Exergy, Exergoeconomic and Exergoenvironomic Analyses of Selected Gas Turbine Power Plants in Nigeria

2014 ◽  
Author(s):  
Richard Olayiwola Fagbenle ◽  
Sunday Sam Adefila ◽  
Sunday Oyedepo ◽  
Moradeyo Odunfa
Keyword(s):  
Environmental Impact ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Co2 Emissions ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Energy Systems ◽  
Energy Utilization ◽  
Inlet Temperature ◽  
Exergy Destruction

Energy supply trends as well as environmental regulations and climate change issues have made it necessary to closely scrutinize the way energy is utilized. Efficient energy utilization thus requires paying more attention to accurate and advanced thermodynamic analysis of thermal systems. Hence, methods aimed at evaluating the performances of energy systems take into account the Energy, Environment and Economics. Therefore, the first and second law of thermodynamics combined with economics and environmental impact represents a very powerful tool for the systematic study and optimization of energy systems. In this study, a thermodynamic analysis of eleven selected gas turbine power plants in Nigeria was carried out using the first and second laws of thermodynamics, economic and environmental impact concepts. Exergetic, exergo-economic and exergo-environmental analyses were conducted using operating data obtained from the power plants to determine the exergy destruction and exergy efficiency of each major component of the gas turbine in each power plant. The exergy analysis confirmed that the combustion chamber is the most exergy destructive component compared to other cycle components as expected. The percentage exergy destruction in combustion chamber varied between 86.05 and 94.6%. Increasing the gas turbine inlet temperature (GTIT), the exergy destruction of this component can be reduced. Exergo-economic analysis showed that the cost of exergy destruction is high in the combustion chamber and by increasing the GTIT effectively decreases this cost. The exergy costing analysis revealed that the unit cost of electricity produced in the plants ranged from cents 1.88/kWh (₦2.99/kWh) to cents 5.65/kWh (₦8.98/kWh). Exergo-environmental analysis showed that the CO2 emissions varied between 100.18 to 408.78 kgCO2/MWh while cost rate of environmental impact varied from 40.18 $/h (N6, 388.62/h) to 276.97 $/h (N44, 038.23/h). The results further showed that CO2 emissions and cost of environmental impact decrease with increasing GTIT.

Performance evaluation of selected gas turbine power plants in Nigeria using energy and exergy methods

2015 ◽  
Vol 12 (2) ◽  
pp. 161-176 ◽  
Author(s):  
S.O. Oyedepo ◽  
R.O Fagbenle ◽  
S.S Adefila ◽  
M.M Alam
Keyword(s):  
Energy Loss ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Power Plants ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
Improvement Potential ◽  
Energy And Exergy ◽  
And Performance

This study presents thermodynamic analysis of the design and performance of eleven selected gas turbine power plants using the first and second laws of thermodynamics concepts. Energy and exergy analyses were conducted using operating data collected from the power plants to determine the energy loss and exergy destruction of each major component of the gas turbine plant. Energy analysis showed that the combustion chamber and the turbine are the components having the highest proportion of energy loss in the plants. Energy loss in combustion chamber and turbine varied from 33.31 to 39.95% and 30.83 to 35.24% respectively. The exergy analysis revealed that the combustion chamber is the most exergy destructive component compared to other cycle components. Exergy destruction in the combustion chamber varied from 86.05 to 94.67%. Combustion chamber has the highest exergy improvement potential which range from 30.21 to 88.86 MW. Also, its exergy efficiency is lower than that of other components studied, which is due to the high temperature difference between working fluid and burner temperature. Increasing gas turbine inlet temperature (GTIT), the exergy destruction of this component can be reduced.

