scholarly journals A 1D mean line model for centrifugal compressors with variable inlet guide vanes

2019 ◽  
Vol 1 (1) ◽  
Author(s):  
Brett Dewar ◽  
Mike Creamer ◽  
Mariana Dotcheva ◽  
Jovana Radulovic ◽  
James M. Buick
Keyword(s):  
Centrifugal Compressors ◽  
Line Model ◽  
Guide Vanes ◽  
Inlet Guide Vanes

scholarly journals The Influence of Adjustable Inlet Guide Vanes on the Performance of Multi-Stage Industrial Centrifugal Compressors

1992 ◽  
Author(s):  
Klaus Lüdtke
Keyword(s):  
Molecular Weight ◽  
Mach Number ◽  
Power Consumption ◽  
Single Stage ◽  
Centrifugal Compressors ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Multi Stage ◽  
Centrifugal Process ◽  
Influential Parameters

Not only single-stage but also multi-stage centrifugal process compressors are often equipped with one row of adjustable Inlet guide vanes before the first stage. The question, frequently asked by the rotating equipment purchaser is whether such an expensive component is justified for multi-stage centrifugal compressors, since it effects first stage head only. Does or does it not improve turn-down or power consumption in comparison with ordinary butterfly valva suction throttling? The paper examines if and to what degree the favorable turn-down and part-load power consumption of IGV-equipped single-stage machines can be transferred to multi-stage compressors. An intuitive answer of-course is: the lower the number of stages, the more advantageous is the IGV-equipped compressor. There are however other influential parameters like molecular weight of the gas, Mach number, number of intercoolers and others. In contrast to axial and integral gear compressors centrifugal single-shaft compressors cannot be equipped with adjustable IGV’s before each stage due to an extreme lack of interstage space dictated by rotordynamic requirements. The maximum number of IGV’s is two for back-to-back arranged centrifugal impellers.

The Effects of Radial Inlet on the Performance of Variable Inlet Guide Vanes in a Centrifugal Compressor Stage

2010 ◽  
Author(s):  
Jiajian Tan ◽  
Datong Qi ◽  
Rui Wang
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Flow Simulation ◽  
Stage Model ◽  
Compressor Stage ◽  
Centrifugal Compressors ◽  
Guide Vanes ◽  
Centrifugal Compressor Stage ◽  
Inlet Guide Vanes ◽  
Stage Performance

Variable inlet guide vanes (VIGVs) can regulate pressure ratio and mass flow at constant rotational speed in centrifugal compressors as a result of inducing a controlled prewhirl in front of impellers. Radial inlets and VIGVs are typical upstream components in front of the first-stage impellers in many pipeline and multistage centrifugal compressors. However, previous investigations on VIGVs in centrifugal compressors were mostly conducted under the condition of axial inlets, and present work aims to focus on the effects of radial inlet on the VIGVs performance of a centrifugal compressor stage. The axial inlet stage model was compared with the radial inlet stage model using numerical flow simulation. The flow from the radial inlet was nonuniform in both circumferential and radial direction, thus the VIGVs, the impeller, the vaneless diffuser, and the return vane channel were modeled with fully 360-deg passages. The three-dimensional flow field was numerically simulated with FINE™/Turbo at VIGVs setting angles range from −20° to +60°. The overall stage performance parameters were obtained by integrating the field quantities. The simulation results show that the performance of VIGVs was significantly degraded by its inlet flow distortions resulting from a radial inlet. The stage performance map indicates that the overall stage polytropic efficiency decreased by an average of 2.5% and total pressure ratio decreased by an average of 1% because of the flow distortions at different VIGVs setting angles, in comparison with the axial stage model.

