Fidelis I. Abam

A Typical Meteorological Year Generation Based on NASA Satellite Imagery (GEOS-I) for Sokoto, Nigeria

Computer simulation of buildings and solar energy systems are being used increasingly in energy assessments and design. This paper evaluates the typical meteorological year (TMY) for Sokoto, northwest region, Nigeria, using 23-year hourly weather data including global solar radiation, dew point temperature, mean temperature, maximum temperature, minimum temperature, relative humidity, and wind speed. Filkenstein-Schafer statistical method was utilized for the creation of a TMY for the site. The persistence of mean dry bulb temperature and daily global horizontal radiation on the five candidate months were evaluated. TMY predictions were compared with the 23-year long-term average values and are found to have close agreement and can be used in building energy simulation for comparative energy efficiency study.

Economics of wind energy utilisation for water pumping and CO2 mitigation potential in Niger Delta, Nigeria

ABSTRACT The wind characteristics of six locations in Niger Delta, Nigeria, and the economics of the application of wind energy for water pumping and possible avoidable CO2 emissions through wind utilisation were examined. The wind data were measured at 10 m height and analysed using the two-parameter Weibull model. Small size wind turbines were accessed with Goulds 45J03 water pump series. The average power density, average energy density and annual energy across locations ranged between  W/m2,  kWh/m2 and  kWh/m2/year, respectively. Bergey Excel-10 kW turbine had the lowest cost of energy and water pumping cost of

Exergetic performance indicators of a direct evaporative cooling system with different evaporative cooling pads

/kWh and

Thermodynamic performance and environmental sustainability of adapted organic Rankine cycles at varying evaporator pressure

/m3, respectively. The annual capacity of water yield varies from 21,847 to 120,206 m3/year on a total dynamic head of 50 m. Furthermore, the annual diesel saved across the locations ranged from 1605 to 8696 l/year (17.47 to 94.67 GJ/year), while the annual averaged CO2 saved was between 4.32 and 22.93 tons/year.

Performance evaluation of aeroderivative gas turbine models derived from a high bypass turbofan for industrial power generation

ABSTRACT Exergetic performance indicators (EPIs) of a direct evaporative cooling system (DECS) with different evaporative cooling pads (ECPs) are presented. The objective is to determine the performance and exergetic sustainability indicators of three ECPs (wood charcoal, shredded foam latex and jute fibre). The EPIs include exergy efficiency (EE), waste exergy ratio (WER), the exergetic coefficient of performance (ECOP), exergy destruction factor (EDF) and sustainability index (SI). The calculated EE values lie between , and for shredded foam, wood charcoal and jute fibre respectively while the EDF, WER, ECOP and SI ranged between, , and respectively. The EDF was the maximum in shredded foam latex and low for wood charcoal. Conversely, a comparative analysis between the DECS and mechanical vapour compression system shows that an average of 18.92 tonnes/year of CO2 emissions can be avoided if the DECS was preferred. Additionally, jute fibre showed good performance and high SI, thus, its adoption in the DECS is worthwhile.

Off-wing fleet maintenance study of a CFM56-3B turbofan engine: the propulsive engine of Boeing 737-300 civil aircraft.

ABSTRACT Thermodynamic performance and environmental sustainability (ES) of adapted organic Rankine cycles (ORCs) at varying evaporator pressure (EVP) are presented. The paper assesses the most sustainable ORCs at varying EVPs. The modified ORCs apart from the generic cycle include the ORC-internal heat exchanger (IHE), ORC-turbine bleeding, and ORC-turbine bleeding and regeneration. The considered performance indicators are power output (POT), overall exergy efficiency and overall exergy destruction (OED), while the ES indicators comprise waste exergy ratio (WER), exergetic sustainability index (ESI) and environmental effect factor (EEF). From the results obtained the OEF, OED and POT for the ORCs ranged between , and , respectively, at EVP of 2 and 3 MPa. Similarly, WER, ESI and EEF ranged between , and correspondingly, for the same EVPs. The findings indicate the ORC-IHE and ORC-turbine bleeding and regeneration are more sustainable using the R113 than R141b refrigerant.

