Influence of Compressor Performance Maps Shape on Wet Compression

2008 ◽  
Author(s):  
Rakesh K. Bhargava ◽  
Michele Bianchi ◽  
Francesco Melino ◽  
Antonio Peretto ◽  
Pier Ruggero Spina
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Axial Compressor ◽  
Combined Cycle ◽  
Water Evaporation ◽  
Compression Process ◽  
Two Phase ◽  
Compressor Performance ◽  
Wet Compression ◽  
Calculation Code

In recent years, a great number of studies were carried out in order to analyze the main features of fogging technologies. The various fogging strategies seem to improve gas turbine and combined cycle power output with low initial investment cost and less installation downtime. In fact, nowadays fogging is successfully installed on several gasturbine and combined cycle power plants worldwide. In particular, overspray fogging and interstage injection involve two-phase flow consideration and water evaporation during compression process (also known as wet compression). The aim of the present paper is to further improve understanding of the wet compression process including stage-by-stage compressor behavior by investigating the influence of the axial compressor performance map shape on the evaporation process of the injected water through the compressor, achievable power boost, the maximum amount of water which can be injected and/or influence on the surge conditions. This analysis is carried out by using a calculation code, named IN.FO.G.T.E. (INterstage FOgging Gas Turbine Evaluation), developed and validated by the Authors.

Influence of Water Droplet Size and Temperature on Wet Compression

2007 ◽  
Author(s):  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto ◽  
P. R. Spina ◽  
S. Ingistov
Keyword(s):  
Gas Turbine ◽  
Water Droplet ◽  
Droplet Diameter ◽  
Axial Compressor ◽  
Combined Cycle ◽  
Water Evaporation ◽  
Air Cooling ◽  
Compression Process ◽  
Two Phase ◽  
Wet Compression

In the last years, among all different gas turbine inlet air cooling techniques, an increasing attention to fogging approach is dedicated. The various fogging strategies seem to be a good solution to improve gas turbine or combined cycle produced power with low initial investment cost and less installation downtime. In particular, overspray fogging and interstage injection involve two-phase flow consideration and water evaporation during compression process (also known as wet compression). According to the Author’s knowledge, the field of wet compression is not completely studied and understood. In the present paper, all the principal aspects of wet compression and in particular the influence of injected water droplet diameter and surface temperature, and their effect on gas turbine performance and on the behavior of the axial compressor (change in axial compressor performance map due to the water injection, redistribution of stage load, etc.) are analyzed by using a calculation code, named IN.FO.G.T.E. (INterstage FOgging Gas Turbine Evaluation), developed and validated by the Authors.

A Parametric Study of Interstage Injection on GE Frame 7EA Gas Turbine

2004 ◽  
Author(s):  
M. Bagnoli ◽  
M. Bianchi ◽  
F. Melino ◽  
A. Peretto ◽  
P. R. Spina ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Axial Compressor ◽  
Combined Cycle ◽  
Water Evaporation ◽  
Air Cooling ◽  
Phase Flow ◽  
Compression Process ◽  
Two Phase ◽  
Wet Compression ◽  
Flow Compression

In recent years, among various available inlet air cooling techniques for gas turbine power enhancement, high pressure fogging has seen an increasing attention mainly because of its comparatively low initial investment cost and less downtime for its installation. The various fogging strategies such as inlet evaporative, overspray (or wet compression) and interstage injection have been implemented in simple and combined cycle applications. Unlike wet compression, air at the compressor inlet is not fully saturated with the interstage injection. However, both wet compression and interstage injection involve multi-phase flow and water evaporation during the compression process. The phenomenon of two phase flow compression in axial compressor is not yet fully understood. This paper investigates effects of interstage injection on the performance of a GE Frame 7EA gas turbine using aero-thermodynamic modeling. In addition to estimating the overall gas turbine performance changes achievable with the interstage injection approach, the study presented here discusses impact of interstage injection on the stage-by-stage compressor performance characteristics of the selected gas turbine. The plausible reasons for the observed performance changes are discussed.

Wet Compression Effects on Axial Compressor Performance Using Pitch-Line Models

2010 ◽  
Author(s):  
Arathi K. Gopinath ◽  
Giridhar Jothiprasad ◽  
Trevor Wood ◽  
Le Tran
Keyword(s):  
Axial Compressor ◽  
Water Evaporation ◽  
Performance Predictions ◽  
Blade Row ◽  
Compressor Inlet ◽  
Droplet Sizes ◽  
Compressor Performance ◽  
Wet Compression ◽  
Compression Effects ◽  
The Impact

The impact of wet compression technology on compressor performance is studied using a coupled water-evaporation-pitch-line numerical model. The model uses an iterative approach to compute the modified flow conditions at blade-row stations due to inter-stage evaporation of water droplets introduced at the compressor inlet. The evaporation rate predicted by the model is compared with experimental data for stationary droplets in a duct. Performance predictions are compared with data for a GE-proprietary compressor. Study of various water droplet sizes and various water-to-air mass ratios is discussed.

