Diffuser Stabilizer Ring for Centrifugal Compressor Recirculation
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Solution Overview
Problem
Centrifugal compressors experience efficiency losses due to significant momentum differences between primary and secondary flows in the diffuser passage, leading to recirculation and non-uniform flow fields, which are not effectively addressed by existing designs that pinch the diffuser passage.
Innovation Solution
Incorporation of a centrifugal acceleration stabilizer ring in the vaneless region between the impeller trailing edge and diffuser leading edge, which accelerates the lower momentum secondary flow to align with the primary flow, stabilizing the flow field and reducing recirculation before the diffuser vanes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the diffuser passage is pinched to address recirculation, then recirculation is reduced, but the momentum differences between primary and secondary flows are not effectively addressed and flow uniformity is not improved
Solution Approach 1:
The stabilizer ring is positioned specifically in the vaneless region at the diffuser inlet, creating a localized modification rather than a general diffuser pinch. This local intervention targets the specific area where secondary flow with lower momentum enters, applying quality change locally to address the momentum difference without affecting the entire diffuser passage
Solution Approach 2:
The stabilizer ring changes the flow parameters (velocity distribution and momentum) in the vaneless region by creating a restricted inlet area. This parameter change transforms the low momentum secondary flow into a more uniform flow field that better matches the primary flow characteristics, thereby improving flow field uniformity while reducing recirculation
2Stability of the object's composition
If a stabilizer ring is added to accelerate secondary flow, then flow field alignment is improved, but device complexity increases
Solution Approach 1:
The stabilizer ring acts as an intermediary element placed in the vaneless region between the impeller and diffuser vanes. It mediates the interaction between primary and secondary flows by accelerating the secondary flow and aligning it with the primary flow, thereby stabilizing the flow field without requiring complex modifications to the main diffuser structure
Solution Approach 2:
The diffuser is segmented into distinct functional regions: the vaneless region containing the stabilizer ring for flow stabilization, and the vane region for diffusion. This segmentation allows the stabilizer ring to perform its flow alignment function independently while maintaining the traditional diffuser structure for pressure recovery, thus minimizing overall device complexity
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 centrifugal acceleration stabilizer ring enhances efficiency by aligning flow fields, minimizing recirculation, and maintaining high diffusion values across the diffuser passage, thereby improving overall compressor performance.
Implementation Method 1
a centrifugal acceleration stabilizer ring configured to increase the radial velocity of a lower momentum region of a flow field flowing in the diffuser
Data Source
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AI summary
A dynamic compressor (100) includes an impeller (104) having impeller blades (108) disposed around a hub (109), a shroud (102), and a diffuser (112) having a shroud surface (122) adjacent to the shroud and a hub surface (124) adjacent to the hub, wherein the diffuser is circumferentially disposed around the impeller. The diffuser (112) includes a plurality of diffuser vanes (114) extending from the hub surface (124) to the shroud surface (122), each having a vane leading edge (115) and a vane trailing edge (117). The diffuser (112) includes a centrifugal acceleration stabilizer ring (120) formed in the shroud surface (122) located in a vaneless region (121) defined between an impeller trailing edge (113) and the vane leading edge (115). The centrifugal acceleration stabilizer ring (120) stabilizes the flow of the fluid by changing the circumferentially-flowing high velocity fluid flow exiting the impeller (104) into a radially-flowing high velocity fluid flow before entering the diffuser (112), improving the efficiency of the dynamic compressor.