Sulaimon Shodiya - Academia.edu (original) (raw)

Papers by Sulaimon Shodiya

Arid Zone Journal of Engineering, Technology and Environment, Jun 1, 2019

The performance of paraffin wax as phase change material (PCM) for thermal energy storage (TES) w... more The performance of paraffin wax as phase change material (PCM) for thermal energy storage (TES) was investigated using a Solar Box Cooker (SBC) exposed to Maiduguri weather condition. Temperature and energy generated by SBC were experimentally established. The result shows tremendous improvement in energy storage compared to SBCs without TES in existence within Maiduguri and environs. The measured temperature and energy generated by the PCM in the experiment were 118oC and 4164.5KJ respectively, an adequate temperature and energy for cooking during off-sunshine hours and beyond. First figure of merit (F1) and second figure of merit (F2) were deduced to be 0.13 and 0.44 with overall SBC efficiency (ɳ) of 63% qualifying the SBC to grade A based on the Bureau of Indian Standards (BIS)

Current Journal: International Journal Applied Technology Research, 2021

Modeling is a basic tool of the real system simulation in translating the Mathematical results in... more Modeling is a basic tool of the real system simulation in translating the Mathematical results into real life. In this study, the Modeling and simulation of photovoltaic Module type PS-P310-36 were developed, and maximum power was obtained. The output I – V and P – V curves of the model were studied and analyzed under different irradiance (200 W/m2, 400 W/m, 600 W/m2, 800 W/m, and 1000 W/m2) at a constant temperature of 25oC. The model attained maximum power of 308, 251.6, 191.4, 129.2, and 64.74 W at 1000, 800, 600, 400, and 200 W/m2 irradiance, respectively. The model results agreed with the characteristics curves of the PV module of previous similar PV studies. The proposed model will serve as quick tools for designers in obtaining the maximum power of PV at distinct irradiance. However, for a more accurate design, more information is needed.

A capillary tube is an expansion and metering device used in small vapor compression refrigeratio... more A capillary tube is an expansion and metering device used in small vapor compression refrigeration systems such as household refrigerators and freezers. This paper presents a new empirical correlation for predicting refrigerant R-22 mass flow rate through adiabatic capillary tube using central composite design. The correlation is based on the previous researches that say the mass flow rate depends on four major parameters, namely the length of capillary tube, inner diameter of capillary tube, condenser temperature and degree of sub cooling. In the present study, the experimental data of the capillary tube covers capillary tube length ranging from 0.75 to 1.75 m, inner diameter from 1.11 to 1.40 mm, condensing temperature from 37 to 52 o C and degree of sub cooling from 2 to 14 o C.The correlation was tested with analysis of variance of 5% level of significance and the result showed that the equation model fitted well with the experimental data.

The ability to predict the quantity of energy to be produced is of paramount importance in every ... more The ability to predict the quantity of energy to be produced is of paramount importance in every country. It would assist in setting up a waste management plan which will lead to a sustainable energy policy. This paper presents the development of a statistical linear regression mathematical model to predict the amount of energy contained in municipal solid wastes from the knowledge of such characteristics of the wastes as physical composition and/or moisture content. Major cities of Kano, Katsina, Dutse, Damaturu, Maiduguri, Bauchi, Birnin Kebbi, Gusau and Sokoto in Northern Nigeria, with high population densities and intense industrial activities constituted the area of study. Ten kilogram each, of the municipal solid waste was collected from the government designated refuse dumping sites in both highly dense populated low income areas and government residential areas, during the hottest months of February, March and April and during the rainy season in the month of August for thre...

