Computer-Aided Analysis of Gas Turbine Cycles

1994 ◽  
Vol 22 (3) ◽  
pp. 209-227 ◽  
Author(s):  
F. Moukalled ◽  
I. Lakkis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Engineering Students ◽  
Turbine Plant ◽  
Design Variables ◽  
Computer Aided Analysis ◽  
Shaft Power ◽  
Overall Performance ◽  
Statistical Survey ◽  
Gas Turbine Cycle

This paper describes a microcomputer-based, interactive, and menu-driven software package designed to help mechanical engineering students to understand gas turbines and to allow them to conduct more analysis of gas turbine cycles than they would normally be able to do by hand-calculation. The program deals with gas turbine cycle analysis so the acronym GTCA is used. GTCA is written in the Pascal computer language and runs on IBM PC, or compatible, computers. Improvements to the basic Brayton cycle, including three compressor and turbine stages, reheater, heat exchanger, intercooler, and precooler are incorporated into the program. The package is highly flexible and allows the user to model cycle schemes formed of any combination of these elements and to handle both shaft power turbines and aircraft turbojet and turbofan turbines. An important feature of the program is its ability to solve for any unknown variables. In addition to this, the program provides a schematic of the turbine plant layout and a temperature-entropy diagram of the cycle, and permits the plotting of the variation of any quantity versus any other quantity. This option enables the student to easily study and understand the effects of changing design variables on the overall performance of the cycle and permits its optimization. The statistical survey conducted along with the examples presented demonstrate the capabilities of the package as a teaching tool.

Thermodynamic Study of Humid Air Gas Turbine Cycle Power Plants

2005 ◽  
Author(s):  
R. Yadav ◽  
P. Sreedhar Yadav
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Substantial Reduction ◽  
Thermodynamic Study ◽  
Humid Air ◽  
Turbine Plant ◽  
Design Engineers ◽  
Gas Turbine Plant ◽  
Gas Turbine Cycle

The major challenges before the design engineers of a gas turbine plant and its variants are the enhancement of power output, substantial reduction in NOx emission and improvement in plant thermal efficiency. There are various possibilities to achieve these objectives and humid air gas turbine cycle power plant is one of them. The present study deals with the thermodynamic study of humid air gas turbine cycle power plants based on first law. Using the modeling and governing equations, the parametric study has been carried out. The results obtained will be helpful in designing the humid air gas turbines, which are used as peaking units. The comparison of performance of humid air gas turbine cycle shows that it is superior to basic gas turbine cycle but inferior and more complex to steam injected cycle.

scholarly journals The Constant Volume Gas Turbine Cycle According to Karavodine

1982 ◽  
Author(s):  
H. Vandermeulen
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Constant Pressure ◽  
Constant Volume ◽  
Theory And Practice ◽  
Pressure Cycle ◽  
Basic Distinction ◽  
Overall Performance ◽  
The One ◽  
Gas Turbine Cycle

The basic distinction between the constant volume cycle and the well known constant pressure cycle for gas turbines is the method of heat supply, which necessitates a system of combustion chamber valves to contain the fluid. The object of the proposed cycle analysis, which is mainly based on the fundamental laws of mass and energy, will consider a solution for the discrepancies between the former theory and practice of constant volume gas turbines. The overall performance characteristics which emerge from this analysis show the distinct superiority of the one-valve Karavodine cycle. Evaluation by experiment for this cycle variant shows, however, besides a refinement of the model, a marginal superiority in performance for the Brayton gas turbine at low pressure ratios. Any application could probably be justified by incorporating it in Brayton turbines to diminish starting power and to improve part load performance.

scholarly journals The Effect of Discrete Pilot Hydrogen Dopant Injection on the Lean Blowout Performance of a Model Gas Turbine Combustor

1999 ◽  
Author(s):  
Oanh Nguyen ◽  
Scott Samuelsen
Keyword(s):  
Gas Turbine ◽  
Atmospheric Pressure ◽  
Gas Turbines ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Lean Blowout ◽  
Lean Combustion ◽  
Attractive Option ◽  
Overall Performance ◽  
Model Gas Turbine Combustor

