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

In this study, performance evaluation and economic analysis (in terms of power outage cost due to system downtime) of a gas turbine power plant in Nigeria have been carried out for the period 2001–2010. The thermal power station consists of nine gas turbine units with total capacity of 301 MW (9 � 31.5 MW). The study reveals that 64.3% of the installed capacity was available in the period. The percentage of shortfall of energy generated in the period ranged from 4.18% to 14.53% as against the acceptable value of 5–10%. The load factor of the plant is between 20.8% and 78.2% as against international best practice of 80%. The average availability of the plant for the period was about 64% as against industry best practice of 95%, while the average use factor was about 92%. The capacity factor of the plant ranged from 20.8% to 78.23% while the utilization factor ranged from 85.47% to 95.82%. For the ten years under review, there was energy generation loss of about 35.7% of expected energy generation of 26.411 TW h with consequent plant performance of 64.3%. The study further reveals that the 35.7% of generation loss resulted in revenue loss of about M$251 (approximately bN40). The simple performance indicator developed to evaluate the performance indices and outage cost for the station can also be applicable to other power stations in Nigeria and elsewhere. Measures to improve the performance indices of the plant have been suggested such as training of operation and maintenance (O & M) personnel regularly, improvement in O & M practices, proper spare parts inventory and improvement in general housekeeping of the plant. From technical point of view, performance of the plant can be improved by retrofitting with a gas turbine air inlet cooling system, heat recovery system or adding modifications (inter-cooling or regeneration) to the simple gas turbine units

Fatty Acids Composition of Three Different Vegetable Oils (Soybean Oil, Groundnut Oil and Coconut Oil) by High-Performance Liquid Chromatography

Edible vegetable oil were extracted from three sources; soyabean, groundnut and coconut. These oils were processed for fatty acid analysis using high performance liquid chromatography. Three saturated fatty acid were present. Palmitic acid; (C16;O) range from 2.092% in coconut oil to 4.756% in groundnut oil, stearic acid (C16;O) range from 1.496% in soya bean oil to 12.075% in groundnut oil. Monounsaturated fatty acid was also obtained. Oleric acid (C18:1) range from 8.584% in coconut oil to 12.722% in groundnut oil. Polyunsaturated (essential) fatty acid identified was linoleic acid (C18:2 Omega-6) at concentration ranges of 5.654% in soyabean oil to 9.198% in groundnut oil. The result showed that the three samples are good sources of two essential fatty acid (lauric and palmitric acid). The predominant component of soyabean oil and coconut oil was myristic acid (C14:O) (41.039% and 33.544% respectively). The highest fatty acid component of groundnut oil is lauric acid (C12:O) at 14.567%. Keywords: Soybean oil, Groundnut Oil, Coconut oil, Fatty acids, HPLC

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

In this study, modelling of gas turbine engine performance is carried out using thermodynamics relations. The model reveals that the influence of operation parameters such as compression ratio, turbine inlet temperature and ambient temperature has significant effect on the performance of gas turbine engine. Energy and exergy analyses were conducted to evaluate the performance of the selected power plant and to assess the effect of operation parameters on energy loss and exergy destruction in the plant. Energy analysis shows that the turbine has the highest proportion of energy loss (31.98%) in the plant. The exergy analysis results reveal that the combustion chamber is the most exergy destructive component compared to other cycle components. Thermal efficiency of the plant is as low as 36.68% while the total efficiency defect and overall exergetic efficiency of the power plant are 40.46 and 19.06%, respectively

Experimental performance of LPG refrigerant charges with varied concentration of TiO2 nano-lubricants in a domestic refrigerator

