Variable Opening Volute for Centrifugal Fan Noise Reduction
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Solution Overview
Problem
Conventional centrifugal fan volutes with equal opening degree and double air inlets suffer from insufficient diffusion, high volute tongue, and high-frequency noise due to mismatched air flow and opening degree.
Innovation Solution
A volute design with double air inlets and variable opening degree, featuring a baffle plate with upper and lower air inlets of different heights and opening degrees, allowing for proper diffusion of air flows and reducing noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a volute with equal opening degree and double air inlets is used, then the structure is simple, but the diffusion is insufficient and high-frequency noise is generated
Solution Approach 1:
The patent applies asymmetry by setting different opening degrees for the upper and lower air inlets of the volute. The first opening degree for the upper air inlet is different from the second opening degree for the lower air inlet, creating an asymmetric configuration that optimizes diffusion and reduces noise generation from airflow mismatch.
Solution Approach 2:
The patent applies local quality by optimizing the opening degree at each air inlet location according to the specific airflow characteristics. The upper and lower air inlets have different opening degrees tailored to their respective flow conditions, allowing each local region to handle airflow appropriately and reduce turbulence-induced noise.
2Ease of manufacture
If a volute with equal opening degree is used, then the manufacturing is simple, but the fan efficiency is reduced due to mismatched air flow
Solution Approach 1:
The patent applies parameter changes by modifying the opening degree parameter for different air inlets. The first opening degree and second opening degree are optimized to match the airflow characteristics from the double air inlets, improving fan efficiency without significantly complicating the manufacturing process.
3Strength
If the volute tongue height is increased, then the structural strength is improved, but the diffusion capability is reduced
Solution Approach 1:
The patent applies local quality by optimizing the volute tongue height at different locations. The volute tongue height is specifically designed to balance structural strength and diffusion capability, ensuring adequate support while maintaining proper airflow diffusion from the double air inlets.
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 volute design achieves significant noise reduction and higher fan efficiency by matching air flow with the opening degree, addressing the issues of insufficient diffusion and high-frequency noise in conventional designs.
Implementation Method 1
The different flows on both sides of a baffle plate can be diffused by proper opening degree at the air outlet
Data Source
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AI summary
The invention relates to a volute with double air inlets and variable opening degree. The volute comprises a volute body (1), a volute tongue (2) and an impeller (3). The volute body comprises a spiral part (11) and an extension part (12). The impeller is located in a central part of the spiral part, with a through hole passing through the spiral part to form an air inlet. The volute tongue (2) comprises a connecting part (21) connected to the spiral part, and an expanding part (22) connected to the connecting part (21), wherein the expanding and extension parts form an air outlet. Upper blades with a height H1, a baffle plate forming an upper air inlet and a lower air inlet, and lower blades with a height H2 are arranged on the impeller (3), wherein H1 is less than H2.