Emmanuel Anyanwu - Academia.edu (original) (raw)

Papers by Emmanuel Anyanwu

Scientific Research Journal, Aug 25, 2021

Evaluation of the energy consumption during the thin-layer drying of yam slices in an exhaust gas... more Evaluation of the energy consumption during the thin-layer drying of yam slices in an exhaust gas waste heat recovery dryer is presented. The study took cognizance of some energy parameters such as the electric power consumption, thermal energy consumption and specific energy consumption during the drying process. Blanched white yam samples of different thicknesses were subjected to varying conditions of drying air temperatures and velocities of 55, 65, and 75°C; and 1.0, 1.5, and 2.0 m/s. The minimum value of electric power consumption (44.63 W-hr) was achieved at the drying air temperature and velocity of 75 ℃ and 1.0 m/s, and slice thickness of 1.0 cm; whereas a maximum value of 157.70 W-hr was obtained at the drying air temperature and velocity of 55 ℃, 2.0 m/s, and 1.0 cm slice thickness, respectively. The specific energy consumption values were in the range of 40.25 to 97.80, 52.33 to 108.79 and 58.77 to 124.16 kW-hr/kg, respectively for 1.0, 1.5 and 2.0 cm slice thicknesses. The results obtained revealed that the drying air temperature and velocity had an appreciable influence on the values of the energy consumption parameters of the dryer for the yam slice drying. It was observed that for all the experimental treatments, the higher the slice thickness of the yam samples, the higher the obtained energy consumption values.

Biofuels, 2014

A review of engine performance tests conducted by several researchers using jatropha biodiesel is... more A review of engine performance tests conducted by several researchers using jatropha biodiesel is presented. The three engine performance parameters considered are Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTH) and Exhaust Gas Temperature (EGT). From the review, jatropha biodiesel functions smoothly in diesel engines. Also, the observation during testing in most engines showed a decrease in brake thermal efficiencies using jatropha biodiesel when compared with pure diesel fuel. In addition, the brake specific fuel consumption increases with jatropha biodiesel when compared with pure diesel. Likewise, the exhaust gas temperature generated from jatropha biodiesel fuel is lower at the exhaust than from diesel fuel. The work revealed that blending jatropha biodiesel with pure diesel (specifically between B5-B30) gave more preferred and appreciable engine performance than when the engine is either run on jatropha biodiesel (B100) or pure diesel (D100) alone. The review also highlights some challenges of using jatropha biodiesel in diesel engines and gives useful recommendations for improving jatropha biodiesel engine utilization.

The Journal of Supercritical Fluids, 2012

ABSTRACT In this study, a three-layer artificial neural network (ANN) model was investigated to p... more ABSTRACT In this study, a three-layer artificial neural network (ANN) model was investigated to predict the extraction yield of essential oils from Diplotaenia cachrydifolia by supercritical fluid extraction. A multilayer feed-forward neural network trained with an error back-propagation algorithm was employed for developing a predictive model. The input parameters chosen of the model are pressure, temperature, extraction time and modifier volume while the extraction yield of essential oils is the output. The Levenberg–Marquardt (LM) algorithm was used to train ANN. The results showed that a network with five hidden neurons was highly accurate in predicting the extraction yield of essential oils of D. cachrydifolia. The mean squared error (MSE) and coefficient of determination (R2) between the actual and predicted values were determined as 0.0014 and 0.9983 for training, 0.0184 and 0.9542 for validation and 0.0221 and 0.9703 for testing date sets. The main components that were extracted with SFE were dillapiole (30.2%), limonene (13.7%) and α-calacorene (20.1%).

