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 1—Blade Damping

2011 ◽  
Author(s):  
Armin Zemp ◽  
Reza S. Abhari ◽  
Beat Ribi
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Operating Conditions ◽  
Inlet Pressure ◽  
Dynamic Strain ◽  
Inlet Guide Vane ◽  
Guide Vanes ◽  
Aerodynamic Damping ◽  
Inlet Guide Vanes ◽  
Vane Angle

Forming the first part of a two-part paper, the quantification of the resonant response levels and the damping quantities for a centrifugal compressor impeller with variable inlet guide vanes under engine representative operating conditions is detailed in this work. The motivation for the investigation is the lack of experimental data that are needed to improve and validate computational tools used during the design phase. Measurements were performed during resonant blade vibrations with the inlet pressure, the inlet guide vane angle and the operating point as the varying parameters. The flow non-uniformity introduced into the inlet flow field was measured with an aerodynamic probe. These measurements showed an increase in flow distortion for increased guide vane angles. The response amplitudes were acquired with dynamic strain gauges. A curve-fit method was applied to estimate the critical damping ratios. The results showed a linear correlation of the aerodynamic damping with the inlet pressure. The mode dependent material damping was therefore derived using a linear extrapolation to vacuum conditions of the inlet pressure dependent overall damping. The resonant blade dynamics could be captured with a single degree of freedom model. The aerodynamic damping and the maximum strain response were found to significantly depend on the inlet guide vane angle setting and on the throttle setting of the compressor.

Inlet Guide Vane Performance at Dry and Wet Gas Conditions

2015 ◽  
Author(s):  
Levi B. Vigdal ◽  
Lars E. Bakken
Keyword(s):  
Gas Flow ◽  
Guide Vane ◽  
Incidence Angle ◽  
Flow Direction ◽  
Volume Flow ◽  
Inlet Guide Vane ◽  
Compressor Stage ◽  
Compressor Wheel ◽  
Wet Gas ◽  
Compressor Impeller

As inlet properties of compressor stage deviates from design point, the compressor stage efficiency will be degraded. A change in properties typically affects the inlet volume flow and inlet Mach number. To maintain optimum performance a static stage called Variable Inlet Guide Vanes (IGV) is implemented before the compressor wheel to manipulate the inlet flow direction. The vanes are of airfoil type geometry, twisted in radial direction to compensate for compressor peripheral speed. The RMS radius has a geometrical flow turning of 20 degrees. Extensive research exists on vane performance in dry gas conditions, but there are however limited results on vane performance shift from dry to wet gas flow. This paper focuses on twisted VIGV performance with GMF down to 80 percent. The VIGV is mounted in front of a centrifugal compressor impeller operating at 9000 rpm. An outlet throttle valve is adjusted to allow for performance at constant gas volume flow. Increased liquid content shows a general reduction in continuity wave size. At low GVF the wave disappeared or was reduced drastically, only to reappear when the incidence angle was increased. This is presumably from the balance of momentum between the pressure side Horse Shoe Vortex and main flow. Flow separation was not observed at any incidence angles or GVF. A vortex at the trailing edge was observed which also allowed the movement of liquid in span-wise direction. Traces of several vortices were observed at all GVF. The general propagation of the vortices fits well with dry gas theory.

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.

scholarly journals Flow Measurements Behind the Inlet Guide Vane of a Centrifugal Compressor

1998 ◽  
Author(s):  
I. Kassens ◽  
M. Rautenberg
Keyword(s):  
Centrifugal Compressor ◽  
Total Pressure ◽  
Guide Vane ◽  
Incidence Angle ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Flow Measurements ◽  
Flow Angle ◽  
Partial Load ◽  
Measurement Location

