Capacity Control Valve Using CS Valve for Startup Pressure Relief
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Solution Overview
Problem
The existing capacity control valves for variable displacement compressors suffer from poor controllability and operation efficiency during continuous driving and restart conditions, particularly due to the auxiliary communication path maintaining a communication state that leads to refrigerant flow from the control port to the suction port, affecting the compressor's performance.
Innovation Solution
A capacity control valve design featuring a primary valve and a CS valve with opposing spring forces, where the primary valve is closed and the CS valve is open during startup to rapidly discharge refrigerant from the control chamber to the suction chamber, and vice versa when the solenoid is not energized to prevent fluid flow, optimizing the valve's operation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If an auxiliary communication path is formed to communicate the control port and suction port, then the responsiveness at startup is improved by rapidly discharging refrigerant from the control chamber, but the controllability deteriorates during continuous driving due to refrigerant flow from control port to suction port
Solution Approach 1:
The patent divides the valve system into two independent valves: a primary valve for normal control operations and a CS (communication start) valve for startup communication. This segmentation allows each valve to perform its specific function independently - the primary valve maintains control during continuous driving while the CS valve provides rapid communication path at startup without interfering with normal operations.
Solution Approach 2:
The CS valve dynamically changes its state based on operating conditions - it is opened during startup to provide rapid refrigerant discharge from the control chamber, and then closed during continuous driving to prevent unwanted refrigerant flow. This dynamic behavior allows the system to achieve both fast startup response and stable controllability during operation.
2Ease of operation
If the auxiliary communication path is kept in communication state, then the fluid discharge function is maintained, but the operation efficiency deteriorates due to continuous refrigerant flow affecting compressor performance
Solution Approach 1:
The CS valve operates periodically - opened briefly during startup to discharge refrigerant from the control chamber, then closed during normal operation. This periodic action ensures the fluid discharge function is available when needed (at startup) while preventing continuous refrigerant flow that would reduce operation efficiency during continuous driving.
3Device complexity
If the primary valve is used for both normal control and startup communication, then the device complexity is reduced, but the controllability deteriorates due to interference between normal control and startup functions
Solution Approach 1:
Instead of using a single valve for both functions, the patent segments the control system into two separate valves: the primary valve dedicated to normal control operations and the CS valve dedicated to startup communication. This segmentation eliminates functional interference and ensures precise controllability for each operation mode, with the added benefit that each valve can be optimized for its specific function.
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 the responsiveness at startup and maintains high operation efficiency by ensuring the control port does not flow into the suction port when not energized, improving the controllability and efficiency of the variable displacement compressor.
Implementation Method 1
a primary valve body driven by a solenoid and opening and closing a communication between the discharge port and the control port by a movement of the primary valve body
Implementation Method 2
a first spring configured to urge the CS valve body in a closing direction of the CS valve, and a second spring urging the CS valve body in an opening direction of the CS valve
Data Source
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AI summary
There is provided a capacity control valve having good operation efficiency while having a fluid discharge function at startup. The capacity control valve V includes a valve housing 10 provided with a discharge port 12 allowing a discharge fluid of a discharge pressure Pd to pass therethrough, suction ports 13 and 15 allowing a suction fluid of a suction pressure Ps to pass therethrough, and a control port 14 allowing a control fluid of a control pressure Pc to pass therethrough and a primary valve 50 including a primary valve seat 10a and a primary valve body 51 driven by a solenoid 80 and opening and closing a communication between the discharge port 12 and the control port 14 by the movement of the primary valve body 51. The capacity control valve V further includes a CS valve 57 which includes a CS valve body 56, a first spring 91 urging the CS valve body 56 in a closing direction, and a second spring 92 urging the CS valve body 56 in an opening direction, the control port 14 and the suction port 15 being opened at a valve closed position of the primary valve body 51, the control port 14 and the suction port 15 being closed at a valve opened position of the primary valve body 51.