This paper shows the feasibility analysis of solar-wind hybrid power generation system and its po... more This paper shows the feasibility analysis of solar-wind hybrid power generation system and its potentials in the city: Maiduguri of Nigeria. The study mainly focuses on finding the wind and solar energy potentials of the study area by evaluating and quantifying the energy generated by the hybrid power system. An average wind speed of 6.72m/s at 30 m height and solar irradiance flux of 6.176kW/m 2 were used at the site, which shows that the potential of using wind-solar hybrid power system to generated power in Maiduguri location is feasible. The analytical data show that the annual energy output from the hybrid system increases in the range of 2-5MWh/m 2 yr, this indicates that the use of hybrid power could be a reliable source of power generation. 1.0 Introduction The importance of energy and needs for human and economic development are globally increasing. Human beings rely on the conventional sources of energy for their daily needs but the depleting and hazardous nature of this energy prompt the world's towards development utilization of renewable energy sources: solar, wind, biogas, tides, geothermal and water. Solar energy and wind energy were shown to be clean, available and inexhaustible which are also eco-friendly, these characteristics have made them more attractive and the energy sector is focusing on how to use these sources on a larger scale. However, all renewable energy sources have some drawbacks that depend on unpredictable factors such as weather and climatic conditions, but this weakness can be overcome by the complementary nature of both the wind and solar energy sources and this brings us to the development of hybrid solar-wind power plant concept (Dalwadi et al., 2012). The search for a more reliable and less costly renewable energy system has brought about the hybrid use of two energy sources: solar and wind energy. A hybrid energy system generates power without harming the environment. Sambo (2005) states that if solar energy appliances with just 5% efficiency are used to cover only 1% of the country's surface area, then 2.54 x 10 6 MWh of electrical energy can be obtained from solar energy. The solar energy potentials of Maiduguri are characterized by the high intensity of solar radiation of 6.176kW/m 2 /day and the average sunshine hours of about 9 hours (Ngala et al., 2013). The wind energy potential of Maiduguri is also characterized by the availability of flat land and an average wind speed of 4.7 m/s (Felix et al., 2012). Despite the abundance of these energy resources, there is persistent electricity supply deficit, which may be attributed to the under utilization of these potentials (Idris et al., 2012). The objective of this paper is to assess the feasibility of hybridizing Solar and Wind energy sources for power supply to meet the load requirements in Maiduguri.

Abstract. The present study both the motive nozzle device, based on the cooling capacity of as re... more Abstract. The present study both the motive nozzle device, based on the cooling capacity of as refrigerant. Previous studies HC290 (propane) in the air conditioner performance (COP). The purpose of replacing as an expansion device improve the COP. In developing the model, conservation laws of mass, momentum and energy equations were applied to each part of the ejector. The numerical results show mm) under varying constant-area decrease that improvement of the COP can reach 32.90 % at °C. From the results ejector can further improve the COP of a split as working fluid.

International Journal of Research in Engineering and Technology, 2016

Modeling and simulation of a PV-Wind hybrid electric power generation system is presented in this... more Modeling and simulation of a PV-Wind hybrid electric power generation system is presented in this paper. The system generates power from wind and solar energy sources and also supplies power to the Faculty of Engineering Teaching Workshop, University of Maiduguri, Nigeria. Ten years meteorological data (wind speed and solar irradiation) for Maiduguri was collected from the National Metrological Agency (NIMET) and analyzed using statistical and simulation software (HOMER). Theoretical models for predicting the electrical power generation potential of the hybrid system was developed and the wind and solar energy potentials of the desired site was investigated and analyzed. According to the results obtained through the analysis, the site has abundant solar energy and wind energy potential, about 2-5MWh/m 2 /yr of electrical power can be generated by using the hybrid system under ideal condition. The electric load of the workshop obtained from the energy audit carried out was about 370kWh/day and the scaled peak load is 140kW. The modeling, simulations and design has been carried out using the HOMER software based on the promising findings of these two renewable energy resource potentials. The software generates the simulation results which are lists of feasible power supply systems have been and arranged in ascending order according to their net present cost.

Arid Zone Journal of Engineering, Technology and Environment, 2017

This paper presents a numerical simulation of air velocity and air temperature distribution in an... more This paper presents a numerical simulation of air velocity and air temperature distribution in an office room of Computer Engineering Department of University of Maiduguri which is naturally ventilated. The office room under investigation with the dimension 5 m × 5 m × 4 m has a door in the East direction, and two windows, one in the East direction and the other in the South direction. For cost effectiveness, numerical solutions of steady-state airflow and heat transfer were done using a complete two-dimensional model. The results showed that the windows and the door could not undertake indoor heat load that can make the occupants to be thermally comfortable. In activity area where people sit and stand, the air velocity is moderate, this is about 0.98 m/s on the average. In addition, the temperature in this area is relatively high of about 302 K (29 °C) on the average. Based on the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) standard for comfor...

