scholarly journals Part Load Performance of the Intercooled Two-Shaft Gas Turbine With Power Output at Constant Speed on the High-Pressure Shaft

1987 ◽  
Author(s):  
N. Gasparovic ◽  
J.-W. Kim
Keyword(s):  
High Pressure ◽  
Power Output ◽  
Gas Turbines ◽  
Internal Heat ◽  
Constant Speed ◽  
Inlet Temperature ◽  
Part Load ◽  
Internal Heat Exchanger ◽  
High Pressure Compressor ◽  
Pressure Compressor

The general analysis of the part load performance of gas turbines indicates that the intercooled cycle with two shafts and power output at constant speed on the high-pressure shaft can have a good part load efficiency. Calculations with fixed geometry of the turbomachines show an intolerable increase of the turbine inlet temperature above the permissible level. By introducing variable geometry in the turbomachines, this disadvantage can be overcome. With variable inlet guide vanes at the high-pressure compressor an excellent part load performance is achieved. Further improvements are possible by adding an internal heat exchanger.

Part Load Conditions of Complex Cycle Power Plants With Intercooled Gas Turbine

1996 ◽  
Author(s):  
A. Peretto
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Working Conditions ◽  
Power Plants ◽  
Pressure Level ◽  
Combined Cycle ◽  
Brayton Cycle ◽  
Part Load ◽  
High Pressure Compressor ◽  
Pressure Compressor

The present paper evaluates the behavior, in design and part load working conditions, of a complex gas turbine cycle with multiple intercooled compression, and the optional preheating of the air at the high pressure compressor outlet by means of the gas turbine outlet hot gas. The results are then compared with those obtained by a Brayton cycle gas turbine, with or without preheating of the air at the high pressure compressor outlet. Subsequently, the performance of complex combined cycles, with intercooled gas turbine as topper and one, two or three pressure level steam cycle as bottomer, in design and part load working conditions is also evaluated. The performance of these complex combined plants is then compared with that obtained by a Brayton cycle gas turbine as topper and one, two or three pressure level steam cycle as bottomer. Part load working conditions are realized by varying either the inlet guide vane angle of the first compressor nozzles or the maximum temperature at the combustor outlet. The study shows that in part load working conditions obtained by varying IGV, the complex cycles, in the examined gas turbine or in the combined cycle power plants, give conversion efficiencies decidedly greater than those obtainable by varying combustor exit temperature. Furthermore it is found that these complex power plant efficiencies, in part load working conditions, are far greater than those obtained by the Brayton cycle gas turbine, or by combined cycle with Brayton cycle gas turbine as topper, if IGV adjustment is adopted. If power variation is obtained with combustor outlet temperature adjustment, the efficiencies of the combined power plants with complex or Brayton cycle gas turbines, are substantially the same, for the same relative power variation.

scholarly journals Aeroelastic assessment of a highly loaded high pressure compressor exposed to pressure gain combustion disturbances

2018 ◽  
Vol 2 ◽  
pp. F72OUU
Author(s):  
Victor Bicalho Civinelli de Almeida ◽  
Dieter Peitsch
Keyword(s):  
High Pressure ◽  
Gas Turbines ◽  
Forced Response ◽  
Thermodynamic Efficiency ◽  
Efficiency Gain ◽  
Aerodynamic Damping ◽  
High Pressure Compressor ◽  
Pressure Gain Combustion ◽  
Pressure Compressor ◽  
Highly Loaded

A numerical aeroelastic assessment of a highly loaded high pressure compressor exposed to flow disturbances is presented in this paper. The disturbances originate from novel, inherently unsteady, pressure gain combustion processes, such as pulse detonation, shockless explosion, wave rotor or piston topping composite cycles. All these arrangements promise to reduce substantially the specific fuel consumption of present-day aeronautical engines and stationary gas turbines. However, their unsteady behavior must be further investigated to ensure the thermodynamic efficiency gain is not hindered by stage performance losses. Furthermore, blade excessive vibration (leading to high cycle fatigue) must be avoided, especially under the additional excitations frequencies from waves traveling upstream of the combustor. Two main numerical analyses are presented, contrasting undisturbed with disturbed operation of a typical industrial core compressor. The first part of the paper evaluates performance parameters for a representative blisk stage with high-accuracy 3D unsteady Reynolds-averaged Navier-Stokes computations. Isentropic efficiency as well as pressure and temperature unsteady damping are determined for a broad range of disturbances. The nonlinear harmonic balance method is used to determine the aerodynamic damping. The second part provides the aeroelastic harmonic forced response of the rotor blades, with aerodynamic damping and forcing obtained from the unsteady calculations in the first part. The influence of blade mode shapes, nodal diameters and forcing frequency matching is also examined.

