In this study, the typical meteorological year (TMY) data for six locations representing the six ... more In this study, the typical meteorological year (TMY) data for six locations representing the six geopolitical zones in Nigeria were generated and analyzed using the Sandia method. The analysis shows that seasonal variations exist in all the selected locations indicating two distinct seasons: the dry and wet seasons with varying lengths from north to south of the country. Due to its high global radiation levels (21–25 MJ/m2/d), the North is a desirable location for solar-thermal systems. In addition, the high monthly mean temperature variations (~18°C), low relative humidity (RHM) (15%) and constant wind speeds (4 m/s) experienced in the first 3 months of the year aid the installation of wind energy systems and the application of evaporative cooling techniques that reduce the thermal load and energy consumption of buildings. On the other side, the high RHM (80%) and mediocre radiation values derived almost throughout the year in the Southwest, Southeast and South–south regions discou...
The aim of this study was to review the significant of waste heat recovery technologies as means ... more The aim of this study was to review the significant of waste heat recovery technologies as means of achieving sustainable energy development. Most developing nations of the World are faced with the enormous release of industrial waste heat of low temperature grade to the environment. Unlike material waste that is clearly visible, waste heat can be difficult to identify and evaluate both in terms of quantity and quality. Hence, understanding the availability of waste heat, and the ability to recover it, offer great opportunity to reduce energy costs and associated environmental impacts. Utilizing low-grade energy from waste heat sources is considered to offer a significant contribution to improving overall energy efficiency in the energy-intensive industrial sectors. The concept of industrial waste heat is explained, potential sources of waste heat from industries are identified, and the technologies available for waste heat recovery are presented in this study. From the review study...
International Journal of Advanced Thermofluid Research, 2018
In this work, the thermodynamic performance of a domestic refrigerator was experimentally studied... more In this work, the thermodynamic performance of a domestic refrigerator was experimentally studied by simultaneously varying the refrigerant charge (mr) and the capillary tube length (L). The potential of replacing R12 by R600a was also investigated. The test rig for the experiment was a vapor compression refrigerator designed to work with R12. The enthalpy of the refrigerants R600a and R12 for each data set for the experimental conditions were obtained by using REFPROP software (version 9.0). The results show that the design temperature of -120C (according to ISO - 8187 standard) and pull – down time of 135 minutes are achieved by using 60g of R600a with L= 1.2m and 1.5m. For R12, the design temperature is achieved at pull – down time of 165 minutes with mr = 40g and L = 0.9m. The appropriate combination of L and mr for R600a to be used as a drop-in refrigerant for R12 is found to be 1.5m and 60g on the basis of power consumption per day, pull-down time and COP, whereas by consideri...
Analysis of power generation systems is of scientific interest and also essential for the efficie... more 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 con...
In this study, modelling of gas turbine engine performance is carried out using thermodynamics re... more 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.
Electricity is one of the most important invention of Man. It powers the economy and everything i... more Electricity is one of the most important invention of Man. It powers the economy and everything in a Nation. This work seeks to carryout a critical review of Nigeria’s energy crisis. A PricewaterhouseCoopers, PwC reports asserts that Nigeria still ranks 2nd worst in the global electricity access charts; a significant portion of electricity is generated from private generators at a higher cost of NGN 120/kWh while grid-based cost NGN 4-5/kWh; more than 50% Nigerians do not have access to electricity, however amongst the other 50% who have access, experience intermittent power supply; 5 - 6 times increase in electricity consumption required to match peer countries with similar GDP per capital; 25 % of potential energy reaches the end-user: Structural inefficiencies across the power value chain prevent electricity from reaching end-users. This work sets out to chronicle Nigeria’s energy crisis: its challenges and prospects. Results from various reviews show that the major issue plaguin...
Selection and peer-review under responsibility of the scientific committee of the 11th Int. Conf.... more Selection and peer-review under responsibility of the scientific committee of the 11th Int. Conf. on Applied Energy (ICAE2019).