ATBU Journal of Science, Technology and Education, 2016

Thermal comfort has a great influence on the productivity and satisfaction of indoor building occ... more Thermal comfort has a great influence on the productivity and satisfaction of indoor building occupants. The exposure to excessive heat or cold during work may cause discomfort and contributed to low productivity among workers. Maiduguri, Borno State is known with its hot and cold condition during summer and hammattan weather respectively. Unimaid Engineering workshop had exposed to excessive temperature during summer and excessive cold during hammattan while working. The study investigates the thermal comfort level experienced by students at Unimaid Engineering workshop during hammattan season. The study had been conducted at the machining section, the foundry unit, fabrication section and engine section. The environmental factors examined were the relative humidity (%), air temperature and air velocity of the workshop area. The environmental factors were measured using Luton apparatus, which is capable of measuring simultaneously those mentioned environmental factors. Then thermal...

ATBU Journal of Science, Technology and Education, 2018

Potiskum, located on latitude 11.42 0 N, longitude 11.02 0 E and Altitude 414.8m 2 was evaluated ... more Potiskum, located on latitude 11.42 0 N, longitude 11.02 0 E and Altitude 414.8m 2 was evaluated for solar radiation for the possibilities of it as a remedy to the fluctuation of electricity in the area. Gunn-Bellani radiation integrator was used to evaluate the solar radiation for this region. Data obtained from the period of 1990 to 2004 was analyzed for clearness index as well as Global solar radiation. This been the only data available using Gunn-Bellani at the station. The result produced was found to be within the allowable value with an average clearness index of 0.66. This means that the sky in this location is clear for most part of the year for solar radiation to be received on a horizontal surface. Hargreaves - Samani’s equation was used as a method of estimating Global solar radiation using climatologically data’s. The mean monthly solar radiation was obtained as 23.59MJ/m 2 which is within the threshold for which Photovoltaic cell can be used to generate power.

ATBU Journal of Science, Technology and Education, 2020

The performance of Groundnut oil as phase change material (PCM) for thermal energy storage (TES) ... more The performance of Groundnut oil as phase change material (PCM) for thermal energy storage (TES) was investigated using a Solar Box Cooker (SBC) exposed to Maiduguri weather condition; Temperature and energy generated by SBC were experimentally established. The result shows tremendous improvement in energy storage compared to SBCs without TES in existence within Maiduguri and environs. The measured temperature and energy generated by the PCM in the experiment were 137 o C and 307KJ respectively, an adequate temperature and energy stored by the PCM for cooking during off-sunshine hours. First figure of merit (F 1 ) and second figure of merit (F 2 ) were deduced to be 0.13 and 0.4 with overall SBC efficiency (ɳ) of 32% qualifying the SBC to grade ‘A’ based on the Bureau of Indian Standards (BIS).

Arid Zone Journal of Engineering, Technology and Environment, 2017

The study presents an application of the artificial neural network model using the back propagati... more The study presents an application of the artificial neural network model using the back propagation learning algorithm to predict the actual calorific value of the municipal solid waste in major cities of the northern part of Nigeria, with high population densities and intense industrial activities. These cities are: Kano, Damaturu, Dutse, Bauchi, Birnin Kebbi, Gusau, Maiduguri, Katsina and Sokoto. Experimental data of the energy content and the physical characterization of the municipal solid waste serve as the input parameter in nature of wood, grass, metal, plastic, food remnants, leaves, glass and paper. Comparative studies were made by using the developed model, the experimental results and a correlation which was earlier developed by the authors to predict the energy content. While predicting the actual calorific value, the maximum error was 0.94% for the artificial neural network model and 5.20% by the statistical correlation. The network with eight neurons and an R2 = 0.9688...

Capillary tubes are expansion device which are commonly used in small vapour compression refriger... more Capillary tubes are expansion device which are commonly used in small vapour compression refrigeration systems. An artificial neural network (ANN), a feed-forward network with back propagation algorithm was developed using alternative refrigerant. The feed-forward ANN with three-layers is used as a universal approximator for the multiple-input and single-output non-linear function. For the ANN training and testing, experimental data for refrigerant HC290/HC600a/HFC407C mixture from open literature was used. The most appropriate number of neurons in the hidden layer was found to be fifteen with average error between the predicted mass flow rate from ANN and experimental data is less than 1.6%. This paper shows the suitability of ANN for the predictions of mass flow rate of alternative refrigerant flowing through adiabatic capillary tube.

