An Economic Assessment Method of Gas Turbine Power Cycles by Means of Genetic Algorithms

2004 ◽  
Author(s):  
Alcides Codeceira Neto ◽  
Pericles Pilidis ◽  
Anestis I. Kalfas
Keyword(s):  
Genetic Algorithms ◽  
Power Plant ◽  
Performance Assessment ◽  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Assessment Method ◽  
Combined Cycle ◽  
Plant Performance ◽  
Exergy Method

The Performance assessment of power plants involves a large number of equations with many variables taking part in the whole calculation. The assessment method described here takes into account a process for optimising a conventional gas turbine combined cycle power plant from the point of view of power plant performance calculations and economic analysis. The process requires optimisation of the whole thermal power plant based on cost considerations. The performance assessment of power plants uses the exergy method and considers the overall plant exergetic efficiency and the exergy destruction in the various components of the plant. The exergy method highlights irreversibility within plant components, and it is of particular interest in this investigation. Generally, the optimisation procedure to determine an optimal solution for a problem considers constraints imposed to some variables and requires the use of an optimisation technique. This paper is precisely concerned with the use of Genetic Algorithms (GAs) as a recommended tool for applying the optimisation process of the whole power plant based on minimising costs of products. Genetic Algorithms (GAs) are adaptive methods which may be used to solve search and optimisation problems. They are based on the genetic processes of biological organisms and do not require complicated mathematical calculations like the evaluation of derivatives necessary to be considered in conventional optimisation techniques.

An Assessment Method of Power Plants Using Genetic Algorithms

2001 ◽  
Author(s):  
Alcides Codeceira Neto ◽  
Pericles Pilidis
Keyword(s):  
Genetic Algorithms ◽  
Performance Assessment ◽  
Power Plants ◽  
New Technologies ◽  
Thermal Power ◽  
Assessment Method ◽  
Combined Cycle ◽  
Exergetic Efficiency ◽  
Exergy Method ◽  
Plant Components

The performance assessment of power plants is a complex task, which involves many calculations. Increasing the number of plant components with the introduction of new technologies available in the international market, it increases the complexity of performance analysis of power cycles. The present paper describes a process for optimising a conventional gas turbine combined cycle power plant. In this paper the method of assessing thermal power plants takes into account the exergy method and carries out along with optimisation of the whole plant based on maximising overall plant exergetic efficiency and minimising energy loss rejected to the atmosphere. The performance assessment of power plants using the exergy method considers the overall plant exergetic efficiency and the exergy destruction in the various components of the plant. The exergy method highlights irreversibility within the plant components, and it is of particular interest in this investigation. Due to the large number of equations with many variables taking part in the whole calculation and also considering constraints imposed to some variables, a genetic algorithm is recommended as the optimisation tool for the assessment method. Genetic Algorithms are adaptive methods which may be used to solve search and optimisation problems. They are based on the genetic processes of biological organisms. Over many generations, natural populations evolve according to the principles of natural selection and “survival of the fittest”, first clearly stated by Charles Darwin in his book “The Origin of Species”. Genetic algorithms do not require complicate mathematical calculations like the evaluation of derivatives necessary to be considered in conventional optimisation techniques.

Development of Performance Deterioration Diagnosis Method for Gas Turbine Combined Cycle Power Plants

2010 ◽  
Author(s):  
Toru Takahashi ◽  
Eiichi Koda ◽  
Yoshinobu Nakao
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Power Plants ◽  
Thermal Power ◽  
Combined Cycle ◽  
Plant Performance ◽  
Maintenance Cost ◽  
Thermal Power Plants ◽  
Performance Deterioration