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
International Journal of Environment and Sustainable Development, 2019
In Nigeria, high and outrageous energy cost constitutes a serious challenge to all aspects of the... more In Nigeria, high and outrageous energy cost constitutes a serious challenge to all aspects of the economy. And this has been a subject of concern in the country over a period of time. A dependable and renewable energy source is of utmost desire to strengthen the nation's economy and this urgent need cannot be overlooked. As a result of the erratic and expensive power supply to the national grid, it has become ultimately necessary to search for other inexpensive sources of energy to meet the ever increasing energy needs for rural and urban dwellers. In view of the above energy situation in Nigeria, this paper aimed at carrying out a comprehensive review on bioenergy technology option as a pathway to achieving sustainable energy development in the country. The potential, current progressive stages, and prospects of bioenergy conversion techniques, in the Nigeria context, are discussed. The barriers to bioenergy technology development in Nigeria with possible solutions are also presented.
World Review of Science, Technology and Sustainable Development, 2019
Gas and oil-fired furnaces require air blower and stirring mechanism to produce homogeneous metal... more Gas and oil-fired furnaces require air blower and stirring mechanism to produce homogeneous metal matrix, alloyed metals and metallic composites. Both the blower and the stirrer require electric power that is not reliable in some urban areas and non-available in some rural communities in sub-Saharan countries. In this paper, a 20 kg oil-fired tilting furnace for melting iron, gold, aluminium, lead, magnesium, copper, tin et cetera and also used to produce metal matrix composites through liquid metallurgy routes, is designed for off-grid locations. Photovoltaic system specification of 250 W solar panel, 20A charge controller, 300 AH deep cycle battery and 1,400 W inverter were used to provide electric power to the air blower and mixing motor of the tilting furnace. With this arrangement, this versatile tilting furnace could be used in cottage industry without electric mains by small and medium-scale enterprises (SMEs), thus reducing unemployment among the populace and reduction of emission products into the atmosphere.
This paper presents technical and economic assessment of a hybrid energy system for electricity g... more This paper presents technical and economic assessment of a hybrid energy system for electricity generation in rural communities in the six geopolitical zones of Nigeria. The study was based on a 500 rural household model having an electric load of 493 kWh per day. To simulate long-term continuous implementation of the hybrid system, 21 years (1992 – 2012) hourly mean global solar radiation and wind speed data for the selected sites were used. The mean annual wind speed and solar radiation for the locations ranged from 2.31 m/s for Warri to 3.52 m/ s for Maiduguri and 4.53 kWh/m2 for Warri to 5.92 kWh/m2 for Maiduguri, respectively. These weather data were used for simulation with the Micro-power Optimization Model software HOMER. From the optimum results of the hybrid system,Warri has the highest NPC and COE of $2,441,222 and $0.721/kWh, respectively while Maiduguri has the least NPC and COE of $2,225,387 and $0.658/kWh, respectively for the 21 years project lifespan. The high value...
International Journal of Energy for a Clean Environment, 2017
Refrigeration plays a signifi cant role in domestic, industrial, commercial, and health sectors f... more Refrigeration plays a signifi cant role in domestic, industrial, commercial, and health sectors for comfort, food storage, medical applications, etc. There are innumerable applications of such systems, and they are the major consumer of electricity around the world (Anand and Tyagi, 2012; Rasti et al., 2012). The high energy consumption by refrigeration systems is due to the large amounts of units being used and also to
European Journal of Sustainable Development Research, 2018
In Nigeria, access to reliable and stable supply of electricity is a major challenge for both the... more In Nigeria, access to reliable and stable supply of electricity is a major challenge for both the urban and rural dwellers. In this study, comprehensive review of accessibility to clean and modern energy in Nigeria has been carried out. Also, this paper examines the potential of renewable energy (RE) resources in Nigeria that can be harnessed for continuous energy supply and the government's efforts to ensure RE's sustainability. Nigeria is endowed with abundant energy resources but the existing electric energy infrastructures are unable to meet the energy demands of teeming population. There is imbalance in energy supply and demand in the country. Over the period from 2000 to 2014, there was an average of about 2.35 billion kWh of energy gap between energy production and energy consumption. The highest electricity consumption per capita recorded so far was 156 kWh in 2012. This makes Nigeria one of the country with the lowest electricity consumption on per capita basis in the world. In order to improve access to clean energy supply and achieve sustainable development, this paper pin points the significance of decentralized renewable energy systems and needs for the government to review the policies on renewable energy development in the country.
