Compressor Casing Coating for Low Gas Permeability Corrosion Control
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Solution Overview
Problem
Conventional compressors fail to consider gas permeability of the coating film, which is crucial for effective moisture and oxygen blocking under varying temperature conditions, leading to potential rust formation.
Innovation Solution
The compressor design includes a coating film with nitrogen gas permeability rates of 2,500 [mol ·µm/(m²·s·Pa)] or less at -40°C, 150 [mol·µm/(m²·s·Pa)] or less at room temperature, and 2,500 [mol ·µm/(m²·s·Pa)] or less at 100°C, using a highly crosslinked epoxy resin with benzene rings, and is evaluated at multiple temperatures including a first temperature below 0°C.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a coating material is selected based primarily on adhesion between substrate and coating film, then corrosion resistance is ensured, but gas permeability of the coating film is not adequately considered, leading to potential moisture and oxygen transmission under varying temperature conditions
Solution Approach 1:
The patent applies parameter changes by specifying the nitrogen gas permeability rate of the coating film at different temperatures (2,500 [mol·μm/(m²·s·Pa)] or less at -40°C, 150 [mol·μm/(m²·s·Pa)] or less at room temperature, and 2,500 [mol·μm/(m²·s·Pa)] or less at 100°C). This ensures the coating maintains appropriate gas barrier properties across the entire operating temperature range of the compressor, resolving the contradiction between ensuring corrosion resistance and adapting to varying temperature conditions.
2Power
If the casing is exposed to high-temperature environment from compressed refrigerant, then compression function is achieved, but the coating film's gas permeability increases at high temperatures, potentially allowing moisture and oxygen transmission
Solution Approach 1:
The patent addresses this contradiction by establishing specific nitrogen gas permeability rate parameters at high temperatures (2,500 [mol·μm/(m²·s·Pa)] or less at 100°C). This parameter control ensures that even when the coating's gas permeability increases due to high-temperature exposure during compression operation, the coating still effectively prevents moisture and oxygen transmission, thus protecting against corrosion while maintaining compression function.
3Temperature
If the casing is cooled by low-temperature refrigerant returning from evaporator, then refrigeration cycle function is achieved, but the coating film's gas permeability increases at low temperatures, potentially allowing moisture and oxygen transmission
Solution Approach 1:
The patent resolves this contradiction by specifying the nitrogen gas permeability rate at low temperatures (2,500 [mol·μm/(m²·s·Pa)] or less at -40°C). This ensures that when the casing is cooled by low-temperature refrigerant during the refrigeration cycle, the coating film's gas permeability remains controlled and does not increase to levels that would allow significant moisture and oxygen transmission, thus maintaining corrosion protection while enabling refrigeration cooling 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
This configuration effectively suppresses moisture and oxygen transmission, preventing rust formation across the compressor's entire casing, enhancing its reliability and anti-corrosion performance.
Implementation Method 1
The nitrogen gas permeability rate of the coating film is (a) 2,500 [mol·µm/(m²·s·Pa)] or less at -40°C, (b) 150 [mol·µm/(m²·s·Pa)] or less at room temperature, and (c) 2,500 [mol·µm/(m²·s·Pa)] or less at 100°C
Data Source
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AI summary
A compressor (1) includes a compression mechanism (13) configured to compress a refrigerant, an electric motor configured to drive the compression mechanism, and a casing accommodating the compression mechanism and the electric motor. The refrigerant compressed by the compression mechanism (13) is discharged from the compressor (1) via a space inside the casing, and the compression mechanism (13) is exposed to a high-temperature environment caused by the compressed refrigerant. The casing includes a base material made of a ferrous metal, and the nitrogen gas permeability rate of a coating film formed on an outer surface of the casing is (a) 2,500 [mol ·µm/(m2·s·Pa)] or less at -40°C, (b) 150 [mol·µm/(m2·s·Pa)] or less at room temperature, and (c) 2,500 [mol ·µm/(m2·s·Pa)] or less at 100°C.