BASIC POSITIONS OF THE ENTHALPY-ENTROPY METHODOLOGY OF THERMODYNAMIC ANALYSIS OF GAS TURBINE POWER PLANTS

2017 ◽  
Author(s):  
Gennadii Liubchik ◽  
◽  
Nataliia Fialko ◽  
Aboubakr Regragui ◽  
Nataliia Meranova ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Thermodynamic Parameters ◽  
Thermodynamic Analysis ◽  
Thermodynamic Modeling ◽  
Power Plants ◽  
Regression Equations ◽  
Thermal Entropy ◽  
Nodal Points ◽  
Computational Diagnostics

The basic positions of the enthalpy-entropy methodology of thermodynamic modeling of processes in gas turbine units (GTUs) and combined power plants on basis GTUs are presented. The main requirements and conditions of this methodology are formulated, they allows the construction of a sequential (without iterations) algorithm for the computational diagnostics of the thermodynamic parameters of the GTU cycle, which includes the calculation blocks for the compressor, combustion chamber, turbine, and exhaust tube of the GTU. The obtained regression equations are presented. The use of these equations simplifies of the procedure for evaluating the thermodynamic parameters of the components at the nodal points of the cycle. The advantages of the proposed methodology in comparison with the traditional thermal-entropy methodology are indicated.

Exergoeconomic analysis and performance assessment of selected gas turbine power plants

2015 ◽  
Vol 12 (3) ◽  
pp. 283-300 ◽  
Author(s):  
S.O. Oyedepo ◽  
R.O. Fagbenle ◽  
S.S. Adefila ◽  
Md. Mahbub Alam
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Power Plants ◽  
Exergy Analysis ◽  
Unit Cost ◽  
Exergy Destruction ◽  
Improvement Potential ◽  
And Performance ◽  
Exergoeconomic Analysis ◽  
The Cost

In this study, exergoeconomic analysis and performance evaluation of selected gas turbine power plants in Nigeria were carried out. The study was conducted using operating data obtained from the power plants to determine the exergy efficiency, exergy destruction, unit cost of electricity and cost of exergy destruction of the major components of a gas turbine engine in the selected power plants. The results of exergy analysis confirmed that the combustion chamber is the most exergy destructive component compared to other cycle components as expected. The total efficiency defects and overall exergetic efficiency of the selected power plants vary from 38.64 to 69.33% and 15.66 to 30.72% respectively. The exergy analysis further shows that the exergy improvement potential of the selected plants varies from 54.04 MW to 159.88 MW. The component with the highest exergy improvement potential is the combustion chamber and its value varies from 30.21 MW to 88.86 MW. The results of exergoeconomic analysis show that the combustion chamber has the greatest cost of exergy destruction compared to other components. Increasing the gas turbine inlet temperature (GTIT), both the exergy destruction and the cost of exergy destruction of this component were found to decrease. The results of this study revealed that an increase in the GTIT of about 200 K can lead to a reduction of about 29% in the cost of exergy destruction. From exergy costing analysis, the unit cost of electricity produced in the selected power plants varies from cents 1.99 /kWh (N3.16 /kWh) to cents 5.65 /kWh (N8.98 /kWh).

Thermodynamic modeling and Exergy Analysis of Gas Turbine Cycle for Different Boundary conditions

2015 ◽  
Vol 6 (2) ◽  
pp. 205 ◽  
Author(s):  
Lalatendu Pattanayak
Keyword(s):  
Ambient Temperature ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Exergy Analysis ◽  
Load Condition ◽  
Exergy Efficiency ◽  
Inlet Temperature ◽  
Exergy Destruction ◽  
And Performance ◽  
Topping Cycle

In this study an exergy analysis of 88.71 MW 13D2 gas turbine (GT) topping cycle is carried out. Exergy analysis based on second law was applied to the gas cycle and individual components through a modeling approach. The analysis shows that the highest exergy destruction occurs in the combustion chamber (CC). In addition, the effects of the gas turbine load and performance variations with ambient temperature, compression ratio and turbine inlet temperature (TIT) are investigated to analyse the change in system behavior. The analysis shows that the gas turbine is significantly affected by the ambient temperature which leads to a decrease in power output. The results of the load variation of the gas turbine show that a reduction in gas turbine load results in a decrease in the exergy efficiency of the cycle as well as all the components. The compressor has the largest exergy efficiency of 92.84% compared to the other component of the GT and combustion chamber is the highest source of exergy destruction of 109.89 MW at 100 % load condition. With increase in ambient temperature both exergy destruction rate and exergy efficiency decreases.

