Differential Capacity Control Valve for Stable Compressor Pressure
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Solution Overview
Problem
The existing capacity control valve for variable displacement compressors has poor controllability and operation efficiency during continuous driving states due to the auxiliary communication path with a through-hole, leading to refrigerant flow from the control port into the suction port, which affects the pressure control of the control chamber.
Innovation Solution
A capacity control valve with a differential CS valve that divides the control pressure chamber into discharge and suction sides, allowing the differential CS valve body to open the second control port and suction port, improving responsiveness by discharging liquefied fluid from the control chamber to the suction chamber, and ensuring high operation efficiency by controlling the differential CS valve based on solenoid drive force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If an auxiliary communication path with a through-hole is provided in the hollow rod to discharge refrigerant from the control chamber to the suction chamber at startup, then startup responsiveness is improved, but during continuous driving state the auxiliary communication path remains open causing refrigerant to flow from the control port into the suction port which deteriorates controllability of the control chamber pressure and reduces operation efficiency
Solution Approach 1:
The patent applies the dynamics principle by making the auxiliary communication path dynamically controllable rather than permanently open. A secondary valve body is introduced that can move between positions to either open or close the auxiliary communication path between the control chamber and suction chamber. During startup, the secondary valve body is positioned to open the auxiliary communication path for rapid pressure equalization. During normal operation, the secondary valve body closes the auxiliary communication path to maintain proper control chamber pressure and ensure efficient operation. This dynamic control mechanism resolves the contradiction between needing the path open for startup responsiveness and needing it closed for operational efficiency.
2Productivity
If the auxiliary communication path is kept open to maintain fluid discharge function, then startup performance is maintained, but operation efficiency deteriorates due to continuous refrigerant flow affecting control chamber pressure
Solution Approach 1:
The patent implements dynamics by introducing a controllable secondary valve that dynamically opens or closes the auxiliary communication path based on operational requirements. During startup, the valve opens to enable rapid refrigerant discharge from the control chamber to the suction chamber, improving startup responsiveness. During continuous operation, the valve closes to prevent unnecessary refrigerant flow, maintaining proper control chamber pressure and ensuring optimal operation efficiency. This dynamic control eliminates the continuous energy loss that would occur with a permanently open auxiliary communication path.
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 differential CS valve configuration enhances startup responsiveness and maintains high operation efficiency by effectively managing fluid flow between the control and suction chambers, improving controllability and reducing pressure fluctuations in the control chamber.
Implementation Method 1
a primary valve which includes a primary valve seat and a primary valve body driven by a solenoid and controls a flow of a fluid between the discharge port and the control port by a movement of the primary valve body
Implementation Method 2
The differential CS valve body is operated by a differential pressure between the discharge side control chamber and the suction side control chamber so as to open the second control port and the suction port
Data Source
AI summary
A capacity control valve includes a valve housing provided with a discharge port, suction ports, a control port and a primary valve driven by a solenoid. The capacity control valve further includes a differential CS valve which includes a differential CS valve body disposed so as to be relatively movable in an axial direction with respect to the primary valve bodies. The differential CS valve body divides a control pressure chamber into a discharge side control chamber communicating with the first control port and a suction side control chamber communicating with the second control port in the axial direction and operates the differential CS valve body by a differential pressure between the discharge side control chamber and the suction side control chamber so as to open the second control port and the suction port.