American Journal of Engineering and Applied Sciences, 2017
In this study, modelling of gas turbine engine performance is carried out using thermodynamics re... more 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.
In this study, exergy costing analysis and performance evaluation of selected gas turbine power p... more 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).
This study presents comprehensive thermoeconomic and thermoenvironomic modeling and analysis of s... more This study presents comprehensive thermoeconomic and thermoenvironomic modeling and analysis of selected gas turbine power plants in Nigeria using the first and second laws of thermodynamics (exergy) concept. Exergetic analysis was 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 results of the study showed that the combustion chamber (CC) is the most exergy destructive component compared to other cycle components. The percentage of exergy destruction in CC varies between 86.05% and 94.6%. By increasing the gas turbine inlet temperature (GTIT), the exergy destruction of this component can be reduced. The total exergy improvement potential of the selected plants varies from 54.04 to 159.88 MW. The component with the highest exergy improvement potential is the CC, which has the value that varies from 30.21 to 88.86 MW. Thermoeconomic analysis showed that the cost of exergy destruction is high in the CC, and an increase in the GTIT effectively decreases this cost. The exergy costing analysis revealed that the unit cost of electricity produced in the plants ranged from cents 1.99/kWh (N3.16/ kWh) to cents 5.65 /kWh (N8.98/kWh). Thermoenvironomic analysis showed that the CO 2 emissions varied between 100.18 and 408.78 kg CO 2 /MWh, while cost rate of environmental impact varied from 40.18 $/h (6, 388.62 N/h) to 276.97 $/h (44, 038. 23 N/h). The results further showed that CO 2 emissions and cost of environmental impact decrease with increasing GTIT. The sustainability index increase with increasing GTIT. Finally, this study will assist efforts to understand the thermodynamic losses in the gas turbine cycle, and to improve efficiency as well as provide future recommendations for better performance, sustainability, and lessening environmental impact of power plant.
This study presents thermodynamic analysis of the design and performance of eleven selected gas t... more 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 compo...
In this study, the experimental analysis of the performance of vapor absorption system was develo... more In this study, the experimental analysis of the performance of vapor absorption system was developed and developed. The influence of generator, evaporator and condenser's temperatures on the system performance was studied using gas burner as source of energy, ammonia-water combination as working fluid and energy equations as governing equations for the work. There was variation in the results when compared with the earlier worker who used kerosene burner as source of energy and ammonia-water combination. Result of this study shows that if higher cooling capacity and also lower evaporator`s temperature are desired from the system, generator`s temperature should be increased considerably. Also the combination of an analyzer, rectifier and heat exchanger would produce better COP of the System.
In this study, performance assessment of selected gas turbine power plants in Nigeria was evaluat... more In this study, performance assessment of selected gas turbine power plants in Nigeria was evaluated using performance indices. The results of the study showed that for the period under review (2006-2010), the percentage shortfalls from the target energy in the selected power plants range from 26.33% to 86.61% as against the acceptable value of 5-10%. The capacity factor of the selected power plants varies from 16.88% to 73.67% as against the international value of 50-80%. The plant use factor varies from 45.89% to 97.03% and the utilization factor varies from 6.31% to 93.074% as against the international best practice of over 95%. From this result, it can be concluded that the generating units were underutilized. This is due to inadequate routine maintenance and equipment fault development. The analyses of reliability indicators revealed that the mean time between failures varies from 5.42 to 378.44 h, the mean time to repair varies from 18.3 to 153.88 h and the plant availability varies from 12.86% to 91.31% as against the Institute of Electrical and Electronics Engineers recommended standard of 99.9%. Evaluation of operating figures of the selected power plants revealed that starting reliability (SR) and operating reliability vary from 71.95% to 93.9% and 5.33% to 55%, respectively. The SR of the selected power plants is low in value compared with standard value of 99.9%. The statistical analysis carried out on plant availability revealed that at 95% confidence level; there is a significant difference in availability of the selected power plants. This indicates differences in their systems installation, operation and maintenance. The performance indicator developed to evaluate the performance indices for the selected stations can also be applicable to other power stations in Nigeria and elsewhere. Measures to improve the performance indices of the plants have been suggested in this paper.
