Dual-Valve Capacity Control for Variable Compressor Pressure
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Solution Overview
Problem
Existing capacity control valves for variable displacement compressors have limitations in controllability of the control pressure due to constant flow path sectional areas and lack of efficient cooperation between CS and DC valves, leading to suboptimal control efficiency.
Innovation Solution
A capacity control valve design that includes a solenoid-driven rod, a CS valve, and a DC valve, where the CS valve controls fluid flow between the suction and control ports, and the DC valve controls fluid flow between the discharge and control ports, allowing for cooperative control of the control pressure with increasing energization, enabling finer control of the control pressure based on the difference in adjustments by both valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single main valve (CS valve or DC valve) is used to control the control chamber pressure, then the valve configuration remains simple, but the controllability of the control pressure is insufficient
Solution Approach 1:
The control function is segmented into two independent valves: CS valve for controlling suction pressure flow to the control chamber, and DC valve for controlling discharge pressure flow to the control chamber. Each valve independently adjusts one aspect of control pressure, enabling fine-grained control while maintaining relatively simple individual valve structures
Solution Approach 2:
The CS valve and DC valve are merged into a single capacity control valve assembly that cooperatively controls the control chamber pressure. The two valves work together in a coordinated manner, with their combined effect providing superior control capability compared to either valve alone
2Productivity
If the CS valve and DC valve are arranged to enhance controllability, then the control efficiency improves, but the cooperation mechanism between valves is not clearly defined
Solution Approach 1:
The control system employs feedback mechanisms where the control computer monitors control chamber pressure and adjusts the opening degrees of both CS and DC valves accordingly. The valves respond to pressure feedback by adjusting their positions, creating a closed-loop control system that optimizes control efficiency
Solution Approach 2:
Both CS valve and DC valve are designed with movable valve bodies that dynamically adjust their opening degrees based on control requirements. The valves transition between fully closed, partially open, and fully open states, enabling dynamic control adaptation to varying operating conditions
3Adaptability or versatility
If a stationary orifice with constant flow path sectional area is used, then the valve structure remains simple, but the adjustability of control pressure is limited
Solution Approach 1:
The stationary orifice is replaced with movable valve bodies for both CS and DC valves. These valve bodies can shift position to dynamically adjust the flow path cross-sectional areas, transforming fixed flow paths into variable ones that adapt to different control pressure requirements
Solution Approach 2:
The flow path parameters (cross-sectional area) are changed from constant to variable by introducing movable valve bodies. The valve bodies adjust their positions to modify the effective flow area, enabling continuous adjustment of control pressure according to system demands
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 control pressure control efficiency, particularly in the intermediate range of control currents, by ensuring the CS valve and DC valve open in the same direction with increasing energization, providing broader control ranges and improved refrigerant flow rate management, thus enhancing the operation efficiency of the variable displacement compressor.
Implementation Method 1
a rod movably arranged in the valve housing and driven by the solenoid
Data Source
AI summary
A capacity control valve includes a valve housing formed with a discharge port, a suction port, and first and second control ports, a rod movably arranged in the valve housing and driven by a solenoid, a CS valve configured to control a fluid flow between the first control port and the suction port in accordance with a movement of the rod, and a DC valve configured to control a fluid flow between the second control port and the discharge port in accordance with the movement of the rod. In a non-energization state, the CS valve is closed and the DC valve is closed. As the energization of the solenoid becomes larger, the CS valve transitions from a closed state to an open state and the DC valve transitions from a closed state to an open state.