Experimental Evaluation of Compressor Blade Fouling

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Rainer Kurz ◽  
Grant Musgrove ◽  
Klaus Brun
Keyword(s):  
Boundary Layer ◽  
Gas Turbines ◽  
Blade Surface ◽  
Air Filtration ◽  
Ambient Conditions ◽  
Compressor Blades ◽  
Performance Deterioration ◽  
Quantitative Results ◽  
The Impact ◽  
Dust Retention

Fouling of compressor blades is an important mechanism leading to performance deterioration in gas turbines over time. Experimental and simulation data are available for the impact of specified amounts of fouling on the performance as well as the amount of foulants entering the engine for defined air filtration systems and ambient conditions. This study provides experimental data on the amount of foulants in the air that actually stick to a blade surface for different conditions. Quantitative results both indicate the amount of dust as well as the distribution of dust on the airfoil, for a dry airfoil, and also the airfoils that were wet from ingested water, in addition to, different types of oil. The retention patterns are correlated with the boundary layer shear stress. The tests show the higher dust retention from wet surfaces compared to dry surfaces. They also provide information about the behavior of the particles after they impact on the blade surface, showing for a certain amount of wet film thickness, the shear forces actually wash the dust downstream and off the airfoil. Further, the effect of particle agglomeration of particles to form larger clusters was observed, which would explain the disproportional impact of very small particles on boundary layer losses.

Experimental Evaluation of Compressor Blade Fouling

2016 ◽  
Author(s):  
Rainer Kurz ◽  
Grant Musgrove ◽  
Klaus Brun
Keyword(s):  
Boundary Layer ◽  
Gas Turbines ◽  
Blade Surface ◽  
Air Filtration ◽  
Ambient Conditions ◽  
Compressor Blades ◽  
Performance Deterioration ◽  
Quantitative Results ◽  
The Impact ◽  
Dust Retention

Fouling of compressor blades is an important mechanism leading to performance deterioration in gas turbines over time. Experimental and simulation data are available for the impact of specified amounts of fouling on performance, as well as the amount of foulants entering the engine for defined air filtration systems and ambient conditions. This study provides experimental data on the amount of foulants in the air that actually stick to a blade surface for different conditions of the blade surface. Quantitative results both indicate the amount of dust as well as the distribution of dust on the airfoil, for a dry airfoil, as well as airfoils that were wet from ingested water, as well as different types of oil. The retention patterns are correlated with the boundary layer shear stress. The tests show the higher dust retention from wet surfaces compared to dry surfaces. They also provide information about the behavior of the particles after they impact on the blade surface, showing that for a certain amount of wet film thickness, the shear forces actually wash the dust downstream, and off the airfoil. Further, the effect of particle agglomeration of particles to form larger clusters was observed, which would explain the disproportional impact of very small particles on boundary layer losses.

Fouling Mechanisms in Axial Compressors

2011 ◽  
Author(s):  
Rainer Kurz ◽  
Klaus Brun
Keyword(s):  
Surface Roughness ◽  
Gas Turbines ◽  
Air Filtration ◽  
Sea Salts ◽  
Compressor Blades ◽  
Axial Compressors ◽  
Performance Deterioration ◽  
Over Time

Fouling of compressor blades is an important mechanism leading to performance deterioration in gas turbines over time. Fouling is caused by the adherence of particles to airfoils and annulus surfaces. Particles that cause fouling are typically smaller than 2 to 10 microns. Smoke, oil mists, carbon, and sea salts are common examples. Fouling can be controlled by appropriate air filtration systems, and can often be reversed to some degree by detergent washing of components. The adherence of particles is impacted by oil or water mists. The result is a build-up of material that causes increased surface roughness and to some degree changes the shape of the airfoil (if the material build up forms thicker layers of deposits). Fouling mechanisms are evaluated based on observed data, and a discussion on fouling susceptibility is provided. A particular emphasis will be on the capabilities of modern air filtration systems.

