Investigation of Choking and Combustion Products' Swirling Frequency Effects on Gas Turbine Compressor Blade Fractures

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
E. Poursaeidi ◽  
M. Arablu ◽  
M. A. Yahya Meymandi ◽  
M. R. Mohammadi Arhani
Keyword(s):  
Mach Number ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
3D Models ◽  
Combustion Products ◽  
Critical Conditions ◽  
Engine Operation ◽  
Mach Number Distribution ◽  
Combustion Flow ◽  
Gas Turbine Compressor

Premature fracture failure of blades occurred in four of a refinery's gas turbine compressors. In order to evaluate the probability of combustion instability's effects on failure of the blades; i.e., choking and chamber resonance problems, 3D models of the combustion chamber structure and combustion flow were studied with finite element and computation fluid dynamics codes, respectively. Comparison of results of combustion chamber natural frequencies with combustion swirl frequency showed that the chamber structure is not under resonance. In order to verify probability of choking, the combustion product flow's Mach number was studied. Results of the Mach number distribution showed that the flow is subsonic in the transition piece area but, due to existence of supersonic flow conditions near the swirl vanes it may become supersonic in some critical conditions. Thus, it is suggested to operators that, for avoiding choking probabilities, it is better that engine operation be maintained close to optimum design conditions. Results of simulations showed that the fracture of the blades is not due to combustion problems.

Siemens SGT-800 Industrial Gas Turbine Enhanced to 50MW: Combustor Design Modifications, Validation and Operation Experience

2013 ◽  
Author(s):  
Daniel Lörstad ◽  
Annika Lindholm ◽  
Jan Pettersson ◽  
Mats Björkman ◽  
Ingvar Hultmark
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Cooling System ◽  
Good Condition ◽  
Combined Cycle ◽  
Combustion Stability ◽  
Combustion System ◽  
Design Work ◽  
Engine Operation ◽  
Cooling Air

Siemens Oil & Gas introduced an enhanced SGT-800 gas turbine during 2010. The new power rating is 50.5MW at a 38.3% electrical efficiency in simple cycle (ISO) and best in class combined-cycle performance of more than 55%, for improved fuel flexibility at low emissions. The updated components in the gas turbine are interchangeable from the existing 47MW rating. The increased power and improved efficiency are mainly obtained by improved compressor airfoil profiles and improved turbine aerodynamics and cooling air layout. The current paper is focused on the design modifications of the combustor parts and the combustion validation and operation experience. The serial cooling system of the annular combustion chamber is improved using aerodynamically shaped liner cooling air inlet and reduced liner rib height to minimize the pressure drop and optimize the cooling layout to improve the life due to engine operation hours. The cold parts of the combustion chamber were redesigned using cast cooling struts where the variable thickness was optimized to maximize the cycle life. Due to fewer thicker vanes of the turbine stage #1, the combustor-turbine interface is accordingly updated to maintain the life requirements due to the upstream effect of the stronger pressure gradient. Minor burner tuning is used which in combination with the previously introduced combustor passive damping results in low emissions for >50% load, which is insensitive to ambient conditions. The combustion system has shown excellent combustion stability properties, such as to rapid load changes and large flame temperature range at high loads, which leads to the possibility of single digit Dry Low Emission (DLE) NOx. The combustion system has also shown insensitivity to fuels of large content of hydrogen, different hydrocarbons, inerts and CO. Also DLE liquid operation shows low emissions for 50–100% load. The first SGT-800 with 50.5MW rating was successfully tested during the Spring 2010 and the expected performance figures were confirmed. The fleet leader has, up to January 2013, accumulated >16000 Equivalent Operation Hours (EOH) and a planned follow up inspection made after 10000 EOH by boroscope of the hot section showed that the combustor was in good condition. This paper presents some details of the design work carried out during the development of the combustor design enhancement and the combustion operation experience from the first units.