Recently, it is more necessary to maintain or improve the thermal efficiency of actual thermal power plants to reduce CO2 emission and energy consumption in the world, and it is also important to reduce the maintenance cost of commercial thermal power plants. Thus, it is crucial to investigate power plant performance deterioration factors and solve problems related to these factors promptly when the thermal efficiency decreases. However, it is difficult to understand the internal state of power plants sufficiently and to determine power plant performance deterioration factors only from operation data because actual thermal plants are composed of many components and are very complex systems. In particular, it is more difficult to understand performance deterioration in gas turbine combined cycle (GTCC) power plants than in steam power plants because the performance changes markedly in GTCC power plants depending on atmospheric conditions (temperature, pressure, humidity). In other words, when thermal efficiency changes, it is difficult to determine whether the cause is the change in external factors or that in the performance of the component. Therefore, we develop a method based on heat balance analysis to calculate the immeasurable quantity of state and the efficiency of each component in GTCC power plants, and to correct the performance of each component in a plant to a standard state using the performance function obtained from long-term operation data. Through the method, the analysis of the effects of deterioration factors on thermal efficiency becomes possible, and the performance of a plant can be simulated when the operation conditions are changed. Thus, we can determine the main factor that affects thermal efficiency using our method.

Repowering: An Option for Refurbishment of Old Thermal Power Plants in Latin-American Countries

2010 ◽  
Author(s):  
Washington Orlando Irrazabal Bohorquez ◽  
Joa˜o Roberto Barbosa ◽  
Luiz Augusto Horta Nogueira ◽  
Electo E. Silva Lora
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Steam Turbine ◽  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Rankine Cycle ◽  
Combined Cycle ◽  
Fuel Oil ◽  
Thermal Power Plants

The operational rules for the electricity markets in Latin America are changing at the same time that the electricity power plants are being subjected to stronger environmental restrictions, fierce competition and free market rules. This is forcing the conventional power plants owners to evaluate the operation of their power plants. Those thermal power plants were built between the 1960’s and the 1990’s. They are old and inefficient, therefore generating expensive electricity and polluting the environment. This study presents the repowering of thermal power plants based on the analysis of three basic concepts: the thermal configuration of the different technological solutions, the costs of the generated electricity and the environmental impact produced by the decrease of the pollutants generated during the electricity production. The case study for the present paper is an Ecuadorian 73 MWe power output steam power plant erected at the end of the 1970’s and has been operating continuously for over 30 years. Six repowering options are studied, focusing the increase of the installed capacity and thermal efficiency on the baseline case. Numerical simulations the seven thermal power plants are evaluated as follows: A. Modified Rankine cycle (73 MWe) with superheating and regeneration, one conventional boiler burning fuel oil and one old steam turbine. B. Fully-fired combined cycle (240 MWe) with two gas turbines burning natural gas, one recuperative boiler and one old steam turbine. C. Fully-fired combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. D. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler and one old steam turbine. The gas turbine has water injection in the combustion chamber. E. Fully-fired combined cycle (242 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners and one old steam turbine. The gas turbine has steam injection in the combustion chamber. F. Hybrid combined cycle (235 MWe) with one gas turbine burning natural gas, one recuperative boiler with supplementary burners, one old steam boiler burning natural gas and one old steam turbine. G. Hybrid combined cycle (235 MWe) with one gas turbine burning diesel fuel, one recuperative boiler with supplementary burners, one old steam boiler burning fuel oil and one old steam turbine. All the repowering models show higher efficiency when compared with the Rankine cycle [2, 5]. The thermal cycle efficiency is improved from 28% to 50%. The generated electricity costs are reduced to about 50% when the old power plant is converted to a combined cycle one. When a Rankine cycle power plant burning fuel oil is modified to combined cycle burning natural gas, the CO2 specific emissions by kWh are reduced by about 40%. It is concluded that upgrading older thermal power plants is often a cost-effective method for increasing the power output, improving efficiency and reducing emissions [2, 7].