Performance and thermo-sustainability analysis of non-hybrid organic Rankine cycles (ORCs) at varying heat source and evaporator conditions

Abstract The paper presents the evaluation of the performance of various aeroderivative gas turbine models (AGTM) derived from a high bypass turbofan engine (HBTE). The objective of the study is to determine the performance and suitability of the developed AGTM for power generation. Furthermore, the models were specified as Model I (two shafts with FPT), Model II (two shafts with direct-drive LP turbine), and Model III (one shaft with FPT). The useful performance data for the AGTM was generated using the turbomatch simulation code. Additionally, the preliminary design point (DP) performance results estimated the power output and thermal efficiency of Models I, II, and III which ranged between and respectively. However, after the preliminary analysis, Model III failed the test based on performance and economic constraint while Models I and II were subjected to further performance study. The analysis indicates that Model II runs into surge at about 72% DP power and would require the installation of bleed valves or variable stator vanes for stability. Hence, additional production costs. Nonetheless, Model I was operationally stable at part-load conditions (< 110% DP Power) with no compressor surging. Based on the observed operational performance of the Models, Model 1 was best preferred and thus suggested for possible development.

Photovoltaic performance prediction in Northern Nigeria using generated typical meteorological year dataset

An off wing fleet maintenance study of the CFM56-3B Turbofan engine that propels the Boeing 737-300 aircraft is presented. The engine performance and deteriorating behavior was modeled with a view to estimate the creep life consumption and operating severity. The predicted severity factor of each degradation was similar to the trend observed by the maintenance, repair and overhauling (MRO) with 0 - 3.1% difference. The combine degradation severity factor of the engine operating at both saline and desert mission areas was 6.4% and 7.5% respectively when compared with compressor fouling or turbine erosion cases. The creep life obtained was 2.5% lower. Combine degradation resulted in high severity factor of 5% emission development index (EDI) and the cost of complete replacement of a damaged blade was USD 256 per flight hour (FH). However, for the isolated cases of degradation, the severity factor was 3% EDI lower and the cost of refurbishing a damage blade was USD 81/FH. This indicates that a refurbishment program can be considered for CFM56-3B engines operating in condition of low severity and replacement program for engines operating in condition of high severity.Keywords: Turbofan engine, Severity factor, Degradation

Cost performance analysis of small scale automotive maintenance firms in Calabar metropolis

Abstract The performance and thermo-sustainability indicators (TSI) of non-hybrid organic Rankine cycles (ORCs) are considered at varying evaporator pressure (EVP) and heat source temperature (HST). The ORCs structures include the ORC-basic, ORC-internal heat exchanger (ORC-IHE), ORC-turbine bleeding and ORC-turbine bleeding/regeneration. The TSI considered exergy efficiency, waste exergy ratio (WER), exergetic sustainability index (ESI) and environmental effect factor (EEF). The calculated overall exergy efficiency varies from 35.35 to 47.23 for evaporator pressure between 2 and 3 MPa and 49.02 to 52.71 for HST between 500 and 650 K. Additionally, WER, ESI and EEF were found to vary from 0.253 to 0.278, 1.15 to 1.87 and 0.547 to 0.82, respectively while ESI decreases for all variants of HST. The results indicate high ESI and low WER in ORC-IHE and the ORC-turbine bleeding /regeneration for all variations in EVP and HST.

Cycle parametric study on the performance of aeroderivative gas turbine models developed from a high bypass turbofan engine

Relevant meteorological files are needed by simulation software to assess the energy performances of buildings or efficiency of renewable energy systems. This paper adopts the Sandia method to generate typical meteorological year (TMY), using a 35-year hourly measured meteorological dataset from four stations in the northern region of Nigeria. The cumulative distribution function (CDF) for each year was compared with that of the long-term composite of all the years in the period for the seven major weather indices made up of relative humidity, wind speed, minimum temperature, global solar radiation, precipitation, mean temperature and maximum temperature. The 12 typical meteorological months (TMMs) selected from the different years were used for formulation of a TMY for the zone. In addition, performance assessment of a 72-cell polycrystalline solar PV module using the generated TMY and long-term (LT) values was also conducted. Two statistical indicators, the mean percentage error and the root mean square error, were adopted to evaluate the performance of each TMY with the LT mean, and also that of the PV energy system. Findings show that the TMMs are evenly spread within the data periods across the sites while closest fit between the long-term mean and TMY are obtained with the global solar radiation followed by the mean temperature in all the sites especially in Bida and Minna. From the energy system analysis carried out, it was found that TMY data are able to predict the performance of the PV system to within 5% of the LT data.