Arid Zone Journal of Engineering, Technology and Environment, 2019

Energy storage in some form is the need of the hour to even out the mismatch between energy suppl... more Energy storage in some form is the need of the hour to even out the mismatch between energy supply and demand. Thermal Energy Storage (TES) system employing a phase change material (PCM) has been widely considered as an effective way to store and retrieve energy due to its high heat storage capacity at almost constant temperature during the phase change. In this work, an energy storage system was designed to study the heat transfer characteristics of stearic acid (as a phase change material in a double compartment solar box cooker (DCSBC) fabricated using wooden materials with high thermal energy storage system. In order to analyze the various characteristics of the PCM, the Bureau of Indian Standards (BIS) was used throughout the experiment. Investigations were performed to determine the first and second figure of merits (F1 and F2) of compartments 1 and 2 (C1 and C2) simultaneously. The results for F1 were found to be (C1= 0.14 and C2= 0.15) and F2 were (C1=0.47 and C2= 0.4) while...

The present study both the motive nozzle and device, based on the cooling capacity of as refriger... more The present study both the motive nozzle and device, based on the cooling capacity of as refrigerant. Previous studies HC290 (propane) in the air conditioner performance (COP). The purpose of replacing as an expansion device i n improve the COP. In developing the model, conservat ion laws of mass, momentum and energy equations were applied to each p rt of the ejector. The numerical results show that the mm) under varying condenser temperature constant-area decreases as that improvement of the COP can reach 32.90% at °C. From the results mentioned ejector can further improve the COP of a split as working fluid.

In a hot climate like Maiduguri, one of the conventional approaches for providing comfortable env... more In a hot climate like Maiduguri, one of the conventional approaches for providing comfortable environment is the use of natural ventilation. In some cases, this strategy does provide the suitable thermal environment in a large space building such as the mosque. This study evaluated the thermal comfort of a naturally ventilated large space building, the university of Maiduguri central mosque in Maiduguri, Borno state during different times of daily prayers. The field study was conducted in 16th December 2015 (harmattan season) and April 2016 (hot season) during subuh, zuhr, Asri, Magrib and Ishai prayer times. During these days, the objective measurement using LUTRON ABH-4224 Cup Anemometer instrument and subjective assessment using questionnaire were accomplished. The objective parameters measured were air temperature, relative humidity and air velocity and the subjective responses concern the thermal condition of the respondents. Through linear regression analysis, Predictive Mean ...

AIP Conference Proceedings, 2012

ABSTRACT

Journal of Engineering and Technological Sciences, 2014

The capillary tube is an important control device used in small vapor compression refrigeration s... more The capillary tube is an important control device used in small vapor compression refrigeration systems such as window air-conditioners, household refrigerators and freezers. This paper develops a non-dimensional correlation based on the test results of the adiabatic capillary tube for the mass flow rate through the tube using a hydrocarbon refrigerant mixture of 89.3% propane and 10.7% butane (HCM). The Taguchi method, a statistical experimental design approach, was employed. This approach explores the economic benefit that lies in studies of this nature, where only a small number of experiments are required and yet valid results are obtained. Considering the effects of the capillary tube geometry and the inlet condition of the tube, dimensionless parameters were chosen. The new correlation was also based on the Buckingham Pi theorem. This correlation predicts 86.67% of the present experimental data within a relative deviation of-10% to +10%. The predictions by this correlation were also compared with results in published literature.

Applied Mechanics and Materials, 2013

This paper presents a numerical approach for determining the motive nozzle and constant-area of a... more This paper presents a numerical approach for determining the motive nozzle and constant-area of an ejector as an expansion device, based on cooling capacity of the split-type air conditioner using R22 as working fluid. The use of an ejector as an expansion device in split-type air conditioner can enhance the coefficient of performance (COP) system. Typically, the split-type air conditioner may be installed on the geographical area with moderate or high outdoor air temperature using capillary tube. For this reason, the motive nozzle and constant-area diameters of the ejector must be designed according to these conditions. The diameters of the ejector are crucial in improving the COP. The results showed that the motive nozzle diameter is constant (1.14 mm) with variations of the condenser temperature, whereas the constant-area diameter decreases as the condenser temperature increases.