International Journal of Engineering and Technologies, 2017

The performance analysis of a single cylinder spark ignition engine fuelled with ethanol-petrol b... more The performance analysis of a single cylinder spark ignition engine fuelled with ethanol-petrol blends were carried out successfully at constant load conditions. E0 (Petrol), E10 (10% Ethanol, 90% Petrol), E20 (20% Ethanol, 80% Petrol) and E30 (30% Ethanol, 70% Petrol) were used as fuel. The Engine speed, mass flow rate, combustion efficiency, maximum pressure developed, brake specific fuel consumption and Exhaust gas temperature values were measured during the experiment. Using the experimental data, a Levenberg Marquardt Artificial Neural Network algorithm and Logistic sigmoid activation transfer function with a 4-10-2 model was developed to predict the brake specific fuel consumption, maximum pressure and combustion efficiency of G200 IMEX spark ignition engine using the recorded engine speed, mass flow rate, biofuels ratio and exhaust gas temperature as input variables. The performance of the Artificial Neural Network was validated by comparing the predicted data with the experimental results. The results showed that the training algorithm of Levenberg Marquardt was sufficient enough in predicting the brake specific fuel consumption, combustion pressure and combustion efficiency of the test engine. Correlation coefficient values of 0.974, 0.996 and 0.995 were obtained for brake specific fuel consumption, combustion efficiency and pressure respectively. These correlation coefficient obtained for the output parameters are very close to one (1) showing good correlation between the Artificial Neural Network predicted results and the experimental data while the Mean Square Errors were found to be very low (0.00018825 @ epoch 10 for brake specific fuel consumption, 1.0023 @ epoch 3 for combustion efficiency and 0.0013284@ epoch 5 for in-cylinder pressure). Therefore, Artificial Neural Network toolbox called up from MATLAB proved to be a useful tool for simulation of engine parameters. Artificial Neural Network model provided accurate analysis of these complex problems and has been found to be very useful for predicting the performance of the spark ignition engine. Thus, this has proved that Artificial Neural Network model could be used for predicting performance values in internal combustion engines, in this way it would be possible to conduct time and cost efficient studies instead of long experimental ones.

Inadequate slurry flow dynamics have been reported to adversely affect biodigestion process resul... more Inadequate slurry flow dynamics have been reported to adversely affect biodigestion process resulting in poor bioreactor performance or outright failure in some cases. The incorporation of appropriate flow features in bioreactor design is expected to provide the basis of effective digestion of organic waste thus leading to high yield in biogas production. Consequently, a bioreactor with integral flow features was designed, fabricated and employed for the experimental studies of anaerobic digestion of organic fraction of municipal solid waste. The reactor comprises two identical cylindrical vessels connected to a central substrate dispensing unit and has a total void volume of 64.8l. Substrate flow features in this reactor were characterized by an upflow coupled with a crossflow and a dispersive downflow. The bioreactor was fed batch, operated at 37oC and with substrate recirculation effected at 450ml per minute by an electromagnetic metering pump. The feedstock was obtained by proce...

ASME 2017 11th International Conference on Energy Sustainability

A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compress... more A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compression ignition engine is presented. The mathematical model equations developed were based on heat transfers in the cylinder liner and subsequently transformed using the finite difference method. Numerical solutions were obtained from computer codes written in MATLAB programming language. A biodiesel produced from Nigerian physic nut oil was used in the study. The result was compared with that obtained for conventional diesel fuel. The results revealed that the cylinder head section of the liner material presented higher temperature distribution compared to the oil sump section of the liner. Over a twelve-minute time range, the liner attained steady state with Jatropha-based biodiesel, recording a maximum temperature of 873.1°C. Conventional diesel recorded the lower temperature of 784.3°C. Results also showed that the cylinder head section of the liner material closest to the combustion ch...

A study aimed at seal selection efficiency for centrifugal pumps in the oil and gas industry is p... more A study aimed at seal selection efficiency for centrifugal pumps in the oil and gas industry is presented. A detailed analysis of mechanical seals in use in exploration and production activities of the oil and gas sector was undertaken. The approach of analysis was using seal design equations as mathematical models for simulating the performance of the mechanical seal. The results showed a mechanical seal with balance value of 0.5, an increased surface area between mating surfaces; provided with a flush system to enhance cooling and with seal face gap of 50 mm or less between the mating surfaces for minimal or zero leakage. The obtained results can aid the industries in seal selection and seal manufacturers in seal specifications.

The exergy based performance analysis of a solid adsorption solar refrigerator is presented. The ... more The exergy based performance analysis of a solid adsorption solar refrigerator is presented. The analysis is based on an exergy balance applied to each component of the refrigeration machine, leading to a general exergy balance equation. The dead state temperature was chosen to coincide with the ambient temperature. Results reveal that maximum exergy destruction occurred in the collector/generator/adsorber during heat up and adsorbate desorption phases with a value of 3747.77 kJ. Values recorded in the condenser and evaporator were 10.51 and 20.11 kJ, respectively while the exergy efficiency was in the range of 0.0008 – 0.012. It was also found that the rate of exergy destruction reduced as soon as adsorbate generation commenced; indicating superior energy and exergy utilization during desorption phase. Thus use of adsorbent and adsorbate with the potential of very early commencement of desorption can significantly improve the exergetic efficiency of the system.

