Centrifugal compressor with liquid injection
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Solution Overview
Problem
Flow separation and pressure waves generated at the trailing edge of the impeller in conventional centrifugal compressors cause compression noise.
Innovation Solution
A two-stage chiller system with first and second stage centrifugal compressors, a return channel flow path, and a plurality of injection ports, where liquid refrigerant is injected into the diffusers and return channel to suppress flow separation and noise.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If liquid refrigerant is injected into the diffusers and return channel, then flow separation and pressure waves are suppressed, but device complexity increases
Solution Approach 1:
Liquid refrigerant is introduced as an intermediary substance into the diffusers and return channel to suppress flow separation and pressure waves. The liquid refrigerant acts as a mediator that interacts with the gas flow to reduce harmful noise effects without requiring fundamental changes to the compressor structure.
Solution Approach 2:
The invention utilizes hydraulic principles by injecting liquid refrigerant into the gas flow path. The liquid phase refrigerant interacts with the vapor phase refrigerant in the diffusers and return channel, using fluid dynamics to suppress flow separation and reduce compression noise through phase interaction rather than mechanical modification.
2Object-affected harmful factors
If liquid refrigerant is injected into the diffusers and return channel, then compression noise is reduced, but energy consumption increases
Solution Approach 1:
The injection of liquid refrigerant into the vapor phase refrigerant flow utilizes phase transition principles. The liquid refrigerant evaporates as it mixes with the warmer vapor in the diffusers and return channel, absorbing heat and potentially reducing the energy required for compression while simultaneously suppressing noise through phase interaction.
Solution Approach 2:
The invention converts what would normally be wasted energy in the form of flow separation and pressure waves into a beneficial effect. By injecting liquid refrigerant, the harmful flow separation is suppressed, and the energy that would have been lost to turbulence and noise is instead used to facilitate liquid evaporation and improve overall system efficiency.
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 injection of liquid refrigerant into the diffusers and return channel effectively suppresses flow separation and pressure waves, reducing compression noise in the centrifugal compressor.
Implementation Method 1
Flow separation and pressure waves generated at a trailing edge of the impeller in a conventional centrifugal compressor can cause compression noise. The injection of liquid refrigerant into the diffusers and return channel effectively suppresses flow separation and pressure waves, reducing compression noise in the centrifugal compressor.
Implementation Method 2
Flow separation and pressure waves generated at a trailing edge of the impeller in a conventional centrifugal compressor can cause compression noise. The injection of liquid refrigerant into the diffusers and return channel effectively suppresses flow separation and pressure waves, reducing compression noise in the centrifugal compressor.
Data Source
AI summary
A two stage chiller includes first and second stage centrifugal compressors, at least one motor, a return channel flow path, and a plurality of injection ports. The first and second stage centrifugal compressors include first and second impellers, and first and second diffusers downstream from the first and second impellers. The at least one motor rotates the first impeller and the second impeller. The return channel flow path connects the first diffuser to the second impeller. The plurality of injection ports are located circumferentially around the second diffuser and within at least one of the first diffuser, and the return channel flow path. The plurality of injection ports located within the second diffuser are downstream of the second upstream edge of the second diffuser to deliver liquid refrigerant to the second diffuser.