scholarly journals An Analysis of Spatial Nonuniformity of the Flow at the Entrance Section of the Axial-Radial Impeller of a Centrifugal Compressor Stage Working on Regulation Modes

2019 ◽  
pp. 30-40
Author(s):  
A.D. Vanyashov ◽  
V.V. Karabanova
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Turning Angle ◽  
Centrifugal Compressor Stage ◽  
Entrance Section ◽  
Spatial Nonuniformity ◽  
Optimum Diameter ◽  
Significant Difference

The article presents an analysis of the experimental data on testing a centrifugal compressor stage on regulation modes by changing the rotational speed of the rotor and the turning angle of the blades in the inlet guide vane unit. The distribution of the angles of attack at the entrance section of the impeller in relation to the blade height is obtained. It is established that a significant difference in the angles of attack from the plug to the periphery influences the polytropic efficiency of the compressor stage. Recommendations are given on the improvement of the mechanism of regulation by the inlet guide vane unit and on the choice of the optimum diameter for the entrance part of the driving impeller blades.

scholarly journals The influence of blade profile shape of inlet guide vane on performance map of centrifugal compressor stage

2020 ◽  
Vol 4 (4) ◽  
pp. 41-48
Author(s):  
V. V. Karabanova ◽  
◽  
A. D. Vanyashov ◽  
V. L. Yusha ◽  
◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Rotor Speed ◽  
Blade Profile ◽  
Centrifugal Compressor Stage ◽  
Profile Shape ◽  
Performance Map ◽  
Lower Loss

The object of the study is a centrifugal compressor stage with an inlet guide vane. The performance map of the stage are investigated in the modes of combined regulation by changing the rotor speed and changing the swirl of the flow in front of the impeller by turning the blades of the inlet guide vane. Two variants of the design of the profile of the blades of the inlet guide vane are considered and the method of turning the blades by performance map. As a result of the study, it is found that a profile with a fixed inlet part at large swept angles has a lower loss coefficient, which contributes to an increase in the efficiency of the stage. The effect of regulation to achieve the set point in terms of pressure and flow for the re-profile stage is achieved at lower speeds

A Practical Approximate Method to Predict Adjusting Performance of a Centrifugal Compressor Stage With Inlet Guide Vane

2011 ◽  
Author(s):  
Changsheng Liu ◽  
Jiajian Tan ◽  
Datong Qi ◽  
Xuejun Wang ◽  
Guoliang Qin
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Prediction Method ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Performance Curve ◽  
Centrifugal Compressor Stage ◽  
Basic Model ◽  
Curve Family

This paper has proposed a method for predicting an adjusting performance curve family of a centrifugal compressor stage with the inlet guide vane (IGV). The method can be separated into two steps. In the first step, a centrifugal compressor model stage is selected as a basic model stage to build the basis of prediction. Both the ordinary performance curve of the model stage without IGV and the adjusting performance curve family of the model stage at various setting angles of the IGV are obtained by experiments. Then, using the ordinary performance curve as a criterion, a non-dimensional mathematical relationship is set up between the ordinary performance curve and each curve in the adjusting performance curve family. In the second step, based on the relationship established above, a prediction is made for the adjusting performance curve family of another centrifugal compressor stage with an IGV. For this prediction, two conditions must be satisfied: 1) The adjustment must be done using the IGV of the same type as used in the first step; 2) The ordinary performance curve of the predicted model stage must have been obtained experimentally. By applying the method, a prediction was carried out for the IGV adjusting performance curve family of a centrifugal compressor stage. Comparison between the predicted results and experimental results shows that although there is relatively great discrepancy between the basic model stage and the predicted stage under the mechanical geometric construction and operating conditions, the two results agree well in most of the areas of the adjusting performance curve family. There are only greater errors of predicted results in areas of large IGV setting angle. Although the current method has some deficiencies, it still possesses some strength featuring simplicity, convenience and reliability, thus providing a practical approximate prediction method available for the centrifugal compressor manufacturers that have the model stage database, but lack the APCF for the model stages with IGV.

Variable Inlet Guide Vane Effect on Centrifugal Compressor Performance in Wet Gas Flow

2016 ◽  
Author(s):  
Levi André B. Vigdal ◽  
Lars E. Bakken
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Flow Direction ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Guide Vanes ◽  
Wet Gas ◽  
Compressor Performance

The introduction of variable inlet guide vanes (VIGVs) upfront of a compressor stage affects performance and permits tuning for off-design conditions. This is of great interest for emerging technology related to subsea compression. Unprocessed gas from the wellhead will contain liquid condensate, which affects the operational condition of the compressor. To investigate the effect of guide vanes on volume flow and pressure ratio in a wet gas compressor, VIGVs are implemented upfront of a centrifugal compressor stage to control the inlet flow direction. The guide vane geometry and test rig setup have previous been presented. This paper documents how changing the VIGV setting affects compressor performance under dry and wet operating conditions. The reduced performance effect and operating range at increased liquid content are of specific interest. Also documented is the change in the VIGV effect relative to the setting angle.