A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compress... more A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compression ignition engine is presented. The mathematical model equations developed were based on heat transfers in the cylinder liner and subsequently transformed using the finite difference method. Numerical solutions were obtained from computer codes written in MATLAB programming language. A biodiesel produced from Nigerian physic nut oil was used in the study. The result was compared with that obtained for conventional diesel fuel. The results revealed that the cylinder head section of the liner material presented higher temperature distribution compared to the oil sump section of the liner. Over a twelve-minute time range, the liner attained steady state with Jatropha-based biodiesel, recording a maximum temperature of 873.1°C. Conventional diesel recorded the lower temperature of 784.3°C. Results also showed that the cylinder head section of the liner material closest to the combustion chamber experienced the greatest temperature rise in comparison to other parts of the liner. These results show that though there are lots of publications confirming that a compression ignition engine previously running on diesel fuel can run on biodiesel fuel or its blend with diesel, there is a need for a further critical study on the development of engine parts like the cylinder liner.

Journal of Energy Engineering

AbstractThe transient model of a hybrid solar collector/nocturnal radiator with thermal energy st... more AbstractThe transient model of a hybrid solar collector/nocturnal radiator with thermal energy storage for solar water heating and its nocturnal radiative cooling was deployed in simulating space c...

Scientific African

Abstract The need to develop alternative automobile fuel other than petrol and diesel in Nigeria ... more Abstract The need to develop alternative automobile fuel other than petrol and diesel in Nigeria is based on the rising cost, environmental pollution, and perennial scarcity of petrol, diesel, etc. Technical analysis of the introduction of compressed natural gas vehicles as a means of public transportation in Nigeria is conducted in this work. Port Harcourt – Onitsha expressway, a major interstate route in Nigeria is used as a case for analysis. 400 compressed natural gas vehicles are estimated to ply the route daily, which makes the total energy requirement per day to be 3856 gasoline gallon equivalent/day. It is recommended from the refueling stations design that five refueling stations with an average dispensing rate of 800 gasoline gallon equivalent/day are installed along the route to take care of the total requirement of 3856 gasoline gallon equivalent/day. Compressor duty analyses are conducted using Hysys, a process simulation software to determine the energy required by the compressors to boost the pressure of the gas from 14.70 psia at the sales point to 3600 psia which is the outlet pressure of the stations. From the analyses using economic indicators, the project is also found to be economically viable. It has a very high net present value of $2.27 million, short pay-out of 4.24 years, internal rate of return of 14.42% and profit per dollar investment after seven years of 0.72. The entire results indicate that adopting compressed natural gas vehicles for public transportation in at least the major interstate routes in Nigeria, will help to reduce the transportation problems encountered in Nigeria due to the pressure on gasoline and diesel.

International Journal of Engineering and Technologies

The performance analysis of a single cylinder spark ignition engine fuelled with ethanol – petrol... more The performance analysis of a single cylinder spark ignition engine fuelled with ethanol – petrol blends were carried out successfully at constant load conditions. E0 (Petrol), E10 (10% Ethanol, 90% Petrol), E20 (20% Ethanol, 80% Petrol) and E30 (30% Ethanol, 70% Petrol) were used as fuel. The Engine speed, mass flow rate, combustion efficiency, maximum pressure developed, brake specific fuel consumption and Exhaust gas temperature values were measured during the experiment. Using the experimental data, a Levenberg Marquardt Artificial Neural Network algorithm and Logistic sigmoid activation transfer function with a 4–10–2 model was developed to predict the brake specific fuel consumption, maximum pressure and combustion efficiency of G200 IMEX spark ignition engine using the recorded engine speed, mass flow rate, biofuels ratio and exhaust gas temperature as input variables. The performance of the Artificial Neural Network was validated by comparing the predicted data with the expe...

Energy and Buildings

Abstract The need for substantial savings in building energy demand is necessitating global house... more Abstract The need for substantial savings in building energy demand is necessitating global households’ switch to solar water heating and nocturnal water cooling for possible incorporation with a hydronic system for controlling the temperature of buildings. Ambient energy technology application plays a prominent role in meeting the heating and cooling energy demands for buildings. These are not only environmental friendly but also require minimal maintenance and operation costs. A review of hybrid solar water heating/nocturnal radiation cooling system using a single collector/radiator for both functions is presented. The collectors that have been used for solar heating and cooling in meeting the building energy demand can be classified as photovoltaic-thermal collectors, water/air solar collectors and spectrally selective surface solar collectors. The performances of these collectors consistent with their usage at different regions of the world are concisely reported. The development of the primary component of the system, namely, the collector/radiator, vis-a-vis the combined heating and cooling function is examined. Current state of global system take ups are reported with factors limiting the widespread implementation. The prospects, technical advancements as well as technical, economic and societal constraints limiting the commercialization of the system are also reported, with suggestions for possible improvements.