This article present an experimental investigation of varied mass charges of Liquefied Petroleum Gas (40 g, 50 g, 60 g and 70 g) enhanced with varied TiO2 nanoparticle/mineral oil concentrations (0.2 g/L, 0.4 g/L and 0.6 g/L nanolubricants) in a R134a compressor of a domestic refrigerator. Performance tests investigated at steady state included: pull down time, power consumption, compressor power input, cooling capacity and coefficient of performance (COP). Analysis was based on temperature and pressure readings obtained from appropriate gauges attached to the test rig. Refrigerant property characteristics were obtained using Ref-Prop NIST 9.0 software. Results obtained showed almost equal evaporator air temperatures and reduction in power consumption for all tested nano-lubricant concentrations except at 70 g charge of LPG using 0.6 g/L nano-lubricant. Furthermore, the lowest compressor power input was found to be 21 W and obtained using 70 g of LPG with either of 0.2 g/L or 0.4 g/L nano-lubricants. At 70 g of LPG using 0.6 g/L concentration of nano-lubricant, highest cooling capacity index of 65 W was obtained while the highest COP of 2.8 was obtained with 40 g charge of LPG using 0.4 g/L concentration of nanolubricant. In conclusion, LPG-TiO2 nano-lubricant mixture works safely and efficiently in domestic refrigerators without modification of capillary tube length, but requires adequate optimization

EXERGETIC AND EXERGOECONOMIC ANALYSIS OF SELECTED GAS TURBINE POWER PLANTS IN NIGERIA

Analysis of power generation systems is of scientific interest and also essential for the efficient utilization of energy resource. The most commonly used method for analysis of the energy conversion process is the first law of thermodynamics - especially for computation of work and heat exchanges as well as thermal efficiency. However, there is increasing interest in combined utilization of both the first and second laws, using such concepts as exergy and exergy destructions in order to evaluate the efficiency with which the available energy is utilized. In this study, a thermodynamic analysis and performance of eleven selected gas turbine power plants in Nigeria was carried out using the first and second laws of thermodynamics and economic concepts. Thermodynamic modelling of industrial gas turbines in power plant applications was performed using a computer code developed specifically for simulation purposes with the Matlab software. Exergetic and exergo-economic 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. Furthermore, the exergy efficiency of the combustion chamber is less than that of any other components of the gas turbines studied, which is due to the high temperature difference between working fluid and burner temperatures. The percentage exergy destruction in combustion chamber varied between 86.05 and 94.6%. In addition, it was found that by 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 that increasing the GTIT effectively decreases this cost. The exergy costing Analysis of power generation systems is of scientific interest and also essential for the efficient utilization of energy resource. The most commonly used method for analysis of the energy conversion process is the first law of thermodynamics - especially for computation of work and heat exchanges as well as thermal efficiency. However, there is increasing interest in combined utilization of both the first and second laws, using such concepts as exergy and exergy destructions in order to evaluate the efficiency with which the available energy is utilized. In this study, a thermodynamic analysis and performance of eleven selected gas turbine power plants in Nigeria was carried out using the first and second laws of thermodynamics and economic concepts. Thermodynamic modelling of industrial gas turbines in power plant applications was performed using a computer code developed specifically for simulation purposes with the Matlab software. Exergetic and exergo-economic 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. Furthermore, the exergy efficiency of the combustion chamber is less than that of any other components of the gas turbines studied, which is due to the high temperature difference between working fluid and burner temperatures. The percentage exergy destruction in combustion chamber varied between 86.05 and 94.6%. In addition, it was found that by 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 that increasing the GTIT effectively decreases this cost. The exergy costingAnalysis of power generation systems is of scientific interest and also essential for the efficient utilization of energy resource. The most commonly used method for analysis of the energy conversion process is the first law of thermodynamics - especially for computation of work and heat exchanges as well as thermal efficiency. However, there is increasing interest in combined utilization of both the first and second laws, using such concepts as exergy and exergy destructions in order to evaluate the efficiency with which the available energy is utilized. In this study, a thermodynamic analysis and performance of eleven selected gas turbine power plants in Nigeria was carried out using the first and second laws of thermodynamics and economic concepts. Thermodynamic modelling of industrial gas turbines in power plant applications was performed using a computer code developed specifically for simulation purposes with the Matlab software. Exergetic and exergo-economic 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. Furthermore, the exergy efficiency of the combustion chamber is less than that of any other components of the gas turbines studied, which is due to the high temperature difference between working fluid and burner temperatures. The percentage exergy destruction in combustion chamber varied between 86.05 and 94.6%. In addition, it was found that by 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 that increasing the GTIT effectively decreases this cost. The exergy costing analysis revealed that the unit cost of electricity produced in the plants ranged from 3.78 cents/kWh (N5.67/kWh) to 5.86 cents/kWh (N8.79/kWh). An examination of the effects of design parameters on exergy efficiency showed that an increase in the air compressor pressure ratio and GTIT increases the total exergy efficiency of the cycle