An Expanded Cost of Electricity Model for Highly Flexible Power Plants

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
S. Can Gülen ◽  
Indrajit Mazumder
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Plant Performance ◽  
Cost Of Electricity ◽  
Renewable Power ◽  
Effective Performance ◽  
The Impact

Cost of electricity (COE) is the most widely used metric to quantify the cost-performance trade-off involved in comparative analysis of competing electric power generation technologies. Unfortunately, the currently accepted formulation of COE is only applicable to comparisons of power plant options with the same annual electric generation (kilowatt-hours) and the same technology as defined by reliability, availability, and operability. Such a formulation does not introduce a big error into the COE analysis when the objective is simply to compare two or more base-loaded power plants of the same technology (e.g., natural gas fired gas turbine simple or combined cycle, coal fired conventional boiler steam turbine, etc.) and the same (or nearly the same) capacity. However, comparing even the same technology class power plants, especially highly flexible advanced gas turbine combined cycle units with cyclic duties, comprising a high number of daily starts and stops in addition to emissions-compliant low-load operation to accommodate the intermittent and uncertain load regimes of renewable power generation (mainly wind and solar) requires a significant overhaul of the basic COE formula. This paper develops an expanded COE formulation by incorporating crucial power plant operability and maintainability characteristics such as reliability, unrecoverable degradation, and maintenance factors as well as emissions into the mix. The core impact of duty cycle on the plant performance is handled via effective output and efficiency utilizing basic performance correction curves. The impact of plant start and load ramps on the effective performance parameters is included. Differences in reliability and total annual energy generation are handled via energy and capacity replacement terms. The resulting expanded formula, while rigorous in development and content, is still simple enough for most feasibility study type of applications. Sample calculations clearly reveal that inclusion (or omission) of one or more of these factors in the COE evaluation, however, can dramatically swing the answer from one extreme to the other in some cases.

Development of a Combined Cycle Gas Turbine/Steam Plant for Training Marine and Power Engineers

2007 ◽  
Author(s):  
W. Peter Sarnacki ◽  
Richard Kimball ◽  
Barbara Fleck
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Power Industry ◽  
Combined Cycle ◽  
Plant Performance ◽  
Engineering Programs ◽  
Hands On ◽  
Steam Plant

The integration of micro turbine engines into the engineering programs offered at Maine Maritime Academy (MMA) has created a dynamic, hands-on approach to learning the theoretical and operational characteristics of a turbojet engine. Maine Maritime Academy is a fully accredited college of Engineering, Science and International Business located on the coast of Maine and has over 850 undergraduate students. The majority of the students are enrolled in one of five majors offered at the college in the Engineering Department. MMA already utilizes gas turbines and steam plants as part of the core engineering training with fully operational turbines and steam plant laboratories. As background, this paper will overview the unique hands-on nature of the engineering programs offered at the institution with a focus of implementation of a micro gas turbine trainer into all engineering majors taught at the college. The training demonstrates the effectiveness of a working gas turbine to translate theory into practical applications and real world conditions found in the operation of a combustion turbine. This paper presents the efforts of developing a combined cycle power plant for training engineers in the operation and performance of such a plant. Combined cycle power plants are common in the power industry due to their high thermal efficiencies. As gas turbines/electric power plants become implemented into marine applications, it is expected that combined cycle plants will follow. Maine Maritime Academy has a focus on training engineers for the marine and stationary power industry. The trainer described in this paper is intended to prepare engineers in the design and operation of this type of plant, as well as serve as a research platform for operational and technical study in plant performance. This work describes efforts to combine these laboratory resources into an operating combined cycle plant. Specifically, we present efforts to integrate a commercially available, 65 kW gas turbine generator system with our existing steam plant. The paper reviews the design and analysis of the system to produce a 78 kW power plant that approaches 35% thermal efficiency. The functional operation of the plant as a trainer is presented as the plant is designed to operate with the same basic functionality and control as a larger commercial plant.