Arid Zone Journal of Engineering, Technology and Environment, Jun 1, 2019

The performance of paraffin wax as phase change material (PCM) for thermal energy storage (TES) w... more The performance of paraffin wax as phase change material (PCM) for thermal energy storage (TES) was investigated using a Solar Box Cooker (SBC) exposed to Maiduguri weather condition. Temperature and energy generated by SBC were experimentally established. The result shows tremendous improvement in energy storage compared to SBCs without TES in existence within Maiduguri and environs. The measured temperature and energy generated by the PCM in the experiment were 118oC and 4164.5KJ respectively, an adequate temperature and energy for cooking during off-sunshine hours and beyond. First figure of merit (F1) and second figure of merit (F2) were deduced to be 0.13 and 0.44 with overall SBC efficiency (ɳ) of 63% qualifying the SBC to grade A based on the Bureau of Indian Standards (BIS)

Current Journal: International Journal Applied Technology Research, 2021

Modeling is a basic tool of the real system simulation in translating the Mathematical results in... more Modeling is a basic tool of the real system simulation in translating the Mathematical results into real life. In this study, the Modeling and simulation of photovoltaic Module type PS-P310-36 were developed, and maximum power was obtained. The output I – V and P – V curves of the model were studied and analyzed under different irradiance (200 W/m2, 400 W/m, 600 W/m2, 800 W/m, and 1000 W/m2) at a constant temperature of 25oC. The model attained maximum power of 308, 251.6, 191.4, 129.2, and 64.74 W at 1000, 800, 600, 400, and 200 W/m2 irradiance, respectively. The model results agreed with the characteristics curves of the PV module of previous similar PV studies. The proposed model will serve as quick tools for designers in obtaining the maximum power of PV at distinct irradiance. However, for a more accurate design, more information is needed.

A capillary tube is an expansion and metering device used in small vapor compression refrigeratio... more A capillary tube is an expansion and metering device used in small vapor compression refrigeration systems such as household refrigerators and freezers. This paper presents a new empirical correlation for predicting refrigerant R-22 mass flow rate through adiabatic capillary tube using central composite design. The correlation is based on the previous researches that say the mass flow rate depends on four major parameters, namely the length of capillary tube, inner diameter of capillary tube, condenser temperature and degree of sub cooling. In the present study, the experimental data of the capillary tube covers capillary tube length ranging from 0.75 to 1.75 m, inner diameter from 1.11 to 1.40 mm, condensing temperature from 37 to 52 o C and degree of sub cooling from 2 to 14 o C.The correlation was tested with analysis of variance of 5% level of significance and the result showed that the equation model fitted well with the experimental data.

The ability to predict the quantity of energy to be produced is of paramount importance in every ... more The ability to predict the quantity of energy to be produced is of paramount importance in every country. It would assist in setting up a waste management plan which will lead to a sustainable energy policy. This paper presents the development of a statistical linear regression mathematical model to predict the amount of energy contained in municipal solid wastes from the knowledge of such characteristics of the wastes as physical composition and/or moisture content. Major cities of Kano, Katsina, Dutse, Damaturu, Maiduguri, Bauchi, Birnin Kebbi, Gusau and Sokoto in Northern Nigeria, with high population densities and intense industrial activities constituted the area of study. Ten kilogram each, of the municipal solid waste was collected from the government designated refuse dumping sites in both highly dense populated low income areas and government residential areas, during the hottest months of February, March and April and during the rainy season in the month of August for thre...

