Thermodynamic Optimization of a Gas Turbine Power Plant With Pressure Drop Irreversibilities

1998 ◽  
Vol 120 (3) ◽  
pp. 233-240 ◽  
Author(s):  
V. Radcenco ◽  
J. V. C. Vargas ◽  
A. Bejan
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Flow Rate ◽  
Power Output ◽  
Pressure Ratio ◽  
Plant Size ◽  
Fuel Flow Rate ◽  
Flow Area ◽  
Fuel Flow ◽  
Gas Turbine Power Plant

In this paper we show that the thermodynamic performance of a gas turbine power plant can be optimized by adjusting the flow rate and the distribution of pressure losses along the flow path. Specifically, we show that the power output has a maximum with respect to the fuel flow rate or any of the pressure drops. The maximized power output has additional maxima with respect to the overall pressure ratio and overall temperature ratio. When the optimization is performed subject to a fixed fuel flow rate, and the power plant size is constrained, the power output and efficiency can be maximized again by properly allocating the fixed total flow area among the compressor inlet and the turbine outlet.

scholarly journals Thermodynamics performance optimization of a hybrid solar gas turbine power plant in Colombia

2022 ◽  
Vol 2163 (1) ◽  
pp. 012004
Author(s):  
F Moreno-Gamboa ◽  
J C Acevedo-Paez ◽  
D Sanin-Villa
Keyword(s):  
Power Plant ◽  
Solar Radiation ◽  
Gas Turbine ◽  
Power Output ◽  
Performance Optimization ◽  
Pressure Ratio ◽  
Direct Solar Radiation ◽  
Performance Point ◽  
Overall Efficiency ◽  
Gas Turbine Power Plant

Abstract A thermodynamic model is presented for evaluation of a solar hybrid gas-turbine power plant. The model uses variable ambient temperature and estimates direct solar radiation at different day times. The plant is evaluated in Barranquilla, Colombia, with a solar concentration system and a combustion chamber that burns natural gas. The hybrid system enables to maintain almost constant the power output throughout day. The model allows optimizing the different plant parameters and evaluating maximum performance point. This work presents pressure ratio ranges where the maximum values of overall efficiency, power output, thermal engine efficiency and fuel conversion rate are found. The study is based on the environmental conditions of Barranquilla, Colombia. The results obtained shows that optimum pressure ratio range for power output and overall efficiency is between 6.4 and 8.3, when direct solar radiation its maximum at noon. This thermodynamic analysis is necessary to design new generations of solar thermal power plants.

EFFECTS OF DUCT BURNER ON BOTTOMING CYCLE IN A COMBINED CYCLE POWER PLANT

2017 ◽  
Vol 79 (7-3) ◽  
Author(s):  
A. Ganjehkaviri ◽  
Mustafa Yusof ◽  
M. N. Mohd Jaafar
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Steam Generator ◽  
Flow Rate ◽  
Heat Recovery ◽  
Combined Cycle ◽  
Heat Recovery Steam Generator ◽  
Fuel Flow Rate ◽  
Fuel Flow ◽  
Duct Burner

In this study, thermodynamic modeling and exergoeconomic assessment of a Combined Cycle Power Plant (CCPP) with a Duct Burner (DB) was performed. Obtaining an optimum condition for the performance of a CCPP, using a DB after gas turbine was investigated by various researchers. DB is installed between gas turbine cycle and Rankine cycle of a CCPP to connect the gas turbine outlet to the Heat Recovery Steam Generator (HRSG) in order to produce steam for bottoming cycle. To find the irreversibility effect in each component of the bottoming cycle, a comprehensive parametric study is performed. In this regard, the effect of DB fuel flow rate on cost efficiency and economic of the bottoming cycle are investigated. To obtain a reasonable result, all the design parameters are kept constant while the DB fuel flow rate is varied. The results indicate that by increasing DB fuel flow rate, the investment cost and the efficiency of CCPP are increased. T-S diagram reveals that by using a DB, higher pressures steam in heat recovery steam generator has higher temperature while the low pressure is decreased. In addition, the exergy of flow gases in heat recovery steam generator increases. So, the exergy efficiency of the whole cycle was increased to around 6 percent, while the cost of the plant reduced by one percent.

scholarly journals A Proper Shape of the Trailing Edge Modification to Solve a Housing Damage Problem in a Gas Turbine Power Plant

