Displacement Control Valve Passages for Faster Compressor Startup
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Solution Overview
Problem
Variable displacement compressors experience prolonged startup times due to liquefied refrigerant accumulation in the control pressure chamber, which increases pressure excessively when vaporized, hindering rapid displacement recovery after activation.
Innovation Solution
A displacement control valve with an electromagnetic solenoid, drive force transmission body, pressure sensitive chamber, and valve bodies that adjust passage cross-sectional areas to facilitate efficient refrigerant flow from the discharge pressure region to the control pressure chamber and release it into the suction pressure region, utilizing gap passages and recesses to reduce flow resistance and expedite refrigerant release.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the displacement control valve keeps the cross-sectional area of the regulation passage in a small state, then the pressure control is maintained, but the liquefied refrigerant cannot be readily released from the control pressure chamber to the suction pressure region
Solution Approach 1:
The valve body is designed with a movable valve portion that can dynamically adjust the cross-sectional area of the regulation passage. When liquefied refrigerant is detected in the control pressure chamber, the valve opens to increase the passage area for rapid refrigerant release. Under normal operating conditions, the valve maintains a small cross-sectional area for precise pressure control. This dynamic adjustment capability resolves the contradiction between maintaining pressure control and enabling rapid refrigerant release.
2Ease of operation
If the variable displacement compressor is activated in a state in which liquefied refrigerant is collected in the control pressure chamber, then the compressor can start, but the pressure increases excessively due to vaporization of the liquefied refrigerant
Solution Approach 1:
The displacement control valve is designed to automatically detect and respond to the presence of liquefied refrigerant in the control pressure chamber before excessive pressure buildup occurs. Upon detecting liquid refrigerant, the valve immediately opens to facilitate rapid release of the liquid to the suction pressure region, preventing vaporization and excessive pressure increase. This preliminary action enables safe compressor startup even when liquid refrigerant is present, resolving the contradiction between ease of operation and pressure control.
3Ease of manufacture
If the terminal portion of the relief passage is a linear passage extending perpendicular to the shaft passage, then the structure is simple, but the flow resistance increases which is not preferable for readily releasing the liquefied refrigerant
Solution Approach 1:
The relief passage is designed with a curved or angled configuration rather than a simple linear passage perpendicular to the shaft passage. This curved design reduces flow resistance by creating a more gradual flow path for the refrigerant, enabling faster release of liquefied refrigerant from the control pressure chamber to the suction pressure region. The curved passage structure maintains manufacturing feasibility while significantly improving refrigerant flow characteristics, resolving the contradiction between ease of manufacture and refrigerant flow efficiency.
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 solution enables quicker recovery of compressor displacement after activation by efficiently releasing liquefied refrigerant, reducing pressure buildup and minimizing the time required for displacement increase, thus enhancing the compressor's startup efficiency.
Implementation Method 1
an electromagnetic solenoid, a drive force transmission body... The drive force transmission body is driven by the electromagnetic solenoid
Implementation Method 2
The pressure sensitive chamber is in communication with the control pressure chamber. The pressure sensitive unit includes a pressure sensitive body arranged in the pressure sensitive chamber
Implementation Method 3
utilizing gap passages and recesses to reduce flow resistance and expedite refrigerant discharge
Data Source
AI summary
A displacement control valve for a variable displacement compressor. The displacement control valve includes a drive force transmission body, a pressure sensitive chamber, an internal passage, and a valve body. The valve body includes an annular seal which is contactable with a valve seat surface facing toward the first valve body. The drive force transmission body includes a drive rod and a valve body structure having a shaft passage and forming the first valve body. The drive rod is fitted to the shaft passage and coupled to the valve body structure so as to form a gap passage between an outer surface of the drive rod and a wall surface of the shaft passage. The internal passage includes a recess arranged radially inward from the annular seal, the shaft passage, and the gap passage. The gap passage is in direct communication with the recess.