Preventive Maintenance Programme consists of actions that improve the condition of system element... more Preventive Maintenance Programme consists of actions that improve the condition of system elements for performance optimization and aversion of unintended system failure or collapse. It involves inspection, servicing, repairing or replacing physical components of machineries, plant and equipment by following the prescribed schedule. It is commonly agreed nowadays that preventive maintenance programme can be very successful in improving equipment reliability while minimizing maintenance related costs. The availability of a complex system, such as steam turbine power plant is strongly associated with its parts reliability and maintenance policy. That policy not only has influence on the parts' repair time but also on the parts' reliability affecting the system integrity, degradation and availability. The objective of this paper is to study the effects of Preventive Maintenance Programme (PMP) implementation on the performance of the Egbin 1320 MW thermal power plant in Nigeria. This paper considers the reliability and availability of the 6 × 220 MW steam turbine units installed in the power station. The reliability and availability of the turbines are computed based on a five-year failure database. The availability analysis of available data from 2005 to 2009 shows different results for each unit and variation in availability for different year: availability of unit1 varies between 59.11% to 91.76%; unit 2, 64.02% to 94.53%; unit 3, 28.79% to 91.57%; unit 4, 80.31% to 92.76% and unit 5, 73.38% to 87.76%. Unit 6 was out of service for the past 2 to 3 years. This indicates differences in their systems installation maintenance and operation.
In this study, the typical meteorological year (TMY) data for six locations representing the six ... more In this study, the typical meteorological year (TMY) data for six locations representing the six geopolitical zones in Nigeria were generated and analyzed using the Sandia method. The analysis shows that seasonal variations exist in all the selected locations indicating two distinct seasons: the dry and wet seasons with varying lengths from north to south of the country. Due to its high global radiation levels (21–25 MJ/m2/d), the North is a desirable location for solar-thermal systems. In addition, the high monthly mean temperature variations (~18°C), low relative humidity (RHM) (15%) and constant wind speeds (4 m/s) experienced in the first 3 months of the year aid the installation of wind energy systems and the application of evaporative cooling techniques that reduce the thermal load and energy consumption of buildings. On the other side, the high RHM (80%) and mediocre radiation values derived almost throughout the year in the Southwest, Southeast and South–south regions discou...
The aim of this study was to review the significant of waste heat recovery technologies as means ... more The aim of this study was to review the significant of waste heat recovery technologies as means of achieving sustainable energy development. Most developing nations of the World are faced with the enormous release of industrial waste heat of low temperature grade to the environment. Unlike material waste that is clearly visible, waste heat can be difficult to identify and evaluate both in terms of quantity and quality. Hence, understanding the availability of waste heat, and the ability to recover it, offer great opportunity to reduce energy costs and associated environmental impacts. Utilizing low-grade energy from waste heat sources is considered to offer a significant contribution to improving overall energy efficiency in the energy-intensive industrial sectors. The concept of industrial waste heat is explained, potential sources of waste heat from industries are identified, and the technologies available for waste heat recovery are presented in this study. From the review study...