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 705
Author(s):  
Thodsaphon Jansaengsuk ◽  
Mongkol Kaewbumrung ◽  
Wutthikrai Busayaporn ◽  
Jatuporn Thongsri
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Structural Dynamics ◽  
Pressure Ratio ◽  
Equivalent Stress ◽  
Total Deformation ◽  
Trailing Edge ◽  
Housing Damage ◽  
The Difference ◽  
Gas Turbine Power Plant

To solve the housing damage problem of a fractured compressor blade (CB) caused by an impact on the inner casing of a gas turbine in the seventh stage (from 15 stages), modifications of the trailing edge (TE) of the CB have been proposed, namely 6.5 mm curved cutting and a combination of 4 mm straight cutting with 6.5 mm curved cutting. The simulation results of the modifications in both aerodynamics variables Cl and Cd and the pressure ratio, including structural dynamics such as a normalized power spectrum, frequency, total deformation, equivalent stress, and the safety factor, found that 6.5 mm curved cutting could deliver the aerodynamics and structural dynamics similar to the original CB. This result also overcomes the previous work that proposed 5.0 mm straight cutting. This work also indicates that the operation of a CB gives uneven pressure and temperature, which get higher in the TE area. The slightly modified CB can present the difference in the properties of both the aerodynamics and the structural dynamics. Therefore, any modifications of the TE should be investigated for both properties simultaneously. Finally, the results from this work can be very useful information for the modification of the CB in the housing damage problem of the other rotating types of machinery in a gas turbine power plant.

Dynamic Simulation of a HRSG System for a Given Start-Up/Shut Down Curve

2011 ◽  
Author(s):  
Hun Cha ◽  
Yoo Seok Song ◽  
Kyu Jong Kim ◽  
Jung Rae Kim ◽  
Sung Min KIM
Keyword(s):  
Dynamic Analysis ◽  
Gas Turbine ◽  
Flow Rate ◽  
Exhaust Gas ◽  
Fuel Flow Rate ◽  
Fuel Flow ◽  
Start Up ◽  
Gas Turbine Exhaust ◽  
Main Steam ◽  
Duct Burner

An inappropriate design of HRSG (Heat Recovery Steam Generator) may lead to mechanical problems including the fatigue failure caused by rapid load change such as operating trip, start-up or shut down. The performance of HRSG with dynamic analysis should be investigated in case of start-up or shutdown. In this study, dynamic analysis for the HRSG system was carried out by commercial software. The HRSG system was modeled with HP, IP, LP evaporator, duct burner, superheater, reheater and economizer. The main variables for the analysis were the temperature and mass flow rate from gas turbine and fuel flow rate of duct burner for given start-up (cold/warm/hot) and shutdown curve. The results showed that the exhaust gas condition of gas turbine and fuel flow rate of duct burner were main factors controlling the performance of HRSG such as flow rate and temperature of main steam from final superheater and pressure of HP drum. The time delay at the change of steam temperature between gas turbine exhaust gas and HP steam was within 2 minutes at any analysis cases.

Model Analysis of Syngas Combustion and Emissions for a Micro Gas Turbine

2015 ◽  
Vol 137 (6) ◽  
Author(s):  
Chi-Rong Liu ◽  
Hsin-Yi Shih
Keyword(s):  
Gas Turbine ◽  
Flow Rate ◽  
Heat Input ◽  
Emission Characteristics ◽  
Nox Emissions ◽  
Fuel Flow Rate ◽  
Micro Gas Turbine ◽  
Fuel Flow ◽  
Temperature Distributions ◽  
Flame Structures

The purpose of this study is to investigate the combustion and emission characteristics of syngas fuels applied in a micro gas turbine, which is originally designed for a natural gas fired engine. The computation results were conducted by a numerical model, which consists of the three-dimension compressible k–ε model for turbulent flow and PPDF (presumed probability density function) model for combustion process. As the syngas is substituted for methane, the fuel flow rate and the total heat input to the combustor from the methane/syngas blended fuels are varied with syngas compositions and syngas substitution percentages. The computed results presented the syngas substitution effects on the combustion and emission characteristics at different syngas percentages (up to 90%) for three typical syngas compositions and the conditions where syngas applied at fixed fuel flow rate and at fixed heat input were examined. Results showed the flame structures varied with different syngas substitution percentages. The high temperature regions were dense and concentrated on the core of the primary zone for H2-rich syngas, and then shifted to the sides of the combustor when syngas percentages were high. The NOx emissions decreased with increasing syngas percentages, but NOx emissions are higher at higher hydrogen content at the same syngas percentage. The CO2 emissions decreased for 10% syngas substitution, but then increased as syngas percentage increased. Only using H2-rich syngas could produce less carbon dioxide. The detailed flame structures, temperature distributions, and gas emissions of the combustor were presented and compared. The exit temperature distributions and pattern factor (PF) were also discussed. Before syngas fuels are utilized as an alternative fuel for the micro gas turbine, further experimental testing is needed as the modeling results provide a guidance for the improved designs of the combustor.

