Centrifugal Compressor Scroll Winding Start Obtuse Angle
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Solution Overview
Problem
Conventional centrifugal compressors experience pressure loss due to fluid separation at the winding start portion of the scroll, particularly at large flow amount operation points.
Innovation Solution
The centrifugal compressor design includes a scroll with a winding start portion connected to the discharge portion at an obtuse angle and a gradually decreasing inner diameter along the rotation axis, which reduces fluid separation by ensuring the fluid flows smoothly into the scroll flow passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the winding start portion is connected to the discharge portion at an acute angle, then the structure is simpler, but fluid separation occurs causing pressure loss
Solution Approach 1:
The patent changes the geometric parameter of the connection angle from acute to obtuse, and modifies the inner diameter profile to gradually decrease then increase. This parameter optimization eliminates fluid separation at the winding start portion while maintaining structural simplicity, resolving the contradiction between structural simplicity and pressure loss prevention
2Loss of energy
If the winding start portion is connected to the discharge portion at an obtuse angle, then fluid separation is reduced, but the structure becomes more complex
Solution Approach 1:
The patent optimizes specific geometric parameters including the connection angle (making it obtuse) and the inner diameter distribution (gradually decreasing then increasing). These targeted parameter changes achieve fluid separation reduction with minimal structural modification, balancing performance improvement with structural simplicity
3Ease of manufacture
If the inner diameter is constant, then the manufacturing is easier, but fluid separation occurs at the winding start portion
Solution Approach 1:
The patent applies local quality by creating a non-uniform inner diameter distribution specifically at the winding start portion and connection area, while keeping other sections simple. The inner diameter gradually decreases toward the winding start portion then increases, providing local flow control to prevent separation without complicating overall manufacturing
4Productivity
If the scroll flow passage area increases from winding start to end, then compression performance is improved, but fluid separation occurs at the winding start portion
Solution Approach 1:
The patent optimizes multiple parameters simultaneously: the connection angle is made obtuse, the inner diameter distribution is modified to gradually decrease then increase, and the flow passage area is optimized. These coordinated parameter changes ensure smooth fluid transition at the winding start portion while maintaining the beneficial area increase along the flow direction for compression performance
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
This design enhances compression performance by minimizing fluid separation at the winding start portion, thereby improving overall compression efficiency.
Implementation Method 1
a fluid compressed by an impeller is introduced into the scroll through a diffuser and is appropriately decreased in speed by the scroll so as to restore a static pressure
Data Source
AI summary
A centrifugal compressor includes a compressor and a scroll which is disposed around the impeller and in which a flow passage including a scroll flow passage is formed in a rotation direction of the impeller, in which the scroll includes a discharge portion connected to a winding end portion of the scroll flow passage—and a winding start portion connected to the discharge portion and the winding start portion on a fluid suction side in a direction along a rotation axis of the impeller is connected to the discharge portion at an obtuse angle.