Estimation of the Particle Deposition on a Transonic Axial Compressor Blade

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Alessio Suman ◽  
Mirko Morini ◽  
Rainer Kurz ◽  
Nicola Aldi ◽  
Klaus Brun ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Particle Deposition ◽  
Fluid Dynamic ◽  
Axial Compressor ◽  
Leading Edge ◽  
Blade Surface ◽  
Air Filtration ◽  
Separation Shock ◽  
Particle Ingestion ◽  
The Impact

Solid particle ingestion is one of the principal degradation mechanisms in the compressor section of heavy-duty gas turbines. Usually, foulants in the ppm range, not captured by the air filtration system, i.e., (0–2) μm cause deposits on blading and result in a severe performance drop of the compressor. It is of great interest to the industry to determine which areas of the compressor airfoils are interested by these contaminants as a function of the location of the power unit. The aim of this work is the estimation of the actual deposits on the blade surface in terms of location and quantity. The size of the particles, their concentrations, and the filtration efficiency are specified in order to perform a realistic quantitative analysis of the fouling phenomena in an axial compressor. This study combines, for the first time, the impact/adhesion characteristic of the particles obtained through a computational fluid dynamics (CFD) and the real size distribution of the contaminants in the air swallowed by the compressor. The blade zones affected by the deposits are clearly reported by using easy-to-use contaminant maps realized on the blade surface in terms of contaminant mass. The analysis showed that particular fluid-dynamic phenomena such as separation, shock waves, and tip leakage vortex strongly influence the pattern deposition. The combination of the smaller particles (0.15 μm) and the larger ones (1.50 μm) determines the highest amounts of deposits on the leading edge (LE) of the compressor airfoil. From these analyses, some guidelines for proper installation and management of the power plant (in terms of filtration systems and washing strategies) can be drawn.

Estimation of the Particle Deposition on a Transonic Axial Compressor Blade

2015 ◽  
Author(s):  
Alessio Suman ◽  
Mirko Morini ◽  
Rainer Kurz ◽  
Nicola Aldi ◽  
Klaus Brun ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Particle Deposition ◽  
Fluid Dynamic ◽  
Axial Compressor ◽  
Leading Edge ◽  
Blade Surface ◽  
Air Filtration ◽  
Separation Shock ◽  
Particle Ingestion ◽  
The Impact

Solid particle ingestion is one of the principal degradation mechanisms in the compressor section of heavy-duty gas turbines. Usually, foulants in the ppm range, not captured by the air filtration system (0–2) μm cause deposits on blading and result in a severe performance drop of the compressor. It is of great interest to the industry to determine which areas of the compressor airfoils are interested by these contaminants as a function of the location of the power unit. The aim of this work is the estimation of the actual deposits on the blade surface in terms of location and quantity. The size of the particles, their concentrations and the filtration efficiency are specified in order to perform a realistic quantitative analysis of the fouling phenomena in an axial compressor. This study combines, for the first time, the impact/adhesion characteristic of the particles obtained through a CFD and the real size distribution of the contaminants in the air swallowed by the compressor. The blade zones affected by deposits are clearly reported by using easy-to-use contaminant maps realized on the blade surface in terms of contaminant mass. The analysis showed that particular fluid-dynamic phenomena such as separation, shock waves and tip leakage vortex strongly influence the pattern deposition. The combination of the smaller particles (0.15 μm) and the larger ones (1.50 μm) determines the highest amounts of deposits on the leading edge of the compressor airfoil. From these analyses, some guidelines for proper installation and management of the power plant (in terms of filtration systems and washing strategies) can be drawn.