Gas Turbine Compressor Performance Characteristics During Wet Compression: Influence of Polydisperse Spray

2009 ◽  
Author(s):  
Rakesh K. Bhargava ◽  
Michele Bianchi ◽  
Mustapha Chaker ◽  
Francesco Melino ◽  
Antonio Peretto ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Characteristics ◽  
Analytical Models ◽  
Lower Amount ◽  
Compression Process ◽  
Surge Margin ◽  
Compressor Performance ◽  
Wet Compression ◽  
The Impact

The available literature shows that there exists a lack of understanding about the impact of wet compression, involving two-phase flow, on the physics of flow in the compressor stages of a gas turbine engine. In recent years, analytical models have been proposed which provide effects of wet compression on the overall compressor performance and in few studies on the stage-by-stage performance. In spite of the fact that the wet compression technology for power augmentation has been commercially implemented on numerous gas turbines from all the major gas turbine manufacturers, many issues such as, effects of polydisperse spray, droplets dynamics, influence on the performance characteristics of individual stages, stage and overall surge margin, etc., remain not completely understood. This investigation clearly shows importance of considering effects of polydisperse spray on the overall and stage-by-stage compressor performance characteristics. The presented results show that for a given droplets distribution and ambient condition, later stages of a compressor are prone to reduced surge margin under wet compression process due to redistribution of stage loading. Moreover, the study shows that smaller distributions allow the achievement of higher performance, but the compressor surge is reached with a lower amount of injected water.

Development and Validation of a Computational Code for Wet Compression Simulation of Gas Turbines

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
M. Bagnoli ◽  
M. Bianchi ◽  
F. Melino ◽  
P. R. Spina
Keyword(s):  
Gas Turbine ◽  
Process Simulation ◽  
Gas Turbines ◽  
Compression Process ◽  
Two Phase ◽  
Flow Compression ◽  
Development And Validation ◽  
Theoretical Results ◽  
Calculation Code ◽  
Good Agreement

In this paper, a calculation code, developed in house by the authors, able to evaluate the performance of a gas turbine with all possible fogging strategies (high pressure fogging, overspray, and interstage injection) is presented and discussed. The code has a flexible structure and can be applied to evaluate the performance of every commercial gas turbine model. The aim of the calculation code is to overcome the limits of the most widespread commercial software, especially with regard to the two phase flow compression process simulation. The calculation code was validated on results available in the literature showing a good agreement with experimental and theoretical results.

Development and Validation of a Computational Code for Wet Compression Simulation of Gas Turbines

2006 ◽  
Author(s):  
M. Bagnoli ◽  
M. Bianchi ◽  
F. Melino ◽  
P. R. Spina
Keyword(s):  
Gas Turbine ◽  
Process Simulation ◽  
Gas Turbines ◽  
The Self ◽  
Phase Flow ◽  
Compression Process ◽  
Two Phase ◽  
Flow Compression ◽  
Development And Validation ◽  
Calculation Code

In this paper, a calculation code developed by DIEM – University of Bologna, able to evaluate the performance of a gas turbine with all possible fogging strategies (high pressure fogging, overspray and interstage injection) is presented and discussed. The aim of the developed calculation code is to overcome the calculation limits of the most widespread commercial software, specially with regards to the two phase flow compression process simulation. The self developed calculation code was validated on results available in literature. The developed code is standard, and can be applied to evaluate the performance of any commercial gas turbine model.

Effects of Inlet Fogging and Wet Compression on Gas Turbine Performance

2006 ◽  
Author(s):  
Sepehr Sanaye ◽  
Hossein Rezazadeh ◽  
Mehrdad Aghazeynali ◽  
Mehrdad Samadi ◽  
Daryoush Mehranian ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Power Plants ◽  
Combined Cycle ◽  
Water Droplets ◽  
Turbine Performance ◽  
Compressor Inlet ◽  
Wet Compression ◽  
Inlet Duct

Inlet fogging has been noticed widely in recent years as a method of gas turbine air inlet cooling for increasing the power output of gas turbines and combined cycle power plants. To study the effects of inlet fogging on gas turbine performance, in the first step, the evaporation of water droplets in the compressor inlet duct was modeled, and at the end of the inlet duct, the diameter of water droplets were estimated. The results of this process were compared with the results of FLUENT software. In the second step, the droplets which were not evaporated in compressor inlet duct were studied during wet compression in the compressor and the reduction in compressor discharge air temperature was predicted. Finally, the effects of both evaporative cooling in inlet duct, and wet compression in compressor, on the power output, and turbine exhaust temperature of a gas turbine with turbine blade cooling were investigated. These results for various amounts of air bleeding, without and with inlet fogging in the range of (0–2%) overspray are reported.