Experimental Investigation of Forced Response Impeller Blade Vibration in a Centrifugal Compressor With Variable Inlet Guide Vanes: Part 2—Forcing Function and FSI Computations

2011 ◽  
Author(s):  
Armin Zemp ◽  
Reza S. Abhari ◽  
Matthias Schleer
Keyword(s):  
Experimental Investigation ◽  
Centrifugal Compressor ◽  
Guide Vane ◽  
Forced Response ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Blade Vibration ◽  
Impeller Blade ◽  
Inlet Guide Vanes ◽  
Vane Angle

As the second part of a two-part paper, this paper presents an experimental investigation of forced response impeller blade vibrations in a centrifugal compressor stage caused by variable inlet guide vanes. Although it is common practice to experimentally test the forced response blade vibration behavior of new impeller designs in terms of strain gauge or tip-timing measurements, the impact of the unsteady blade pressure distribution acting as an unsteady load on the blade surfaces is still not known. A centrifugal compressor impeller was therefore instrumented with dynamic strain gauges and fast-response pressure transducers to measure the forcing of the impeller blades for different compressor operating points and various inlet guide vane angle settings. The results showed a decrease in the excitation amplitudes for reduced mass flow rates of the compressor stage. The inlet guide vane angle setting affected the convection speed of the distortion pattern along the blade surface. An increase in the negative inlet guide vane angle caused higher excitation amplitudes especially in the inducer part of the blade. However, the largest negative inlet guide vane setting caused the smallest excitation amplitudes as this setup introduced the smallest amount of inlet distortion to the inlet flow field. A series of unidirectional fluid structure interaction calculations was performed to show the limitations and requirements of today’s numerical tools.

Effect of Cavities on Impeller Aeromechanical Forcing in a Low Pressure Ratio Centrifugal Compressor Stage

2014 ◽  
Author(s):  
Cathal Clancy ◽  
François Moyroud ◽  
Kishore Ramakrishnan
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Forced Response ◽  
Navier Stokes ◽  
Compressor Stage ◽  
Centrifugal Compressor Stage ◽  
Force Magnitude ◽  
Acoustic Interaction ◽  
Significant Difference ◽  
Modal Force

Previous experimental and CFD investigation on a GE Oil & Gas centrifugal compressor stage with a vaneless diffuser revealed a complex excitation mechanism caused by aero-acoustic interaction between three blade rows. Recent published studies have indicated that cavities enclosing shrouded impellers may strongly amplify the acoustic excitation of the impeller by Tyler-Sofrin modes. In this current research therefore, the previous CFD study is expanded to include a model of the disk and shroud cavities. A linearized Navier-Stokes frequency sweep in forced response mode shows a well-defined peak in cavity acoustic activity at a certain frequency. It also shows that the inclusion of cavities noticeably increases the modal forcing on the impeller, qualitatively confirming findings in existing literature. A significant difference in modal force magnitude is found between the shroud-disk out-of-phase mode and the in-phase mode, which is consistent with experimental measurements of vibratory response.

An Investigation of the Stability Enhancement of a Centrifugal Compressor Stage Using a Porous Throat Diffuser

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Lee Galloway ◽  
Stephen Spence ◽  
Sung In Kim ◽  
Daniel Rusch ◽  
Klemens Vogel ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Compressor Stage ◽  
Vaned Diffuser ◽  
Flow Rates ◽  
Stall Inception ◽  
Centrifugal Compressor Stage ◽  
Operating Range ◽  
Stable Operating ◽  
The Stability ◽  
Circumferential Pressure

The stable operating range of a centrifugal compressor stage of an engine turbocharger is limited at low mass flow rates by aerodynamic instabilities which can lead to the onset of rotating stall or surge. There have been many techniques employed to increase the stable operating range of centrifugal compressor stages. The literature demonstrates that there are various possibilities for adding special treatments to the nominal diffuser vane geometry, or including injection or bleed flows to modify the diffuser flow field in order to influence diffuser stability. One such treatment is the porous throat diffuser (PTD). Although the benefits of this technique have been proven in the existing literature, a comprehensive understanding of how this technique operates is not yet available. This paper uses experimental measurements from a high pressure ratio (PR) compressor stage to acquire a sound understanding of the flow features within the vaned diffuser which affect the stability of the overall compression system and investigate the stabilizing mechanism of the porous throat diffuser. The nonuniform circumferential pressure imposed by the asymmetric volute is experimentally and numerically examined to understand if this provides a preferential location for stall inception in the diffuser. The following hypothesis is confirmed: linking of the diffuser throats via the side cavity equalizes the diffuser throat pressure, thus creating a more homogeneous circumferential pressure distribution, which delays stall inception to lower flow rates. The results of the porous throat diffuser configuration are compared to a standard vaned diffuser compressor stage in terms of overall compressor performance parameters, circumferential pressure nonuniformity at various locations through the compressor stage and diffuser subcomponent analysis. The diffuser inlet region was found to be the element most influenced by the porous throat diffuser, and the stability limit is mainly governed by this element.

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