International Journal of Energy for a Clean Environment

International Journal of Fluid Mechanics & Thermal Sciences

This paper examines the experimental study on a line axis concentrating solar energy collector fo... more This paper examines the experimental study on a line axis concentrating solar energy collector for water heating. The system considered consists of cylindrical solar radiation concentrator with a black coated tubular absorber positioned along its axis. A cold water tank is placed above the collector and a hot water tank positioned below it such that fluid flows in and out of the set up. Solar radiation absorber inlet header is connected to the cold water tank while its outlet header is connected to the hot water tank. These major components are supported by angle iron raised at a distance from the ground that depends on the location and function. Valves are used at strategic points on the connecting pipe lines to isolate the flow of water. When water is poured into the cold water chamber, and the control valve turned on, the water flows under gravity into the receiver/absorber tube. At the absorber section, heat is transferred from the steel tube to the circulating water and is consequently heated. The heated water, then flows into the returning tube against gravity, thereby restricting the heated water from flowing into the storage tank. At this stage, thermo-siphoning effect comes into play. As the temperature of the water increases, its density reduces while the mass remains constant in order to balance the effect of the reduction in density. Thus, there is a resultant increase in volume which consequently pushes the water level further along the returning pipe. Further increase in temperature reduces the water density and increases the volume of the water, thereby causing the heated water to flow into the insulated tank. Several experimental tests were carried out under meteorological condition at the Federal University of Technology Owerri, Nigeria at three different mass flow rates of 0.001kg/s, 0.002kg/s and 0.003kg/s. The solar water heater was tested while oriented in the East-West and North-South directions in order to determine the effects of orientation on the performance. Results obtained showed that a maximum temperature of 69.5°C, corresponding to 34.5°C increase in water temperature and a maximum instantaneous efficiency of 51.01% is possible. The aim of the study is to design a cheaper solar energy system capable of reducing energy bill within the developing countries of the world.

International Journal of Engineering and Technologies

The effects of compatibilizer (maleic anhydride-graft-polyethylene) on the mechanical properties ... more The effects of compatibilizer (maleic anhydride-graft-polyethylene) on the mechanical properties of pineapple leaf powder (PALP) filled high density polyethylene (HDPE) composites were studied. HDPE and PALP composites in the presence, or absence of the compatibilizer, maleic anhydride -graft- polyethylene (MA-g-PE) were prepared by injection moulding technique. The filler (PALP) contents investigated were 2, 4, 6, 8, and 10 wt%, while the MA-g-PE content was 3 wt% of the filler content for each formulation. The result of the mechanical tests carried out on the HDPE/PALP composites showed that the tensile strength, tensile modulus, abrasion resistance, and hardness of the composites increased as the filler content increases both in the presence, or absence of the compatibilizer (MA-g-PE) for all the filler contents investigated, while the elongation at break (EB) for PALP/HDPE composites was found to decrease as the filler content increases both in the presence, or absence of MA-g-P...

International Journal of Energy for a Clean Environment

The effects of compatibilizer (maleic anhydride-graft-polyethylene) on the mechanical properties ... more The effects of compatibilizer (maleic anhydride-graft-polyethylene) on the mechanical properties of pineapple leaf powder (PALP) filled high density polyethylene (HDPE) composites were studied. HDPE and PALP composites in the presence, or absence of the compatibilizer, maleic anhydride -graft- polyethylene (MA-g-PE) were prepared by injection moulding technique. The filler (PALP) contents investigated were 2, 4, 6, 8, and 10 wt%, while the MA-g-PE content was 3 wt% of the filler content for each formulation. The result of the mechanical tests carried out on the HDPE/PALP composites showed that the tensile strength, tensile modulus, abrasion resistance, and hardness of the composites increased as the filler content increases both in the presence, or absence of the compatibilizer (MA-g-PE) for all the filler contents investigated, while the elongation at break (EB) for PALP/HDPE composites was found to decrease as the filler content increases both in the presence, or absence of MA-g-P...

