Scroll Compressor Injection Port Positioning for Oil Dilution
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Solution Overview
Problem
Conventional low-pressure shell scroll compressors face issues with refrigerant injection, leading to refrigerant overflow into the oil sump, dilution of compressor oil, and inefficient performance due to dead volume compression in existing designs.
Innovation Solution
The design incorporates injection ports that directly open to the suction chambers, reducing refrigerant flow into the oil sump and eliminating dead volume compression by ensuring injection refrigerant only enters the suction chambers, thereby maintaining oil viscosity and enhancing compressor efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the injection port is disposed distant from the suction chamber to reduce discharge temperature, then the discharge temperature is reduced, but the injection refrigerant overflows into the oil sump and dilutes the refrigerating machine oil
Solution Approach 1:
The suction chamber serves as an intermediary space that receives injection refrigerant from the injection port and directs it into the compression chamber. This mediator prevents direct overflow into the oil sump while maintaining the temperature-reducing effect of injection refrigerant.
Solution Approach 2:
The internal space is segmented into distinct functional zones: the suction chamber for receiving injection refrigerant, the compression chamber for compressing refrigerant, and the oil sump for storing oil. This segmentation prevents mixing between injection refrigerant and oil, maintaining system reliability.
2Reliability
If the injection port communicates only with the compression chamber to prevent oil dilution, then the reliability is maintained, but dead volume is created that does not contribute to compression
Solution Approach 1:
The communication path of the injection port is made dynamic rather than static. During injection operation, the injection port communicates with the suction chamber to receive refrigerant. During non-injection operation, the suction chamber dynamically directs all refrigerant into the compression chamber, eliminating dead volume and maintaining high productivity.
3Productivity
If the injection port communicates with the compression chamber in most rotation phases to maintain continuous compression, then the productivity is improved, but dead volume compression occurs causing performance degradation
Solution Approach 1:
The injection port communication path is extracted and separated from the main compression chamber communication. Instead of directly communicating with the compression chamber in all phases, the injection port communicates with the suction chamber, which then selectively directs refrigerant to the compression chamber only when needed, eliminating unnecessary dead volume compression.
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 reduces refrigerant overflow, maintains oil viscosity, and improves compressor performance by ensuring efficient refrigerant compression without unnecessary work on dead volumes.
Implementation Method 1
injection ports (202) for introducing refrigerant into the suction chambers (70a, 70b) with which they open, respectively
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
An object is to obtain a scroll compressor that can reduce an outflow of injection refrigerant into an oil sump, reduce degradation of reliability associated with a decrease in viscosity of refrigerating machine oil stored in the oil sump, and reduce degradation of performance caused by compression of dead volume, and thereby achieve high efficiency, and to also obtain a refrigeration cycle apparatus. An injection port opens only to a suction chamber and is provided in a baseplate of a fixed scroll. In all phases of rotation of a rotation shaft, the injection port is located on an inner side of an outer edge of a structure unit that is configured by meshing a spiral body of the fixed scroll and a spiral body of an orbiting scroll with each other.