Influence of Disturbances on Transients of a Gas Turbine Ship Propulsion System — Preliminary Investigations

2000 ◽  
Author(s):  
Marek Dzida ◽  
Zygfryd Domachowski
Keyword(s):  
Angular Velocity ◽  
Gas Turbine ◽  
Flow Rate ◽  
Temperature Response ◽  
Outlet Temperature ◽  
Propeller Shaft ◽  
Fuel Flow Rate ◽  
Ship Propulsion ◽  
Fuel Flow ◽  
Ship Propeller

A gas turbine ship propulsion control system transients have been investigated. On the basis of a mathematical model composed of blocks modelling a two-shaft gas turbine, a gear (mechanical or electric), and a coupling shaft, some preliminary simulations have been carried out. Ship propeller shaft angular velocity, fuel flow rate, and gas turbine combustion chamber outlet temperature response to the ship propeller shaft angular velocity set point, and fuel flow rate, changes have been analyzed. Influences of limiters in the controller action on analyzed transients have been compared.

Simulation of Maneuvering Characteristics of a Destroyer Study Ship Using a Modified Nonlinear Model

1975 ◽  
Vol 19 (04) ◽  
pp. 254-265
Author(s):  
Samuel H. Brown ◽  
Reidar Alvestad
Keyword(s):  
Mathematical Model ◽  
Gas Turbine ◽  
Flow Rate ◽  
Equations Of Motion ◽  
Analog Computer ◽  
Fuel Flow Rate ◽  
Turbine Engine ◽  
Engine Torque ◽  
Ship Propulsion ◽  
Fuel Flow

This paper describes an analog computer maneuvering simulation of a destroyer study ship. The mathematical model used includes the ship propulsion machinery dynamics and the ship equations of motion. The model couples the ship propulsion dynamics equations with nonlinear maneuvering equations. The power plant representation consists of a simplified mathematical model of a General Electric LM2500 gas turbine engine and is primarily an engine mapping of engine torque versus engine speed using fuel flow. rate as a parameter. The simulation is used to accurately predict slow transients in ship speed during maneuvers resulting from slow increases in the fuel flow rate to the gas turbine. The advantage of the modified model presented in this paper over those not including propulsion dynamics is that it permits simulations of the effects of maneuvering on the propulsion plant.

Emf, Maximum Power and Efficiency of Fuel Cells

1993 ◽  
Vol 115 (2) ◽  
pp. 100-104 ◽  
Author(s):  
R. A. Gaggioli ◽  
W. R. Dunbar
Keyword(s):  
Free Energy ◽  
Fuel Cells ◽  
Gibbs Free Energy ◽  
Flow Rate ◽  
Power Output ◽  
Local Characteristic ◽  
Work Output ◽  
Fuel Flow Rate ◽  
Fuel Flow ◽  
The Ideal

The ideal voltage of steady-flow fuel cells is usually expressed by Emf = −ΔG°/nF where ΔG° is the “Gibbs free energy of reaction” for the oxidation of the fuel at the supposed temperature of operation of the cell. Furthermore, the ideal power of the cell is expressed as the product of the fuel flow rate with this emf. Such viewpoints are flawed in several respects. While it is true that if a cell operates isothermally, the maximum conceivable electrical work output is equal to the difference between the Gibbs free energy of the incoming reactants and that of the leaving products; nevertheless, even if the cell operates isothermally, the use of the conventional ΔG° of reaction (a) assumes that the products of reaction leave separately from one another (and from any unused fuel); and (b) when ΔS of reaction is positive, it assumes that a free heat source exists at the operating temperature, whereas if ΔS is negative, it neglects the potential power which theoretically could be obtained from the heat released during oxidation. Moveover, (c) the usual cell does not operate isothermally, but (virtually) adiabatically. Comment (a) is often accounted for by employing the Nernst equation to correct for the dilution of reactants and/or products. Nevertheless, comments (b) and (c) remain pertinent. Rather than with emf, the proper starting place is with power output. The ideal power is that which would be obtained if the fuel were oxidized without irreversible entropy generation. Among other factors, this ideal power output depends upon the ratio of oxidant to fuel flow rate (e.g., air-fuel ratio) and the percentage of fuel oxidation. The ideal voltage is deduced from the ideal power, because it is defined as electrical work output per unit of charge delivered. It is a local characteristic which varies with the percent of fuel oxidized. Therefore, (d) ideal power is not equal to the product of emf with current (unless the amount of fuel utilized is infinitesimal). Examples are presented which illustrate such affects and their importance for the evaluation of ideal power and of efficiency.

