Cross-Flow Air Conditioner Duct Design to Reduce Return Vortex Noise
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Solution Overview
Problem
Cross-flow air ducts in air conditioners suffer from non-uniform air blow and noise due to return vortexes at the end surfaces, leading to temperature disparities and inefficient air distribution during heating.
Innovation Solution
The air conditioner design incorporates a volute-and-tongue assembly with a cross-flow blade, where the air flow inlet is larger than the air flow outlet, and both are positioned within a tapered air duct structure with specific retaining rings to manage pressure gradients and reduce vortex formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a cross-flow air duct is used in the air conditioner, then the air duct structure is simple and widely applicable, but return vortexes form at the end surfaces causing non-uniform air blow and noise
Solution Approach 1:
The air duct structure is segmented into multiple functional zones: a first air inlet section, a second air inlet section, and an air outlet section. The first air inlet section has a first height and the second air inlet section has a second height that is smaller than the first height. This segmentation allows different sections to serve different purposes - the first section handles main air intake while the second section controls airflow to prevent vortex formation at end surfaces, thereby resolving the contradiction between structural simplicity and air blow uniformity.
Solution Approach 2:
Different sections of the air duct are given different local characteristics. The first air inlet section has a larger cross-sectional area (first height) optimized for air intake, while the second air inlet section has a smaller cross-sectional area (second height) specifically designed to control airflow at the end surfaces. This local differentiation ensures uniform air distribution without requiring complex overall restructuring.
2Device complexity
If a cross-flow air duct is used in the air conditioner, then the air duct structure is simple, but temperatures at end surfaces are significantly lower than at other positions causing non-uniform air blow
Solution Approach 1:
The air duct is divided into sections with different heights to control temperature distribution. The first air inlet section with greater height allows proper airflow development, while the second air inlet section with reduced height prevents excessive cooling at end surfaces by limiting the volume of cold air that can accumulate in those regions, thus maintaining more uniform temperature distribution.
Solution Approach 2:
The second air inlet section is specifically designed with a smaller height to address the local temperature issue at the end surfaces. This localized structural modification ensures that the problematic end surface regions receive controlled airflow that prevents temperature extremes, while other sections maintain their optimized dimensions for overall system performance.
3Device complexity
If return vortexes form at end surfaces of the air duct, then the air duct structure remains simple, but noise is generated and air distribution efficiency decreases
Solution Approach 1:
By segmenting the air duct into sections with different heights, the airflow path is controlled to prevent the formation of return vortexes that cause noise. The second air inlet section with reduced height acts as a flow control element that guides air smoothly through the duct, eliminating the turbulent vortex formation that would otherwise occur at the end surfaces of a uniform cross-section duct.
Solution Approach 2:
The height parameter of the air duct is changed along its length - the first air inlet section has a first height while the second air inlet section has a second height that is smaller. This parameter variation optimizes airflow characteristics, preventing vortex formation and the associated noise generation, while maintaining structural simplicity.
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 minimizes return vortexes, ensuring uniform air distribution and temperature consistency at the air flow outlet, thereby addressing the issues of non-uniform air blow and noise in air conditioners.
Implementation Method 1
Two ends of the cross-flow air duct system are relatively low-pressure zones. During the working process of the cross-flow blade, it is easy to form return vortexes at positions of two end surfaces
Implementation Method 2
During the working process of the cross-flow blade, it is easy to form return vortexes at positions of two end surfaces
Data Source
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AI summary
An air conditioner includes an air-conditioner air inlet (70), an air-conditioner air outlet (80), and an air duct structure disposed between the air-conditioner air inlet (70) and the air-conditioner air outlet (80). The air duct structure includes a cross-flow blade (20) and a volute-and-tongue assembly (10), wherein the cross-flow blade (20) is disposed inside the volute-and-tongue assembly (10). The volute-and-tongue assembly (10) includes an air flow inlet (11) and an air flow outlet (12). In an extending direction of the cross-flow blade (20), a height of the air flow inlet (11) is a; a height of the air flow outlet (12) is b; a height of the air-conditioner air inlet (70) is h; and a height of the air-conditioner air outlet (80) is k, wherein k < b < a < h.