Capacity Control Valve With Differential Pressure Startup Exhaust
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Solution Overview
Problem
Existing capacity control valves for variable displacement compressors face challenges in startup responsiveness and operational efficiency due to slow liquefied fluid exhaustion and pressure differential issues, leading to decreased maximum displacement state maintenance.
Innovation Solution
A capacity control valve design incorporating a differential pressure valve that opens based on pressure differences between the control and suction pressures, enhancing fluid exhaustion during startup and maintaining equal pressures for efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a single pressure-sensitive valve is used to exhaust liquefied fluid during startup, then the valve structure is simple, but the fluid exhaustion speed is insufficient and startup responsiveness is slow
Solution Approach 1:
The single pressure-sensitive valve is divided into two separate valves: a first pressure-sensitive valve and a second pressure-sensitive valve. Each valve has its own valve body, valve seat, and pressure-sensitive chamber configuration. This segmentation increases the total fluid exhaustion speed by providing two parallel flow paths while keeping each individual valve structure relatively simple.
Solution Approach 2:
The two pressure-sensitive valves are combined within the same valve housing and operate simultaneously during startup. Their pressure-sensitive chambers are connected to the control chamber through different communication passages, creating a merged system that achieves rapid fluid exhaustion through coordinated operation of both valves.
2Stability of the object's composition
If the suction pressure is lowered to maintain maximum displacement state, then the maximum displacement can be maintained, but the pressure differential causes piston stroke wobbles and reduces operational efficiency
Solution Approach 1:
The second pressure-sensitive valve provides feedback control by monitoring the pressure difference between the control chamber and suction chamber. When the suction pressure drops too low during maximum displacement state, the second valve opens to allow suction pressure into the control chamber, preventing excessive pressure differential and stabilizing piston stroke without significantly reducing operational efficiency.
Solution Approach 2:
The system dynamically adjusts the pressure parameters in the control chamber by using the second pressure-sensitive valve to introduce suction pressure when needed. This parameter change prevents the suction pressure from dropping too low, maintaining operational efficiency while still allowing the system to operate in maximum displacement state.
3Reliability
If the control pressure is kept much higher than suction pressure during startup, then the liquefied fluid can be exhausted, but it takes a long time to reach maximum displacement
Solution Approach 1:
The exhaust function is segmented between two pressure-sensitive valves with different characteristics. The first valve handles the primary exhaust function with a larger opening area for rapid fluid removal, while the second valve provides supplementary exhaust and pressure balancing. This segmentation enables much faster achievement of maximum displacement compared to a single valve system.
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
Improves startup responsiveness by rapid liquefied fluid exhaustion and maintains maximum displacement state efficiency by equalizing control and suction pressures, enhancing operational efficiency.
Implementation Method 1
a pressure-sensitive body 160 that is disposed in the third valve chamber 140 to apply a biasing force to the main valve body 151 in a valve opening direction of a main valve according to a surrounding fluid pressure
Implementation Method 2
a main valve body 151 that integrally includes a first valve portion 151a which comes into contact with and separates from the first valve seat 110a in the first valve chamber 120 to open and close a communication between the discharge chamber and the control chamber, and a second valve portion 151b which comes into contact with and separates from the second valve seat 182a in the second valve chamber 130 to open and close a communication between the control chamber and the suction chamber, and that reciprocates to perform opening and closing operations in opposite directions;
Implementation Method 3
a differential pressure valve that is capable of opening and closing, depending on a pressure difference between the pressure of the pressure-sensitive chamber and the pressure of the Ps port which act opposite to each other
Data Source
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AI summary
Provided is a capacity control valve having a good startup responsiveness and a good operational efficiency. A capacity control valve V includes a valve housing 10 provided with a Pc port, a Pd port and a Ps port; a main valve body 51 that includes a main valve portion 51a which comes into contact with and separates from a main valve seat 10a to close and open a communication between a Pd port and the Pc port using a driving force of a solenoid 80; a pressure-sensitive valve 53 that is capable of opening and closing, depending on a surrounding pressure, a first communication passage 55 through which the Pc port and the Ps port are communicable with each other; and a differential pressure valve 90 that is capable of opening and closing, depending on a pressure difference, a second communication passage through which the Pc port and the Ps port are communicable with each other.