The effects of radial inlet with splitters on the performance of variable inlet guide vanes in a centrifugal compressor stage

2011 ◽  
Vol 225 (9) ◽  
pp. 2089-2105 ◽  
Author(s):  
J Tan ◽  
X Wang ◽  
D Qi ◽  
R Wang
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Stage Model ◽  
Compressor Stage ◽  
Centrifugal Compressors ◽  
Guide Vanes ◽  
Centrifugal Compressor Stage ◽  
Inlet Guide Vanes ◽  
Flow Loss ◽  
Stage Performance

Variable inlet guide vanes (VIGVs) can regulate pressure ratio and mass flow at constant rotational speed in centrifugal compressors as a result of inducing a controlled prewhirl in front of impellers. Radial inlets and VIGVs are typical upstream components in front of the first-stage impellers in many industrial centrifugal compressors. However, previous investigations on VIGVs in centrifugal compressors were mostly conducted under the condition of axial inlets, and this study aims to focus on the effects of radial inlet on the VIGVs performance of a centrifugal compressor stage. The axial inlet stage model is compared with the radial inlet stage model with splitters using numerical flow simulation. The flow from the radial inlet was non-uniform in both circumferential and radial directions; thus, the VIGVs, the impeller, the vaneless diffuser, and the return vane channel are modelled with fully 360° passages. The three-dimensional (3D) flow field is numerically simulated at VIGVs setting angles ranging from - 20° to 60°. The overall stage performance parameters are obtained by integrating the field quantities. Though the splitters are equipped in the radial inlet, the overall stage polytropic efficiency decreases by an average of 4 per cent and total pressure ratio decreases by an average of 3.3per cent in comparison with the axial stage model. This can be attributed to the effect of both flow non-uniformity induced by radial inlet and flow loss in the radial inlet at different VIGV setting angles. The flow loss in the radial inlet with splitters is the main reason of the stage performance decrease compared with the flow non-uniformity. The simulation results show that the performance of VIGVs is degraded by its inlet flow distortions resulting from a radial inlet. The results in this study can be applied to centrifugal compressor design and optimization.

Improvements in Performance Characteristics of Single-Stage and Multistage Centrifugal Compressors by Simultaneous Adjustments of Inlet Guide Vanes and Diffuser Vanes

1987 ◽  
Vol 109 (1) ◽  
pp. 41-47 ◽  
Author(s):  
H. Simon ◽  
T. Wallmann ◽  
T. Mo¨nk
Keyword(s):  
Performance Characteristic ◽  
Guide Vane ◽  
Three Dimensional ◽  
Maximum Efficiency ◽  
Inlet Guide Vane ◽  
Centrifugal Compressors ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
The Individual ◽  
Simultaneous Adjustment

Nowadays, multistage geared centrifugal compressors are most often equipped with three-dimensional impellers and adjustable inlet guide vane cascades, at least upstream of the first stage. Optimum stage efficiencies are made possible by optimum axial in-flow into each stage and freely selectable pinion shaft speeds. Combined with intercooling of the medium, the result is high machine efficiency with good operating ranges. Additional increases in efficiency can be achieved by means of vaned diffusers. Due to the attendant restriction to the working range, this solution is not common in production compressors. Nevertheless, the working range can be distinctly expanded by adjusting the diffuser vanes. In addition, the combination of simultaneous adjustment to inlet guide vanes and diffuser vanes enables an increase in machine efficiency over the entire operating range as compared with regulation using only inlet guide vanes or diffuser vanes. This paper reports on the development of centrifugal compressor stages equipped with vaned diffusers. The impellers have backward-curved blades. Experimental determination of suitable schedules for simultaneous adjustment of both inlet guide vanes and diffuser vanes, depending on the desired performance characteristic, will be dealt with in detail. Furthermore, some examples of the overall performance maps for multistage inter-cooled geared compressors will be shown as a result of combining the performance characteristic curves of the individual stages. The operating ranges and regions of maximum efficiency are optimally matched to the requirements in question by means of suitable adjustment schedules.

