scholarly journals Preliminary Design Considerations for Variable Geometry Radial Turbines with Multi-Points Specifications

2018 ◽  
Vol 3 (4) ◽  
pp. 22
Author(s):  
Pierre-Thomas Lauriau ◽  
Nicolas Binder ◽  
Sandrine Cros ◽  
Mathieu Roumeas ◽  
Xavier Carbonneau
Keyword(s):  
Flow Diagram ◽  
Speed Ratio ◽  
Preliminary Design ◽  
Variable Geometry ◽  
Operating Range ◽  
Design Considerations ◽  
Radial Turbines ◽  
Nozzle Opening

Radial turbines’ preliminary designs are usually carried out through some dimensionless approaches, such as the loading-to-flow-diagram and/or the blade speed ratio. In case of variable nozzle radial turbines, multi-points specifications must be considered, related to the improvement of the operating range. As preliminary design correlations and standards usually taken into consideration arise from studies dedicated to fixed geometry radial turbines, they need to be updated with regard to nozzle off-design opening configurations. This paper provides some theoretical basics in order to help designers considering variable geometry problems. Some complementary elements about the dimensionless methods are given by taking into account the nozzle opening effect. Then, useful considerations are brought regarding the preliminary design of variable geometry radial turbines with multi-points specifications.

scholarly journals Preliminary Design Considerations for Variable Geometry Radial Turbines with Multi-Points Specifications

2017 ◽  
Author(s):  
Pierre-Thomas Lauriau ◽  
Nicolas Binder ◽  
Xavier Carbonneau ◽  
Sandrine Cros ◽  
Mathieu Roumeas
Keyword(s):  
Preliminary Design ◽  
Variable Geometry ◽  
Design Considerations ◽  
Radial Turbines

Design and Performance Analysis of a Supercritical CO2 Centrifugal Compressor With Variable Geometry

2021 ◽  
Author(s):  
Gang Fan ◽  
Kang Chen ◽  
Shaoxiong Zheng ◽  
Yang Du ◽  
Yiping Dai ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Optimization Design ◽  
High Efficiency ◽  
Superior Performance ◽  
Variable Geometry ◽  
Power Cycles ◽  
Operating Range ◽  
Stable Operating ◽  
And Performance ◽  
Geometry Method

Abstract The supercritical carbon dioxide (SCO2) Brayton cycle is one of the most promising power cycles due to its high efficiency, compactness and environmentally friendliness. The centrifugal compressor is a key component of small and medium SCO2 Brayton cycles, and its efficiency has a significant impact on the cycle efficiency. Since the required electric load of power cycles always fluctuates over the year, the SCO2 compressor will operate away from its design point and the narrow stable operating range of a compressor is always a restriction. In this paper, the variable-geometry method, which refers to the combination of a variable inlet-guide-vanes and variable diffuser vanes is proposed for the operating range extension of SCO2 compressors. A set of one-dimensional (1D) loss correlations has been found to accurately predict various losses of the SCO2 compressor components. Based on the 1D thermodynamic model, two programs with internal MATLAB codes coupled with the NIST REFPROP database have been developed for preliminary optimization design and off-design performance predictions of the variable geometry SCO2 compressor. The contributions from the variable-inlet prewhirl and variable diffuser vanes to the shifts of the surge line and choke line are discussed in this paper. The results show the variable-geometry SCO2 compressor has a superior performance at off-design conditions and a wider operating range.

scholarly journals The Effect of Variable Geometry on the Operating Range and Surge Margin of a Centrifugal Compressor

1976 ◽  
Author(s):  
A. Whitfield ◽  
F. J. Wallace ◽  
R. C. Atkey
Keyword(s):  
Centrifugal Compressor ◽  
Peak Pressure ◽  
Pressure Ratio ◽  
Variable Geometry ◽  
Vaneless Diffuser ◽  
Flow Rates ◽  
Lower Flow ◽  
Operating Range ◽  
Surge Margin ◽  
Isentropic Efficiency

Two variable geometry techniques have been applied to a small turbocharger compressor, with the objective of trying to move the peak pressure ratio operating point to lower flow rates, thereby yielding a broad flow range map. Variable prewhirl guide vanes and variable vaneless diffuser passage height have been studied separately. The results obtained with both techniques are compared and the relative merits and demerits with respect to improved flow range and isentropic efficiency penalties are considered.

scholarly journals Advanced tokamak reactors based on the spherical torus (ATR/ST). Preliminary design considerations

1986 ◽  
Author(s):  
R.L. Miller ◽  
R.A. Krakowski ◽  
C.G. Bathke ◽  
C. Copenhaver ◽  
N.M. Schnurr ◽  
...  
Keyword(s):  
Preliminary Design ◽  
Spherical Torus ◽  
Design Considerations ◽  
Tokamak Reactors

scholarly journals The Performance of a Centrifugal Compressor With High Inlet Prewhirl

1997 ◽  
Author(s):  
A. Whitfield ◽  
A. H. Abdullah
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Low Flow ◽  
Variable Geometry ◽  
Pressure Pulsations ◽  
Operating Range ◽  
Swirl Generator ◽  
Geometry Design ◽  
Wide Range ◽  
Inlet Swirl

The performance requirements of centrifugal compressors usually include a broad operating range between surge and choke. This becomes increasingly difficult to achieve as increased pressure ratio is demanded. In order to suppress the tendency to surge and extend the operating range at low flow rates inlet swirl is often considered through the application of inlet guide vanes. To generate high inlet swirl angles efficiently an inlet volute has been applied as the swirl generator, and a variable geometry design developed in order to provide zero swirl. The variable geometry approach can be applied to progressively increase the swirl or to switch rapidly from zero swirl to maximum swirl. The variable geometry volute and the swirl conditions generated are described. The performance of a small centrifugal compressor is presented for a wide range of inlet swirl angles. In addition to the basic performance characteristics of the compressor the onset of flow reversals at impeller inlet are presented, together with the development of pressure pulsations, in the inlet and discharge ducts, through to full surge. The flow rate at which surge occurred was shown, by the shift of the peak pressure condition and by the measurement of the pressure pulsations, to be reduced by over 40%.

The Development of High Performance Centrifugal Compressor Using CFD and Other Considerations

2017 ◽  
Author(s):  
C. Xu ◽  
M. Muller
Keyword(s):  
Power Distribution ◽  
High Performance ◽  
High Efficiency ◽  
Low Noise ◽  
Field Application ◽  
Air Separation ◽  
Operating Range ◽  
Design Considerations ◽  
Reliable Design ◽  
Air Compression

Air compression is one of the most important processes of air separation. Reliable design, higher performance, low noise, no resonant frequencies in the operating range and economic to manufacture are the goals of compressor design. Although CFD has been widely used in the compressor designs, there are many design considerations need to be addressed during the design. In this paper, the detailed design considerations for compressor configuration, power distribution for each stage, and possible field application issues are discussed in detail. The aerodynamic and structural optimization using CFD and FEA are performed to obtain a high efficiency and wide operating range compressor stage with for robust operation. The new compressor development process addressed in this paper provides the basic design guidance for future new compressor development.

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