This paper shows the feasibility analysis of solar-wind hybrid power generation system and its po... more This paper shows the feasibility analysis of solar-wind hybrid power generation system and its potentials in the city: Maiduguri of Nigeria. The study mainly focuses on finding the wind and solar energy potentials of the study area by evaluating and quantifying the energy generated by the hybrid power system. An average wind speed of 6.72m/s at 30 m height and solar irradiance flux of 6.176kW/m 2 were used at the site, which shows that the potential of using wind-solar hybrid power system to generated power in Maiduguri location is feasible. The analytical data show that the annual energy output from the hybrid system increases in the range of 2-5MWh/m 2 yr, this indicates that the use of hybrid power could be a reliable source of power generation. 1.0 Introduction The importance of energy and needs for human and economic development are globally increasing. Human beings rely on the conventional sources of energy for their daily needs but the depleting and hazardous nature of this energy prompt the world's towards development utilization of renewable energy sources: solar, wind, biogas, tides, geothermal and water. Solar energy and wind energy were shown to be clean, available and inexhaustible which are also eco-friendly, these characteristics have made them more attractive and the energy sector is focusing on how to use these sources on a larger scale. However, all renewable energy sources have some drawbacks that depend on unpredictable factors such as weather and climatic conditions, but this weakness can be overcome by the complementary nature of both the wind and solar energy sources and this brings us to the development of hybrid solar-wind power plant concept (Dalwadi et al., 2012). The search for a more reliable and less costly renewable energy system has brought about the hybrid use of two energy sources: solar and wind energy. A hybrid energy system generates power without harming the environment. Sambo (2005) states that if solar energy appliances with just 5% efficiency are used to cover only 1% of the country's surface area, then 2.54 x 10 6 MWh of electrical energy can be obtained from solar energy. The solar energy potentials of Maiduguri are characterized by the high intensity of solar radiation of 6.176kW/m 2 /day and the average sunshine hours of about 9 hours (Ngala et al., 2013). The wind energy potential of Maiduguri is also characterized by the availability of flat land and an average wind speed of 4.7 m/s (Felix et al., 2012). Despite the abundance of these energy resources, there is persistent electricity supply deficit, which may be attributed to the under utilization of these potentials (Idris et al., 2012). The objective of this paper is to assess the feasibility of hybridizing Solar and Wind energy sources for power supply to meet the load requirements in Maiduguri.

Abstract. The present study both the motive nozzle device, based on the cooling capacity of as re... more Abstract. The present study both the motive nozzle device, based on the cooling capacity of as refrigerant. Previous studies HC290 (propane) in the air conditioner performance (COP). The purpose of replacing as an expansion device improve the COP. In developing the model, conservation laws of mass, momentum and energy equations were applied to each part of the ejector. The numerical results show mm) under varying constant-area decrease that improvement of the COP can reach 32.90 % at °C. From the results ejector can further improve the COP of a split as working fluid.

International Journal of Research in Engineering and Technology, 2016

Modeling and simulation of a PV-Wind hybrid electric power generation system is presented in this... more Modeling and simulation of a PV-Wind hybrid electric power generation system is presented in this paper. The system generates power from wind and solar energy sources and also supplies power to the Faculty of Engineering Teaching Workshop, University of Maiduguri, Nigeria. Ten years meteorological data (wind speed and solar irradiation) for Maiduguri was collected from the National Metrological Agency (NIMET) and analyzed using statistical and simulation software (HOMER). Theoretical models for predicting the electrical power generation potential of the hybrid system was developed and the wind and solar energy potentials of the desired site was investigated and analyzed. According to the results obtained through the analysis, the site has abundant solar energy and wind energy potential, about 2-5MWh/m 2 /yr of electrical power can be generated by using the hybrid system under ideal condition. The electric load of the workshop obtained from the energy audit carried out was about 370kWh/day and the scaled peak load is 140kW. The modeling, simulations and design has been carried out using the HOMER software based on the promising findings of these two renewable energy resource potentials. The software generates the simulation results which are lists of feasible power supply systems have been and arranged in ascending order according to their net present cost.

Arid Zone Journal of Engineering, Technology and Environment, 2017

This paper presents a numerical simulation of air velocity and air temperature distribution in an... more This paper presents a numerical simulation of air velocity and air temperature distribution in an office room of Computer Engineering Department of University of Maiduguri which is naturally ventilated. The office room under investigation with the dimension 5 m × 5 m × 4 m has a door in the East direction, and two windows, one in the East direction and the other in the South direction. For cost effectiveness, numerical solutions of steady-state airflow and heat transfer were done using a complete two-dimensional model. The results showed that the windows and the door could not undertake indoor heat load that can make the occupants to be thermally comfortable. In activity area where people sit and stand, the air velocity is moderate, this is about 0.98 m/s on the average. In addition, the temperature in this area is relatively high of about 302 K (29 °C) on the average. Based on the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) standard for comfor...

