The Performance Influences of a Centrifugal Compressor Due to Volute Local Deformation

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Numerical Analysis ◽  
Centrifugal Compressor ◽  
Engine Performance ◽  
Local Deformation ◽  
Hydraulic Diameter ◽  
Cfd Analysis ◽  
Compressor Stage ◽  
Gas Compression ◽  
The Future ◽  
Compressor Performance

Centrifugal compressors have broad applications in gas compression processes, especially in automobile turbocharger. During the turbocharger installation, there are many installation limitations in the compressor stage. Due to the restriction in the size of the engine bay, it always has limitations of installation for turbochargers. The compressor package always requests to modify the compressor geometry to fit specific constraints. The volute is the largest geometry of the turbocharger package in most of the case. Very often modifications of the volute were performed to meet the space constraints. In this study, the authors investigated the compressor performance for an initially designed volute and a modified volute. The study followed by an on engine performance comparisons, compressor performance gas stand tests and computational fluid fynamics (CFD) analysis. The studies provided the performance impacts of the local volute deformation due to installation constraints, i.e., a kink in a volute. The studies showed the local volute kink has small implications on compressor performance when the maximum kink depth is less than 10% of the local volute hydraulic diameter. The numerical analysis is in favorable agreements with experiments. The results of this study can be used as a basic guideline for local deformation performance impacts for the future turbocharger compressor volute modifications.

Analyses of the Compressor Performance Impacts of Centrifugal Compressor Scroll Deformation Due to Installation

2010 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Compressor ◽  
Local Deformation ◽  
Discharge Pipe ◽  
Gas Compression ◽  
Study Results ◽  
Computational Fluid Dynamics Cfd ◽  
Compressor Performance ◽  
And Performance

Centrifugal compressors have widely applications in industrial gas compression processes. Limitations of installation and compressor package always request to modify the compressor geometry to fit certain constrains. Very often, the modifications of the scroll were performed to meet the space constrains. To meet the installation and package requirements, we always modify the scroll and discharge pipe of the compressors. In this study, an original designed scroll and a modified scroll were analyzed by using the Computational Fluid Dynamics (CFD). The study is focused on the performance impacts of the scroll local deformation due to installation constrains. The CFD showed favorable agreements with experiments for original scroll. The detailed flow characters and performance impacts were discussed and results showed that current modifications of the scroll did not have significant impacts to the compressor performance. The study results can be used as a basic guidance for a compressor manufactures.

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.

Wet Gas Performance of a Single Stage Centrifugal Compressor

2008 ◽  
Author(s):  
O̸yvind Hundseid ◽  
Lars E. Bakken ◽  
Trond G. Gru¨ner ◽  
Lars Brenne ◽  
Tor Bjo̸rge
Keyword(s):  
Performance Analysis ◽  
Centrifugal Compressor ◽  
Single Stage ◽  
Water Mixture ◽  
Performance Parameters ◽  
Operating Range ◽  
Wet Gas ◽  
Gas Compression ◽  
Compressor Performance ◽  
The Impact

This paper evaluates the performance analysis of wet gas compression. It reports the performance of a single stage gas centrifugal compressor tested on wet gas. These tests were performed at design operating range with real hydrocarbon mixtures. The gas volume fraction was varied from 0.97 to 1.00, with alternation in suction pressure. The range is representative for many of the gas/condensate fields encountered in the North Sea. The machine flow rate was varied to cover the entire operating range. The compressor was also tested on a hydrocarbon gas and water mixture to evaluate the impact of liquid properties on performance. No performance and test standards currently exist for wet gas compressors. To ensure nominated flow under varying fluid flow conditions, a complete understanding of compressor performance is essential. This paper gives an evaluation of real hydrocarbon multiphase flow and performance parameters as well as a wet gas performance analysis. The results clearly demonstrate that liquid properties influence compressor performance to a high degree. A shift in compressor characteristics is observed under different liquid level conditions. The results in this paper confirm the need for improved fundamental understanding of liquid impact on wet gas compression. The evaluation demonstrates that dry gas performance parameters are not applicable for wet gas performance analysis. Wet gas performance parameters verified against results from the tested compressor is presented.

