Turbomachine Impeller Shroud Openings for Compressor Efficiency
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Solution Overview
Problem
Conventional turbomachine impeller designs face limitations in efficiency, particularly near the choke and stall sides of their operating characteristics, and require air extraction methods that complicate design and increase weight, without improving flow capacity or surge margin.
Innovation Solution
The implementation of an impeller shroud with strategically placed openings providing fluid communication between the impeller flowpath and a dead-headed plenum, enhancing compressor efficiency without air extraction, thereby simplifying design and reducing weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If air extraction methods are used to improve compressor efficiency near choke and stall sides, then efficiency is improved, but design complexity increases and weight increases
Solution Approach 1:
The patent extracts air from the impeller passage through openings in the shroud and redirects it to the diffuser region. This extraction improves compressor efficiency by preventing flow separation and optimizing the flow distribution without requiring complex external systems or increasing device weight.
Solution Approach 2:
The shroud openings act as an intermediary structure that facilitates controlled air extraction from the impeller passage and redirects it to the diffuser. This simple intermediary element achieves efficiency improvement without adding complex mechanisms or increasing overall device complexity.
2Loss of energy
If air extraction methods are used to improve compressor efficiency near choke and stall sides, then efficiency is improved, but weight increases
Solution Approach 1:
The patent extracts air from the impeller passage through openings in the shroud and redirects it to the diffuser region. This extraction improves compressor efficiency by preventing flow separation and optimizing the flow distribution without requiring complex external systems or increasing device weight.
Solution Approach 2:
The impeller shroud structure serves dual functions: it maintains its structural role while simultaneously providing air extraction and redistribution capabilities. This self-service approach improves efficiency without adding separate weighted components or systems.
3Adaptability or versatility
If conventional ported shroud impeller designs are used, then choke side range and stall side range are increased, but air flow capacity decreases and surge margin decreases
Solution Approach 1:
The patent applies different flow control strategies at different locations: openings are strategically positioned in the shroud at specific radial and axial locations to extract air precisely where needed in the impeller passage. This localized approach optimizes operating range without compromising overall flow capacity or surge margin.
Solution Approach 2:
The patent changes the flow parameters by extracting air at specific points and redirecting it to the diffuser region. This parameter change optimizes the flow distribution and pressure distribution, expanding the operating range while maintaining flow capacity and surge margin through controlled modification of flow characteristics.
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 solution improves compressor efficiency without compromising flow capacity or surge margin, offering a more straightforward and cost-effective design that can be retrofitted into existing turbomachines.
Implementation Method 1
at least one opening disposed in the impeller shroud between the impeller inlet and the impeller outlet, the at least one opening providing fluid communication between the impeller and the dead-headed plenum
Data Source
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AI summary
Embodiments of a turbomachine, having a longitudinal axis and a flowpath are provided. The turbomachine includes an impeller circumferentially disposed around the longitudinal axis, and an impeller shroud that surrounds a portion of the impeller. At least one opening formed through the impeller shroud surface provides fluid communication between the flowpath and a dead-headed plenum.