Capacity Control Valve with Dynamic CS Valve Pressure Isolation
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Solution Overview
Problem
Existing capacity control valves for variable displacement compressors suffer from poor control precision and energy efficiency due to the continuous communication between the suction and control ports, leading to inefficient fluid discharge during normal operation.
Innovation Solution
A capacity control valve design that includes a CS valve between the control and suction ports, controlled by the dynamic pressure of the discharge fluid, preventing control fluid discharge through the suction port during normal operation, and utilizing a pressure drive valve for rapid fluid discharge during startup.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the auxiliary communication passage is provided to enable communication between the intermediary communication passage and the third valve chamber, then the fluid discharge performance at startup is improved, but the control precision and energy efficiency during normal operation deteriorate due to continuous communication between suction and control ports
Solution Approach 1:
The communication passage is segmented into different sections with different valve elements. The first valve element controls communication between the discharge chamber and control chamber, while the second valve element controls communication between the control chamber and suction chamber. This segmentation allows independent control of fluid flow paths, enabling the system to achieve both rapid fluid discharge at startup and precise control during normal operation by selectively opening or closing specific valve sections.
Solution Approach 2:
The valve elements are designed to dynamically change their position and sealing state based on operating conditions. During startup, both valve elements are positioned to allow communication between all chambers for rapid fluid discharge. During normal operation, the valve elements move to their respective sealed positions to prevent continuous communication between suction and control ports, thereby maintaining control precision and energy efficiency.
2Quantity of substance
If the main valve is opened to allow fluid flow from discharge chamber to control chamber, then the fluid circulation is improved, but the control pressure is lost due to discharge through the suction port
Solution Approach 1:
The first valve element acts as an intermediary between the discharge chamber and control chamber, controlling the flow of fluid while preventing direct communication with the suction chamber. The second valve element serves as an intermediary between the control chamber and suction chamber, ensuring that when the first valve element is open for fluid circulation, the second valve element remains closed to maintain control pressure and prevent discharge through the suction port.
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 enhances control precision and energy efficiency during normal operation while ensuring rapid fluid discharge at startup, maintaining maximum capacity and operational efficiency.
Implementation Method 1
a main valve element to be moved in the axial direction by electromagnetic force generated in a solenoid
Implementation Method 2
a pressure sensitive body arranged in the third valve chamber, the pressure sensitive body that applies bias force in the valve opening direction of a main valve to the main valve element in accordance with surrounding fluid pressure
Data Source
AI summary
A capacity control valve includes a valve housing provided a discharge port through which a discharge fluid of discharge pressure Pd passes, a suction port through which a suction fluid of suction pressure Ps passes, and a control port through which a control fluid of control pressure Pc passes, a rod configured to be driven by a solenoid, a main valve formed by a main valve seat and a main valve element and configured for opening and closing a communication between the discharge port and the control port in accordance with a movement of the rod, and a CS valve provided between the control port and the suction port and controlled by a dynamic pressure of a fluid flowing from the discharge port to the control port at an opening state of the main valve.