Control valve for variable displacement compressor
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Solution Overview
Problem
Existing control valves for variable displacement compressors face challenges in maintaining high operating efficiency and efficiently switching compressor operations, particularly in scenarios where quick transitions between minimum and maximum capacity are required, leading to potential reductions in air conditioner power and refrigeration cycle performance.
Innovation Solution
A control valve system comprising a first valve between the discharge and control chambers, and second and third valves between the control and suction chambers, with a solenoid to control valve opening and closing based on current supply, and a pressure sensing mechanism to adjust valve operation according to sensed pressures, allowing simultaneous operation of the second and third valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If internal circulation is increased to ensure sufficient refrigerant flow during variable capacity operation, then refrigerant circulation is improved, but air conditioner power decreases due to unnecessary internal circulation
Solution Approach 1:
The control valve dynamically adjusts the opening degree of the first valve based on compressor discharge capacity requirements. During maximum capacity operation, the first valve is fully open to minimize internal circulation. During minimum capacity operation, the first valve opening is reduced to ensure sufficient refrigerant supply to the suction chamber, maintaining reliable refrigerant circulation while adapting to varying operational demands.
Solution Approach 2:
The system changes the flow resistance parameter by adjusting the first valve opening degree. This variable resistance control allows the system to optimize refrigerant circulation paths dynamically - reducing internal circulation when external circulation is sufficient (improving power efficiency) while maintaining adequate refrigerant supply when needed (ensuring reliability).
2Stability of the object's composition
If compressor capacity switching is delayed to maintain stable operation, then operational stability is improved, but response time to load changes increases
Solution Approach 1:
The control valve incorporates pressure sensing that provides feedback on refrigerant pressures in the suction and discharge chambers. This feedback mechanism enables the system to detect load changes and automatically adjust the first valve opening degree accordingly, achieving rapid response to vehicle load conditions while maintaining stable compressor operation through continuous pressure-based regulation.
Solution Approach 2:
The control system dynamically adjusts compressor discharge capacity by varying the first valve opening degree in response to real-time pressure feedback. This dynamic adjustment allows rapid switching between minimum and maximum capacity operations when vehicle load changes, eliminating delayed response while maintaining operational stability through continuous adaptive control.
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 maintains high compressor efficiency and enables efficient operation switching, reducing internal circulation and enhancing external circulation, thereby improving air conditioner power and fuel efficiency while eliminating the need for a fixed orifice.
Implementation Method 1
a solenoid to generate a drive force in a closing direction of the first valve and an opening direction of the second valve depending on an amount of supplied current
Implementation Method 2
a pressure sensing part to sense a pressure in the suction chamber or a pressure in the control chamber, and generate a counterforce against the drive force from the solenoid depending on a magnitude of the sensed pressure
Data Source
Figure 1
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Figure 3
AI summary
A control valve (1, 201, 301) includes: a first valve (7) to control a flow rate of refrigerant flowing from a discharge chamber to a control chamber of a compressor; a second valve (8) to control a flow rate of the refrigerant flowing from the control chamber to a suction chamber; a solenoid (3, 203, 303) to generate a drive force in a first valve (7) closing direction and a second valve (8) opening direction depending on supplied current; a biasing member (42, 242) to generate a biasing force in a first valve (7) opening direction and a second valve (8) closing direction; and a pressure sensing part (6) to sense a pressure (Ps, PC) in the suction chamber or the control chamber, and generate a counterforce against the drive force depending on the sensed pressure. A state in which both of the first and second valves (7, 8) are open is present during a process in which the amount of current supplied to the solenoid (3, 203, 303) is increased from zero to an upper limit current value, and an increase rate of an opening degree of the first valve (7) is increased during a process in which the amount of current supplied to the solenoid (3, 203, 303) is decreased, a predetermined lower limit current value being an inflection point of the increase.