Scroll Compressor Back Pressure Passage Angle Optimization
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Solution Overview
Problem
In variable capacity type scroll compressors, the proximity of the back pressure passage and injection passage can lead to refrigerant leakage into the back pressure chamber, causing excessive pressure and frictional loss, which degrades the reliability and performance of the compressor.
Innovation Solution
The angle between the back pressure passage and the injection passage is set to be greater than approximately 30°, with the second injection hole positioned closer to the discharge side of the compression chamber than the second back pressure hole, preventing refrigerant leakage and maintaining appropriate pressure within the back pressure chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the back pressure passage and injection passage are positioned close to each other to simplify the structure, then the device complexity is reduced, but refrigerant leaks into the back pressure chamber causing excessive pressure and frictional loss
Solution Approach 1:
The patent applies asymmetry by positioning the back pressure passage and injection passage at different radial distances from the center of the compression chamber. The back pressure passage is positioned closer to the center while the injection passage is positioned farther away, creating an asymmetric configuration that prevents refrigerant leakage while maintaining structural simplicity.
Solution Approach 2:
The patent resolves the contradiction by introducing a radial dimension consideration - passages are arranged not only in circumferential position but also at different radial distances from the center. This dimensional approach allows passages to be close in overall structure while maintaining sufficient separation in the radial direction to prevent leakage.
2Reliability
If the angle between back pressure passage and injection passage is increased to prevent refrigerant leakage, then reliability is improved, but the passage configuration becomes more complex
Solution Approach 1:
The patent applies parameter changes by optimizing the angle between the back pressure passage and injection passage to be within 30-150 degrees, with preference for 60-120 degrees. This quantitative parameter specification prevents refrigerant leakage while avoiding excessive complexity in passage arrangement.
Solution Approach 2:
The patent applies local quality by making the passage configuration locally optimized rather than uniformly complex. The passages are arranged with specific angular relationships and radial positions that locally prevent leakage without requiring complex overall structure.
3Stress or pressure
If refrigerant is allowed to enter the back pressure chamber to maintain pressure, then pressure stability is improved, but frictional loss increases due to excessive pressure
Solution Approach 1:
The patent introduces the compression chamber as an intermediary between the suction chamber and back pressure chamber. Refrigerant flows through the compression chamber first, and only appropriately pressurized refrigerant enters the back pressure chamber through the back pressure passage, acting as a mediator that controls pressure and prevents excessive frictional loss.
Solution Approach 2:
The patent applies preliminary action by ensuring refrigerant is pre-compressed in the compression chamber before entering the back pressure chamber. This preliminary compression action ensures that only refrigerant at appropriate pressure enters the back pressure chamber, preventing excessive pressure and frictional loss.
Data Source
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AI summary
A scroll compressor and a refrigerating apparatus having the same are provided. In the scroll compressor, an angle formed between an injection passage that guides refrigerant from a condenser back into an intermediate compression chamber and a back pressure passage that guides refrigerant from the intermediate compression chamber into a back pressure chamber may be designed so as to prevent leakage of refrigerant from the intermediate compression chamber into the back pressure chamber. This allows an appropriate pressure to be maintained the back pressure chamber, and increases an amount of refrigerant supplied into the compression chambers, thereby improving performance of the scroll compressor and a refrigerating apparatus in which such a scroll compressor is installed.