Form Factor for the Top-Level Comparison of the Condition of Supply of High-Pressure Compressor Blades

2012 ◽  
Author(s):  
Marcus Schrade ◽  
Stephan Staudacher ◽  
Matthias Weißschuh ◽  
Matthias Voigt
Keyword(s):  
High Pressure ◽  
Form Factor ◽  
Gas Turbines ◽  
Principal Component ◽  
Complex Geometries ◽  
Compressor Blades ◽  
High Pressure Compressor ◽  
Geometric Deviations ◽  
Pressure Compressor ◽  
Component Feature

High-pressure compressor (HPC) performance and maintenance of gas turbines is influenced by blade production scatter and in-service deterioration. Complex geometries in HPC, especially at blades, yield to a large amount of component features, which individually influence performance and maintenance characteristics. This results in a highly complex and poorly observable system. Hence, the correlation of a single component feature to performance or maintenance characteristics is not purposeful and a reduction of the parameter space is advantageous. A form factor is introduced that reduces geometric deviations of component features to a scalar. Principal component analysis (PCA) of measured HPC blades is used to support the form factor concept. The meaningfulness of this approach is shown in identifying process capabilities of different forges based on the form factor.

Aero-Thermodynamic Simulation of a Double-Shaft Industrial Evaporative Gas Turbine

2000 ◽  
Author(s):  
S. M. Camporeale ◽  
B. Fortunato
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Power Output ◽  
Gas Turbines ◽  
Thermodynamic Simulation ◽  
Inlet Temperature ◽  
Part Load ◽  
Design Performance ◽  
Water Rate ◽  
Advanced Cycles

A modeling study has been carried out in order to determine the behavior of evaporative industrial gas turbines power plants at part-load and for varying ambient temperature. On-design and off-design performance have been analyzed by means of a computational program developed for the analysis of advanced cycles. In order to verify the mathematical model and to evaluate the characteristics of up-to-date gas turbine technology, an industrial engine, presently available on the market, has been simulated. A double-shaft gas turbine for power generation has been considered. On-design performance and ratings vs. ambient temperature have been evaluated, with good accordance. It is assumed that, in order to realize a Recuperated Water Injected (RWI) cycle, the industrial gas turbine could be modified, maintaining substantially unchanged the compression system and modifying the turbine blades. The thermodynamic analysis of the cycle has been carried out in order to determine efficiency and power output as a function of the amount of water addition. The RWI cycle gas turbine has been designed and the characteristic maps of the two new turbines have been evaluated. The regulation is performed by means of the simultaneous manipulation of fuel flow rate, water rate, and position of the free turbine nozzle guide vanes (NGV). The regulation criteria, the interaction among the input variables, the safety of the operations (max. turbine inlet temperature, surge limits) and the optimization of the part-load efficiency, are examined and discussed. Ratings as a function of the ambient temperature are examined. The possibility to manipulate the water rate and the position of the NGV in order to provide high efficiency and power output, even on hot days, has been examined. The paper shows that maintaining constant the temperature at the power turbine exit, ratings decrease of 17% in power and 5% in efficiency.

Numerical Investigation of Influence of Radial Inlet Distortion on Compressor Performance in 2-Stage Turbocharging System

2014 ◽  
Author(s):  
Jinke Chen ◽  
Xinqian Zheng ◽  
Chenfang Wang ◽  
Weilin Zhuge ◽  
Yangjun Zhang
Keyword(s):  
High Pressure ◽  
Inlet Temperature ◽  
Flow Distortion ◽  
Two Stage ◽  
Inlet Condition ◽  
Inlet Distortion ◽  
High Pressure Compressor ◽  
Turbocharging System ◽  
Compressor Performance ◽  
Pressure Compressor

As the result of strict emission regulations and the demand of fuel reduction, an increasing number of engines are highly boosted with complex two-stage turbocharging systems. In a two-stage turbocharging system, an additional intercooler between LP compressor and HP compressor is usually used to reduce the inlet temperature of the HP compressor for extending its life and reducing the compression work. Spatial restrictions of the turbocharging system lead to reduced distances between different components of the two-stage turbocharging system. Consequently, each component’s performance is influenced by the upstream and downstream ones. The high pressure compressor performance is affected by the inlet flow condition, which is significantly distorted by the intercooler. In this paper, the characteristics of flow distortion caused by the intercooler and its evolution process are analyzed. Performances of the downstream high pressure compressor under uniform inlet condition and distorted inlet condition caused by the intercooler are analyzed and compared. The results show that the inlet distortion caused by intercooler deteriorates the compressor pressure ratio, flow range, and efficiency.

Numerical Investigations of a High Pressure Compressor Exposed to Unsteady Pressure Gain Combustion Employing Data-Driven Methods

2021 ◽  
Author(s):  
Victor Bicalho Civinelli de Almeida ◽  
Dieter Peitsch
Keyword(s):  
High Pressure ◽  
Gas Turbines ◽  
Data Driven ◽  
Thermodynamic Efficiency ◽  
Dynamic Mode ◽  
Numerical Work ◽  
High Pressure Compressor ◽  
Pressure Gain Combustion ◽  
Flow Features ◽  
Pressure Compressor