International Journal of Advanced Thermofluid Research, 2018
In this work, the thermodynamic performance of a domestic refrigerator was experimentally studied... more In this work, the thermodynamic performance of a domestic refrigerator was experimentally studied by simultaneously varying the refrigerant charge (mr) and the capillary tube length (L). The potential of replacing R12 by R600a was also investigated. The test rig for the experiment was a vapor compression refrigerator designed to work with R12. The enthalpy of the refrigerants R600a and R12 for each data set for the experimental conditions were obtained by using REFPROP software (version 9.0). The results show that the design temperature of -120C (according to ISO - 8187 standard) and pull – down time of 135 minutes are achieved by using 60g of R600a with L= 1.2m and 1.5m. For R12, the design temperature is achieved at pull – down time of 165 minutes with mr = 40g and L = 0.9m. The appropriate combination of L and mr for R600a to be used as a drop-in refrigerant for R12 is found to be 1.5m and 60g on the basis of power consumption per day, pull-down time and COP, whereas by consideri...
Analysis of power generation systems is of scientific interest and also essential for the efficie... more 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 con...
In this study, modelling of gas turbine engine performance is carried out using thermodynamics re... more 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.
Electricity is one of the most important invention of Man. It powers the economy and everything i... more Electricity is one of the most important invention of Man. It powers the economy and everything in a Nation. This work seeks to carryout a critical review of Nigeria’s energy crisis. A PricewaterhouseCoopers, PwC reports asserts that Nigeria still ranks 2nd worst in the global electricity access charts; a significant portion of electricity is generated from private generators at a higher cost of NGN 120/kWh while grid-based cost NGN 4-5/kWh; more than 50% Nigerians do not have access to electricity, however amongst the other 50% who have access, experience intermittent power supply; 5 - 6 times increase in electricity consumption required to match peer countries with similar GDP per capital; 25 % of potential energy reaches the end-user: Structural inefficiencies across the power value chain prevent electricity from reaching end-users. This work sets out to chronicle Nigeria’s energy crisis: its challenges and prospects. Results from various reviews show that the major issue plaguin...
Selection and peer-review under responsibility of the scientific committee of the 11th Int. Conf.... more Selection and peer-review under responsibility of the scientific committee of the 11th Int. Conf. on Applied Energy (ICAE2019).
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
International Journal of Environment and Sustainable Development, 2019
In Nigeria, high and outrageous energy cost constitutes a serious challenge to all aspects of the... more In Nigeria, high and outrageous energy cost constitutes a serious challenge to all aspects of the economy. And this has been a subject of concern in the country over a period of time. A dependable and renewable energy source is of utmost desire to strengthen the nation's economy and this urgent need cannot be overlooked. As a result of the erratic and expensive power supply to the national grid, it has become ultimately necessary to search for other inexpensive sources of energy to meet the ever increasing energy needs for rural and urban dwellers. In view of the above energy situation in Nigeria, this paper aimed at carrying out a comprehensive review on bioenergy technology option as a pathway to achieving sustainable energy development in the country. The potential, current progressive stages, and prospects of bioenergy conversion techniques, in the Nigeria context, are discussed. The barriers to bioenergy technology development in Nigeria with possible solutions are also presented.
World Review of Science, Technology and Sustainable Development, 2019
Gas and oil-fired furnaces require air blower and stirring mechanism to produce homogeneous metal... more Gas and oil-fired furnaces require air blower and stirring mechanism to produce homogeneous metal matrix, alloyed metals and metallic composites. Both the blower and the stirrer require electric power that is not reliable in some urban areas and non-available in some rural communities in sub-Saharan countries. In this paper, a 20 kg oil-fired tilting furnace for melting iron, gold, aluminium, lead, magnesium, copper, tin et cetera and also used to produce metal matrix composites through liquid metallurgy routes, is designed for off-grid locations. Photovoltaic system specification of 250 W solar panel, 20A charge controller, 300 AH deep cycle battery and 1,400 W inverter were used to provide electric power to the air blower and mixing motor of the tilting furnace. With this arrangement, this versatile tilting furnace could be used in cottage industry without electric mains by small and medium-scale enterprises (SMEs), thus reducing unemployment among the populace and reduction of emission products into the atmosphere.
