Heat Transfer and Fluid Flow Characteristics Study for In-Line Tube Bank in Cross-Flow

This research investigates the heat transfer coefficient as a function of tube position and pressure drop, for in-line tube bank in cross-flow. Experimentation was essentially used to generate log-mean temperature curves and pressure heads upstream and down stream of the test section. The heat transfer and flow parameters such as Nusselt number, Reynolds number, and pressure drop across the bank were calculated. In addition, heat transfer correlations, Nusselt number (Nu) were obtained by power-law curve fitting for each position of the tube in the tube bank. FEMLAB 3.0 was use for numerical simulation and the results obtained compared favourably with that of the experimental results. Numerical results also reveal the important aspects of the local heat transfer and flow features within the tube bank. These characteristics include boundary layer developments between tubes, formation of vortices, local variations of the velocity and temperature distribution

Experimental investigation and thermal analysis of solar air heater having rectangular rib roughness on the absorber plate

Thisstudypresentsexperimentalinvestigationandthermalanalysisofsolarairheaterhavingrectangularroughnessontheabsorberplate.Thesolarairheaterusedfortheexperimentwaslocallyfabricated.Themaximumintensityofsolarradiation,ambientandsolarairheatertem-perature were 827.87W/m2, 33.77 and 112.0°C respectively during the day time period of9:00–18:00hoperation.Thecalculatedthermalefficiencyvaluerangedbetween14.0to56.5%.Thesimulatedminimumandmaximumtemperatureofthesolarairheaterwere21and127°Crespectively,whichwereinreasonableagreementwithexperimentresultof20and112°C.Thus,the solar air heater was considered capable of handling processes such as drying of variousagriculturalproducts,waterheatingetc.withtemperaturecontrolmechanism

Wind Energy Systems for Omu Aran, Kwara State, Nigeria

The quest for energy from renewable and sustainable sources has led to the investment on exploration and installations of wind energy systems to harness energy from wind for use by mankind. Various wind energy systems exist and they are quite expensive. Selections of appropriate systems for installation are dependent on the wind power available in a location. It is therefore important that proper wind assessment is done before investments on infrastructures for harnessing wind power are put in place. Wind data between 2014 and 2018 were obtained from the Landmark University Weather Station in Omu Aran and the pattern of wind speed distribution in the location over the years in focus were determined by the Weibull function. The power law was used to estimate the wind speeds at heights of 10 and 20 metres respectively. Recommendations on appropriate wind energy systems suitable for Omu Aran region were made based on the wind speed pattern

CONSTRUCTIONOF INVERTER POWEREDLAWN MOWER

The need for the maintenance of lawns through cutting and trimming cannot be overlooked in sporting fields, residential houses, hotel, hospital and others.Furthermore; some lawns are specially bred for the sake of aesthetic.However, in some places like hospitals, special health care and rehabilitationcenters, the natural beauty of the environment is believedto contribute to a great deal in aiding the recovery and healing the mentally and physically challenged patients. This contributory effect onthe lawn has made lawn care to be involved with a great admiration. An inverter powered lawnmower was designed and constructed using the locally available materials such as a 2KVA inverter, prime mover (electric motor) of a rating of 370W, a 60Amphour battery and a 12 Voltbattery. It is of advantage over the existing ones because it uses no fuel consumption, it emits no smoke which causes air pollution, and it has no internal combustion engine to drive the motor of the machine. This lawnmower was designed to mow for a period of two (2) hours and the discharged battery can be recharged with theaid of the inverter when connected to an A.C supply.Thisstudy showed that this type of machineis most suitable in Nigeriabecause no fuel is needed to power this machine. The unit is simple, light and easy to maneuver

Co-digestion of Theobroma cacao(Cocoa)pod husk and poultry manure for energy generation: Effects of pretreatment methods

In this study, biogas was produced from the anaerobic co-digestion of Cocoa pod husk (CPH) and poultry manure. Pretreatment of the CPH was carried out using sulfuric acid and hydrogen peroxide. The physicochemical, elemental and structural analyses were carried out on the CPH before and after pretreatment. The microbial composition of the fermenting materials were also determined using standard method while the Fourier Transform Infra-red (FTIR) spectroscopy was used to identify the structural changes that took place after pretreatments. Use of alkaline hydrogen peroxide caused high solubilization of the lignin component of the CPH and reduced up to 81% of lignin i.e. initial value of 21.7% m.m−1 to final value of 4.2% m.m−1. Similarly, the alkali reduced the hemicellulose content of the CPH from 27.0% m.m−1 to 8.5% m.m−1. Overall, there was 68% increase in biogas volume from the alkaline pretreated CPH

Experimental Comparison of Staggered and In-line Tube-bank Thermal Performance.

