Scroll Compressor Bypass Valve for Refrigerant Stability
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Solution Overview
Problem
Conventional scroll compressors using refrigerants with small global warming potential, such as hydrofluoroolefin, face instability and decomposition due to excessive compression, leading to reduced reliability and durability in long-term use in appliances like air conditioners and refrigerators.
Innovation Solution
Incorporating bypass holes with check valves in the scroll compressor to allow early communication between compression chambers and the discharge chamber, minimizing temperature increase and decomposition risk by reducing pressure resistance and optimizing the aspect ratio of the bypass holes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional scroll compressors use refrigerants with small global warming potential (such as hydrofluoroolefin), then environmental impact is reduced, but the refrigerant decomposes at high temperatures caused by excessive compression, leading to reduced stability and reliability
Solution Approach 1:
The discharge port is positioned to communicate with the compression chamber at an optimal timing before the compression stroke completes, allowing the refrigerant to be discharged at a predetermined pressure before excessive pressure increase occurs. This preliminary discharge action prevents the temperature rise that would cause decomposition of the environmentally friendly refrigerant.
Solution Approach 2:
The invention changes the discharge timing parameter by strategically positioning the discharge port relative to the compression chamber geometry. This parameter change ensures that discharge occurs at the optimal moment in the compression cycle, maintaining refrigerant stability while achieving effective compression.
2Productivity
If the discharge port communicates with the compression chamber at certain timing, then compression efficiency is improved, but excessive pressure increase occurs causing unstable behavior of the orbiting scroll (separation or abnormal pressure)
Solution Approach 1:
The discharge port is positioned to initiate communication with the compression chamber at an optimal point in the compression cycle, allowing pressure to be released at a predetermined level before excessive pressure buildup occurs. This preliminary discharge action maintains both compression efficiency and scroll stability.
Solution Approach 2:
The geometric relationship between the discharge port and compression chamber creates an automatic feedback mechanism where pressure buildup naturally triggers discharge at the optimal moment, preventing both excessive pressure and maintaining compression efficiency through self-regulation.
3Stress or pressure
If the refrigerant is compressed to high pressure, then the compression function is achieved, but the temperature increases causing decomposition of the refrigerant containing hydrofluoroolefin
Solution Approach 1:
The discharge port is positioned to enable early communication with the compression chamber, allowing the refrigerant to be discharged at a predetermined pressure before the compression stroke completes. This preliminary discharge action prevents the temperature rise that would occur with full compression, thereby preventing decomposition of the hydrofluoroolefin-based refrigerant.
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 enhances the compressor's efficiency, reliability, and durability by preventing excessive temperature increases and decomposition of the refrigerant, thereby ensuring stable performance in refrigerating cycles.
Implementation Method 1
check valves to allow refrigerant to flow from the compression chambers to the discharge chamber
Implementation Method 2
allow the compression chambers to communicate with the discharge chamber before the compression chambers communicate with the discharge port, thereby making it possible to minimize an increase in temperature of a discharged refrigerant
Data Source
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AI summary
A scroll compressor employs therein a refrigerant having a small global warming potential and a small ozone depletion potential and mainly comprising hydrofluoroolefin having a carbon-carbon double bond. A stationary scroll 12 has and end plate and a discharge port 18 defined in the end plate at a central portion thereof so as to open into a discharge chamber. The stationary scroll 12 also has a bypass hole 68 defined in the end plate to allow a plurality of compression chambers 15 to communicate with the discharge chamber before the compression chambers 15 communicate with the discharge port 18. A check valve 19 is provided on the bypass hole 18 to allow the refrigerant to flow from the compression chambers to the discharge chamber. This construction can restrain a baneful influence on the global environment, reduce a temperature increase caused by excessive compression, and restrain decomposition of the refrigerant even in long-term use.