In view of increasingly stringent NOx emissions regulations on stationary gas turbines, lean combustion offers an attractive option to reduce reaction temperatures and thereby decrease NOx production. Under lean operation, however, the reaction is vulnerable to blowout. It is herein postulated that pilot hydrogen dopant injection, discretely located, can enhance the lean blowout performance without sacrificing overall performance. The present study addresses this hypothesis in a research combustor assembly, operated at atmospheric pressure, and fired on natural gas using rapid mixing injection, typical of commercial units. Five hydrogen injector scenarios are investigated. The results show that (1) pilot hydrogen dopant injection, discretely located, leads to improved lean blowout performance and (2) the location of discrete injection has a significant impact on the effectiveness of the doping strategy.

scholarly journals An Optimizing Design Point Program for Selection of a Gas Turbine Cycle

1977 ◽  
Author(s):  
G. K. Conkol ◽  
T. Singh
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Design Parameters ◽  
Turbine Engines ◽  
Original Design ◽  
Ground Vehicle ◽  
Design Point ◽  
Optimizing Design ◽  
Volume Characteristics ◽  
Gas Turbine Cycle

As vehicles evolve through the concept phase, a wide variety of engines are usually considered. For long-life vehicles such as heavy armored tracked vehicles, gas turbines have been favored because of their weight and volume characteristics at high hp levels (1500 to 2000 hp). Many existing gas turbine engines, however, are undesirable for vehicular use because their original design philosophy was aircraft oriented. In a ground vehicle, mass flow and expense are only two areas in which these engines differ greatly. Because the designer generally is not given the freedom to design an engine from scratch, he must evaluate modifications of the basic Brayton cycle. In this study, various cycles are evaluated by using a design point program in order to optimize design parameters and to recommend a cycle for heavy vehicular use.

Pulsed Impingement Turbine Cooling and its Effect on the Efficiency of Gas Turbines With Pressure Gain Combustion

2020 ◽  
Author(s):  
Nicolai Neumann ◽  
Dieter Peitsch ◽  
Arne Berthold ◽  
Frank Haucke ◽  
Panagiotis Stathopoulos
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Impingement Cooling ◽  
Turbine Cooling ◽  
Pressure Gain Combustion ◽  
Cooling Air ◽  
Gas Turbine Cycle ◽  
Cycle Efficiency

Abstract Performance improvements of conventional gas turbines are becoming increasingly difficult and costly to achieve. Pressure Gain Combustion (PGC) has emerged as a promising technology in this respect, due to the higher thermal efficiency of the respective ideal gas turbine cycle. Previous cycle analyses considering turbine cooling methods have shown that the application of pressure gain combustion may require more turbine cooling air. This has a direct impact on the cycle efficiency and reduces the possible efficiency gain that can potentially be harvested from the new combustion technology. Novel cooling techniques could unlock an existing potential for a further increase in efficiency. Such a novel turbine cooling approach is the application of pulsed impingement jets inside the turbine blades. In the first part of this paper, results of pulsed impingement cooling experiments on a curved plate are presented. The potential of this novel cooling approach to increase the convective heat transfer in the inner side of turbine blades is quantified. The second part of this paper presents a gas turbine cycle analysis where the improved cooling approach is incorporated in the cooling air calculation. The effect of pulsed impingement cooling on the overall cycle efficiency is shown for both Joule and PGC cycles. In contrast to the authors’ anticipation, the results suggest that for relevant thermodynamic cycles pulsed impingement cooling increases the thermal efficiency of Joule cycles more significantly than it does in the case of PGC cycles. Thermal efficiency improvements of 1.0 p.p. for pure convective cooling and 0.5 p.p. for combined convective and film with TBC are observed for Joule cycles. But just up to 0.5 p.p. for pure convective cooling and 0.3 p.p. for combined convective and film cooling with TBC are recorded for PGC cycles.

