Resonance-type silencer
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Solution Overview
Problem
Existing silencers for turbo chillers reduce blade passing frequency (BPF) noise but cause high back pressure and pressure loss, leading to efficiency reduction and noise leakage.
Innovation Solution
A resonance-type silencer with a small-diameter resonance pipe inside the air supply pipe, expanding noise into a chamber, maximizing cross-sectional area ratio, and minimizing pressure loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If existing silencers are installed to reduce BPF noise, then noise reduction effect is achieved, but high back pressure is formed resulting in pressure loss and efficiency reduction
Solution Approach 1:
The patent applies resonance principle where noise waves at specific frequencies (BPF) are made to resonate within the silencer chamber through carefully designed cavity dimensions. This resonance causes destructive interference that cancels out the harmful noise frequencies while allowing other frequencies to pass through with minimal pressure loss
Solution Approach 2:
The patent optimizes specific parameters including the length and cross-sectional area of the silencer chamber, the diameter and positioning of inlet/outlet ports, and the resonance frequency matching to achieve maximum noise reduction at target BPF frequencies while minimizing pressure drop across the silencer
2Object-affected harmful factors
If multiple partitions are used to block and resonate noise, then noise improvement effect is achieved, but high back pressure is formed which may cause large loss in efficiency
Solution Approach 1:
Instead of using multiple solid partitions that create high back pressure, the patent employs a resonance chamber design where sound waves are allowed to propagate and resonate within a large open volume. This approach achieves noise cancellation through acoustic resonance rather than physical blocking, maintaining high fluid flow efficiency
Solution Approach 2:
The patent extracts the noise reduction function from traditional partition-based structures and implements it through a standalone resonance chamber with optimized acoustic properties. This separates the noise control function from the flow path obstruction, allowing efficient fluid passage while achieving targeted noise reduction
3Object-affected harmful factors
If silencer is designed with large cross-sectional area expansion to maximize resonance effect, then noise reduction is improved, but device size and complexity increase
Solution Approach 1:
The patent achieves effective noise reduction by optimizing the resonance chamber dimensions and inlet/outlet port configurations rather than simply increasing overall size. By carefully tuning the chamber volume, port areas, and their relative positions, the design achieves maximum resonance effect at target frequencies with a compact structure
Solution Approach 2:
The patent utilizes three-dimensional space efficiently within the resonance chamber, creating acoustic pathways and resonance patterns in multiple dimensions. This allows achieving effective noise reduction in a compact footprint by exploiting spatial acoustic phenomena rather than requiring large linear dimensions
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 silencer effectively reduces primary and secondary BPF noises while minimizing pressure loss and maintaining the efficiency of the turbo chiller, with a noise reduction effect of up to 32.7 dB in sensitive frequency bands.
Implementation Method 1
a resonance-type silencer causes noise corresponding to a specific frequency discharged through a compressor discharge portion to pass through a resonance pipe with a small diameter in an air supply pipe and then expands the noise in a chamber
Data Source
AI summary
A resonance-type silencer includes a housing (10) having an air supply port formed on one side, an air exhaust port formed on the other side, and a chamber (13) formed thereinside, an air supply pipe (20) connected to the air supply port, an air exhaust pipe (30) connected to the air exhaust port, and a plurality of resonance pipes (110, 120) provided inside at least one of the air supply pipe (20) or the air exhaust pipe (30).