Abstract Pressure gain combustion (PGC) should substantially improve the thermodynamic efficiency of gas turbines by increasing the fluid total pressure as it traverses the combustion chamber. However, PGC introduces additional unsteadiness to the intrinsically complex turbomachinery flow. A high pressure compressor, located right upstream of the PGC section, is therefore constantly exposed to flow fluctuations, experiencing drop in efficiency, increase in pressure loss as well as higher stalling and structural failure risks. This numerical work analyzes how one stage of a well-established engine, namely the NASA EEE core compressor, reacts to the disturbances induced by the potential implementation of PGC. Unsteady computational fluid dynamics are employed with boundary conditions simulating the combustion unsteadiness. The main focus of the current paper is the application of data-driven methods, including the proper orthogonal decomposition (POD) and the dynamic mode decomposition (DMD), when comparing the high pressure compressor baseline operation with the PGC-disturbed case. Representative flow features and their frequency content, not identifiable with typical methods such as phase-averaging, are easily extracted from snapshots sequences. The results not only allow the identification of the most relevant coherent structures present in the unsteady flow, but also show how they change in the presence of PGC. This contribution sheds light on how novel PGC technology can be integrated with turbomachinery components, identifying modifications in the main flow features with the use of advanced decomposition techniques.

Numerical Investigation of Vortex Reducer Flows in the High Pressure Compressor of Modern Aeroengines

2002 ◽  
Author(s):  
Dieter Peitsch ◽  
Manuela Stein ◽  
Stefan Hein ◽  
Reinhard Niehuis ◽  
Ulf Reinmo¨ller
Keyword(s):  
High Pressure ◽  
Gas Turbines ◽  
Efficient Operation ◽  
Pressure Losses ◽  
High Pressure Compressor ◽  
Air System ◽  
The Difference ◽  
Secondary Air ◽  
Set Up ◽  
Pressure Compressor

Modern jet engines require very high cycle temperatures for efficient operation. In turn, cooling air is needed for the turbine, since the materials are not yet capable of taking these temperatures. Air is taken from the compressor for the purpose of cooling and turbine rim sealing, bypassing the main combustion circuit. Since this affects the efficiency of the engine in a negative manner, measures are taken to reduce the amount of air to an absolute minimum. These measures include the investigation of reducing pressure losses within the involved subsystems. One of these subsystems in the BR700 aeroengine series of Rolls-Royce is the vortex reducer device, which delivers bleed air to the secondary air system of the engine. The German government has set up a research project, aiming for an overall improvement of aeroengines. This program, Engine 3E, where 3E reflects Efficiency, Economy and Environment, concentrates on the main components of gas turbines. Programmes for the high pressure turbine and for the combustion chamber have been set up. The high pressure compressor has been identified as key component as well. A new 9-stage compressor is being developed at Rolls-Royce Deutschland to adress the respective needs. From the point of view of the secondary air system, the vortex reducer in this component plays a major role with respect to the efficient use of cooling and sealing air. Rolls-Royce Deutschland has performed CFD studies on the performance of different vortex reducer geometries, which currently are considered for incorporation into the future engine. The results of these investigations wil be converted into more simple design rules for proper reflection of the behaviour of this system for future designs. The paper presents the set up of the geometries, the applied boundary conditions as well as the final results. To tackle the difference between a high pressure compressor rig and a typical two-shaft engine, a dedicated investigation to assess the difference between a pure high pressure core without an internal shaft and a realistic high/low pressure shaft configuration has been carried out and is included in the paper. Recommendations to improve the design with respect to minimized pressure losses will be shown as well.

Review on the aerodynamics of intermediate compressor duct

2020 ◽  
Vol 14 (4) ◽  
pp. 7446-7468
Author(s):  
Manish Sharma ◽  
Beena D. Baloni
Keyword(s):  
High Pressure ◽  
Pressure Loss ◽  
Flow Analysis ◽  
Outer Wall ◽  
Optimization Techniques ◽  
Optimum Pressure ◽  
Research Areas ◽  
Static Pressure Distribution ◽  
High Pressure Compressor ◽  
Pressure Compressor

In a turbofan engine, the air is brought from the low to the high-pressure compressor through an intermediate compressor duct. Weight and design space limitations impel to its design as an S-shaped. Despite it, the intermediate duct has to guide the flow carefully to the high-pressure compressor without disturbances and flow separations hence, flow analysis within the duct has been attractive to the researchers ever since its inception. Consequently, a number of researchers and experimentalists from the aerospace industry could not keep themselves away from this research. Further demand for increasing by-pass ratio will change the shape and weight of the duct that uplift encourages them to continue research in this field. Innumerable studies related to S-shaped duct have proven that its performance depends on many factors like curvature, upstream compressor’s vortices, swirl, insertion of struts, geometrical aspects, Mach number and many more. The application of flow control devices, wall shape optimization techniques, and integrated concepts lead a better system performance and shorten the duct length.  This review paper is an endeavor to encapsulate all the above aspects and finally, it can be concluded that the intermediate duct is a key component to keep the overall weight and specific fuel consumption low. The shape and curvature of the duct significantly affect the pressure distortion. The wall static pressure distribution along the inner wall significantly higher than that of the outer wall. Duct pressure loss enhances with the aggressive design of duct, incursion of struts, thick inlet boundary layer and higher swirl at the inlet. Thus, one should focus on research areas for better aerodynamic effects of the above parameters which give duct design with optimum pressure loss and non-uniformity within the duct.

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