Effect of housing surface roughness on the performance of a centrifugal compressor for turbocharger: Experimental and numerical study

2021 ◽  
pp. 146808742110475
Author(s):  
Ealumalai Karunakaran ◽  
Sanket Mulye ◽  
Jawali Maharudrappa Mallikarjuna
Keyword(s):  
Surface Roughness ◽  
Numerical Analysis ◽  
Centrifugal Compressor ◽  
High Speed ◽  
Numerical Study ◽  
Experimental Results ◽  
Wall Turbulence ◽  
Low Flow ◽  
Pressure Losses ◽  
Compressor Performance

Centrifugal compressor plays a vital role in the performance of a turbocharger. The compressor contains an impeller and housing, including the vaneless diffuser and a volute. The high-speed flow from the impeller is diffused in the diffuser and volute, before being delivered to the engine. Hence, the housing flow characteristics affect the compressor performance and operating range. Generally, housing has noticeable surface roughness, especially in the volute. This study evaluates the effect of the volute surface roughness on the compressor performance by experimental and numerical analysis. The experiments are conducted for three different volute surface roughness levels to measure the overall compressor pressure ratio and efficiency. The uncertainty in the efficiency for experimental results is within ±0.5% pts. Also, steady-state numerical simulations are performed to analyse the flow mechanisms causing pressure losses. Then, a numerical analysis is done to understand the effect of roughness of the diffuser hub and shroud walls on the compressor performance. From the experimental results, it is found that the increase in the roughness level of the volute from the smooth surface by circa 900% and 1400% shows a significant reduction in the compressor efficiency at the design speed (N) and off-design speeds (0.87 and 1.13 N). The reductions of efficiency are about 0.5%–1% pts at the near surge point, 1%–1.5% pts at the peak efficiency point and 2%–2.5% pts at the near choke flow point. The CFD analyses show significantly higher near-wall turbulence and wall shear resulting in additional pressure losses. Also, it is found that the pressure losses are more sensitive to roughness of the diffuser shroud-wall than that of the hub-wall. On the other hand, the diffuser hub-wall roughness increases the radial momentum in the diffuser passage which suppress the flow separation at low flow rates.

Effect of Impeller-Extended Shrouds on Centrifugal Compressor Performance as a Function of Specific Speed

1983 ◽  
Vol 105 (3) ◽  
pp. 457-465 ◽  
Author(s):  
L. Sapiro
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Centrifugal Compressors ◽  
Gas Compression ◽  
Blade Tip ◽  
Compressor Performance ◽  
The Subject ◽  
Specific Speed ◽  
Vaneless Diffusers ◽  
Outside Diameter

Centrifugal compressors for gas compression applications usually employ low-pressure ratio, backward-swept impellers with vaneless diffusers. To increase the compressor flow range and speed, impeller blades are occasionally trimmed, resulting in an extended shroud configuration. The effect of extended front and back impeller shrouds on the performance of centrifugal compressors with vaneless diffusers, and the variation of this effect as a function of specific speed, is thus of concern and is the subject of this paper. An investigation was carried out on two backward-swept shrouded impellers of common blade tip and inducer hub diameters, but different inducer tip diameters (corresponding to low and high specific speeds), with the front and back shrouds extending 20 percent above the blade’s outside diameter.

Investigation of two pipe diffuser configurations for a compact centrifugal compressor

2017 ◽  
Vol 232 (4) ◽  
pp. 716-728
Author(s):  
Ge Han ◽  
Xingen Lu ◽  
Yanfeng Zhang ◽  
Shengfeng Zhao ◽  
Chengwu Yang ◽  
...  
Keyword(s):  
Performance Improvement ◽  
Centrifugal Compressor ◽  
Positive Impact ◽  
Aerodynamic Performance ◽  
Computational Studies ◽  
Compressor Stage ◽  
Wake Structure ◽  
Detailed Understanding ◽  
Swirl Angle ◽  
Compressor Performance

Diffusers are one of the most important factors determining the centrifugal compressor performance. The present work is aimed at providing a detailed understanding of the underlying flow and loss mechanisms in three different diffusers in a compact centrifugal compressor stage. Experimental and computational studies were conducted for various diffuser configurations, e.g. two pipe diffusers and one wedge diffuser, while keeping the throat in all the three geometries. It was found that both the pipe diffuser configurations had better aerodynamic performance than the original wedge diffuser. Furthermore, the pipe diffuser with a fishtail arrangement exhibited greater performance improvement, but had more distortion outflow than the wedge diffuser and the radial pipe diffuser because of the strong jet and wake structure caused by the fishtail turn. Nevertheless, the fishtail configuration has a smaller discharge swirl angle, which would have a positive impact on the performance of the combustor. As a result, the fishtail pipe diffuser configuration was recommended in compact centrifugal compressors.