Trial Operation Results of the Fully-Fired Combined Cycle Generating Plants in Chita

1995 ◽  
Author(s):  
T. Mita ◽  
N. Ando ◽  
A. Kawauchi ◽  
K. Morikawa
Keyword(s):  
Power Plant ◽  
Electric Power ◽  
Gas Turbine ◽  
Power Plants ◽  
Thermal Power ◽  
Good Condition ◽  
Combined Cycle ◽  
Thermal Power Plants ◽  
Total Plant ◽  
Operation Results

A fully-fired combined cycle power plant (FFCCPP) combines a steam thermal power plant with a gas turbine. Hot exhaust gases fed from the gas turbine are used as combustion air for the boiler, thus increasing total plant output and efficiency. An unusually hot spell in Japan in the summer of 1990 brought about such a rapid surge in power demand for air conditioning so that all electric power companies registered record highs in consumption. This promoted Chubu Electric Power Co. to decide to add a 154-MW gas turbine to each of its six existing steam thermal power plants (four 700-MW and two 375-MW units), thus repowering their system into an FFCCPP. Construction work began in 1992. In September, 1994, two 700-MW steam thermal power plants (Chita Thermal Power Plant’s No. 6 unit and Chita Second Thermal Power Plant’s No. 1 unit) were modified into FFCCPPs, which then began operating in a trouble-free manner. This paper reports the characteristics and test-run results of the above two plants, which have been operating in good condition as the largest-capacity FFCCPPs in the world.

Assessment of Gas Turbine and Combined Cycle Power Plant Performance Degradation

2011 ◽  
Author(s):  
Nina Hepperle ◽  
Dirk Therkorn ◽  
Ernst Schneider ◽  
Stephan Staudacher
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Heat Rate ◽  
Performance Degradation ◽  
Empirical Method ◽  
Combined Cycle ◽  
Performance Data ◽  
Plant Performance ◽  
Water Steam

Recoverable and non-recoverable performance degradation has a significant impact on power plant revenues. A more in depth understanding and quantification of recoverable degradation enables operators to optimize plant operation. OEM degradation curves represent usually non-recoverable degradation, but actual power output and heat rate is affected by both, recoverable and non-recoverable degradation. This paper presents an empirical method to correct longterm performance data of gas turbine and combined cycle power plants for recoverable degradation. Performance degradation can be assessed with standard plant instrumentation data, which has to be systematically stored, reduced, corrected and analyzed. Recoverable degradation includes mainly compressor and air inlet filter fouling, but also instrumentation degradation such as condensate in pressure sensing lines, condenser or bypass valve leakages. The presented correction method includes corrections of these effects for gas turbine and water steam cycle components. Applying the corrections on longterm operating data enables staff to assess the non-recoverable performance degradation any time. It can also be used to predict recovery potential of maintenance activities like compressor washings, instrumentation calibration or leakage repair. The presented correction methods are validated with long-term performance data of several power plants. It is shown that the degradation rate is site-specific and influenced by boundary conditions, which have to be considered for degradation assessments.

scholarly journals Comparative Assessment of Thermal Power Systems Performance Under Uncertainty

2018 ◽  
Vol 3 (7) ◽  
pp. 50
Author(s):  
Anthony Kpegele Le-ol ◽  
Sidum Adumene ◽  
Kenneth Israel
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Economic Performance ◽  
Return On Investment ◽  
Power Plants ◽  
Net Present Value ◽  
Thermal Power ◽  
Energy System ◽  
Combined Cycle ◽  
Operating Conditions

This work presents a comparative analysis of the thermo-economic performance of a simple, retrofitted and built-in combined cycle power plants within the Delta. The data were obtained from a 25MW gas turbine plant-based engine, retrofitted and MATLAB software was used to model the thermodynamic performance of the plants. The economic prediction of the plants was done using a developed net present value(NPV), internal rate of return (IRR), cost of investment (COR) and payback period (PBP).  The economic concept for plants performance was analysed under uncertainty constraints of energy need, operating conditions, energy cost and energy supply variability. Three plants configuration; simple gas turbine (SGT), retrofitted combined cycle (RCC) and Built-in combined cycle (BCC) was analysed based on these economic performance indicators. The three configurations show a positive NPV, PBP and IRR, with the BCC showing the optimum return on investment. Although the RCC show minimum initial cost on investment compare to BCC, the BCC demonstrates greater overall return with an NPV of $30,755,454.18, IRR of 17.1% and PBP of 6.3years for the period of 20years. The analysis shows cash flow of 34.1% and 52.6% for the RCC and BCC respectively. The result also showed that the plant performs better at a lower ambient temperature and higher relative humidity with a higher return on investment. This research provides great insight into the thermo-economic analysis, and benefits of combined cycle power plant and will aid energy system investors on the choice of the power plant for power generation in the Niger Delta.

