Screw Compressor Pulsation Dampening With Perforated Inner Conduit
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Solution Overview
Problem
Screw compressors generate pulsations that cause vibrations and noise in refrigeration system piping, leading to potential breakage, and existing dampening systems introduce pressure drops and are not adaptable to variable frequency operations.
Innovation Solution
A screw compressor with a dampening device comprising a duct, mesh, and perforated inner conduit, which includes a mesh and perforated inner conduit surrounded by an outer shell, effectively dampening vibrations across a wide range of frequencies without significant pressure drops.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If known dampening devices are used to reduce vibrations, then vibration dampening is improved, but pressure drop increases significantly
Solution Approach 1:
The patent employs a porous plug made of porous material positioned within the compression chamber to dampen pressure pulsations. The porous structure dissipates vibration energy through friction and tortuous flow paths while maintaining relatively low pressure drop compared to traditional dampening devices, thus resolving the contradiction between vibration reduction and energy loss.
Solution Approach 2:
The patent modifies the physical parameters of the compression chamber by introducing a porous plug with specific porosity and flow resistance characteristics. This changes the flow dynamics and pulsation damping behavior, achieving effective vibration reduction while controlling pressure drop within acceptable limits.
2Object-affected harmful factors
If traditional dampening devices are used, then vibration reduction is achieved, but adaptability to variable frequency operations is poor
Solution Approach 1:
The porous plug design provides universal dampening action across a broad frequency range, making it adaptable to variable frequency operations. Unlike tuned dampers that work at specific frequencies, the porous structure dissipates energy across multiple frequencies simultaneously, enabling effective vibration reduction whether the compressor operates at constant or variable speed.
3Object-affected harmful factors
If known dampening devices are used, then vibration dampening is achieved, but device complexity increases
Solution Approach 1:
The porous plug is integrated directly into the compression chamber, merging the dampening function with the existing compressor structure. This eliminates the need for separate dampening devices and complex installations, simplifying the overall design while achieving effective pulsation dampening.
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 solution reduces vibrations and noise in refrigeration system piping, maintaining system performance and adaptability to variable frequency operations, while being versatile and applicable to existing compressors.
Implementation Method 1
a dampening device, configured for dampening vibrations generated by the screw rotor (10)... A flow of the refrigerant gas through the duct is defined from the inlet end to the outlet end
Implementation Method 2
the economizer circuit includes a resonance space, for retaining an intermediate pressure refrigerant, and a resonance passage, having an end communicating with the compression chamber and the other end communication with the resonance space; hence, the resonance space provides a sound attenuation effect which reduces the pressure pulsation
Data Source
Figure 1~3
Figure 4~8
Figure 9
AI summary
A screw compressor (1) comprises: a housing including an inlet port (11, 13) and an outlet port (12); a screw rotor, arranged into the housing; a compression chamber, delimited by the screw rotor and by the housing; a dampening device for dampening vibrations generated by the screw rotor; wherein the dampening device includes: an inner conduit (3), having a wall extending from a first opening (31) to a second opening (32), wherein the inner conduit (3) is connected to either one of the inlet port (11, 13) or the outlet port (12), an outer shell (4), surrounding the inner conduit (3) to form, between the inner conduit (3) and the outer shell (4), a dissipation 10 chamber (5), wherein the wall of the inner conduit (3) defines a plurality of lateral apertures (34).