Throttling device and refrigeration cycle
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Solution Overview
Problem
Conventional throttling devices in refrigeration cycles face issues with foreign particles adhering to coil springs, leading to unstable operation and noise generation due to fluid flow, as the coil spring is exposed in the fluid path.
Innovation Solution
A throttling device design where the biasing means, such as a coil spring, is covered by a stopper section, and a pressure-equalizing path is included to maintain stable valve opening based on differential pressure, preventing foreign particle adhesion and reducing vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the coil spring is arranged in the primary side of the throttling section to provide biasing force, then the valve opening degree can be controlled by differential pressure, but foreign particles may adhere to the coil spring preventing proper compression and stable operation
Solution Approach 1:
A cover member is introduced as an intermediary component that surrounds the coil spring, preventing foreign particles from directly contacting and adhering to the spring while still allowing the spring to function. The cover member acts as a protective barrier between the coil spring and the refrigerant flow containing potential contaminants.
Solution Approach 2:
The cover member creates a protected environment around the coil spring, isolating it from the reactive refrigerant flow. This protective enclosure prevents foreign particles in the refrigerant from adhering to the coil spring, maintaining a clean and stable operating environment for the biasing mechanism.
2Speed
If the coil spring is disposed in the fluid flow path, then it can respond to differential pressure changes, but vibration and noise are generated by the fluid flow
Solution Approach 1:
The cover member serves as a mediator that allows the coil spring to remain positioned in the primary chamber for rapid pressure response while simultaneously protecting it from direct fluid flow impacts. The cover member transmits pressure changes to the spring while filtering out turbulent flow effects that cause vibration.
Solution Approach 2:
The cover member acts as a flexible protective shell that surrounds the coil spring, allowing pressure transmission while dampening fluid flow-induced vibrations. The shell structure provides a stable environment for the spring while isolating it from noisy turbulent flow.
3Ease of operation
If the valve opening degree property is determined by differential pressure and spring constant, then the throttling function is achieved, but the system is sensitive to pressure changes causing instability
Solution Approach 1:
The cover member acts as a pressure equalization intermediary, with communication paths that allow gradual pressure equalization between the primary chamber and the coil spring environment. This mediates rapid pressure changes, allowing the valve to respond smoothly to differential pressure changes while maintaining stability during transient conditions.
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 solution ensures stable operation by preventing foreign particle adhesion and noise reduction due to reduced vibrations, while maintaining valve opening stability even with rapid pressure changes in the primary chamber.
Implementation Method 1
a coil spring biasing a valve body in a valve close direction against the differential pressure
Implementation Method 2
a pressure-equalizing path for communicating an interior of the cover means with the primary chamber
Data Source
AI summary
A throttling device is equipped with a valve seat in which a valve port for connecting a primary chamber and a secondary chamber is formed, a needle valve, a needle section which is inserted into the valve port, a guide section for guiding a slide shaft of the needle valve, and a coil spring for biasing the needle valve in a valve-closing direction. The guide section and the coil spring are positioned on the primary chamber side. The coil spring is covered by a stopper section. A gap between the stopper section and a main body case functions as a main body path for delivering a refrigerant from the primary chamber to the valve port.