Variable-Backsweep Impeller Blades for Broader Compressor Operation

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Solution Overview

Problem

Conventional impeller designs with fixed backsweep angles in centrifugal compressors lack flexibility to adapt to varying operational demands, compromising efficiency and operational range.

Innovation Solution

An impeller with blades that have an unattached portion free to deflect, allowing the backsweep angle to adjust within a predefined range based on rotational speed, enhancing operational flexibility and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the backsweep angle of impeller blades is fixed, then the impeller structure is simple and manufacturing is easy, but the impeller cannot adapt to varying operational demands and efficiency is compromised

Engineering Contradiction:
Improveadaptability to varying operational demandsVSAvoidimpeller structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The impeller blades are designed with a variable backsweep angle that dynamically adjusts based on rotational speed. The blades transition from a higher backsweep angle at lower speeds to a lower backsweep angle at higher speeds, allowing the impeller to adapt to varying operational demands without requiring multiple impeller designs or complex external control mechanisms.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The backsweep angle parameter of the impeller blades is made variable rather than fixed. By allowing the backsweep angle to change as a function of rotational speed, the impeller can optimize its performance across different operating conditions. This parameter change is achieved through the geometric design of the blades and hub interaction, eliminating the need for additional actuators or control systems.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If the backsweep angle is adjusted to optimize efficiency at one operational condition, then efficiency at that condition improves, but the impeller cannot maintain optimal efficiency across different operational conditions

Engineering Contradiction:
ImproveefficiencyVSAvoidoperational range
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The impeller employs dynamic blade geometry where the backsweep angle automatically varies with rotational speed. At lower speeds, the blades maintain a higher backsweep angle to optimize efficiency, while at higher speeds, the backsweep angle decreases to maintain optimal performance. This dynamic adaptation allows the impeller to achieve high efficiency across a broad range of operational conditions without requiring external control systems.

Inventive Principle:
Principle #15Dynamics

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 adjustable backsweep angle improves the overall performance and operating range of centrifugal compressors by optimizing efficiency across different operational conditions.

Implementation Method 1

the unattached portion of the blades is free to deflect based on a rotational speed of the impeller and correspondingly adjust a backsweep angle of the corresponding blades

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Data Source

PatentEP4617503A1Impeller with variable backsweep angle
Publication Date: 2025.09.17 CARRIER CORP
  • EP4617503A1 patent drawingFigure 1A
  • EP4617503A1 patent drawingFigure 1B
  • EP4617503A1 patent drawingFigure 1C

AI summary

An impeller (100) for a flow device comprises a hub (102), and a plurality of blades (104) extending radially outwards from the hub, wherein each of the blades is at least partially attached to an outer surface (102A) of the hub such that at least a portion of a tip end, opposite to the hub, of the corresponding blades remains unattached to the outer surface of the hub, wherein the unattached portion of the blades (L) is free to deflect based on a rotational speed of the impeller and correspondingly adjust a backsweep angle (β) of the corresponding blades within a predefined range.