Variable Capacity Compressor Pressure Release Valve
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Solution Overview
Problem
Variable capacity compressors face challenges in rapidly adjusting discharge capacity during sudden acceleration or cut-off control, leading to delayed pressure release in the control pressure chamber, which impairs start-up performance and increases internal refrigerant circulation.
Innovation Solution
A variable capacity compressor design with a first control valve that adjusts the supply passage and a second control valve on the bleed passage, featuring a spool housing recess, a movable spool, and a back pressure chamber, where the back pressure chamber is selectively connected to either the discharge chamber or the inlet chamber to control the bleed passage, allowing rapid pressure release and adjustment of discharge capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the supply passage is opened to introduce high-pressure gas into the control pressure chamber for discharge capacity control, then the discharge capacity can be adjusted, but the pressure release becomes delayed when liquid refrigerant is accumulated
Solution Approach 1:
The patent introduces a three-way valve as an intermediary device that selectively connects the back pressure chamber to either the discharge chamber or the inlet chamber. This mediator allows the system to choose the optimal pressure source based on operational conditions, enabling rapid pressure release by connecting to the inlet chamber (lower pressure) when needed, rather than being constrained to the discharge chamber (higher pressure).
Solution Approach 2:
The system dynamically switches the connection state of the back pressure chamber between the discharge chamber and the inlet chamber based on operational requirements. The three-way valve enables this dynamic reconfiguration, allowing the compressor to adapt pressure release pathways in real-time, transforming a static pressure control system into a dynamic one that can respond rapidly to changing conditions.
2Productivity
If the compressor is activated from a counterbalanced state, then the refrigerant can be discharged via the bleed passage, but the pressure remains at saturation pressure due to liquid refrigerant accumulation
Solution Approach 1:
The patent extracts the liquid refrigerant problem from the control pressure chamber by providing a dedicated pressure release pathway. The three-way valve enables selective connection to the inlet chamber, creating a separate extraction route for liquid refrigerant that bypasses the saturation pressure constraint, allowing liquid to be removed without maintaining high pressure in the control chamber.
Solution Approach 2:
The system performs preliminary action by pre-configuring the three-way valve and back pressure chamber connection before the pressure release operation. This allows the system to establish a low-resistance discharge pathway in advance, enabling rapid pressure equalization when activation occurs, rather than relying on the slower natural vaporization process.
3Stress or pressure
If a fixed throttle is provided on the supply passage downstream of the back pressure chamber connection, then the pressure in the back pressure chamber increases, but the bleed passage closing becomes less reliable
Solution Approach 1:
The system dynamically adjusts the back pressure chamber connection state using the three-way valve, switching between connection to the discharge chamber (higher pressure) and the inlet chamber (lower pressure) based on operational needs. This dynamic capability allows the system to maintain reliability by selecting the appropriate pressure source rather than relying on a fixed high-pressure connection that may compromise bleed passage closing.
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 enhances start-up performance by rapidly releasing refrigerant from the control pressure chamber, reducing the time for liquid vaporization and discharge, and minimizing internal refrigerant circulation during intermediate strokes, thereby improving the compressor's ability to quickly adjust discharge capacity.
Implementation Method 1
a spool housed in the spool housing recess and configured to be movable to open and close the bleed passage; a back pressure chamber segmentalized in the spool housing recess behind the spool
Implementation Method 2
a compression chamber configured to compress a working fluid
Implementation Method 3
the pressure in the control pressure chamber is maintained at a saturation pressure even when the refrigerant in the control pressure chamber is discharged into the inlet chamber via the bleed passage, and thus the discharge capacity control cannot be performed
Data Source
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AI summary
[Object] To provide a variable capacity compressor configured to achieve an enhancement of an activation performance of a compressor and reduce an amount of internally circulating refrigerant during an intermediate stroke in a simple structure. [Solving Means] A supply passage 40 configured to cause a discharge chamber 34 and a control pressure chamber 4 to communicate with each other; a first bleed passage 42 configured to cause the control pressure chamber 4 and an inlet chamber 33 to communicate with each other; a first control valve 50 configured to adjust an opening degree of the supply passage 40; and a second control valve 45 provided on the first bleed passage 42 are provided, and the second control valve 45 includes: a spool 47 housed in a spool housing recess formed on a bleed passage and configured to open and close the first bleed passage 42, a back pressure chamber 48 formed behind the spool 47, and biasing means (compression spring 49) configured to bias the spool 47 in a direction of opening the first bleed passage 42. The back pressure chamber 48 of the second control valve 45 is selectively connected to the discharge chamber 34 or the inlet chamber 33 via the first control valve 50.