A Decomposition Strategy for Thermoeconomic Optimization

1989 ◽  
Vol 111 (3) ◽  
pp. 111-120 ◽  
Author(s):  
Y. M. El-Sayed
Keyword(s):  
Objective Function ◽  
Gas Turbine ◽  
Point Of View ◽  
Thermal Design ◽  
Second Law ◽  
System Configuration ◽  
Power Cycle ◽  
Design Variables ◽  
Second Law Analysis ◽  
Optimal Values

An optimal thermal design of a considered system configuration is conveniently decided when the system is modeled as made up of one thermodynamic subsystem and of the essential number of design subsystems. The thermodynamic subsystem decides the performance of the components and the design subsystems decide their best matching geometry and costs. An optimizer directs all decisions to an extremum of a given objective function. This decomposition strategy is illustrated by investigating the optimal values of seven decision design variables for a regenerative gas turbine power cycle when a cost-objective function is minimized. The results seen from the point of view of second law analysis and costing are discussed.

Performance Evaluation of Selected Combustion Gas Turbine Cogeneration Systems Based on First and Second-Law Analysis

1990 ◽  
Vol 112 (1) ◽  
pp. 117-121 ◽  
Author(s):  
F. F. Huang
Keyword(s):  
Performance Evaluation ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Decision Makers ◽  
Utilization Efficiency ◽  
Second Law ◽  
Pinch Point ◽  
Combustion Gas ◽  
Second Law Analysis ◽  
Industrial Gas Turbines

The thermodynamic performance of selected combustion gas turbine cogeneration systems has been studied based on first-law as well as second-law analysis. The effects of the pinch point used in the design of the heat recovery steam generator, and pressure of process steam on fuel-utilization efficiency (first-law efficiency), power-to-heat ratio, and second-law efficiency, are examined. Results for three systems using state-of-the-art industrial gas turbines show clearly that performance evaluation based on first-law efficiency alone is inadequate. Decision makers should find the methodology contained in this paper useful in the comparison and selection of cogeneration systems.

Improving Emission and Blow-Out Characteristics of Novel Natural Gas Low NOx Burners for Heavy Duty Gas Turbine

2019 ◽  
Author(s):  
Matteo Cerutti ◽  
Michele Roma ◽  
Alessio Picchi ◽  
Riccardo Becchi ◽  
Bruno Facchini
Keyword(s):  
Objective Function ◽  
Gas Turbine ◽  
Mathematical Formulation ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Design Parameters ◽  
Design Variables ◽  
Geometrical Features ◽  
Heavy Duty Gas Turbine ◽  
Operating Window

Abstract The development and the optimization of a novel dry low NOx burner may require several steps of improvement. The first step of the overall development process has been documented by authors in a previous paper and included an exhaustive experimental characterization of a set of novel geometries. The in-depth results analysis allowed to correlate the investigated design parameters to burner performances, discovering possible two-fold optimization paths. Recurrent verifications of the assumptions made to define prototypes design are considered a mandatory step to avoid significant deviation from the correct optimization path, which strongly depends on both objective function definition and selection of design variables. Concerning the objective function, a proper mathematical formulation was proposed in the previous work, which represented a balance between two apparently conflicting aspect like flame stability and low emissions. Concerning design variables, outcomes of the first test campaign have been used in the present work to define new burner geometries. Starting from a new baseline who has showed the widest low NOx operating window, additional geometrical features have been considered in this survey as potentially affecting flame stabilization. Thanks to the degree of freedom offered by DMLM technology, rapid prototyping of alternative geometries allowed to easily setup a new experimental plan for the second optimization step. Exploiting the same approach used in the first test campaign, new geometries have been tested in a single-cup test rig at gas turbine relevant operating conditions, showing Stable low-NOx operating windows have been evaluated throughout dedicated objective functions for all geometries and results showed lower NOx and CO emissions as a consequence of the newly introduced geometrical modifications. Moreover, the comparison with the estimates of the previous campaign proved the existence of the identified optimization path. Indeed, it furnished valid elements for further using of the proposed methodology for the improvement of emission and blow-out characteristics of novel burners and, more in general, for the development of a novel dry low NOx technology.

Second law analysis for optimal thermal design of radial fin geometry by convection

2007 ◽  
Vol 27 (8-9) ◽  
pp. 1363-1370 ◽  
Author(s):  
B.N. Taufiq ◽  
H.H. Masjuki ◽  
T.M.I. Mahlia ◽  
R. Saidur ◽  
M.S. Faizul ◽  
...  
Keyword(s):  
Thermal Design ◽  
Second Law ◽  
Second Law Analysis

scholarly journals Thermodynamical motivation of the Polish energy policy

2011 ◽  
Vol 33 (4) ◽  
pp. 3-21 ◽  
Author(s):  
Andrzej Ziębik
Keyword(s):  
Energy Policy ◽  
High Efficiency ◽  
Second Law Of Thermodynamics ◽  
Primary Energy ◽  
Point Of View ◽  
Second Law ◽  
Special Importance ◽  
Second Law Analysis ◽  
Transmission And Distribution ◽  
Exergy Losses