In a centrifugal compressor adjustable inlet guide vanes (IGV) in front of the impeller are used to regulate the pressure ratio and the mass flow. The stationary measurement of the velocity profile in front of the impeller with different angles of the IGV displays shock losses at the inlet edge of blade of the impeller. In the partial-load region (e.g. partial-load efficiency) the radial distribution of the flow influences considerably the performance of the impeller. The tested compressor consists of an adjustable IGV with straight vanes, a shrouded impeller and a vaneless, parallel diffuser. In the first measurement location, behind the IGV, total pressure, static pressure and flow angle were measured with a 5-hole cylinder probe. In the second measurement location, in front of the impeller, the measurement of the total pressure was carried out with a Kiel probe and the flow angle with a Cobra probe accordingly the static wall pressure was measured. Taking into consideration the fundamental thermodynamical equations it was possible to determine the velocity profiles because of the measured distributions of the flow angle in these two measurement locations. For different angles of the IGV and with various mass flows the distributions of the deflection defect behind the IGV are described. Starting with the measured distributions of the flow in front of the impeller the flow angles at the impeller inlet are calculated and the distributions of the incidence angle at the impeller inlet are figured out.

The performance of a centrifugal compressor with a tandem impeller in off-design conditions

2019 ◽  
Vol 234 (2) ◽  
pp. 156-172 ◽  
Author(s):  
Ziliang Li ◽  
Xingen Lu ◽  
Ge Han ◽  
Yanfeng Zhang ◽  
Shengfeng Zhao ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Performance Enhancement ◽  
Pressure Ratio ◽  
Operating Conditions ◽  
Complex Flow ◽  
Maximum Enhancement ◽  
Operating Range ◽  
Wide Range ◽  
Compressor Performance ◽  
Low Efficiency

Centrifugal compressors often suffer relatively low efficiency and a terrible operating range particularly due to the complex flow structure and intense impeller/diffuser interaction. Numerous studies have focused on improving the centrifugal compressor performance using many innovative ideas, such as the tandem impeller, which has become increasingly attractive due to its ability to achieve the flow control with no additional air supply configurations and control costs in compressor. However, few studies that attempted to the investigation of tandem impeller have been published until now and the results are always contradictory. To explore the potential of the tandem impeller to enhance the compressor performance and the underlying mechanism of the flow phenomena in the tandem impellers, this paper numerically investigated a high-pressure-ratio centrifugal compressor with several tandem impellers at off-design operating speeds. The results encouragingly demonstrate that the tandem impeller can achieve a performance enhancement over a wide range of operating conditions. Approximately 1.8% maximum enhancement in isentropic efficiency and 5.0% maximum enhancement in operating range are achieved with the inducer/exducer circumferential displacement of [Formula: see text] = 25% and 50%, respectively. The observed stage performance gain of the tandem impellers decreases when the operating speed increases due to the increased inducer shock, increased wake losses, and deteriorated tandem impeller discharge flow uniformity. In addition, the tandem impeller can extend the impeller operating range particularly at low rotation speeds, which is found to be a result from the suppression of the low-momentum fluid radial movement. The results also indicate that the maximum flux capacity of the tandem impeller decreases due to the restriction of the inducer airfoil Kutta–Joukowsky condition.

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.

Performance Degradation Due to Fouling and Recovery After Washing in a Multistage Test Compressor

2021 ◽  
Vol 143 (3) ◽  
Author(s):  
Nicola Casari ◽  
Michele Pinelli ◽  
Pier Ruggero Spina ◽  
Alessio Suman ◽  
Alessandro Vulpio
Keyword(s):  
Guide Vane ◽  
Characteristic Curve ◽  
Pressure Ratio ◽  
Inlet Guide Vane ◽  
Performance Curve ◽  
Internal Surfaces ◽  
Before And After ◽  
Stator Vane ◽  
Compressor Performance ◽  
Dust Ingestion

Abstract Land-based power units have to fulfill even more high levels of production and reliability. In harsh environments (desert and tropical installations, typically), the power unit ingests high amounts of dust that might deposit inside the compressor. In this paper, the analysis of a multistage compressor performance that operates under sandy and humid conditions has been assessed. The compressor units, which equips the Allison 250 C18 compressor, has been subjected to multiple runs under severe conditions of soil dust ingestion. The compressor has been operated according to subsequent runs, and at the end of each run, the performance curve was recorded; the performance losses, in terms of pressure ratio, have been measured during the operations. The characteristic curve of each run is representative of the level of contamination of the unit. Finally, the compressor has been washed, and the performance curve, in the recovered conditions, has been recorded. The results show the modification and the downward shift of the characteristic curves which lead to a gradual loss of the compressor performance. The curves realized after dust ingestion have been compared with the recovered curve after online washing. The measurement shows a promising recovery of the performances, even if the compressor flow path appears affected by localized deposits able to resist to the droplet removal action. Detailed photographic reports of the inlet guide vane (IGV) and the first compressor stages have been included in this analysis. After each run, the IGV, the rotor blade and stator vane of the first stage, and the hub and the shroud surfaces have been photographed. The pictures show the deposition patterns on the blades and the compressor surfaces. The comparison of the pictures of the internal surfaces, before and after the washing, highlights the parts that are more critical to clean and needy of attention during offline washing and overhaul.

