Variable Displacement Compressor Valve Startup Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional displacement control valves for variable displacement compressors experience reduced operating efficiency due to unnecessary refrigerant gas flow from the control chamber into the suction chamber, especially during startup, which prolongs startup time and reduces efficiency.
Innovation Solution
The displacement control valve is designed with an auxiliary communicating passage and specific valve geometry, where the opening area between the third valve section and the third valve seat surface is set smaller than the auxiliary communicating passage, and the valve seat surface is formed in a stepped or cylindrical shape to minimize the Pc-Ps flow path area, allowing rapid vaporization of refrigerant liquid and maintaining efficiency throughout the control range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If an auxiliary communicating passage is added to enable rapid discharge of liquid refrigerant in the control chamber at startup, then startup time is reduced, but refrigerant gas flows unnecessarily from the control chamber into the suction chamber during control operation, reducing operating efficiency
Solution Approach 1:
The valve seat surface is designed with different opening areas at different locations: the auxiliary communicating passage has a larger opening area for rapid liquid discharge, while the third communicating passage has a smaller opening area that restricts gas flow during control operation. This local differentiation allows the system to achieve rapid startup while preventing energy loss during normal operation.
Solution Approach 2:
The valve element dynamically adjusts the opening areas of both the auxiliary communicating passage and the third communicating passage based on operating conditions. During startup, the valve element position allows both passages to be open for rapid liquid discharge. During control operation, the valve element adjusts to restrict the third communicating passage while maintaining auxiliary passage functionality, thus preventing unnecessary gas flow.
2Productivity
If the opening area of the third valve section is increased to improve control responsiveness, then control performance is improved, but the minimum area of the Pc-Ps flow path increases, reducing operating efficiency
Solution Approach 1:
The third valve section is designed with a localized small opening area at the critical flow path location, while other portions of the valve can maintain larger dimensions for structural integrity and responsiveness. This localized restriction minimizes the minimum Pc-Ps flow path area, preventing energy loss during control operation while maintaining adequate control responsiveness.
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 reduces the minimum area of the Pc-Ps flow path, thereby decreasing startup time and improving operating efficiency during compressor control, while maintaining the minimum area of the flow path as large as in conventional designs.
Implementation Method 1
a solenoid unit mounted to the valve body for actuating the valve element in a travel direction to open and close the valve sections of the valve element according to a current
Implementation Method 2
a pressure-sensitive element that is disposed in the first valve chest and extends and contracts in response to suction pressure
Data Source
Figure 1
Figure 2(a)~2(c)
Figure 3
AI summary
A displacement control valve improved in the function of discharging a liquid refrigerant in a control chamber at startup achieves a reduction in startup time and an improvement in operating efficiency during control of a variable displacement compressor simultaneously. An opening area S2 between a third valve section 21C and a third valve seat surface 31A in a control area to control the flow rate or pressure in a working control chamber is set smaller than an area S1 of an auxiliary communicating passage 11, thereby reducing the minimum area of a Pc-Ps flow path in the control area.