Capacity Control Valve With Variable Bypass Area for Fast Start-Up
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Solution Overview
Problem
The existing capacity control valve suffers from poor responsiveness during start-up and control accuracy issues due to fluid flow from the control chamber into the suction chamber through auxiliary communication paths, even when the main valve is closed, leading to prolonged time in achieving target discharge amounts during compressor start-up.
Innovation Solution
A capacity control valve design featuring a valve housing with separate ports for control, discharge, and suction pressures, a main valve element, a pressure-sensitive valve, and an auxiliary communication path that increases flow path cross-sectional area during start-up and decreases it during normal control, allowing for precise control and efficient fluid discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the auxiliary communication path maintains a constant flow path cross-sectional area, then the structure is simple, but the responsiveness during start-up is poor and control accuracy deteriorates
Solution Approach 1:
The auxiliary communication path employs a movable main valve element that can change the flow path cross-sectional area dynamically. During start-up, the valve opens to increase the area for rapid fluid discharge. During normal operation, the valve closes to reduce the area and improve control accuracy. This dynamic adjustment resolves the contradiction between responsiveness and control accuracy.
2Measurement precision
If the main valve remains closed during normal control, then control accuracy is maintained, but fluid discharge during start-up is delayed
Solution Approach 1:
The valve system is segmented into a main valve for controlling the auxiliary communication path and a pressure-sensitive valve for fluid discharge. The main valve can be independently controlled to open during start-up for rapid discharge, then close during normal operation to maintain control accuracy. This segmentation allows the system to achieve both fast response and precise control.
3Productivity
If the flow path cross-sectional area of the auxiliary communication path is increased, then fluid discharge speed improves, but control precision deteriorates due to fluid leakage
Solution Approach 1:
The flow path cross-sectional area of the auxiliary communication path is dynamically adjusted by the main valve element. During start-up, the area is increased to maximize fluid discharge rate. During normal control, the area is reduced to minimize fluid leakage and maintain control precision. This dynamic adjustment resolves the contradiction between productivity and measurement precision.
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 responsiveness during start-up by promptly discharging fluids and improves controllability by maintaining precise control pressure, ensuring accurate and efficient operation of the air conditioning system.
Implementation Method 1
a main valve element which integrally includes a first valve portion 151a coming into contact with and separating from the first valve seat 110a in the first valve chamber 120 so as to open and close the communication between the discharge chamber and the control chamber and a second valve portion 151b coming into contact with and separating from a second valve seat 182a in the second valve chamber 130 so as to open and close the communication between the control chamber and the suction chamber and performs an opening and closing operation in the opposite directions by the reciprocating movement, a solenoid 180 which applies a drive force to the main valve element 151
Implementation Method 2
a pressure-sensitive element 160 which is disposed inside the third valve chamber 140 and applies a biasing force to the main valve element 151 in the main valve opening direction in response to an ambient fluid pressure
Data Source
AI summary
A capacity control valve for controlling a capacity of a fluid includes: a valve housing; a main valve closing and opening a communication between a Pc port and a Pd port when a main valve portion of a main valve element driven by a drive force of a solenoid comes into contact with and separates from a main valve seat; a pressure-sensitive valve which is opened by an ambient pressure; a hollow tube member which forms a part of the pressure-sensitive valve and allows the Pc port to communicate with a Ps port through a hollow communication path formed therein when the pressure-sensitive valve is opened; and an auxiliary communication path allows the Pc port to communicate with the Ps port independently of the pressure-sensitive valve, and the auxiliary communication path is configured to be able to increase a flow path cross-sectional area after the main valve is closed.