Valveless-Gas-Turbine Combustors With Pressure Gain

1958 ◽  
Author(s):  
Carroll D. Porter
Keyword(s):  
Steady Flow ◽  
Gas Turbine ◽  
Total Pressure ◽  
High Efficiency ◽  
Combustion Products ◽  
Efficiency Gain ◽  
Developmental Problems ◽  
Gas Turbine Combustors ◽  
Turbine Inlet ◽  
Gas Turbine Compressor

A valveless combustor has been developed which has been tested at one to three atmospheres of pressure. It discharged combustion products at practical turbine-inlet temperatures and at a total pressure above that of the inlet. Developmental problems encountered and results are discussed. The smooth combustor cycle, a phased system of combustor tubes and pulsation traps, achieves steady flow at the inlet and outlet of the combustor system to preserve the high efficiency of today’s turbines and compressors. The combustor will soon be tested on a gas-turbine compressor to verify efficiency gain estimates.

scholarly journals Modified Combined Cycle With Pressure Fluidized Bed Combustion Boiler

1992 ◽  
Author(s):  
Jacek Dzierzgowski ◽  
Stanislaw Sobkowski
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Fluidized Bed ◽  
Flue Gas ◽  
Thermal Efficiency ◽  
Combined Cycle ◽  
The Other ◽  
Fluidized Bed Combustion ◽  
Air Stream ◽  
Gas Turbine Compressor

The article describes conversion of conventional steam cycle with 200 MW turbine into combined steam-gas cycle with pressure fluidized bed combustion boiler. In order to raise cycle thermal efficiency an additional combustion chamber before a gas turbine was introduced. Two modifications of the combined cycle were considered. In one of them natural gas in the additional combustion chamber is burnt with the boiler flue gas only. In the other gas is burnt with additional air stream taken from behind the gas turbine compressor. Optimizing calculations of the cycle thermal efficiency in function of some cycle’s main parameters were carried out.

Introduction and Performance Prediction of a Nutating-Disk Engine

2004 ◽  
Vol 126 (2) ◽  
pp. 294-299 ◽  
Author(s):  
T. Korakianitis ◽  
L. Meyer ◽  
M. Boruta ◽  
H. E. McCormick
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Engine ◽  
Thermodynamic Cycle ◽  
Simple Cycle ◽  
Specific Power ◽  
Engine Operation ◽  
And Performance ◽  
Stroke Engine

A new type of internal combustion engine and its thermodynamic cycle are introduced. The core of the engine is a nutating nonrotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk nutates. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The accumulator and combustion chamber are kept at constant pressures. The engine has a few analogies with piston-engine operation, but like a gas turbine it has dedicated spaces and devices for compression, burning, and expansion. The thermal efficiency is similar to that of comparably sized simple-cycle gas turbines and piston engines. For the same engine volume and weight, this engine produces less specific power than a simple-cycle gas turbine, but approximately twice the power of a two-stroke engine and four times the power of a four-stroke engine. The engine has advantages in the 10 kW to 200 kW power range. This paper introduces the geometry and thermodynamic model for the engine, presents typical performance curves, and discusses the relative advantages of this engine over its competitors.

Introduction and Performance Prediction of a Nutating-Disk Engine

1999 ◽  
Author(s):  
T. Korakianitis ◽  
L. Meyer ◽  
M. Boruta ◽  
H. E. McCormick
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Engine ◽  
Thermodynamic Cycle ◽  
Rotating Disk ◽  
Simple Cycle ◽  
Specific Power ◽  
Engine Operation ◽  
Stroke Engine

A new type of internal combustion engine and its thermodynamic cycle are introduced. The core of the engine is a nutating non-rotating disk, with the center of its hub mounted in the middle of a Z-shaped shaft. The two ends of the shaft rotate, while the disk nutates. The motion of the disk circumference prescribes a portion of a sphere. A portion of the area of the disk is used for intake and compression, a portion is used to seal against a center casing, and the remaining portion is used for expansion and exhaust. The compressed air is admitted to an external accumulator, and then into an external combustion chamber before it is admitted to the power side of the disk. The accumulator and combustion chamber are kept at constant pressures. The engine has a few analogies with piston-engine operation, but like a gas turbine it has dedicated spaces and devices for compression, burning and expansion. The thermal efficiency is similar to that of comparably-sized simple-cycle gas turbines and piston engines. For the same engine volume and weight, this engine produces less specific power than a simple-cycle gas turbine, but approximately twice the power of a two-stroke engine and four times the power of a four-stroke engine. The engine has advantages in the 10 kW to 200 kW power range. This paper introduces the geometry and thermodynamic model for the engine, presents typical performance curves, and discusses the relative advantages of this engine over its competitors.

scholarly journals The possibility of significantly increasing the degree of regeneration in regenerative gas turbine plants without increasing the size of the recuperator.