An Assessment of Wet Compression Process in Gas Turbine Systems with an Analytical Modeling

2012 ◽  
Vol 234 ◽  
pp. 23-27
Author(s):  
Kyoung Hoon Kim ◽  
Dong Joo Kim ◽  
Kyoung Jin Kim ◽  
Seong Wook Hong
Keyword(s):  
Gas Turbine ◽  
Analytical Modeling ◽  
High Efficiency ◽  
Water Injection ◽  
Transient Behavior ◽  
Combined Cycle ◽  
Specific Power ◽  
Outlet Temperature ◽  
Compression Process ◽  
Wet Compression

Recently humidified gas turbine systems in which water or steam is injected have attracted much attention, since they can offer a high efficiency and a high specific power with a relatively low cost compared to combined-cycle gas turbine systems, and therefore they have a potential for future power generation. In this study, performance analysis of the wet compression process is carried out with an analytical modeling which was developed from heat and mass transfer, and thermodynamic analyses based on droplet evaporation. Wet compression variables such as temperature-averaged polytropic coefficient, compressor outlet temperature, and compression work are estimated. Parametric studies show the effect of system parameters such as droplet size, water injection ratio or compression ratio on transient behavior.

Thermoeconomic optimization of combined cycle gas turbine power plants using genetic algorithms

2003 ◽  
Vol 23 (17) ◽  
pp. 2169-2182 ◽  
Author(s):  
Manuel Valdés ◽  
Ma Dolores Durán ◽  
Antonio Rovira
Keyword(s):  
Genetic Algorithms ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle

Compressor Performance and Operability in Swirl Distortion

2010 ◽  
Author(s):  
Yogi Sheoran ◽  
Bruce Bouldin ◽  
P. Murali Krishnan
Keyword(s):  
Gas Turbine ◽  
Complex Geometry ◽  
Full Range ◽  
Axial Compressor ◽  
Cfd Model ◽  
Generator System ◽  
Sliding Mesh ◽  
Wide Range ◽  
Compressor Performance ◽  
The Impact

Inlet swirl distortion has become a major area of concern in the gas turbine engine community. Gas turbine engines are increasingly installed with more complicated and tortuous inlet systems, like those found on embedded installations on Unmanned Aerial Vehicles (UAVs). These inlet systems can produce complex swirl patterns in addition to total pressure distortion. The effect of swirl distortion on engine or compressor performance and operability must be evaluated. The gas turbine community is developing methodologies to measure and characterize swirl distortion. There is a strong need to develop a database containing the impact of a range of swirl distortion patterns on a compressor performance and operability. A recent paper presented by the authors described a versatile swirl distortion generator system that produced a wide range of swirl distortion patterns of a prescribed strength, including bulk swirl, twin swirl and offset swirl. The design of these swirl generators greatly improved the understanding of the formation of swirl. The next step of this process is to understand the effect of swirl on compressor performance. A previously published paper by the authors used parallel compressor analysis to map out different speed lines that resulted from different types of swirl distortion. For the study described in this paper, a computational fluid dynamics (CFD) model is used to couple upstream swirl generator geometry to a single stage of an axial compressor in order to generate a family of compressor speed lines. The complex geometry of the analyzed swirl generators requires that the full 360° compressor be included in the CFD model. A full compressor can be modeled several ways in a CFD analysis, including sliding mesh and frozen rotor techniques. For a single operating condition, a study was conducted using both of these techniques to determine the best method given the large size of the CFD model and the number of data points that needed to be run to generate speed lines. This study compared the CFD results for the undistorted compressor at 100% speed to comparable test data. Results of this study indicated that the frozen rotor approach provided just as accurate results as the sliding mesh but with a greatly reduced cycle time. Once the CFD approach was calibrated, the same techniques were used to determine compressor performance and operability when a full range of swirl distortion patterns were generated by upstream swirl generators. The compressor speed line shift due to co-rotating and counter-rotating bulk swirl resulted in a predictable performance and operability shift. Of particular importance is the compressor performance and operability resulting from an exposure to a set of paired swirl distortions. The CFD generated speed lines follow similar trends to those produced by parallel compressor analysis.

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