Fouling Mechanisms in Axial Compressors

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Rainer Kurz ◽  
Klaus Brun
Keyword(s):  
Surface Roughness ◽  
Gas Turbines ◽  
Air Filtration ◽  
Sea Salts ◽  
Compressor Blades ◽  
Axial Compressors ◽  
Performance Deterioration ◽  
Over Time

Fouling of compressor blades is an important mechanism leading to performance deterioration in gas turbines over time. Fouling is caused by the adherence of particles to airfoils and annulus surfaces. Particles that cause fouling are typically smaller than 2 to 10 microns. Smoke, oil mists, carbon, and sea salts are common examples. Fouling can be controlled by appropriate air filtration systems, and can often be reversed to some degree by detergent washing of components. The adherence of particles is impacted by oil or water mists. The result is a build up of material that causes increased surface roughness and to some degree changes the shape of the airfoil (if the material build up forms thicker layers of deposits), with subsequent deterioration in performance. Fouling mechanisms are evaluated based on observed data, and a discussion on fouling susceptibility is provided. A particular emphasis will be on the capabilities of modern air filtration systems.

scholarly journals Industrial Gas Turbine Performance: Compressor Fouling and On-Line Washing

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Uyioghosa Igie ◽  
Pericles Pilidis ◽  
Dimitrios Fouflias ◽  
Kenneth Ramsden ◽  
Panagiotis Laskaridis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Engine Performance ◽  
Operating Conditions ◽  
Compressor Cascade ◽  
Compressor Blades ◽  
Turbine Performance ◽  
Industrial Gas Turbines ◽  
On Line ◽  
The Impact

Industrial gas turbines are susceptible to compressor fouling, which is the deposition and accretion of airborne particles or contaminants on the compressor blades. This paper demonstrates the blade aerodynamic effects of fouling through experimental compressor cascade tests and the accompanied engine performance degradation using turbomatch, an in-house gas turbine performance software. Similarly, on-line compressor washing is implemented taking into account typical operating conditions comparable with industry high pressure washing. The fouling study shows the changes in the individual stage maps of the compressor in this condition, the impact of degradation during part-load, influence of control variables, and the identification of key parameters to ascertain fouling levels. Applying demineralized water for 10 min, with a liquid-to-air ratio of 0.2%, the aerodynamic performance of the blade is shown to improve, however most of the cleaning effect occurred in the first 5 min. The most effectively washed part of the blade was the pressure side, in which most of the particles deposited during the accelerated fouling. The simulation of fouled and washed engine conditions indicates 30% recovery of the lost power due to washing.

Evaluation of Air Filtration Options for an Industrial Gas Turbine

2015 ◽  
Author(s):  
Christopher A. Perullo ◽  
Josh Barron ◽  
Dale Grace ◽  
Leonard Angello ◽  
Tim Lieuwen
Keyword(s):  
Pressure Drop ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
High Efficiency ◽  
Air Filtration ◽  
Unit Output ◽  
Almost All ◽  
The Cost ◽  
The Impact ◽  
Unit Performance

Gas turbines ingest large quantities of air during operation. As a result, large quantities of foreign particles ranging in size from smoke (0.01 to 1.0 micron) to pollen (10 micron) enter the unit and can contribute to both fouling and erosion depending on particle size. Fouling and erosion both lead to reductions in unit output and efficiency resulting in increased operational cost. Operators have historically combatted fouling through a combination of online water washes, more effective off-line water washes, and air filtration. As is the case with almost all engineering problems, the trade-off between the cost and effectiveness of these methods must be evaluated. Online washing is somewhat effective but has led to first stage blade erosion and unit trips in some cases. Off-line washing is more effective at cleaning the unit, but requires the unit to be shut down for extended periods of time. Air filtration can help prevent foreign particles from entering the unit, but higher efficiency filters are generally associated with a larger inlet pressure drop, leading to decreased unit output; this is balanced against reduced fouling rates. These tradeoffs between the costs associated with higher efficiency filters and the frequency of compressor washing need to be evaluated on a plant-by-plant basis to determine the best combination of air filtration and compressor washing programs. This paper presents a field study carried out to determine the effectiveness of high efficiency filters in preventing compressor fouling. Fourteen units at four sites were monitored over a 9 month to 3 year time period to determine the changes in unit performance and the impact of water washes on unit performance for both pre and final filters of lower and higher efficiency ratings. Results to date indicate that higher efficiency filters are effective at reducing the need for off-line water washes and potentially reduce life-cycle cost. Reduced output from the higher pressure drop, high efficiency filters is offset by the better performance retention offered from reduced fouling rates.