Thermal energy assessment of oil bean stalk as a novel additive to building ceilings

The thermal properties of oil bean stalk, an agro-waste, are inadequately studied; thus this research seeks to assess its property suitability as a prospective material for ceiling tile production. The material was cut to 50mm diameter with jig saw to fit into brass profile of the automatic Lee's disc thermal conductivity apparatus. This profile was also used to conduct the specific heat capacity test by employing the method of mixtures. The specific heat capacity, density, thermal conductivity, thermal resistivity, thermal diffusivity, thermal effusivity and cooling rate are 1563J/kgK, 158kg/m3, 0.12 Wm−1K−1, 8.68mKW−1, 4.86 x 10−7 m2s−1, 172.15 Jm−2K−1s−1/2 and 0.0014 °C/sec. The high energy values of specific heat and thermal effusivity shows the reluctance of the material to dissipate energy to the surrounding which approves it as a building material insulator. The values are within the class of insulating material required in building technology such as building ceiling tiles. This potential insulating material can be explored in the building industries as the material is readily available in the environment

Performance assessment of the firefighting personal protective tunic

Although there have been reported cases of rapid improvement in the research and development of materials used for the betterment of firefighting tunics in developed countries, however, in developing countries, especially in Nigeria, the dearth of such research and development has led to the loss of lives and properties on numerous occasions due to the use of substandard firefighting tunics when combating fire. Hence, it is necessary to carry out a performance assessment on the firefighting tunic available in Nigeria. The safety of the firefighters is important as it is only then that they can fully carry out their duties and tasks. Of all the products that make up a complete assemble of the firefighters’ Personal Protective Equipment (PPE), it is their personal protective tunic that was employed for this research. The city of Ota in Nigeria was used as a case study due to the high concentration of industries and teeming population which makes it a target for pipeline explosions amongst others. Having a single fire station in the city, a sample of the firefighters’ personal protective tunic was obtained and specified experiments were carried out to determine its thermophysical and elemental properties with a goal to understand its quality and standard. The research seeks to provide useful information to stakeholders in the firefighting industry on the standard of protective tunics used in fire stations

Thermal Emission and heat transfer characteristics of ceiling materials: a necessity

The investigation of the thermal insulation properties of ceiling materials in comparison to the heat transfer constituent is a necessity because materials recommended as building ceiling due to their excellent thermal insulation nature may not necessarily reflect their heat transfer nature. This will eventually give insight to all building stakeholders on factors to consider in ceiling design from initiation to final stage thereby yielding excellent and enviable building ceiling product

Asbestos-Free Aluminium Dross Brake Pad: A Mini Review

Asbestos-related materials are avoided due to cancer-causing asbestosis that is a health risk to users. A brake pad that is eco-friendly with the use of aluminium dross industrial waste and epoxy binder is therefore proposed. Various applications of aluminium dross have been explored by researchers with the view of reducing hazardous waste from the environment. Compressive strength, hardness, specific gravity, microstructural analysis, flame resistance, oil, and water absorption, and wear characteristics are significant tests carried out on the brake pad. Waste materials such as banana peel, bagasse, periwinkle shell, palm kernel shell, amongst others, were employed as common additives in the production of the brake pad. Exploring utilizing industrial and agro-waste in the development of a viable brake pad as an alternative to the existing brake pad is therefore reviewed

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)