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Solution Overview
Problem
The refrigerant with a single double bond in its molecular structure has relatively low volume resistivity, leading to degraded voltage insulating properties and increased leakage current in refrigeration apparatus compressors.
Innovation Solution
A refrigeration apparatus using a fluoropropene refrigerant with a refrigerant oil having high volume resistivity, compatibility with the refrigerant, and specific properties such as viscosity and surface tension to enhance lubrication and reduce leakage current, along with the use of insulating materials resistant to high-temperature high-pressure conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If refrigerant of formula (1) with a single double bond is used, then ozone layer protection is improved, but voltage insulating properties degrade and leakage current increases
Solution Approach 1:
The patent introduces refrigerant oil as an intermediary substance between the refrigerant and the electrical components. This refrigerant oil with high volume resistivity acts as a mediator that prevents direct contact between the low-insulation refrigerant and the electrical parts, thereby blocking the harmful effect of leakage current while allowing the beneficial refrigeration function to continue.
Solution Approach 2:
The patent employs refrigerant oil as a consumable medium that can be easily replaced. Rather than trying to modify the refrigerant itself to improve insulation, the system uses a separate, replaceable refrigerant oil that provides insulation protection. This approach allows the primary refrigerant to maintain its excellent ozone-layer-friendly properties while the refrigerant oil handles the insulation function.
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 solution effectively reduces leakage current from electric motors by ensuring adequate lubrication and maintaining high volume resistivity of the refrigerant oil, improving operational efficiency and reliability of the refrigeration apparatus.
Implementation Method 1
using refrigerant oil having a volume resistivity of ≥10 10 Ω·m
Implementation Method 2
an electric motor (85) for driving the fluid machine (82) and using refrigerant oil
Implementation Method 3
such refrigerant is evaporated in the evaporator
Implementation Method 4
refrigerant compressed in the compressor is condensed by releasing heat to air in the condenser
Implementation Method 5
The pressure of the refrigerant condensed in the condenser is reduced by the expansion valve
Data Source
Figure 1
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Figure 3
AI summary
A refrigeration apparatus (20) includes a refrigerant circuit (10) in which refrigerant is circulated by a compressor (30) to perform a refrigeration cycle. The compressor (30) includes a fluid machine (82) for compressing refrigerant; and an electric motor (85) for driving the fluid machine (82). Refrigerant oil having volume resistivity of equal to or greater than 1010 Ω·m at 20°C is used for the compressor (30).