Thermodynamic Analysis and Optimization of IT-SOFC-Based Integrated Coal Gasification Fuel Cell Power Plants

2011 ◽  
Vol 8 (4) ◽  
Author(s):  
Matteo C. Romano ◽  
Stefano Campanari ◽  
Vincenzo Spallina ◽  
Giovanni Lozza
Keyword(s):  
Fuel Cell ◽  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Coal Gasification ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Utilization Factor ◽  
Best Available Technologies ◽  
Integrated Gasification

This work discusses the thermodynamic analysis of integrated gasification fuel cell plants, where a simple cycle gas turbine works in a hybrid cycle with a pressurized intermediate temperature–solid oxide fuel cell (SOFC), integrated with a coal gasification and syngas cleanup island and a bottoming steam cycle (reflecting the arrangement of integrated gasification combined cycle (IGCC) plants) to optimize heat recovery and maximize efficiency. This work addresses the optimization of the plant layout, discussing the effect of the SOFC fuel utilization factor and the possibility of a fuel bypass to increase the gas turbine total inlet temperature and reduce the plant expected investment costs. Moreover, a discussion of technological issues related to the feasibility of the connection among the plant high temperature components is carried out, presenting the effects of different limitations of the maximum temperatures reached by the plant piping. With the proposed plant configurations, which do not include—apart from the SOFC—any component far from the nowadays best available technologies, a net electric lower heating value efficiency approaching 52–54% was calculated, showing a remarkable increase with respect to state-of-the-art advanced IGCCs.

Exergoenvironomic modelling and performance assessment of selected gas turbine power plants

2016 ◽  
Vol 13 (2) ◽  
pp. 149-162
Author(s):  
Sunday Olayinka Oyedepo ◽  
Richard Olayiwola Fagbenle ◽  
Samuel Sunday Adefila ◽  
Md Mahbub Alam
Keyword(s):  
Environmental Impact ◽  
Gas Turbine ◽  
Environmental Impacts ◽  
Flow Rate ◽  
Power Plants ◽  
Inlet Temperature ◽  
Content Type ◽  
Total Cost ◽  
Sustainability Index ◽  
Cost Flow

Purpose This study aims to use an environomics method to assess the environmental impacts of selected gas turbine power plants in Nigeria. Design/methodology/approach In this study, exergoenvironomic analysis has been carried out to investigate the environmental impact of selected gas turbine power plants in Nigeria from an exergetic point of view. Findings The exergy analysis reveals that the combustion chamber is the most exergy destructive component compared to other cycle components. The exergy destruction of this component can be reduced by increasing gas turbine inlet temperature (GTIT). The results of the study show that thermodynamic inefficiency is responsible for the environmental impact associated with gas turbine components. The study further shows that CO2 emissions and cost of environmental impact decrease with increasing GTIT. Originality/value The exergo-environomic parameters computed in this study are CO2 emission in kg per MWh of electricity generated, depletion number, sustainability index, cost flow rate of environmental impacts (Ċenv) in $/h and total cost rates of products (ĊTot) in $/hr. For the period considered, the CO2 emissions for the selected plants vary from 100.18 to 408.78 kgCO2/MWhm, while cost flow rate of environmental impacts varies from $40.18 /h to $276.97 /h and the total cost rates of products vary from $2935.69/h to $12,232.84/h. The depletion number and sustainability index vary from 0.69 to 0.84 and 1.20 to 1.44, respectively.

