Acoustic noise reduction device for reducing the radiation of noise generated by a fan of a heat pump system
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Solution Overview
Problem
Existing solutions for reducing noise radiation from heat pump systems, such as acoustic dampening walls, require significant thickness and dense materials, leading to increased weight and installation space, while methods like reducing fan speed compromise heating or cooling power.
Innovation Solution
An acoustic noise reduction device that splits the air flow created by the fan into two paths of different lengths, reintroducing the flows to create interference in noise frequencies, thereby reducing perceived noise without increasing weight or installation space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If acoustic dampening walls are used to reduce noise radiation, then noise reduction performance is improved, but weight and installation space increase
Solution Approach 1:
The air flow path is segmented into multiple flow paths with different lengths. By dividing the single flow path into parallel paths of different lengths, the invention creates phase differences in the sound waves without requiring dense acoustic materials, thus reducing noise without increasing weight.
Solution Approach 2:
The invention transitions from using acoustic dampening walls (a spatial dimension solution requiring thickness and density) to using flow path length differentiation (a temporal/phase dimension solution). By controlling the length difference between flow paths, phase differences are created that interfere with noise frequencies, achieving noise reduction without increasing installation space or weight.
2Object-affected harmful factors
If acoustic dampening walls are used to reduce noise radiation, then noise reduction performance is improved, but installation space increases
Solution Approach 1:
The air flow path is segmented into multiple flow paths with different lengths. By dividing the single flow path into parallel paths of different lengths, the invention creates phase differences in the sound waves without requiring dense acoustic materials, thus reducing noise without increasing installation space.
Solution Approach 2:
The invention transitions from using acoustic dampening walls (requiring significant thickness) to using flow path length differentiation. The housing can be made compact because the noise reduction mechanism relies on the length difference between flow paths rather than on the thickness of acoustic materials, significantly reducing installation space requirements.
3Object-affected harmful factors
If fan speed is reduced to lower noise, then noise is reduced, but heating or cooling power decreases
Solution Approach 1:
The invention extracts the noise generation mechanism from the fan operation itself. Instead of reducing fan speed to lower noise, the invention takes the already-generated sound waves and redirects them through flow paths of different lengths, creating phase differences that cause destructive interference and cancel out the noise while maintaining the fan's original power output.
Solution Approach 2:
The invention converts the harmful sound waves generated by the fan into a beneficial effect. By guiding the air flow containing sound waves through paths of different lengths, the sound waves interfere destructively with each other, transforming the noise (harm) into quiet (benefit) while maintaining full heating or cooling power.
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 device effectively reduces noise disturbance from heat pump systems by introducing interference into noise frequencies, achieving high noise reduction performance while maintaining acceptable pressure drop and compact design.
Implementation Method 1
Due to the combination of the sub-air flows,, interferences are introduced into the noise frequencies which reduce the perceived noise generated by the fan
Data Source
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AI summary
The present invention relates to an acoustic noise reduction device for reducing the radiation of noise generated by a fan of a heat pump system, wherein the fan is creating an air flow and the acoustic noise reduction device comprises a housing that provides at least one first flow path for the air flow through the acoustic noise reduction device and at least one second flow path for the air flowthrough the acoustic noise reduction device, the first flow path and the second flow path are fluidically separated from each other, wherein the first flow path has a first length and the second flow path has a second length, the first length being different from the second length