Scientific Research Journal, Aug 25, 2021

Evaluation of the energy consumption during the thin-layer drying of yam slices in an exhaust gas... more Evaluation of the energy consumption during the thin-layer drying of yam slices in an exhaust gas waste heat recovery dryer is presented. The study took cognizance of some energy parameters such as the electric power consumption, thermal energy consumption and specific energy consumption during the drying process. Blanched white yam samples of different thicknesses were subjected to varying conditions of drying air temperatures and velocities of 55, 65, and 75°C; and 1.0, 1.5, and 2.0 m/s. The minimum value of electric power consumption (44.63 W-hr) was achieved at the drying air temperature and velocity of 75 ℃ and 1.0 m/s, and slice thickness of 1.0 cm; whereas a maximum value of 157.70 W-hr was obtained at the drying air temperature and velocity of 55 ℃, 2.0 m/s, and 1.0 cm slice thickness, respectively. The specific energy consumption values were in the range of 40.25 to 97.80, 52.33 to 108.79 and 58.77 to 124.16 kW-hr/kg, respectively for 1.0, 1.5 and 2.0 cm slice thicknesses. The results obtained revealed that the drying air temperature and velocity had an appreciable influence on the values of the energy consumption parameters of the dryer for the yam slice drying. It was observed that for all the experimental treatments, the higher the slice thickness of the yam samples, the higher the obtained energy consumption values.

Biofuels, 2014

A review of engine performance tests conducted by several researchers using jatropha biodiesel is... more A review of engine performance tests conducted by several researchers using jatropha biodiesel is presented. The three engine performance parameters considered are Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTH) and Exhaust Gas Temperature (EGT). From the review, jatropha biodiesel functions smoothly in diesel engines. Also, the observation during testing in most engines showed a decrease in brake thermal efficiencies using jatropha biodiesel when compared with pure diesel fuel. In addition, the brake specific fuel consumption increases with jatropha biodiesel when compared with pure diesel. Likewise, the exhaust gas temperature generated from jatropha biodiesel fuel is lower at the exhaust than from diesel fuel. The work revealed that blending jatropha biodiesel with pure diesel (specifically between B5-B30) gave more preferred and appreciable engine performance than when the engine is either run on jatropha biodiesel (B100) or pure diesel (D100) alone. The review also highlights some challenges of using jatropha biodiesel in diesel engines and gives useful recommendations for improving jatropha biodiesel engine utilization.

The Journal of Supercritical Fluids, 2012

ABSTRACT In this study, a three-layer artificial neural network (ANN) model was investigated to p... more ABSTRACT In this study, a three-layer artificial neural network (ANN) model was investigated to predict the extraction yield of essential oils from Diplotaenia cachrydifolia by supercritical fluid extraction. A multilayer feed-forward neural network trained with an error back-propagation algorithm was employed for developing a predictive model. The input parameters chosen of the model are pressure, temperature, extraction time and modifier volume while the extraction yield of essential oils is the output. The Levenberg–Marquardt (LM) algorithm was used to train ANN. The results showed that a network with five hidden neurons was highly accurate in predicting the extraction yield of essential oils of D. cachrydifolia. The mean squared error (MSE) and coefficient of determination (R2) between the actual and predicted values were determined as 0.0014 and 0.9983 for training, 0.0184 and 0.9542 for validation and 0.0221 and 0.9703 for testing date sets. The main components that were extracted with SFE were dillapiole (30.2%), limonene (13.7%) and α-calacorene (20.1%).