Experimental investigation of fluid flow and heat transfer were performed for cross-flow tube-type heat exchanger in staggered and in-line arrangement. The purpose of this work was to determine the process of forced convection heat transfer of air over a heated cylindrical pure copper rod. Also, the work was to compare the performance of both staggered and in-line tube bundle configurations. Tube bank with staggered arrangement consisted of 25 mm transverse pitch, 18.75 mm longitudinal pitch, 20 cylindrical rods of diameter12.5 mm, in a 125 x 125 mm cross section. An in-line tube arrangement was constructed based on the staggered tube bank dimensions. During the test, the working sections were placed one after the other in a specially design testing rig air channel through which the fluid flowed normal to the tube. A complete set of test were taken with the heated element in each of the four banks of tube for ten different throttle openings in the range of 10 to 100%. The test results show that the heat transfer coefficient associated with the tube is a function of its position in the tube bank. Higher heat transfer coefficients were obtained in the subsequent tube bank downstream of the first row. However, the heat transfer coefficients stabilize, such that little change occurs for tube beyond the fourth row. The overall heat transfer coefficient for staggered tube arrangement was found to be 4.28% higher than of the in-line tube arrangement

Characterization and projection of dry season municipal solid waste for energy production in Ilorin metropolis, Nigeria

This research investigates the quantity of municipal solid waste produced during the dry season, and its characterization at Eyenkorin dumpsite of Ilorin metropolis, along the Lagos-Ilorin express way. The physicochemical and thermal compositions of the combustible fractions of municipal solid waste were analysed, to ascertain the available calorific value. In this research, the quantity (tonnes) of waste generated, the rate of generation (kg per capita per day), its sustainability and the likely energy and power potentials in the dry season, were essentially predicted. The population responsible for municipal solid waste generation during this study was 1,120,834 people. During the characterization study from November 2018 to February 2019, it was established that 203,831 tonnes of municipal solid waste was produced during the four months of the dry season, at the rate of 1.12 kg per capita per day. It was found that 280 tonnes/day of municipal solid waste with low heating value of 19 MJ kg-1, would generate 1478 MWh of heat energy and 18 MW of electrical energy potentials discretely, and grid of 13 kW

PROMOTING ECO-FRIENDLY CORROSION INHIBITOR USING BITTER KOLA LEAVES IN CARBON MILD STEEL USING HCLACIDIC MEDIA

Corrosion of mild steel in HCl was investigated using the weight loss method. The mild steel used was cut into 16 coupons with 5.0 cm x 5.0 cm x 0.2 cm dimensions which weredegreased with ethanol and washed with distilled water and finally weighed. The mild steel coupons were exposed to HCl with varied concentrations (0, 10, 25 and 40%) of Garcinia kola extracts used as corrosion inhibitors for 4 hours at 400C and 600C respectively. The result showed that at 400C; the inhibition efficiency of 65.5% was observed at 25 % HCl concentration and 62.9% at 40% HCl concentration while at 600C; inhibition efficiency of 87.7% was at 25% HCl concentration and 88.1% at 40% concentration respectively. It can be concluded that increase in concentration increases the inhibition efficiency. The presence of flavonoid and alkanoids in bitter kola stem is a good inhibito

Health Risk Assessment of Groundwater in Omu-Aran, Nigeria

Pollution of groundwater by bathroom, laundry and kitchen effluent has been documented to have non-desirable health and environmental effects. There is little information about the quality of groundwater and associated health effects in Omu-Aran. The present research therefore meets the need to investigate the levels of heavy metals, the pollution effects, and the long term human health risk effect on local inhabitants in Omu-Aran. Thirty water samples were collected from five hand dug wells (HWs) in different parts of Omu-Aran spanning a period of three months and the heavy metal parameters were determined using standard protocol. The non-carcinogenic risk was evaluated using hazard index (HI) according to United States Environmental Protection Agency (USEPA) risk assessment method. Data analysis were carried out by the use of descriptive statistics. From the result, mean values and SD of heavy metals in the water samples obtained from selected HWs ranged from 0.16 ± 0.13 to 0.29 ± 0.18 mg/L, 0.29 ± 0.02 to 1.36 ± 0.07 mg/L, 0.00 ± 0.00 to 0.72 ± 0.04 mg/L, 0.00 ± 0.00 to 0.51 ± 0.09 mg/L, 0.01 ± 0.01 to 5.26 ± 0.07 mg/L, and from 0.03 ± 0.01 to 12.96 ± 2.82 mg/L for Al, Fe, Mn, Cr, Cu, and Zn respectively. The heavy metals were all above the WHO limits except Pb and Fe. The hazard index values ranged from 1.406 to 10.075 indicating significant non-carcinogenic risk. The findings of the study, has shown that there is considerable amount of heavy metal pollution which stems from anthropogenic sources. There was no observable risk via dermal pathways based on hazard quotient values while non-carcinogenic risk via ingestion was observed for all the locations. There is therefore a need to bring awareness to the community for the purpose of ensuring safety of its active water sources

Climate Change and Potential Environmental Hazards with Perspective Adaptation Technologies in Nigeria, A review

Abstract. Climate change is a global phenomenon with multifarious unique regional consequences. Contemporary studies have established Climate change as a product of anthropogenic activities. Studies have linked extreme weather events, heat waves, increase pollution, crop failure as some of the many discernable effects of climate change. Hence, the spatial temporal effects of Climate change are of concern to policy makers, researchers, innovators and the entire public to develop veritable mitigation strategies. This paper examines climate change in Nigeria as a case study; the research adopted desk research method to collect secondary data from literature about hazards caused by climate change and potential adaptation strategies in Nigeria. The findings revealed that a potential environmental hazard caused by climate change in Nigeria includes that of biological, chemical, physical, mechanical and psycho-social. Moreover, this review further showed adaptation technologies that can be used in adapting and mitigating climate change in Nigeria