Abstract Basing on the first and second law of thermodynamics the fundamental trends in the Polish energy policy are analysed, including the aspects of environmental protection. The thermodynamical improvement of real processes (reduction of exergy losses) is the main way leading to an improvement of the effectivity of energy consumption. If the exergy loss is economically not justified, we have to do with an error from the viewpoint of the second law analysis. The paper contains a thermodynamical analysis of the ratio of final and primary energy, as well as the analysis of the thermo-ecological cost and index of sustainable development concerning primary energy. Analyses of thermo-ecological costs concerning electricity and centralized heat production have been also carried out. The effect of increasing the share of high-efficiency cogeneration has been analyzed, too. Attention has been paid to an improved efficiency of the transmission and distribution of electricity, which is of special importance from the viewpoint of the second law analysis. The improvement of the energy effectivity in industry was analyzed on the example of physical recuperation, being of special importance from the point of view of exergy analysis.

scholarly journals Steam Plant for Electricity Generation From Solid Urban Refuse With Gas-Turbine Blown Pressurized Fluidized Bed Combustion

1986 ◽  
Author(s):  
Enrico Sciubba
Keyword(s):  
Steam Turbine ◽  
Gas Turbine ◽  
Waste Heat ◽  
Point Of View ◽  
Second Law ◽  
Economic Plant ◽  
Fluidized Bed Combustion ◽  
Waste Heat Boiler ◽  
Reheat Steam ◽  
Pressurized Fluidized Bed Combustion

An innovative gas turbine/steam turbine coupled process is described and evaluated. The process consists of a gas turbine-driven PFBC of the recirculating type, in which urban refuse can be burnt with a minimum of preprocessing. The hot exhaust from the PFBC is then used in a waste-heat boiler to produce steam for a conventional reheat steam turbine powerplant. The proposed process is evaluated from a conventional First-Law (energy balance) point of view, and shown to have a higher limit efficiency than comparable existing cycles. A Second-Law (exergy-) analysis is then performed to show that the Second-Law efficiency of this coupled cycle is also higher than that of comparable cycles; this means that the proposed process effectively reduces the intrinsic irreversibilities in the energy-transfer subcycles. Finally, a conservative, conventional economic analysis is performed to compute the global economic plant parameters of engineering interest. The simple payback, among others, is shown to be in the range considered feasible for cogeneration cycles.

Second Law Analysis of a Combined Cycle With Integrated Compressor Inlet Air Cooling

2001 ◽  
Author(s):  
A. Razani ◽  
M. Patterson ◽  
K. J. Kim
Keyword(s):  
Combined Cycle ◽  
Second Law ◽  
Air Cooling ◽  
Refrigeration Cycle ◽  
Power Cycle ◽  
System Parameters ◽  
Second Law Analysis ◽  
Compressor Inlet ◽  
Environmental Air ◽  
Topping Cycle

Abstract A gas/ammonia combined cycle is proposed in which exhaust gases from a Brayton gas topping cycle are used to produce superheated ammonia in a Heat Recovery Ammonia Generator (HRAG). To increase the power of the gas turbine in the combined cycle, when the environmental air temperature is high, inlet air to the compressor is cooled in the evaporator of an ammonia refrigeration cycle added to the combined air/ammonia power cycle. In this integrated combined power cycle a small fraction of high-pressure ammonia liquid, from the exit of the ammonia pump, is used in the ammonia refrigeration cycle to cool the air. The second law analysis and optimization of the above combined cycle is presented. The effect of important system parameters on the irreversibility of components in the cycle and the exergy of exhaust streams are evaluated. Reasonable constraints for system components are assumed. The power and efficiency of the cycle are evaluated and their dependences on system parameters are presented.

Optimization of a Micro Gas Turbine Using Genetic Algorithm

2011 ◽  
Author(s):  
Maryam Pourhasanzadeh ◽  
Sajjad Bigham
Keyword(s):  
Genetic Algorithm ◽  
Combustion Chamber ◽  
Objective Function ◽  
Gas Turbine ◽  
Distributed Generation ◽  
Gas Turbines ◽  
Design Parameters ◽  
Micro Gas Turbine ◽  
Design Variables ◽  
Isentropic Efficiency

Distributed generation is an attractive way of producing energy, minimizing transport losses and enhancing energy efficiency. Micro gas turbines in distributed generation systems add other advantages such as low emissions and fuel flexibility. In the present work, a 100 kW micro gas turbine is considered. The optimization procedure is done by Genetic Algorithm method which is a new method in optimizing problems. The plant is comprised of an air compressor, recuperator, combustion chamber and gas turbine. The design Parameters of the plant, were chosen as: compressor pressure ratio, compressor isentropic efficiency, gas turbine isentropic efficiency, combustion chamber inlet temperature and the temperature of the combustion gas at the gas turbine inlet. In order to find the design parameters optimally, a thermo-economic approach has been followed. An objective function, representing the total cost of the plant in terms of dollar per second, was defined as the sum of the operating cost, related to the fuel consumption, the capital investment which stands for equipment purchase and maintenance cost. Subsequently, different parts of the objective function have been expressed in terms of design variables. Finally, the optimal values of design variables were obtained by minimizing the objective function using Genetic Algorithm code that is developed in Matlab software programming.

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