International Journal of Engineering and Technologies, 2017

The performance analysis of a single cylinder spark ignition engine fuelled with ethanol-petrol b... more The performance analysis of a single cylinder spark ignition engine fuelled with ethanol-petrol blends were carried out successfully at constant load conditions. E0 (Petrol), E10 (10% Ethanol, 90% Petrol), E20 (20% Ethanol, 80% Petrol) and E30 (30% Ethanol, 70% Petrol) were used as fuel. The Engine speed, mass flow rate, combustion efficiency, maximum pressure developed, brake specific fuel consumption and Exhaust gas temperature values were measured during the experiment. Using the experimental data, a Levenberg Marquardt Artificial Neural Network algorithm and Logistic sigmoid activation transfer function with a 4-10-2 model was developed to predict the brake specific fuel consumption, maximum pressure and combustion efficiency of G200 IMEX spark ignition engine using the recorded engine speed, mass flow rate, biofuels ratio and exhaust gas temperature as input variables. The performance of the Artificial Neural Network was validated by comparing the predicted data with the experimental results. The results showed that the training algorithm of Levenberg Marquardt was sufficient enough in predicting the brake specific fuel consumption, combustion pressure and combustion efficiency of the test engine. Correlation coefficient values of 0.974, 0.996 and 0.995 were obtained for brake specific fuel consumption, combustion efficiency and pressure respectively. These correlation coefficient obtained for the output parameters are very close to one (1) showing good correlation between the Artificial Neural Network predicted results and the experimental data while the Mean Square Errors were found to be very low (0.00018825 @ epoch 10 for brake specific fuel consumption, 1.0023 @ epoch 3 for combustion efficiency and 0.0013284@ epoch 5 for in-cylinder pressure). Therefore, Artificial Neural Network toolbox called up from MATLAB proved to be a useful tool for simulation of engine parameters. Artificial Neural Network model provided accurate analysis of these complex problems and has been found to be very useful for predicting the performance of the spark ignition engine. Thus, this has proved that Artificial Neural Network model could be used for predicting performance values in internal combustion engines, in this way it would be possible to conduct time and cost efficient studies instead of long experimental ones.

Inadequate slurry flow dynamics have been reported to adversely affect biodigestion process resul... more Inadequate slurry flow dynamics have been reported to adversely affect biodigestion process resulting in poor bioreactor performance or outright failure in some cases. The incorporation of appropriate flow features in bioreactor design is expected to provide the basis of effective digestion of organic waste thus leading to high yield in biogas production. Consequently, a bioreactor with integral flow features was designed, fabricated and employed for the experimental studies of anaerobic digestion of organic fraction of municipal solid waste. The reactor comprises two identical cylindrical vessels connected to a central substrate dispensing unit and has a total void volume of 64.8l. Substrate flow features in this reactor were characterized by an upflow coupled with a crossflow and a dispersive downflow. The bioreactor was fed batch, operated at 37oC and with substrate recirculation effected at 450ml per minute by an electromagnetic metering pump. The feedstock was obtained by proce...

ASME 2017 11th International Conference on Energy Sustainability

A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compress... more A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compression ignition engine is presented. The mathematical model equations developed were based on heat transfers in the cylinder liner and subsequently transformed using the finite difference method. Numerical solutions were obtained from computer codes written in MATLAB programming language. A biodiesel produced from Nigerian physic nut oil was used in the study. The result was compared with that obtained for conventional diesel fuel. The results revealed that the cylinder head section of the liner material presented higher temperature distribution compared to the oil sump section of the liner. Over a twelve-minute time range, the liner attained steady state with Jatropha-based biodiesel, recording a maximum temperature of 873.1°C. Conventional diesel recorded the lower temperature of 784.3°C. Results also showed that the cylinder head section of the liner material closest to the combustion ch...

A study aimed at seal selection efficiency for centrifugal pumps in the oil and gas industry is p... more A study aimed at seal selection efficiency for centrifugal pumps in the oil and gas industry is presented. A detailed analysis of mechanical seals in use in exploration and production activities of the oil and gas sector was undertaken. The approach of analysis was using seal design equations as mathematical models for simulating the performance of the mechanical seal. The results showed a mechanical seal with balance value of 0.5, an increased surface area between mating surfaces; provided with a flush system to enhance cooling and with seal face gap of 50 mm or less between the mating surfaces for minimal or zero leakage. The obtained results can aid the industries in seal selection and seal manufacturers in seal specifications.

The exergy based performance analysis of a solid adsorption solar refrigerator is presented. The ... more The exergy based performance analysis of a solid adsorption solar refrigerator is presented. The analysis is based on an exergy balance applied to each component of the refrigeration machine, leading to a general exergy balance equation. The dead state temperature was chosen to coincide with the ambient temperature. Results reveal that maximum exergy destruction occurred in the collector/generator/adsorber during heat up and adsorbate desorption phases with a value of 3747.77 kJ. Values recorded in the condenser and evaporator were 10.51 and 20.11 kJ, respectively while the exergy efficiency was in the range of 0.0008 – 0.012. It was also found that the rate of exergy destruction reduced as soon as adsorbate generation commenced; indicating superior energy and exergy utilization during desorption phase. Thus use of adsorbent and adsorbate with the potential of very early commencement of desorption can significantly improve the exergetic efficiency of the system.

