Scroll Compressor Pressure-Ratio Back Pressure Control for Sealing
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Solution Overview
Problem
Existing scroll compressors, particularly high-pressure types, face challenges in maintaining consistent performance across varying operating conditions due to unregulated back pressure, leading to inefficient operation and potential refrigerant leakage.
Innovation Solution
A scroll compressor design that includes a back pressure hole and flow paths allowing controlled communication between the compression chamber and back pressure chambers, with pressure control pins to adjust back pressure based on operating conditions, ensuring the orbiting scroll moves axially to maintain sealing and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a back pressure hole is provided in the fixed scroll to communicate with the back pressure chamber, then the back pressure can be adjusted, but the structure becomes more complex and manufacturing difficulty increases
Solution Approach 1:
The back pressure hole is segmented into multiple flow paths (first flow path and second flow path) with different functions. The first flow path communicates with the compression chamber and the second flow path communicates with the back pressure chamber, allowing independent control of different pressure zones while maintaining a relatively simple overall structure.
Solution Approach 2:
The end plate groove in the orbiting scroll acts as an intermediary structure that connects the back pressure chamber to the compression chamber through the back pressure hole in the fixed scroll. This intermediary groove allows controlled communication between chambers while maintaining sealing at other interfaces.
2Reliability
If the back pressure chamber is isolated, then sealing is improved, but pressure regulation capability is reduced
Solution Approach 1:
The system transitions from a static isolated back pressure chamber to a dynamic system where the back pressure chamber can communicate with the compression chamber through the back pressure hole when needed. The end plate groove dynamically opens or closes the communication path based on operating conditions, allowing both sealing and pressure regulation.
Solution Approach 2:
The back pressure in the back pressure chamber is dynamically adjusted by controlling the communication through the back pressure hole. By changing the pressure parameter in the back pressure chamber based on operating conditions, the system can adapt to different compression requirements while maintaining reliable sealing when communication is closed.
3Adaptability or versatility
If the orbiting scroll is allowed to move axially freely, then adaptation to pressure changes is improved, but control precision is reduced
Solution Approach 1:
The back pressure chamber serves as a feedback mechanism where pressure changes in the compression chamber are transmitted through the back pressure hole to the back pressure chamber. This pressure feedback causes the orbiting scroll to automatically adjust its axial position in response to loading conditions, achieving adaptive control with inherent precision through pressure equilibrium.
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 design achieves consistent performance across different operating regions by actively adjusting back pressure, reducing refrigerant leakage, and enhancing the efficiency of the scroll compressor.
Implementation Method 1
a back pressure hole (146) disposed between the compression chamber (P) and a first back pressure chamber (137a) in which gas discharged from the compression chamber (P) is received, and the back pressure hole (146) is capable of communicating with the first back pressure chamber (137a) and the compression chamber (P) on a basis of a predetermined pressure ratio of the compression chamber (P)
Implementation Method 2
an orbiting scroll (150) actively moves in an axial direction by a relationship of forces between a back pressure chamber and a compression chamber
Data Source
AI summary
A scroll compressor including an orbiting scroll that performs an orbiting motion; a fixed scroll coupled to the orbiting scroll so as to form a compression chamber; and a main frame that rotatably supports the orbiting scroll at an opposite side of the fixed scroll with the orbiting scroll interposed therebetween, and supportably connected to the fixed scroll. The fixed scroll is provided with a back pressure hole formed between a first back pressure chamber in which gas discharged from the compression chamber is received, and the compression chamber. The back pressure hole may communicate with the first back pressure chamber and the compression chamber on the basis of a predetermined pressure ratio of the compression chamber.