This paper presents technical and economic assessment of a hybrid energy system for electricity g... more This paper presents technical and economic assessment of a hybrid energy system for electricity generation in rural communities in the six geopolitical zones of Nigeria. The study was based on a 500 rural household model having an electric load of 493 kWh per day. To simulate long-term continuous implementation of the hybrid system, 21 years (1992 – 2012) hourly mean global solar radiation and wind speed data for the selected sites were used. The mean annual wind speed and solar radiation for the locations ranged from 2.31 m/s for Warri to 3.52 m/ s for Maiduguri and 4.53 kWh/m2 for Warri to 5.92 kWh/m2 for Maiduguri, respectively. These weather data were used for simulation with the Micro-power Optimization Model software HOMER. From the optimum results of the hybrid system,Warri has the highest NPC and COE of $2,441,222 and $0.721/kWh, respectively while Maiduguri has the least NPC and COE of $2,225,387 and $0.658/kWh, respectively for the 21 years project lifespan. The high value...
International Journal of Energy for a Clean Environment, 2017
Refrigeration plays a signifi cant role in domestic, industrial, commercial, and health sectors f... more Refrigeration plays a signifi cant role in domestic, industrial, commercial, and health sectors for comfort, food storage, medical applications, etc. There are innumerable applications of such systems, and they are the major consumer of electricity around the world (Anand and Tyagi, 2012; Rasti et al., 2012). The high energy consumption by refrigeration systems is due to the large amounts of units being used and also to
European Journal of Sustainable Development Research, 2018
In Nigeria, access to reliable and stable supply of electricity is a major challenge for both the... more In Nigeria, access to reliable and stable supply of electricity is a major challenge for both the urban and rural dwellers. In this study, comprehensive review of accessibility to clean and modern energy in Nigeria has been carried out. Also, this paper examines the potential of renewable energy (RE) resources in Nigeria that can be harnessed for continuous energy supply and the government's efforts to ensure RE's sustainability. Nigeria is endowed with abundant energy resources but the existing electric energy infrastructures are unable to meet the energy demands of teeming population. There is imbalance in energy supply and demand in the country. Over the period from 2000 to 2014, there was an average of about 2.35 billion kWh of energy gap between energy production and energy consumption. The highest electricity consumption per capita recorded so far was 156 kWh in 2012. This makes Nigeria one of the country with the lowest electricity consumption on per capita basis in the world. In order to improve access to clean energy supply and achieve sustainable development, this paper pin points the significance of decentralized renewable energy systems and needs for the government to review the policies on renewable energy development in the country.
American Journal of Engineering and Applied Sciences, 2017
In this study, modelling of gas turbine engine performance is carried out using thermodynamics re... more 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.
In this study, exergy costing analysis and performance evaluation of selected gas turbine power p... more 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).
This study presents comprehensive thermoeconomic and thermoenvironomic modeling and analysis of s... more This study presents comprehensive thermoeconomic and thermoenvironomic modeling and analysis of selected gas turbine power plants in Nigeria using the first and second laws of thermodynamics (exergy) concept. Exergetic analysis was 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 results of the study showed that the combustion chamber (CC) is the most exergy destructive component compared to other cycle components. The percentage of exergy destruction in CC varies between 86.05% and 94.6%. By increasing the gas turbine inlet temperature (GTIT), the exergy destruction of this component can be reduced. The total exergy improvement potential of the selected plants varies from 54.04 to 159.88 MW. The component with the highest exergy improvement potential is the CC, which has the value that varies from 30.21 to 88.86 MW. Thermoeconomic analysis showed that the cost of exergy destruction is high in the CC, and an increase in the GTIT effectively decreases this cost. The exergy costing analysis revealed that the unit cost of electricity produced in the plants ranged from cents 1.99/kWh (N3.16/ kWh) to cents 5.65 /kWh (N8.98/kWh). Thermoenvironomic analysis showed that the CO 2 emissions varied between 100.18 and 408.78 kg CO 2 /MWh, while cost rate of environmental impact varied from 40.18 $/h (6, 388.62 N/h) to 276.97 $/h (44, 038. 23 N/h). The results further showed that CO 2 emissions and cost of environmental impact decrease with increasing GTIT. The sustainability index increase with increasing GTIT. Finally, this study will assist efforts to understand the thermodynamic losses in the gas turbine cycle, and to improve efficiency as well as provide future recommendations for better performance, sustainability, and lessening environmental impact of power plant.