Gas Turbine Engine Emissions—Part I: Volatile Organic Compounds and Nitrogen Oxides

2010 ◽  
Vol 132 (6) ◽  
Author(s):  
Michael T. Timko ◽  
Scott C. Herndon ◽  
Ezra C. Wood ◽  
Timothy B. Onasch ◽  
Megan J. Northway ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Turbine ◽  
Gas Phase ◽  
Organic Compounds ◽  
Flow Rate ◽  
Fuel Flow Rate ◽  
Engine Emissions ◽  
Turbine Engine ◽  
Fuel Flow ◽  
Volatile Organic

The potential human health and environmental impacts of aircraft gas turbine engine emissions during normal airport operation are issues of growing concern. During the JETS/Aircraft Particle Emissions eXperiment(APEX)-2 and APEX-3 field campaigns, we performed an extensive series of gas phase and particulate emissions measurements of on-wing gas turbine engines. In all, nine different CFM56 style engines (including both CFM56-3B1 and -7B22 models) and seven additional engines (two RB211-535E4-B engines, three AE3007 engines, one PW4158, and one CJ6108A) were studied to evaluate engine-to-engine variability. Specific gas-phase measurements include NO2, NO, and total NOx, HCHO, C2H4, CO, and a range of volatile organic compounds (e.g., benzene, styrene, toluene, naphthalene). A number of broad conclusions can be made based on the gas-phase data set: (1) field measurements of gas-phase emission indices (EIs) are generally consistent with ICAO certification values; (2) speciation of gas phase NOx between NO and NO2 is reproducible for different engine types and favors NO2 at low power (and low fuel flow rate) and NO at high power (high fuel flow rate); (3) emission indices of gas-phase organic compounds and CO decrease rapidly with increasing fuel flow rate; (4) plotting EI-CO or volatile organic compound EIs against fuel flow rate collapses much of the variability between the different engines, with one exception (AE3007); (5) HCHO, ethylene, acetaldehyde, and propene are the most abundant volatile organic compounds present in the exhaust gases that we can detect, independent of engine technology differences. Empirical correlations accurate to within 30% and based on the publicly available engine parameters are presented for estimating EI-NOx and EI-NO2. Engine-to-engine variability, unavailability of combustor input conditions, changing ambient temperatures, and complex reaction dynamics limit the accuracy of global correlations for CO or volatile organic compound EIs.

Combustion Analysis of Syngas Fuels Applied in a Micro Gas Turbine Combustor With a Rotating Casing

2019 ◽  
Author(s):  
Maaz Ajvad ◽  
Hsin-Yi Shih
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Flow Rate ◽  
Combustion Process ◽  
Future Application ◽  
Injection Velocity ◽  
Fuel Flow Rate ◽  
Micro Gas Turbine ◽  
Fuel Flow ◽  
Exit Temperature

Abstract Combustion characteristics of a can combustor with a rotating casing for an innovative micro gas turbine have been modeled. The effects of syngas compositions and the rotating speed on the combustor performance were investigated. The effects of rotation on the combustion performance have been studied previously with methane as the fuel. This work extended the investigation for future application with syngas blended fuels. Two typical compositions of syngas were used namely: H2-rich (H2:CO=80:20, by volume) and equal molar (H2:CO=50:50). The analyses were performed with a computational model, which consists of three-dimension compressible k-ε realizable turbulent flow model and presumed probability density function for combustion process invoking a laminar flamelet assumption generated by detailed chemical kinetics from GRI 3.0. As syngas is substituted for methane at a constant fuel flow rate, the high temperature flame is stabilized along the wall of the combustor liner. With the casing rotating, pattern factor and exit temperature increase, but the lower heating value of syngas causes a power shortage. To make up the power, the fuel flow rate is raised to maintain the thermal load. Consequently, the high temperature flame is pushed downstream due to increased fuel injection velocity. NOx emission decreases as the rotational speed increases in both cases. Pattern factor decreases but exit temperature increases with the increase of roatation speed indicating a higher combustion efficiency. However, there is possible hotspots at exit due to higher pattern factor (PF>0.3) for H2-rich and equal molar syngas at lower speed of rotation, which needs to be resolved by improving the cooling strategy.

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