ATBU Journal of Science, Technology and Education, 2016

Thermal comfort has a great influence on the productivity and satisfaction of indoor building occ... more Thermal comfort has a great influence on the productivity and satisfaction of indoor building occupants. The exposure to excessive heat or cold during work may cause discomfort and contributed to low productivity among workers. Maiduguri, Borno State is known with its hot and cold condition during summer and hammattan weather respectively. Unimaid Engineering workshop had exposed to excessive temperature during summer and excessive cold during hammattan while working. The study investigates the thermal comfort level experienced by students at Unimaid Engineering workshop during hammattan season. The study had been conducted at the machining section, the foundry unit, fabrication section and engine section. The environmental factors examined were the relative humidity (%), air temperature and air velocity of the workshop area. The environmental factors were measured using Luton apparatus, which is capable of measuring simultaneously those mentioned environmental factors. Then thermal...

ATBU Journal of Science, Technology and Education, 2018

Potiskum, located on latitude 11.42 0 N, longitude 11.02 0 E and Altitude 414.8m 2 was evaluated ... more Potiskum, located on latitude 11.42 0 N, longitude 11.02 0 E and Altitude 414.8m 2 was evaluated for solar radiation for the possibilities of it as a remedy to the fluctuation of electricity in the area. Gunn-Bellani radiation integrator was used to evaluate the solar radiation for this region. Data obtained from the period of 1990 to 2004 was analyzed for clearness index as well as Global solar radiation. This been the only data available using Gunn-Bellani at the station. The result produced was found to be within the allowable value with an average clearness index of 0.66. This means that the sky in this location is clear for most part of the year for solar radiation to be received on a horizontal surface. Hargreaves - Samani’s equation was used as a method of estimating Global solar radiation using climatologically data’s. The mean monthly solar radiation was obtained as 23.59MJ/m 2 which is within the threshold for which Photovoltaic cell can be used to generate power.

ATBU Journal of Science, Technology and Education, 2020

The performance of Groundnut oil as phase change material (PCM) for thermal energy storage (TES) ... more The performance of Groundnut oil as phase change material (PCM) for thermal energy storage (TES) was investigated using a Solar Box Cooker (SBC) exposed to Maiduguri weather condition; Temperature and energy generated by SBC were experimentally established. The result shows tremendous improvement in energy storage compared to SBCs without TES in existence within Maiduguri and environs. The measured temperature and energy generated by the PCM in the experiment were 137 o C and 307KJ respectively, an adequate temperature and energy stored by the PCM for cooking during off-sunshine hours. First figure of merit (F 1 ) and second figure of merit (F 2 ) were deduced to be 0.13 and 0.4 with overall SBC efficiency (ɳ) of 32% qualifying the SBC to grade ‘A’ based on the Bureau of Indian Standards (BIS).

Arid Zone Journal of Engineering, Technology and Environment, 2017

The study presents an application of the artificial neural network model using the back propagati... more The study presents an application of the artificial neural network model using the back propagation learning algorithm to predict the actual calorific value of the municipal solid waste in major cities of the northern part of Nigeria, with high population densities and intense industrial activities. These cities are: Kano, Damaturu, Dutse, Bauchi, Birnin Kebbi, Gusau, Maiduguri, Katsina and Sokoto. Experimental data of the energy content and the physical characterization of the municipal solid waste serve as the input parameter in nature of wood, grass, metal, plastic, food remnants, leaves, glass and paper. Comparative studies were made by using the developed model, the experimental results and a correlation which was earlier developed by the authors to predict the energy content. While predicting the actual calorific value, the maximum error was 0.94% for the artificial neural network model and 5.20% by the statistical correlation. The network with eight neurons and an R2 = 0.9688...

Capillary tubes are expansion device which are commonly used in small vapour compression refriger... more Capillary tubes are expansion device which are commonly used in small vapour compression refrigeration systems. An artificial neural network (ANN), a feed-forward network with back propagation algorithm was developed using alternative refrigerant. The feed-forward ANN with three-layers is used as a universal approximator for the multiple-input and single-output non-linear function. For the ANN training and testing, experimental data for refrigerant HC290/HC600a/HFC407C mixture from open literature was used. The most appropriate number of neurons in the hidden layer was found to be fifteen with average error between the predicted mass flow rate from ANN and experimental data is less than 1.6%. This paper shows the suitability of ANN for the predictions of mass flow rate of alternative refrigerant flowing through adiabatic capillary tube.