scholarly journals Development of Centrifugal Compressor for 100 kW Automotive Ceramic Gas Turbine

1994 ◽  
Author(s):  
Hiroshi Uchida ◽  
Mutsuo Shiraki ◽  
Akinobu Bessho ◽  
Yoichi Yagi
Keyword(s):  
Research And Development ◽  
Gas Turbine ◽  
Centrifugal Compressor ◽  
High Efficiency ◽  
Operating Conditions ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Surge Margin ◽  
Partial Load ◽  
Compressor Performance

In Japan, a program of research and development of a 100 kW automotive ceramic gas turbine (CGT) has been carried out in the Petroleum Energy Center with active cooperation of petroleum, automobile and ceramics industries as well as other related industries. As a part of this research and development program, we have studied and developed a centrifugal compressor with variable inlet guide vanes for CGT engines. There has been a strong demand for a compressor with a high efficiency and a wide flow range. The compressor performance goals are an adiabatic efficiency of 81% and a surge margin of 8% under maximum power operating conditions. This paper describes the methods for designing impellers, diffusers and variable inlet guide vanes, and presents the results of compressor performance tests. The test results reveal that the surge margin and compressor efficiency at partial load are improved by using inlet guide vanes.

Study of a Surge-Free Centrifugal Compressor With Automatically Variable Inlet and Diffuser Vanes

1996 ◽  
Author(s):  
Hideomi Harada
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Low Flow ◽  
Inlet Guide Vane ◽  
Analysis Method ◽  
Unstable Flow ◽  
Flow Angle ◽  
Operating Range

In order to improve the operating range of a centrifugal compressor, computer-controlled variable inlet and diffuser vanes were attached to a compressor with a pressure ratio of 2.5. Low-solidity cascade vanes capable of controlling the vane angle up to 0 degrees from the tangential direction were used for the vaned diffuser. The compressor’s overall performance was then tested using a closed-loop test stand. By automatically adjusting the diffuser vanes to the most suitable flow angle, pressure fluctuations caused by the unstable flow in the diffuser during low-flow operation of the centrifugal compressor could be suppressed, and the compressor could be operated nearly up to the shut-off flow rate without any surge. The author experimentally confirmed the critical operating range of both the impeller and diffuser at two different tip speeds and five inlet guide vane angles. Furthermore, a three-dimensional viscous flow-analysis method was applied to the impeller, and a three-dimensional momentum integral analysis method was applied to the diffuser. Then the critical operating ranges obtained in the experiments were qualitatively validated. The operating range of a centrifugal compressor under low-flow conditions, which has until now been limited because of surge, dramatically improved in this study, thereby demonstrating that it may be possible to develop a surge-free centrifugal compressor.

scholarly journals The Mach 2 Axial Flow Compressor Stage

1975 ◽  
Author(s):  
F. A. E. Breugelmans
Keyword(s):  
High Pressure ◽  
Guide Vane ◽  
Pressure Ratio ◽  
Axial Flow ◽  
Inlet Guide Vane ◽  
Variable Geometry ◽  
Compressor Stage ◽  
High Pressure Ratio ◽  
Flow Compressor ◽  
Original Configuration

A supersonic compressor stage has been designed for a high pressure ratio at a tip relative inlet Mach number of 2. The stage was operated in the original configuration, but serious inlet stall occurred at part-speed operation. An inlet blockage ring, a bleed system and a variable geometry inlet guide vane have been analyzed and applied to this configuration. The results obtained with the bleed system in the complete stage are presented. The rotor performance is discussed and compared with the stage performance.

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