2021 ◽  
Author(s):  
Sergei V. Sevtsov
Keyword(s):  
Heat Exchanger ◽  
Combustion Chamber ◽  
Heat Pipe ◽  
Gas Turbine ◽  
Air Flow ◽  
Combustion Products ◽  
Secondary Cooling ◽  
Fuel Oxidation ◽  
Turbine Installation

The proposed article considers the theoretical prerequisites and proposes a scheme for a regenerative gas turbine installation with an increase in the degree of regeneration at constant recuperator sizes in order to increase the efficiency of the installation. The new scheme excludes the supply of secondary (cooling the heat pipe and combustion products in the combustion chamber) air to the heat exchanger for heating. Reducing the air flow in the recuperator to the values of only the primary (for fuel oxidation) air flow with the recuperator area unchanged leads to an increase in the degree of regeneration and, accordingly, the efficiency of the plant.

Application of CFD-Based Analysis Technique for Design and Optimization of Gas Turbine Combustors

2004 ◽  
Author(s):  
I. G. Koutsenko ◽  
S. F. Onegin ◽  
A. M. Sipatov
Keyword(s):  
Nitric Oxide ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Combustion Products ◽  
Combustion Chambers ◽  
Design And Optimization ◽  
Gas Turbine Combustors ◽  
Analysis Technique ◽  
Nitric Oxide Emissions ◽  
Operational Development

The design and operational development of gas turbine combustors is a complex process, involving a great volume of design and experimental work. The application of computational fluid dynamics (CFD) methods allows to lower the volume of experimental works on operational development of combustors and to make changes to the design of combustion chambers on early design stages. In this paper the application of commercial CFD package CFX-TASCflow for calculation of flow structure and analysis of nitric oxide formation process in the combustion chamber of the PS-90A gas turbine and its modifications is considered. The results of the analysis show, that the basic determinative criterion of a nitric oxide emission level is the residence time of a combustion products in high-temperature zones. With help of this criterion, an optimization of the PS-90A combustion chamber was performed. A design of an optimized combustion chamber allows to achieve a low level of nitric oxide emissions.

New Airfoil Design to Extend Gas Turbine Compressor Surge Margin

2003 ◽  
Author(s):  
Vivek Sahai ◽  
Dah-Yu Cheng
Keyword(s):  
Mach Number ◽  
Gas Turbine ◽  
Flow Separation ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Rotating Stall ◽  
Trailing Edge ◽  
Flow Area ◽  
Moment Coefficient ◽  
Gas Turbine Compressor

In many industrial gas turbine compressor designs, the compressors later stage blade angles are reduced in a constant flow area section as a means to even out the per stage workload. Most compressors use NACA 65 series type airfoils, which are good for high subsonic and supersonic flow, but are poor for middle or low subsonic flows. The temperature increases as the compression ratio increases; which cause the Mach number to drop. With reduced blade cascade overlaps, a reduction in axial blade solidity results. The compounding effect of low solidity and a low Mach number can cut the stalling angle by several degrees. This recent study found that compressor stall more or less is linked to the change of moment coefficient Cm, rather than lift coefficient Cl. Designing the airfoil, by extending the constant moment coefficient to a higher angle of attack region can delay the trailing edge upper surface separation to a higher angle of attack, the main source of rotating stall. This separated flow exhibits itself more clearly on the moment coefficient, but is obscured by an increase in lift coefficient before “aerodynamic” stall. This new design is based on the second order derivative of the camber line, with a low drag symmetrical airfoil thickness. Numerical simulation of a single airfoil and cascade of the new airfoil is compared with other shapes. The results show that the trailing edge flow separation begins at a 9.5-degree angle of attack for the NACA 65 series airfoils. The NACA 0012 separation (i.e. change in Cm) starts at 5 degrees (total stall occurs at 11 degrees). The new airfoil CFS18-0010 exhibits no separation for a single airfoil of up to 12 degrees. The cascade results showed no flow separation up to an angle of 15 degrees, which is enough to eliminate most of the rotating stall.

Sign in / Sign up

Export Citation Format

Share Document