Samuel Sunday Adefila

Exergy costing analysis and performance evaluation of selected gas turbine power plants

Abstract In this study, exergy costing analysis and performance evaluation of selected gas turbine power plants in Nigeria are carried out. The results of exergy analysis confirmed that the combustion chamber is the most exergy destructive component compared to other cycle components. The exergetic efficiency of the plants was found to depend significantly on a change in gas turbine inlet temperature (GTIT). The increase in exergetic efficiency with the increase in turbine inlet temperature is limited by turbine material temperature limit. This was observed from the plant efficiency defect curve. As the turbine inlet temperature increases, the plant efficiency defect decreases to minimum value at certain GTIT (1,200 K), after which it increases with GTIT. This shows degradation in performance of gas turbine plant at high turbine inlet temperature. Exergy costing analysis shows that the combustion chamber has the greatest cost of exergy destruction compared to other components. Increasing the GTIT, both the exergy destruction and the cost of exergy destruction of this component are found to decrease. Also, from exergy costing analysis, the unit cost of electricity produced in the power plants varies from cents 1.99/kWh (N3.16/kWh) to cents 5.65/kWh (N8.98/kWh).

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

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.

Exergoeconomic analysis and performance assessment of selected gas turbine power plants

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).

Exergoenvironomic modelling and performance assessment of selected gas turbine power plants

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

Performance evaluation and economic analysis of a gas turbine power plant in Nigeria

/h and total cost rates of products (ĊTot) in

Assessment of performance indices of selected gas turbine power plants in Nigeria

/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

Modelling and Assessment of Effect of Operation Parameters on Gas Turbine Power Plant Performance using First and Second Laws of Thermodynamics

40.18 /h to

Exergetic and exergoeconomic analysis of selected gas turbine power plants in Nigeria

276.97 /h and the total cost rates of products vary from

Assessment of effect of operation parameters on gas turbine power plant performance using first and second laws

2935.69/h to

MECHANICAL ENGINEERING | RESEARCH ARTICLE Exergy costing analysis and performance evaluation of selected gas turbine power plants

12,232.84/h. The depletion number and sustainability index vary from 0.69 to 0.84 and 1.20 to 1.44, respectively.