A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compress... more A numerical study of temperature distribution in the cylinder liner of biodiesel-powered compression ignition engine is presented. The mathematical model equations developed were based on heat transfers in the cylinder liner and subsequently transformed using the finite difference method. Numerical solutions were obtained from computer codes written in MATLAB programming language. A biodiesel produced from Nigerian physic nut oil was used in the study. The result was compared with that obtained for conventional diesel fuel. The results revealed that the cylinder head section of the liner material presented higher temperature distribution compared to the oil sump section of the liner. Over a twelve-minute time range, the liner attained steady state with Jatropha-based biodiesel, recording a maximum temperature of 873.1°C. Conventional diesel recorded the lower temperature of 784.3°C. Results also showed that the cylinder head section of the liner material closest to the combustion chamber experienced the greatest temperature rise in comparison to other parts of the liner. These results show that though there are lots of publications confirming that a compression ignition engine previously running on diesel fuel can run on biodiesel fuel or its blend with diesel, there is a need for a further critical study on the development of engine parts like the cylinder liner.

Journal of Energy Engineering

AbstractThe transient model of a hybrid solar collector/nocturnal radiator with thermal energy st... more AbstractThe transient model of a hybrid solar collector/nocturnal radiator with thermal energy storage for solar water heating and its nocturnal radiative cooling was deployed in simulating space c...

Scientific African

Abstract The need to develop alternative automobile fuel other than petrol and diesel in Nigeria ... more Abstract The need to develop alternative automobile fuel other than petrol and diesel in Nigeria is based on the rising cost, environmental pollution, and perennial scarcity of petrol, diesel, etc. Technical analysis of the introduction of compressed natural gas vehicles as a means of public transportation in Nigeria is conducted in this work. Port Harcourt – Onitsha expressway, a major interstate route in Nigeria is used as a case for analysis. 400 compressed natural gas vehicles are estimated to ply the route daily, which makes the total energy requirement per day to be 3856 gasoline gallon equivalent/day. It is recommended from the refueling stations design that five refueling stations with an average dispensing rate of 800 gasoline gallon equivalent/day are installed along the route to take care of the total requirement of 3856 gasoline gallon equivalent/day. Compressor duty analyses are conducted using Hysys, a process simulation software to determine the energy required by the compressors to boost the pressure of the gas from 14.70 psia at the sales point to 3600 psia which is the outlet pressure of the stations. From the analyses using economic indicators, the project is also found to be economically viable. It has a very high net present value of $2.27 million, short pay-out of 4.24 years, internal rate of return of 14.42% and profit per dollar investment after seven years of 0.72. The entire results indicate that adopting compressed natural gas vehicles for public transportation in at least the major interstate routes in Nigeria, will help to reduce the transportation problems encountered in Nigeria due to the pressure on gasoline and diesel.

International Journal of Engineering and Technologies

The performance analysis of a single cylinder spark ignition engine fuelled with ethanol – petrol... more The performance analysis of a single cylinder spark ignition engine fuelled with ethanol – petrol blends were carried out successfully at constant load conditions. E0 (Petrol), E10 (10% Ethanol, 90% Petrol), E20 (20% Ethanol, 80% Petrol) and E30 (30% Ethanol, 70% Petrol) were used as fuel. The Engine speed, mass flow rate, combustion efficiency, maximum pressure developed, brake specific fuel consumption and Exhaust gas temperature values were measured during the experiment. Using the experimental data, a Levenberg Marquardt Artificial Neural Network algorithm and Logistic sigmoid activation transfer function with a 4–10–2 model was developed to predict the brake specific fuel consumption, maximum pressure and combustion efficiency of G200 IMEX spark ignition engine using the recorded engine speed, mass flow rate, biofuels ratio and exhaust gas temperature as input variables. The performance of the Artificial Neural Network was validated by comparing the predicted data with the expe...

Energy and Buildings

Abstract The need for substantial savings in building energy demand is necessitating global house... more Abstract The need for substantial savings in building energy demand is necessitating global households’ switch to solar water heating and nocturnal water cooling for possible incorporation with a hydronic system for controlling the temperature of buildings. Ambient energy technology application plays a prominent role in meeting the heating and cooling energy demands for buildings. These are not only environmental friendly but also require minimal maintenance and operation costs. A review of hybrid solar water heating/nocturnal radiation cooling system using a single collector/radiator for both functions is presented. The collectors that have been used for solar heating and cooling in meeting the building energy demand can be classified as photovoltaic-thermal collectors, water/air solar collectors and spectrally selective surface solar collectors. The performances of these collectors consistent with their usage at different regions of the world are concisely reported. The development of the primary component of the system, namely, the collector/radiator, vis-a-vis the combined heating and cooling function is examined. Current state of global system take ups are reported with factors limiting the widespread implementation. The prospects, technical advancements as well as technical, economic and societal constraints limiting the commercialization of the system are also reported, with suggestions for possible improvements.