This study presents thermodynamic analysis of the design and performance of eleven selected gas t... more 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 compo...
In this study, the experimental analysis of the performance of vapor absorption system was develo... more In this study, the experimental analysis of the performance of vapor absorption system was developed and developed. The influence of generator, evaporator and condenser's temperatures on the system performance was studied using gas burner as source of energy, ammonia-water combination as working fluid and energy equations as governing equations for the work. There was variation in the results when compared with the earlier worker who used kerosene burner as source of energy and ammonia-water combination. Result of this study shows that if higher cooling capacity and also lower evaporator`s temperature are desired from the system, generator`s temperature should be increased considerably. Also the combination of an analyzer, rectifier and heat exchanger would produce better COP of the System.
In this study, performance assessment of selected gas turbine power plants in Nigeria was evaluat... more In this study, performance assessment of selected gas turbine power plants in Nigeria was evaluated using performance indices. The results of the study showed that for the period under review (2006-2010), the percentage shortfalls from the target energy in the selected power plants range from 26.33% to 86.61% as against the acceptable value of 5-10%. The capacity factor of the selected power plants varies from 16.88% to 73.67% as against the international value of 50-80%. The plant use factor varies from 45.89% to 97.03% and the utilization factor varies from 6.31% to 93.074% as against the international best practice of over 95%. From this result, it can be concluded that the generating units were underutilized. This is due to inadequate routine maintenance and equipment fault development. The analyses of reliability indicators revealed that the mean time between failures varies from 5.42 to 378.44 h, the mean time to repair varies from 18.3 to 153.88 h and the plant availability varies from 12.86% to 91.31% as against the Institute of Electrical and Electronics Engineers recommended standard of 99.9%. Evaluation of operating figures of the selected power plants revealed that starting reliability (SR) and operating reliability vary from 71.95% to 93.9% and 5.33% to 55%, respectively. The SR of the selected power plants is low in value compared with standard value of 99.9%. The statistical analysis carried out on plant availability revealed that at 95% confidence level; there is a significant difference in availability of the selected power plants. This indicates differences in their systems installation, operation and maintenance. The performance indicator developed to evaluate the performance indices for the selected stations can also be applicable to other power stations in Nigeria and elsewhere. Measures to improve the performance indices of the plants have been suggested in this paper.
Preventive Maintenance Programme consists of actions that improve the condition of system element... more Preventive Maintenance Programme consists of actions that improve the condition of system elements for performance optimization and aversion of unintended system failure or collapse. It involves inspection, servicing, repairing or replacing physical components of machineries, plant and equipment by following the prescribed schedule. It is commonly agreed nowadays that preventive maintenance programme can be very successful in improving equipment reliability while minimizing maintenance related costs. The availability of a complex system, such as steam turbine power plant is strongly associated with its parts reliability and maintenance policy. That policy not only has influence on the parts' repair time but also on the parts' reliability affecting the system integrity, degradation and availability. The objective of this paper is to study the effects of Preventive Maintenance Programme (PMP) implementation on the performance of the Egbin 1320 MW thermal power plant in Nigeria. This paper considers the reliability and availability of the 6 × 220 MW steam turbine units installed in the power station. The reliability and availability of the turbines are computed based on a five-year failure database. The availability analysis of available data from 2005 to 2009 shows different results for each unit and variation in availability for different year: availability of unit1 varies between 59.11% to 91.76%; unit 2, 64.02% to 94.53%; unit 3, 28.79% to 91.57%; unit 4, 80.31% to 92.76% and unit 5, 73.38% to 87.76%. Unit 6 was out of service for the past 2 to 3 years. This indicates differences in their systems installation maintenance and operation.
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