On the Combined Effect on Operating Range of Adjustable Inlet Guide Vanes and Variable Speed in Process Multistage Centrifugal Compressors

2014 ◽  
Vol 136 (8) ◽  
Author(s):  
Alberto Scotti Del Greco ◽  
Libero Tapinassi
Keyword(s):  
Centrifugal Compressor ◽  
Control Device ◽  
Variable Speed ◽  
Centrifugal Compressors ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Speed Regulation ◽  
Wide Range ◽  
Mach Numbers ◽  
Multistage Centrifugal Compressor

Adjustable inlet guide vanes (IGVs) and variable speed drivers are known as providing process compressors with an effective regulation all throughout the operating envelope of the machine. A large amount of work exists in literature reporting the successful control of multistage centrifugal compressors by means of IGVs or speed separately, while a few studies document the combined use of both devices and their effect on compressor performance. The present paper details the off-design behavior of a multistage centrifugal compressor equipped with both types of control. It is shown that classical IGVs' advantage in extending the operating envelope of a fixed speed multistage compressor tends to reduce when speed regulation is active too. In this sense, the average level of peripheral Mach numbers inside the compressor may be interpreted as a sort of threshold since it deeply affects the stage mismatching at off-design conditions. This consideration is corroborated by a number of applications in a wide range of design peripheral Mach numbers. Based on those cases, the paper reviews the general effectiveness of the combined regulation, thus outlining some general rules of thumb for the choice of the optimal control device for a multistage centrifugal compressor.

Investigation of Electrohydraulic Control of A Gas Turbine Engine’s Inlet Guide Vanes

2017 ◽  
Vol 17 (17) ◽  
pp. 1-10
Author(s):  
Mostafa Samy ◽  
Mohamed Metwally ◽  
Wael Elmayyah ◽  
Ibrahem Elsherif
Keyword(s):  
Gas Turbine ◽  
Guide Vanes ◽  
Inlet Guide Vanes

Redesign of a Compressor Stage for a High-Performance Electric Supercharger in a Heavily Downsized Engine

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Peng Wang ◽  
Mehrdad Zangeneh ◽  
Bryn Richards ◽  
Kevin Gray ◽  
James Tran ◽  
...  
Keyword(s):  
Design Method ◽  
Pressure Ratio ◽  
Compressor Stage ◽  
Impeller Blade ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Surge Margin ◽  
Stable Operating ◽  
Inverse Design Method ◽  
Ported Shroud

Engine downsizing is a modern solution for the reduction of CO2 emissions from internal combustion engines. This technology has been gaining increasing attention from industry. In order to enable a downsized engine to operate properly at low speed conditions, it is essential to have a compressor stage with very good surge margin. The ported shroud, also known as the casing treatment, is a conventional way used in turbochargers to widen the working range. However, the ported shroud works effectively only at pressure ratios higher than 3:1. At lower pressure ratio, its advantages for surge margin enhancements are very limited. The variable inlet guide vanes are also a solution to this problem. By adjusting the setting angles of variable inlet guide vanes, it is possible to shift the compressor map toward the smaller flow rates. However, this would also undermine the stage efficiency, require extra space for installing the inlet guide vanes, and add costs. The best solution is therefore to improve the design of impeller blade itself to attain high aerodynamic performances and wide operating ranges. This paper reports a recent study of using inverse design method for the redesign of a centrifugal compressor stage used in an electric supercharger, including the impeller blade and volute. The main requirements were to substantially increase the stable operating range of the compressor in order to meet the demands of the downsized engine. The three-dimensional (3D) inverse design method was used to optimize the impeller geometry and achieve higher efficiency and stable operating range. The predicted performance map shows great advantages when compared with the existing design. To validate the computational fluid dynamics (CFD) results, this new compressor stage has also been prototyped and tested. It will be shown that the CFD predictions have very good agreement with experiments and the redesigned compressor stage has improved the pressure ratio, aerodynamic efficiency, choke, and surge margins considerably.

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