International Journal of Energy for a Clean Environment

International Journal of Fluid Mechanics & Thermal Sciences

This paper examines the experimental study on a line axis concentrating solar energy collector fo... more This paper examines the experimental study on a line axis concentrating solar energy collector for water heating. The system considered consists of cylindrical solar radiation concentrator with a black coated tubular absorber positioned along its axis. A cold water tank is placed above the collector and a hot water tank positioned below it such that fluid flows in and out of the set up. Solar radiation absorber inlet header is connected to the cold water tank while its outlet header is connected to the hot water tank. These major components are supported by angle iron raised at a distance from the ground that depends on the location and function. Valves are used at strategic points on the connecting pipe lines to isolate the flow of water. When water is poured into the cold water chamber, and the control valve turned on, the water flows under gravity into the receiver/absorber tube. At the absorber section, heat is transferred from the steel tube to the circulating water and is consequently heated. The heated water, then flows into the returning tube against gravity, thereby restricting the heated water from flowing into the storage tank. At this stage, thermo-siphoning effect comes into play. As the temperature of the water increases, its density reduces while the mass remains constant in order to balance the effect of the reduction in density. Thus, there is a resultant increase in volume which consequently pushes the water level further along the returning pipe. Further increase in temperature reduces the water density and increases the volume of the water, thereby causing the heated water to flow into the insulated tank. Several experimental tests were carried out under meteorological condition at the Federal University of Technology Owerri, Nigeria at three different mass flow rates of 0.001kg/s, 0.002kg/s and 0.003kg/s. The solar water heater was tested while oriented in the East-West and North-South directions in order to determine the effects of orientation on the performance. Results obtained showed that a maximum temperature of 69.5°C, corresponding to 34.5°C increase in water temperature and a maximum instantaneous efficiency of 51.01% is possible. The aim of the study is to design a cheaper solar energy system capable of reducing energy bill within the developing countries of the world.

International Journal of Engineering and Technologies

The effects of compatibilizer (maleic anhydride-graft-polyethylene) on the mechanical properties ... more The effects of compatibilizer (maleic anhydride-graft-polyethylene) on the mechanical properties of pineapple leaf powder (PALP) filled high density polyethylene (HDPE) composites were studied. HDPE and PALP composites in the presence, or absence of the compatibilizer, maleic anhydride -graft- polyethylene (MA-g-PE) were prepared by injection moulding technique. The filler (PALP) contents investigated were 2, 4, 6, 8, and 10 wt%, while the MA-g-PE content was 3 wt% of the filler content for each formulation. The result of the mechanical tests carried out on the HDPE/PALP composites showed that the tensile strength, tensile modulus, abrasion resistance, and hardness of the composites increased as the filler content increases both in the presence, or absence of the compatibilizer (MA-g-PE) for all the filler contents investigated, while the elongation at break (EB) for PALP/HDPE composites was found to decrease as the filler content increases both in the presence, or absence of MA-g-P...

International Journal of Energy for a Clean Environment

The effects of compatibilizer (maleic anhydride-graft-polyethylene) on the mechanical properties ... more The effects of compatibilizer (maleic anhydride-graft-polyethylene) on the mechanical properties of pineapple leaf powder (PALP) filled high density polyethylene (HDPE) composites were studied. HDPE and PALP composites in the presence, or absence of the compatibilizer, maleic anhydride -graft- polyethylene (MA-g-PE) were prepared by injection moulding technique. The filler (PALP) contents investigated were 2, 4, 6, 8, and 10 wt%, while the MA-g-PE content was 3 wt% of the filler content for each formulation. The result of the mechanical tests carried out on the HDPE/PALP composites showed that the tensile strength, tensile modulus, abrasion resistance, and hardness of the composites increased as the filler content increases both in the presence, or absence of the compatibilizer (MA-g-PE) for all the filler contents investigated, while the elongation at break (EB) for PALP/HDPE composites was found to decrease as the filler content increases both in the presence, or absence of MA-g-P...