Numerical Investigation of the Return Channel of a High-Flow Centrifugal Compressor Stage

2015 ◽  
Author(s):  
Holger Franz ◽  
Christoph Rube ◽  
Matthias Wedeking ◽  
Peter Jeschke
Keyword(s):  
Detailed Analysis ◽  
Centrifugal Compressor ◽  
High Flow ◽  
Compressor Stage ◽  
Test Rig ◽  
Cfd Simulations ◽  
Flow Phenomena ◽  
Compressor Performance ◽  
Return Channel ◽  
Insight Into

Steady-state simulations of a high-flow centrifugal compressor stage with return channel for industrial applications are carried out to determine the flow conditions in a new compressor test rig at the RWTH Aachen University. Overall performance predictions, conducted by means of CFD simulations, will be shown and discussed in this paper. Furthermore, a detailed analysis of the stage components is presented, providing an insight into the flow phenomena responsible for the compressor performance. Thereby, the analysis focuses on the return channel. The compressor has a shrouded impeller with 3D-twisted blades, operating at a high flow coefficient and moderate pressure ratios, as usual for multistage single-shaft compressors. The complete computational domain consists of an inlet duct, the impeller, a vaneless diffuser and return channel with bends to guide the flow. All CFD simulations have been carried out in advance of the test rig construction. The results of the simulations have been used to define the measurement locations within the test rig. Within this paper, the predicted flow phenomena in the return channel, which are strongly three-dimensional, are detailed and analyzed against the backdrop of their origin and their contribution to the overall losses. Furthermore, the available measurement results of the overall compressor performance are compared to the numerical simulations to validate the numerical setup. The objective of this paper is to give a detailed analysis of the flow in the return channel of a new compressor test rig built up at the Institute of Jet Propulsion and Turbomachinery of the RWTH Aachen University. The investigation is conducted to get an insight into the formation processes of the dominant flow phenomena affecting the overall stage performance. These investigations can form the basis for developing new strategies for return channel improvements.

Effect of Impeller Extended Shrouds on Centrifugal Compressor Performance as a Function of Specific Speed

1982 ◽  
Author(s):  
L. Sapiro
Keyword(s):  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Centrifugal Compressors ◽  
Gas Compression ◽  
Blade Tip ◽  
Compressor Performance ◽  
The Subject ◽  
Specific Speed ◽  
Vaneless Diffusers ◽  
Outside Diameter

Centrifugal compressors for gas compression applications usually employ low-pressure ratio, backward-swept impellers with vaneless diffusers. To increase the compressor flow range and speed, impeller blades are occasionally trimmed, resulting in an extended shroud configuration. The effect of extended front and back impeller shrouds on the performance of centrifugal compressors with vaneless diffusers, and the variation of this effect as a function of specific speed, is thus of concern and is the subject of this paper. An investigation was carried out on two backward-swept shrouded impellers of common blade tip and inducer hub diameters, but different inducer tip diameters (corresponding to low and high specific speeds), with the front and back shrouds extending 20 percent above the blade’s outside diameter.

A centrifugal compressor stage with wide flow range vaned diffusers and different inlet configurations

2002 ◽  
Vol 216 (4) ◽  
pp. 307-320 ◽  
Author(s):  
Y Kim ◽  
A Engeda ◽  
R Aungier ◽  
N Amineni
Keyword(s):  
Centrifugal Compressor ◽  
Design Procedure ◽  
Substantial Improvement ◽  
Primary Objective ◽  
Compressor Stage ◽  
Vaned Diffuser ◽  
Centrifugal Compressor Stage ◽  
Stable Operating ◽  
Compressor Performance ◽  
Competitive Efficiency

In most cases, the diffuser system of a centrifugal compressor comes in the two general categories of a vaneless or a vaned diffuser. The vaned diffuser can generally be subdivided into two types depending on channel geometry (straight or curved channel) or depending on solidity. For the three different vaned diffusers of a centrifugal compressor stage, the design procedure is presented and experimental data are compared. The primary objective of the diffuser design was to achieve substantial improvement, compared with the stage currently used for the intended application, for the stable operating flow range as well as for the head rise from design to surge flow. The design goals also included achieving competitive efficiency levels, which required a significant efficiency improvement. Test results showed a much wider stable operating range than had been expected. This stage operated well beyond the expected vaned diffuser stall limit. The inlet configuration and inlet flow structure are known significantly to affect the compressor performance. Each of the three diffusers is tested for two different types of inlet configuration, and the relative performances are assessed.

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