Axial Compressor Degradation Effects on Heavy Duty Gas Turbines Overall Performances

2013 ◽  
Author(s):  
Pio Astrua ◽  
Stefano Cecchi ◽  
Stefano Piola ◽  
Andrea Silingardi ◽  
Federico Bonzani
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Axial Compressor ◽  
Performance Parameters ◽  
Heavy Duty ◽  
Compressor Blades ◽  
Modular Model ◽  
Secondary Air ◽  
The Impact ◽  
Insight Into

The operation of a gas turbine is the result of the aero-thermodynamic matching of several components which necessarily experience aging and degradation over time. An approach to treat degradation phenomena of the axial compressor is provided, with an insight into the impact they have on compressor operation and on overall GT performances. The analysis is focused on the surface fouling of compressor blades and on rotor tip clearances variation. A modular model is used to simulate the gas turbine operation in design and off-design conditions and the aerodynamic impact of fouling and rotor tip clearances increase is assessed by means of dedicated loss and deviation correlations implemented in the 1D mid-streamline code of the compressor modules. The two different degradation sources are individually considered and besides the overall GT performance parameters, the analysis includes an evaluation of the compressor degradation impact on the secondary air system.

Experimental Heat Transfer and Boundary Layer Measurements on a Ceramic Matrix Composite Surface

2020 ◽  
Author(s):  
Peter H. Wilkins ◽  
Stephen P. Lynch ◽  
Karen A. Thole ◽  
San Quach ◽  
Tyler Vincent
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Surface Morphology ◽  
Gas Turbines ◽  
Ceramic Matrix Composite ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Composite Surface ◽  
Weave Pattern ◽  
The Impact

Abstract Ceramic matrix composites (CMCs) are quickly becoming more prevalent in the design of gas turbines due to their advantageous weight and thermal properties. While there are many advantages, the CMC surface morphology differs from that of conventional cast airfoil components. Despite a great deal of research focused on the material properties of CMCs, little public work has been done to investigate the impact that the CMC surface morphology has on the boundary layer development and resulting heat transfer. In this study, a scaled-up CMC weave pattern was developed and tested in a low speed wind tunnel to evaluate both heat transfer and boundary layer characteristics. Results from these experiments indicate that the CMC weave pattern results in augmented heat transfer and flow field properties that significantly vary locally when compared to a smooth surface.

Performance Deterioration of Intake Air Filters for Gas Turbines in Offshore Installations

2010 ◽  
Author(s):  
Olaf Brekke ◽  
Lars E. Bakken
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Oil And Gas ◽  
Operating Experience ◽  
Gas Production ◽  
Differential Pressure ◽  
Air Filtration ◽  
Turbine Inlet ◽  
Offshore Installations ◽  
Performance Deterioration

Efficient inlet air filtration is a key element for limiting fouling, erosion, and corrosion in the compressor section of offshore gas turbine installations. Current filtration systems are normally successful in preventing serious erosion and corrosion problems in the compressor section, but significant performance deterioration caused by compressor fouling still remains a challenge. This performance deterioration increases fuel consumption and emissions and has a particularly severe economic impact when it reduces oil and gas production. Operating experience from different offshore installations has shown that the deterioration rate in gas turbine performance increases when the turbines are operating in wet or humid weather and that the differential pressure loss over the intake system is affected by ambient humidity. An experimental test rig has been built in the laboratory at the Norwegian University of Science and Technology (NTNU) in order to increase understanding of the fundamentals related to gas turbine inlet air filtration. This paper presents the results from an experimental investigation of the performance of gas turbine inlet air filter elements that have been in operation offshore. Performance under both dry and wet conditions is assessed. Different types of filter elements show significantly different changes in differential pressure signature when exposed to moisture, and all of the tested filter elements demonstrate a loss of accumulated contamination after operating in wet conditions. Hence, contaminants originally accumulated by the filter elements are re-entrained into the airstream on the downstream side of the filters when they are exposed to moisture. The change in differential pressure signature as a result of operating in wet conditions demonstrates another weakness of solely applying differential pressure for condition monitoring of the filter system.

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