Energy and Exergy Analysis of Gas Turbine – Fuel Cell Based Combined Cycle Power Plant

2011 ◽  
Author(s):  
M. Sreeramulu ◽  
A. V. S. S. K. S. Gupta ◽  
T. Srinivas
Keyword(s):  
Power Generation ◽  
Fuel Cell ◽  
Gas Turbine ◽  
Compression Ratio ◽  
Gas Turbines ◽  
System Modeling ◽  
Combined Cycle ◽  
Energy Utilization ◽  
Inlet Temperature ◽  
Exergy Destruction

The newer power generation systems are becoming more important for the society due to increase in demand for the electrical energy utilization and higher energy conversion efficiencies. Though it is not new, fuel cell technology is one of the promising systems for cleaner and competitive alternate power generation system. When the fuel cells are integrated with the gas turbines, the total thermal efficiency of the combined cycle can be obtained greater than 60%. This is appreciably better exergetic performance when compared to traditional gas turbine cycle. In this work, thermodynamic analysis of SOFC-GT combined system (2.898MW) has been carried out, to evaluate energy efficiency, exergy efficiency and exergy destruction of each component is calculated. The effect of compression ratio (rp), turbine inlet temperature (TIT), air fuel ratio and ambient temperature of air, on the performance of the system has been analyzed by adopting the different fuels. The outcome of the system modeling reveals that SOFC and combustion chamber are the main sources of exergy destruction. When the methane, natural gas and coal gas are used as fuels, at the optimum compression ratio 9, the total thermal efficiencies are found to be 63.3%, 62.12% and 61.02% respectively. The exergy efficiencies are obtained respectively as 60.85%, 59.16% and 60.06%.

Optimal Gas-Turbine Design for Hybrid Solar Power Plant Operation

2012 ◽  
Author(s):  
James Spelling ◽  
Björn Laumert ◽  
Torsten Fransson
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Power Plants ◽  
Solar Power ◽  
Pressure Ratio ◽  
Inlet Temperature ◽  
Electricity Cost ◽  
Conflicting Objectives ◽  
Dynamic Simulation Model ◽  
A Minor

A dynamic simulation model of a hybrid solar gas-turbine power plant has been developed, allowing determination of its thermodynamic and economic performance. In order to examine optimum gas-turbine designs for hybrid solar power plants, multi-objective thermoeconomic analysis has been performed, with two conflicting objectives: minimum levelized electricity costs and minimum specific CO2 emissions. Optimum cycle conditions: pressure-ratio, receiver temperature, turbine inlet temperature and flow rate, have been identified for a 15 MWe gas-turbine under different degrees of solarization. At moderate solar shares, the hybrid solar gas-turbine concept was shown to provide significant water and CO2 savings with only a minor increase in the levelized electricity cost.

FEATURES OF THE METHODOLOGY OF THERMODYNAMIC MODELING OF GAS TURBINE AND COMBINED ON THEIR BASIS POWER PLANTS

2017 ◽  
Author(s):  
Gennadii Liubchik ◽  
◽  
Nataliia Fialko ◽  
Aboubakr Regragui ◽  
Julii Sherenkovskii ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Thermodynamic Modeling ◽  
Power Plants ◽  
High Efficiency ◽  
Technical Facility

The article presents the enthalpy-entropy methodology of thermodynamic analysis of gas turbine and combined power plants on their basis, the results of testing the method on a real technical facility, proving its high efficiency.

Thermodynamic Analysis of Intercooled Gas-Steam Combined and Steam Injected Gas Turbine Power Plants

2004 ◽  
Author(s):  
R. Yadav ◽  
Sunil Kumar Jumhare ◽  
Pradeep Kumar ◽  
Samir Saraswati
Keyword(s):  
Beneficial Effect ◽  
Gas Turbine ◽  
Thermodynamic Analysis ◽  
Power Plants ◽  
Power Production ◽  
Specific Work ◽  
Surface Type ◽  
The Cost ◽  
Current Emphasis ◽  
Plant Efficiency

The current emphasis on the development of gas turbine related power plants such as combined and steam injected is on increasing the plant efficiency and specific work while minimizing the cost of power production per kW and emission. The present work deals with the thermodynamic analysis of intercooled (both surface and evaporative) gas/steam combined and steam injected cycle power plants. The intercooling has a beneficial effect on both plant efficiency and specific work if the optimum intercooling pressure is chosen between 3 and 4. The evaporative intercooler is superior to surface type with reference to plant efficiency and specific work.

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