Expansion valve
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Solution Overview
Problem
Existing expansion valves in refrigeration cycles generate noise due to turbulent flow and air bubble rupture, and miniaturization limits the muffler effect, making it difficult to achieve sufficient noise reduction in compact designs.
Innovation Solution
The expansion valve incorporates a rectifier with a hollow convex portion projecting into the outlet passage and a throttle hole, which increases the volume of the expansion chamber while maintaining a compact size, enhancing the muffler effect by reducing turbulence and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the expansion valve is miniaturized to meet car air conditioner requirements, then the device size is reduced, but the volume of the expansion chamber is restricted and the muffler effect cannot be sufficiently exhibited
Solution Approach 1:
The hollow convex portion is inserted into the outlet passage, creating a nested structure where the rectifier's expansion chamber is positioned within the limited space of the outlet passage. This allows the expansion chamber volume to be increased without increasing the overall valve size, effectively nesting the noise reduction function within the compact valve body.
Solution Approach 2:
The hollow convex portion extends in the refrigerant flow direction, utilizing the longitudinal dimension of the outlet passage to create expansion chamber volume. By projecting the convex portion into the passage, the design transforms the limited radial space into effective volumetric space for noise reduction, adding a dimensional solution to the compact design constraint.
2Object-generated harmful factors
If the volume of the expansion chamber is increased to enhance the muffler effect, then noise reduction is improved, but the expansion valve size increases
Solution Approach 1:
The rectifier with hollow convex portion is nested within the outlet passage, allowing the expansion chamber to occupy space that would otherwise be part of the passage volume. This nested arrangement increases the effective expansion chamber volume for noise reduction without increasing the external dimensions of the expansion valve.
Solution Approach 2:
The hollow convex portion creates a localized expansion region specifically within the outlet passage where noise reduction is needed. This local quality change concentrates the noise reduction function in a specific area rather than requiring uniform expansion throughout the entire valve, enabling effective muffling in a compact configuration.
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 effectively reduces noise by increasing the volume of the expansion chamber, achieving a greater muffling effect and maintaining a compact form, suitable for car air conditioners and similar applications.
Implementation Method 1
an expansion chamber that includes an orifice configured to reduce a pressure of the refrigerant introduced into the valve chamber
Implementation Method 2
when passing through the throttle opening, the air bubbles in the refrigerant are subdivided, thereby reducing the noise caused by the rupturing of these air bubbles
Implementation Method 3
the traveling direction of the refrigerant changes by approximately 90 degrees, which may invite the risk of turbulent flow which causes noise. Therefore, by throttling the expanded refrigerant once again with the rectifier throttle opening, it is possible to prevent the generation of turbulence and to achieve noise reduction
Data Source
Figure 1
Figure 2(a)~2(c)
Figure 3
AI summary
The present invention provides an expansion valve which is compact and can further enhance muffling performance. The expansion valve includes a valve main body including an inlet passage configured to introduce a high-pressure refrigerant, a valve chamber configured to communicate with the inlet passage, an expansion chamber that includes an orifice configured to reduce a pressure of the refrigerant introduced into the valve chamber, and an outlet passage disposed downstream of the expansion chamber and configured to discharge the refrigerant that passes through the expansion chamber, a rectifier disposed in the valve main body and configured to partition the expansion chamber and the outlet passage, a valve member configured to open and close the orifice, and a valve member driving device configured to drive the valve member. The rectifier includes a hollow convex portion projecting toward the outlet passage and a throttle hole formed at a distal end of the hollow convex portion, and the refrigerant that enters the expansion chamber when the orifice opens passes through the throttle hole and travels toward the evaporator.