Application of On-Line Optimization Technology to Plant Operation

2000 ◽  
Author(s):  
Rodney R. Gay
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Heat Rate ◽  
Combined Cycle ◽  
Plant Performance ◽  
Plant Operation ◽  
Budget Analysis ◽  
On Line

Traditionally optimization has been thought of as a technology to set power plant controllable parameters (i.e. gas turbine power levels, duct burner fuel flows, auxiliary boiler fuel flows or bypass/letdown flows) so as to maximize plant operations. However, there are additional applications of optimizer technology that may be even more beneficial than simply finding the best control settings for current operation. Most smaller, simpler power plants (such as a single gas turbine in combined cycle operation) perceive little need for on-line optimization, but in fact could benefit significantly from the application of optimizer technology. An optimizer must contain a mathematical model of the power plant performance and of the economic revenue and cost streams associated with the plant. This model can be exercised in the “what-if” mode to supply valuable on-line information to the plant operators. The following quantities can be calculated: Target Heat Rate Correction of Current Plant Operation to Guarantee Conditions Current Power Generation Capacity (Availability) Average Cost of a Megawatt Produced Cost of Last Megawatt Cost of Process Steam Produced Cost of Last Pound of Process Steam Heat Rate Increment Due to Load Change Prediction of Future Power Generation Capability (24 Hour Prediction) Prediction of Future Fuel Consumption (24 Hour Prediction) Impact of Equipment Operational Constraints Impact of Maintenance Actions Plant Budget Analysis Comparison of Various Operational Strategies Over Time Evaluation of Plant Upgrades The paper describes examples of optimizer applications other than the on-line computation of control setting that have provided benefit to plant operators. Actual plant data will be used to illustrate the examples.

An Expanded Cost of Electricity Model for Highly Flexible Power Plants

2012 ◽  
Author(s):  
S. Can Gülen ◽  
Indrajit Mazumder
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Combined Cycle ◽  
Plant Performance ◽  
Cost Of Electricity ◽  
Renewable Power ◽  
Effective Performance ◽  
The Impact

Cost of electricity (COE) is the most widely used metric to quantify the cost-performance trade-off involved in comparative analysis of competing electric power generation technologies. Unfortunately, the currently accepted formulation of COE is only applicable to comparisons of power plant options with the same annual electric generation (kilowatt-hours) and same technology as defined by reliability, availability and operability. Such a formulation does not introduce a big error into the COE analysis when the objective is simply to compare two or more baseloaded power plants of the same technology (e.g., natural gas fired gas turbine simple or combined cycle, coal fired conventional boiler steam turbine, etc.) and the same (or nearly the same) capacity. However, comparing even the same technology class power plants, especially highly flexible advanced gas turbine combined cycle units with cyclic duties, comprising a high number of daily starts and stops in addition to emissions-compliant low-load operation to accommodate the intermittent and uncertain load regimes of renewable power generation (mainly wind and solar) requires a significant overhaul of the basic COE formula. This paper develops an expanded COE formulation by incorporating crucial power plant operability and maintainability characteristics such as reliability, unrecoverable degradation, and maintenance factors as well as emissions into the mix. The core impact of duty cycle on the plant performance is handled via effective output and efficiency utilizing basic performance correction curves. The impact of plant start and load ramps on the effective performance parameters is included. Differences in reliability and total annual energy generation are handled via energy and capacity replacement terms. The resulting expanded formula, while rigorous in development and content, is still simple enough for most feasibility study type of applications. Sample calculations clearly reveal that inclusion (or omission) of one or more of these factors in the COE evaluation, however, can dramatically swing the answer from one extreme to the other in some cases.

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