Capacity Matching of Aeroderivative Gas Generator With Free Power Turbine: Challenges, Uncertainties, and Opportunities

2019 ◽  
Author(s):  
Deepak Thirumurthy ◽  
Jose Carlos Casado Coca ◽  
Kanishka Suraweera
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Systems Approach ◽  
Gas Generator ◽  
Performance Guarantees ◽  
Design Variables ◽  
Performance Trends ◽  
Power Turbine ◽  
Parameter Matching ◽  
Turbine Capacity

Abstract For gas turbines with free power turbines, the capacity or flow parameter matching is of prime importance. Accurately matched capacity enables the gas turbine to run at its optimum conditions. This ensures maximum component efficiencies, and optimum shaft speeds within mechanical limits. This paper presents the challenges, uncertainties, and opportunities associated with an accurate matching of a generic two-shaft aeroderivative HP-LP gas generator with the free power turbine. Additionally, generic performance trends, uncertainty quantification, and results from the verification program are also discussed. These results are necessary to ensure that the final free power turbine capacity is within the allowable range and hence the product meets the performance guarantees. The sensitivity of free power turbine capacity to various design variables such as the vane throat area, vane trailing edge size, and manufacturing tolerance is presented. In addition, issues that may arise due to not meeting the target capacity are also discussed. To conclude, in addition to design, analysis, and statistical studies, a system-of-systems approach is mandatory to meet the allowed variation in the free power turbine capacity and hence the desired gas turbine performance.

Aerodynamic Design and Numerical Investigation on Overall Performance of a Micro Radial Turbine With Millimeter-Scale

2009 ◽  
Author(s):  
Lei Fu ◽  
Yan Shi ◽  
Qinghua Deng ◽  
Zhenping Feng
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Turbine Rotor ◽  
Rotor Blades ◽  
Micro Gas Turbine ◽  
Radial Turbine ◽  
Overall Performance ◽  
Low Reynolds ◽  
Exit Mach Number ◽  
Installation Technology

For millimeter-scale microturbines, the principal challenge is to achieve a design scheme to meet the aerothermodynamics, geometry restriction, structural strength and component functionality requirements while in consideration of the applicable materials, realizable manufacturing and installation technology. This paper mainly presents numerical investigations on the aerothermodynamic design, geometrical design and overall performance prediction of a millimeter-scale radial turbine with rotor diameter of 10mm. Four kinds of turbine rotor profiles were designed, and they were compared with one another in order to select the suitable profile for the micro radial turbine. The leaving velocity loss in micro gas turbines was found to be a large source of inefficiency. The approach of refining the geometric structure of rotor blades and the profile of diffuser were adopted to reduce the exit Mach number thus improving the total-static efficiency. Different from general gas turbines, micro gas turbines are operated in low Reynolds numbers, 104∼105, which has significant effect on flow separation, heat transfer and laminar to turbulent flow transition. Based on the selected rotor profile, several micro gas turbine configurations with different tip clearances of 0.1mm, 0.2mm and 0.3mm, respectively; two different isothermal wall conditions; and two laminar-turbulent transition models were investigated to understand the particular influence of low Reynolds number. These influences on the overall performance of the micro gas turbine were analyzed in details. The results indicate that these configurations should be included and emphasized during the design process of the millimeter-scale micro radial turbines.

Influence of Steam Injection on Thermal Efficiency and Operating Temperature of GE-F5 Gas Turbines Applying VODOLEY System

2005 ◽  
Author(s):  
Mohsen Ghazikhani ◽  
Nima Manshoori ◽  
Davood Tafazoli
Keyword(s):  
Power Plant ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Thermal Efficiency ◽  
Gas Turbines ◽  
Steam Injection ◽  
Gas Turbine Cycle