Arid Zone Journal of Engineering, Technology and Environment, 2019

Energy storage in some form is the need of the hour to even out the mismatch between energy suppl... more Energy storage in some form is the need of the hour to even out the mismatch between energy supply and demand. Thermal Energy Storage (TES) system employing a phase change material (PCM) has been widely considered as an effective way to store and retrieve energy due to its high heat storage capacity at almost constant temperature during the phase change. In this work, an energy storage system was designed to study the heat transfer characteristics of stearic acid (as a phase change material in a double compartment solar box cooker (DCSBC) fabricated using wooden materials with high thermal energy storage system. In order to analyze the various characteristics of the PCM, the Bureau of Indian Standards (BIS) was used throughout the experiment. Investigations were performed to determine the first and second figure of merits (F1 and F2) of compartments 1 and 2 (C1 and C2) simultaneously. The results for F1 were found to be (C1= 0.14 and C2= 0.15) and F2 were (C1=0.47 and C2= 0.4) while...

The present study both the motive nozzle and device, based on the cooling capacity of as refriger... more The present study both the motive nozzle and device, based on the cooling capacity of as refrigerant. Previous studies HC290 (propane) in the air conditioner performance (COP). The purpose of replacing as an expansion device i n improve the COP. In developing the model, conservat ion laws of mass, momentum and energy equations were applied to each p rt of the ejector. The numerical results show that the mm) under varying condenser temperature constant-area decreases as that improvement of the COP can reach 32.90% at °C. From the results mentioned ejector can further improve the COP of a split as working fluid.

In a hot climate like Maiduguri, one of the conventional approaches for providing comfortable env... more In a hot climate like Maiduguri, one of the conventional approaches for providing comfortable environment is the use of natural ventilation. In some cases, this strategy does provide the suitable thermal environment in a large space building such as the mosque. This study evaluated the thermal comfort of a naturally ventilated large space building, the university of Maiduguri central mosque in Maiduguri, Borno state during different times of daily prayers. The field study was conducted in 16th December 2015 (harmattan season) and April 2016 (hot season) during subuh, zuhr, Asri, Magrib and Ishai prayer times. During these days, the objective measurement using LUTRON ABH-4224 Cup Anemometer instrument and subjective assessment using questionnaire were accomplished. The objective parameters measured were air temperature, relative humidity and air velocity and the subjective responses concern the thermal condition of the respondents. Through linear regression analysis, Predictive Mean ...

AIP Conference Proceedings, 2012

ABSTRACT

Journal of Engineering and Technological Sciences, 2014

The capillary tube is an important control device used in small vapor compression refrigeration s... more The capillary tube is an important control device used in small vapor compression refrigeration systems such as window air-conditioners, household refrigerators and freezers. This paper develops a non-dimensional correlation based on the test results of the adiabatic capillary tube for the mass flow rate through the tube using a hydrocarbon refrigerant mixture of 89.3% propane and 10.7% butane (HCM). The Taguchi method, a statistical experimental design approach, was employed. This approach explores the economic benefit that lies in studies of this nature, where only a small number of experiments are required and yet valid results are obtained. Considering the effects of the capillary tube geometry and the inlet condition of the tube, dimensionless parameters were chosen. The new correlation was also based on the Buckingham Pi theorem. This correlation predicts 86.67% of the present experimental data within a relative deviation of-10% to +10%. The predictions by this correlation were also compared with results in published literature.

Applied Mechanics and Materials, 2013

This paper presents a numerical approach for determining the motive nozzle and constant-area of a... more This paper presents a numerical approach for determining the motive nozzle and constant-area of an ejector as an expansion device, based on cooling capacity of the split-type air conditioner using R22 as working fluid. The use of an ejector as an expansion device in split-type air conditioner can enhance the coefficient of performance (COP) system. Typically, the split-type air conditioner may be installed on the geographical area with moderate or high outdoor air temperature using capillary tube. For this reason, the motive nozzle and constant-area diameters of the ejector must be designed according to these conditions. The diameters of the ejector are crucial in improving the COP. The results showed that the motive nozzle diameter is constant (1.14 mm) with variations of the condenser temperature, whereas the constant-area diameter decreases as the condenser temperature increases.