Compressor Swirl Nozzles for Part-Load Efficiency and Surge Margin

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Solution Overview

Problem

Existing compressors face challenges in achieving optimum efficiency during part-load conditions due to aerodynamic losses and surge margin issues, particularly in the impeller region.

Innovation Solution

Incorporating swirl nozzles downstream of inlet guide vanes and upstream of the impeller, with adjustable outlet directions and controlled fluid flow, to introduce swirl in the intake passage and optimize the incidence angle of fluid onto the impeller blades, thereby enhancing efficiency and surge margin.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If inlet guide vanes are used to control fluid flow, then flow control capability is improved, but aerodynamic losses increase under part-load conditions

Engineering Contradiction:
Improveflow control capabilityVSAvoidaerodynamic losses
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The flow control function is segmented between inlet guide vanes and swirl nozzles. The inlet guide vanes provide coarse flow control, while the swirl nozzles provide fine adjustment of the incidence angle, allowing independent optimization of each component's function to reduce overall aerodynamic losses

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The swirl nozzles act as an intermediary element between the inlet guide vanes and the impeller blades. They modify the fluid flow characteristics by introducing controlled swirl, thereby optimizing the incidence angle before the fluid reaches the impeller blades and reducing aerodynamic losses

Inventive Principle:
Principle #24Intermediary (Mediator)

2Use of energy by moving object

If fluid flow rate is reduced for part-load operation, then energy consumption is reduced, but compressor efficiency and surge margin deteriorate

Engineering Contradiction:
Improveenergy consumptionVSAvoidcompressor efficiency and surge margin
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The swirl nozzles change the flow parameters (incidence angle and swirl intensity) of the fluid entering the impeller. By adjusting these parameters, the compressor can operate efficiently at reduced flow rates, maintaining surge margin and efficiency even during part-load conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system dynamically adjusts the swirl nozzle operation based on load conditions. During part-load operation, the swirl nozzles are activated to optimize flow characteristics, while during full-load operation, the inlet guide vanes provide primary control, creating a dynamic adaptation strategy

Inventive Principle:
Principle #15Dynamics

3Reliability

If swirl nozzles are added to optimize incidence angle, then compressor efficiency is improved, but device complexity increases

Engineering Contradiction:
Improvecompressor efficiencyVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The swirl nozzles are designed to serve multiple functions: controlling incidence angle, introducing optimal swirl, and working in conjunction with inlet guide vanes. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The swirl nozzle assembly is integrated with the existing inlet structure and impeller system. The outlets are positioned to work in conjunction with the inlet guide vanes, merging the swirl generation function with the existing flow control architecture rather than adding completely separate systems

Inventive Principle:
Principle #5Merging (Combining)

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 introduction of swirl nozzles improves compressor efficiency and surge margin by compensating for inlet guide vane effects, especially under part-load conditions, by optimizing fluid interaction with impeller blades.

Implementation Method 1

The swirl nozzles are configured to introduce fluid into the intake passage to cause swirl of fluid in the intake passage between the plurality of inlet guide vanes and the impeller

Methodology Applied
Scientific EffectSwirl flow: Vortex Ring

Implementation Method 2

The impeller includes a plurality of blades and directs fluid from the intake passage toward an outlet

Methodology Applied
Scientific EffectCentrifugal compression: Centrifugal Force

Data Source

PatentEP4137700B1Compressor including aerodynamic swirl between inlet guide vanes and impeller blades
Publication Date: 2025.09.24 CARRIER CORP
  • EP4137700B1 patent drawingFigure 1~2

AI summary

A compressor (20) includes an inlet (22) defining an intake passage, a plurality of inlet guide vanes (24), an impeller (26), and a plurality of swirl nozzles (40). Fluid flow through the plurality of inlet guide vanes (24) into the intake passage is selectively adjustable to control fluid flow through at least the portion of the intake passage downstream of the swirl nozzles (40). The impeller (26) includes a plurality of blades (28) and directs fluid from the intake passage toward an outlet. The swirl nozzles (40) have outlets positioned downstream of the plurality of inlet guide vanes (24) and upstream of the impeller (26). The swirl nozzles (40) are configured to introduce fluid into the intake passage to cause swirl of fluid in the intake passage between the plurality of inlet guide vanes (24) and the impeller (26).