Rotary Compressor Vane Back Pressure Management
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Solution Overview
Problem
Existing vane-type rotary compressors experience chattering phenomena due to high-pressure refrigerant accumulation, leading to efficiency and reliability issues, particularly when liquid flows in and back pressure drops, causing the vane to be pushed back and resulting in reduced performance and reliability.
Innovation Solution
A rotary compressor design where the discharge back pressure is maintained up to the suction port, preventing the vane from being pushed back until high-pressure refrigerant is bypassed to the suction port, using a structure with annular cylinder, vane slots, and back pressure pockets to manage pressure and reduce chattering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If discharge back pressure is maintained up to the contact point, then friction loss in suction section is reduced, but chattering phenomenon occurs when vane passes contact point due to high-pressure refrigerant pushing vane back
Solution Approach 1:
The patent divides the back pressure maintenance region into two distinct zones: first back pressure maintenance region (from contact point to suction port) and second back pressure maintenance region (from suction port to discharge port). This segmentation allows different pressure control strategies in different regions, preventing vane back-push while maintaining efficient friction loss characteristics.
Solution Approach 2:
The patent introduces an intermediate pressure region between the suction port and the first back pressure maintenance region. This intermediate pressure zone is created in advance to gradually transition the pressure, preventing sudden pressure changes that would cause vane back-push and chattering when the vane passes the contact point.
2Reliability
If discharge back pressure is maintained to prevent vane back-push, then chattering is reduced, but high-pressure refrigerant accumulates in dead volume between rotor and vane nose causing efficiency loss
Solution Approach 1:
The patent extracts the high-pressure refrigerant from the dead volume between the rotor and vane nose by creating a bypass path through the second back pressure maintenance region. This allows the accumulated high-pressure refrigerant to be discharged to the suction port, eliminating the efficiency loss while maintaining chattering reduction.
Solution Approach 2:
The intermediate pressure region acts as a mediator between the suction port and the first back pressure maintenance region. It facilitates smooth pressure transition and prevents sudden pressure changes that would cause vane back-push, while also allowing controlled discharge of accumulated high-pressure refrigerant to maintain efficiency.
3Productivity
If vane is allowed to move freely to reduce friction loss, then efficiency improves, but vane stability deteriorates due to back pressure variations causing chattering
Solution Approach 1:
The patent implements dynamic back pressure control by creating different back pressure maintenance regions with different pressure characteristics. The first region maintains stable back pressure to ensure vane stability, while the second region allows pressure variation to enable efficient refrigerant discharge, achieving both stability and efficiency through dynamic pressure management.
Solution Approach 2:
The patent applies different back pressure control characteristics to different regions along the vane's path. The first back pressure maintenance region provides stable pressure for vane stability, while the second region allows pressure variation for efficient refrigerant discharge. This local differentiation of pressure control achieves both vane stability and compressor efficiency simultaneously.
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 design effectively reduces chattering and leakage, improving the compressor's performance and reliability by maintaining a stable back pressure and efficiently bypassing high-pressure refrigerant, thus enhancing the compressor's efficiency and mechanical reliability.
Implementation Method 1
maintaining a discharge back pressure so as not to push the vane back
Implementation Method 2
allow the front end surface of the vane to come into contact with the inner periphery of the cylinder until the high-pressure refrigerant is bypassed to the suction port
Implementation Method 3
a rotary compressor uses a method of compressing a fluid by a roller that eccentrically rotates inside a cylinder
Implementation Method 4
the vanes come into contact with the inner peripheral surface of the cylinder to define a plurality of compression chambers
Data Source
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AI summary
The present disclosure provides a rotary compressor including a cylinder having an inner peripheral surface defined in an annular shape to define a compression space, and provided with a suction port configured to communicate with the compression space to suck and provide refrigerant; a roller rotatably provided in the compression space of the cylinder, and provided with a plurality of vane slots providing a back pressure at one side thereinside at a predetermined interval along an outer peripheral surface; and a plurality of vanes slidably inserted into the vane slots to rotate together with the roller, front end surfaces of which come into contact with an inner periphery of the cylinder by the back pressure to partition the compression space into a plurality of compression chambers, wherein high-pressure refrigerant is accommodated between one of the plurality of vanes and an inner periphery of the cylinder.