Lubricant for compression type refrigerating machines
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Solution Overview
Problem
Current lubricating oils for compression-type refrigerators using R32 refrigerant suffer from phase separation at temperatures lower than −20° C., which can lead to reduced lubricity and heat exchange efficiency, and existing polyvinyl ether compounds do not provide sufficient miscibility with R32 refrigerant at low temperatures.
Innovation Solution
A lubricating oil comprising a polyvinyl ether compound with a carbon/oxygen molar ratio of 3.0 to less than 4.0, specifically a polymer with a structural unit represented by general formula (I-1) or a polymer having an alkylene glycol unit and a vinyl ether unit, ensuring miscibility with R32 refrigerant even at low temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing polyvinyl ether compounds are used as lubricating oil for R32 refrigerant, then the lubricating performance is maintained, but phase separation occurs at temperatures below −20° C. due to insufficient miscibility
Solution Approach 1:
The invention changes the chemical composition parameters of the polyvinyl ether compound by controlling the carbon/oxygen molar ratio to be 4.2 or less and introducing oxyalkylene structures into side chains, which fundamentally alters the molecular properties to achieve better miscibility with R32 refrigerant at low temperatures
Solution Approach 2:
The invention creates a composite molecular structure by combining polyvinyl ether backbone with oxyalkylene side chains (such as polyethylene glycol or polypropylene glycol structures), resulting in a compound that exhibits both lubricating properties and enhanced miscibility with R32 refrigerant across a wide temperature range
2Reliability
If the carbon/oxygen molar ratio of polyvinyl ether compound is increased to improve lubricating performance, then lubrication is enhanced, but miscibility with R32 refrigerant at low temperatures deteriorates
Solution Approach 1:
The invention applies local quality by introducing oxyalkylene structures specifically into the side chains of the polyvinyl ether compound while maintaining the main backbone structure for lubrication, creating different functional regions within the same molecule that simultaneously provide both lubricating performance and low-temperature miscibility
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 maintains miscibility with R32 refrigerant at temperatures below −20° C., preventing phase separation and enhancing the lubrication performance and heat exchange efficiency, thus contributing to the use of R32 refrigerant with a low global warming coefficient.
Implementation Method 1
the miscibility of the two is insufficient... the lubricating oil to be used therein is desired to be miscible with the refrigerant with no separation even at a temperature lower than −20° C.
Data Source
AI summary
The present invention is a lubricating oil for compression-type refrigerators using a difluoromethane (R32) refrigerant. The lubricating oil for compression-type refrigerators contains a first polyvinyl ether compound that is a polymer having a structural unit of a specific structure and has a carbon/oxygen molar ratio of from 3.0 to less than 4.0.