Scroll Compressor Control Valve Back Pressure Optimization
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Solution Overview
Problem
Existing control valves for scroll compressors face challenges in maintaining optimal back pressure control, leading to increased frictional resistance and power loss due to high back pressure, and require complex rubber fixation processes that are prone to refrigerant leaks.
Innovation Solution
A control valve design that adjusts its valve opening characteristics based on the flow rate of fluid through the valve section, incorporating an intermediate pressure mechanism to enhance suction-pressure dependence while maintaining discharge-pressure dependence, thereby optimizing back pressure control without the need for fluid seal techniques.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If high discharge pressure is used to increase back pressure, then responsiveness of back pressure control is improved, but frictional resistance between scrolls increases and power loss increases
Solution Approach 1:
An intermediate pressure chamber is introduced between the discharge chamber and the back pressure chamber. This intermediate chamber receives pressure from the discharge chamber and transmits it to control the back pressure, acting as a mediator that decouples the direct relationship between discharge pressure and back pressure. The valve element controls the flow of refrigerant into the intermediate pressure chamber, which then regulates the back pressure applied to the scrolls, improving responsiveness while preventing excessive back pressure and reducing power loss.
2Reliability
If rubber segments are used to seal pressure chambers, then fluid sealing is achieved, but the fixation process becomes troublesome and refrigerant leaks may occur
Solution Approach 1:
The rubber sealing segments are completely removed from the pressure chamber structure. Instead of using rubber segments to seal the first, second, and third pressure chambers, the patent employs fixed partitions and sealed passages formed directly in the valve body. The valve element and its driving mechanism operate within a sealed environment created by the valve body structure itself, eliminating the need for separate rubber sealing components and their complex fixation processes.
3Adaptability or versatility
If multiple pressure chambers and rubber segments are used, then suction pressure sensing capability is improved, but device complexity increases
Solution Approach 1:
The suction pressure sensing function is integrated directly into the valve body structure through a suction pressure chamber that communicates with the suction chamber. The partition that separates the first pressure chamber also serves as the boundary for the suction pressure chamber, and the valve element's movement in response to suction pressure differences directly controls the back pressure. This merging of functions reduces the number of separate components and simplifies the overall device structure while maintaining the ability to sense and respond to suction pressure variations.
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 design effectively increases suction-pressure dependence and maintains discharge-pressure dependence, reducing frictional resistance and power loss, while eliminating the need for complex rubber fixation processes and preventing refrigerant leaks.
Implementation Method 1
A control valve to be applied to a scroll compressor (100) including a suction chamber (166), a discharge chamber (132), and a back pressure chamber (156), for controlling a pressure in the back pressure chamber (156). The control valve (1) includes a valve section for adjusting a flow of fluid introduced from the discharge chamber (132) into the back pressure chamber (156) or fluid delivered from the back pressure chamber (156) into the suction chamber (166). A change in valve opening characteristics is dependent on a flow rate of the fluid flowing through the valve section.
Data Source
Figure 1
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Figure 3
AI summary
A control valve (1) is to be applied to a scroll compressor including a suction chamber, a discharge chamber, and a back pressure chamber, to control a pressure in the back pressure chamber. The control valve (1) includes a valve section that adjusts a flow of fluid introduced from the discharge chamber into the back pressure chamber or fluid delivered from the back pressure chamber into the suction chamber. The control valve (1) has valve opening characteristics that change depending on the flow rate of the fluid flowing through the valve section.