Air Conditioner Expansion Valve Control to Prevent Strainer Clogging
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Solution Overview
Problem
The existing air-conditioning apparatus faces issues with the expansion valve being clogged by impurities due to a narrower gap than the strainer diameter, leading to potential damage and refrigerant leakage, and finer mesh structures increase pressure loss and cost.
Innovation Solution
The air-conditioning apparatus controls the expansion valve to maintain an opening greater than the strainer mesh diameter, allowing impurities to be swept away downstream, preventing clogging without increasing the number of meshes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the hole diameter of the mesh structure is made finer to prevent clogging, then the expansion valve protection is improved, but the pressure loss in the refrigerant circuit increases
Solution Approach 1:
The strainer is divided into multiple mesh layers with different mesh diameters. The first mesh layer has a larger mesh diameter for primary filtration, while the second mesh layer has a smaller mesh diameter for fine filtration. This segmentation allows the system to achieve effective clogging prevention without requiring all layers to have fine meshes, thereby reducing overall pressure loss.
Solution Approach 2:
Different parts of the strainer have different mesh diameters tailored to their specific functions. The first mesh layer uses larger holes suitable for its position and function, while the second mesh layer uses smaller holes where fine filtration is most needed. This local differentiation optimizes filtration effectiveness while minimizing pressure loss across the entire strainer structure.
2Reliability
If the number of meshes is increased to improve filtration, then the expansion valve protection is improved, but the pressure loss increases
Solution Approach 1:
The strainer is divided into multiple mesh layers with different mesh diameters. The first mesh layer has a larger mesh diameter for primary filtration, while the second mesh layer has a smaller mesh diameter for fine filtration. This segmentation allows the system to achieve effective clogging prevention without requiring all layers to have fine meshes, thereby reducing overall pressure loss.
Solution Approach 2:
Different parts of the strainer have different mesh diameters tailored to their specific functions. The first mesh layer uses larger holes suitable for its position and function, while the second mesh layer uses smaller holes where fine filtration is most needed. This local differentiation optimizes filtration effectiveness while minimizing pressure loss across the entire strainer structure.
3Loss of energy
If the surface area of the mesh structure is increased to reduce pressure loss, then the pressure loss is reduced, but the volume of the strainer increases
Solution Approach 1:
The second mesh layer is positioned inside or nested within the structure of the first mesh layer, creating a compact multi-layer filtration system. This nesting arrangement allows the strainer to achieve increased effective filtration surface area without proportionally increasing the overall external volume of the strainer component.
4Reliability
If the mesh diameter is reduced to prevent clogging, then the expansion valve protection is improved, but the cost of the strainer increases
Solution Approach 1:
The strainer is divided into multiple mesh layers with different mesh diameters. The first mesh layer has a larger mesh diameter for primary filtration, while the second mesh layer has a smaller mesh diameter for fine filtration. This segmentation allows the system to achieve effective clogging prevention without requiring all layers to have fine meshes, thereby reducing overall pressure loss.
Solution Approach 2:
Different parts of the strainer have different mesh diameters tailored to their specific functions. The first mesh layer uses larger holes suitable for its position and function, while the second mesh layer uses smaller holes where fine filtration is most needed. This local differentiation optimizes filtration effectiveness while minimizing pressure loss across the entire strainer structure.
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 approach effectively prevents expansion valve clogging, reduces refrigerant leakage, and minimizes pressure loss, enhancing the durability and energy efficiency of the system while maintaining a lower cost and reduced strainer volume.
Implementation Method 1
a strainer that has a mesh structure to collect impurities flowing through a refrigerant pipe
Implementation Method 2
A gap between a valve and a valve sheet during refrigerant circulation is about 0.05 mm to about 0.5 mm because of characteristics of the expansion valve
Data Source
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AI summary
An air-conditioning apparatus includes a refrigerant circuit including a compressor, a strainer, and an expansion valve, and a controller configured to control the expansion valve in the refrigerant circuit. In the air-conditioning apparatus, in a case where the expansion valve is closed, the controller performs control to close the expansion valve after opening the expansion valve to cause an opening port diameter of the expansion valve to be greater than a mesh diameter of the strainer.