operation.
3Ease of operation
If traditional refrigerant oils are used, then the system can function, but the oil viscosity increases and sludge forms due to oxidation and hydrolysis, reducing system performance
Solution Approach 1:
The patent applies preliminary protective action by incorporating oxidation inhibitors and hydrolysis inhibitors into the oil formulation before degradation can occur. These additives are pre-positioned to intercept and neutralize oxidizing and hydrolyzing agents before they can attack the base oil, preventing viscosity increase and sludge formation before they impact system performance.
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 effectively reduces the acid value increase in refrigerator oil, maintaining stability even with higher HFO content, thus ensuring long-term performance under severe operating conditions.
Implementation Method 1
the oil deteriorates due to oxidation and hydrolysis reactions
Implementation Method 2
the oil deteriorates due to oxidation and hydrolysis reactions
Implementation Method 3
viscosity modifiers which prevent excessive thickening of the refrigerant oil
Data Source
AI summary
Provided is a refrigerator oil composition used for a refrigerant containing one or more unsaturated fluorinated hydrocarbon compounds selected from the compounds represented by general formula (1): CxFyHz (1) [wherein x is an integer of 2 to 6, y is an integer of 1 to 11, and z is an integer of 1 to 11, and one or more carbon-carbon unsaturated bonds are present in the molecule], the refrigerator oil composition containing a base oil (A) selected from the group consisting of a polyalkylene glycol compound, a polyvinyl ether compound, a copolymer of poly(oxy)alkylene glycol or a monoether thereof and polyvinyl ether, and a polyol ester compound; and an epoxy compound (B), wherein the epoxy compound (B) satisfies the following requirements (B1) and (B2): (B1) at least one divalent group represented by the following formula (1) is present in the molecule; (B2) at least one ester group is present in the molecule. According to the refrigerator oil composition, it is possible to provide a refrigerator oil composition capable of effectively suppressing an increase in the acid value even when the ratio of the unsaturated fluorinated hydrocarbon compound (HFO) in the refrigerant is increased.