An industrial gas turbine has the characteristic that turbine output decreases on hot summer days when electricity demand peaks. For GE-F5 gas turbines of Mashad Power Plant when ambient temperature increases 1° C, compressor outlet temperature increases 1.13° C and turbine exhaust temperature increases 2.5° C. Also air mass flow rate decreases about 0.6 kg/sec when ambient temperature increases 1° C, so it is revealed that variations are more due to decreasing in the efficiency of compressor and less due to reduction in mass flow rate of air as ambient temperature increases in constant power output. The cycle efficiency of these GE-F5 gas turbines reduces 3 percent with increasing 50° C of ambient temperature, also the fuel consumption increases as ambient temperature increases for constant turbine work. These are also because of reducing in the compressor efficiency in high temperature ambient. Steam injection in gas turbines is a way to prevent a loss in performance of gas turbines caused by high ambient temperature and has been used for many years. VODOLEY system is a steam injection system, which is known as a self-sufficient one in steam production. The amount of water vapor in combustion products will become regenerated in a contact condenser and after passing through a heat recovery boiler is injected in the transition piece after combustion chamber. In this paper the influence of steam injection in Mashad Power Plant GE-F5 gas turbine parameters, applying VODOLEY system, is being observed. Results show that in this turbine, the turbine inlet temperature (T3) decreases in a range of 5 percent to 11 percent depending on ambient temperature, so the operating parameters in a gas turbine cycle equipped with VODOLEY system in 40° C of ambient temperature is the same as simple gas turbine cycle in 10° C of ambient temperature. Results show that the thermal efficiency increases up to 10 percent, but Back-Work ratio increases in a range of 15 percent to 30 percent. Also results show that although VODOLEY system has water treatment cost but by using this system the running cost will reduce up to 27 percent.

Combustion Chamber Steam Injection for Gas Turbine Performance Improvement During High Ambient Temperature Operations

2008 ◽  
Vol 130 (4) ◽  
Author(s):  
Abdallah Bouam ◽  
Slimane Aissani ◽  
Rabah Kadi
Keyword(s):  
Ambient Temperature ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Large Scale ◽  
Pressure Ratio ◽  
Performance Testing ◽  
Steam Injection ◽  
Climatic Conditions ◽  
Gas Turbine Cycle

The gas turbines are generally used for large scale power generation. The basic gas turbine cycle has low thermal efficiency, which decreases in the hard climatic conditions of operation, so the cycles with thermodynamic improvement is found to be necessary. Among several methods shown their success in increasing the performances, the steam injected gas turbine cycle (STIG) consists of introducing a high amount of steam at various points in the cycle. The main purpose of the present work is to improve the principal characteristics of gas turbine used under hard condition of temperature in Algerian Sahara by injecting steam in the combustion chamber. The suggested method has been studied and compared to a simple cycle. Efficiency, however, is held constant when the ambient temperature increases from ISO conditions to 50°C. Computer program has been developed for various gas turbine processes including the effects of ambient temperature, pressure ratio, injection parameters, standard temperature, and combustion chamber temperature with and without steam injection. Data from the performance testing of an industrial gas turbine, computer model, and theoretical study are used to check the validity of the proposed model. The comparison of the predicted results to the test data is in good agreement. Starting from the advantages, we recommend the use of this method in the industry of hydrocarbons. This study can be contributed for experimental tests.

A Cost-Effective Indirect Coal-Fired Gas Turbine Power and Water-From-Air Cycle

1985 ◽  
Vol 107 (4) ◽  
pp. 861-869 ◽  
Author(s):  
P. R. Trumpler
Keyword(s):  
Gas Turbine ◽  
Cost Effective ◽  
Inlet Temperature ◽  
Turbine Plant ◽  
Air Heater ◽  
Gas Turbine Plant ◽  
The Cost ◽  
Gas Turbine Cycle ◽  
Steam Plant ◽  
Plant Capacity

An ideal open gas turbine cycle with multiple-stage intercooled compression and multiple-stage reheat expansion theoretically approaches Carnot thermal efficiency. A proposed practicable process to utilize this cycle with indirect firing of coal as fuel, with an air heater in place of the boiler, a turbine inlet temperature of 1700°F (927°C) and top pressure of 788 psia (53.6 atm) gives promise of lowering power plant station heat rates (HHV) from 8970 Btu/kWh currently realized by the best scrubber-equipped coal fired steam plants to 7460, a reduction of 16.8% in fuel consumption and consequently the cost of flue gas scrubbers. In addition, a 316 MW plant delivers at rated output 130,000 gal per day water stripped from atmospheric air. Primarily because of an expensive air heater and regenerator the gas turbine plant is penalized by an estimated increase in initial cost from $1000/kW for a steam plant to $1433/kW. With coal priced at $3/million Btu, water selling at 2¢/gal, money at 8% interest, inflation at 5%, and an 81% plant capacity factor, the payback period is 17 years.

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