http://hdl.handle.net/123456789/125 2026-04-08T01:10:30Z http://hdl.handle.net/123456789/2374 DEVELOPMENT OF INTEGRATED MEASURES FOR PERFORMANCE ANALYSIS OF A GAS TURBINE POWER PLANT BASSEY, Joseph Benedict Performance analysis of gas turbine power plant is imperative for its optimal operations and maintenance. Reliability, exergy efficiency and emission characteristics are measures that have been used independently to assess its performance. However, this independent assessment approach has not adequately expressed the actual state of the plant performance. While other approaches are being explored, literature on Integrated Assessment Approach (IAA) is sparse. This study therefore focused on development of performance measures of IAA for the evaluation of gas turbine power plants. Four-year (year-1, year-2, year-3 and year-4) available data of a 180 MW simple cycle gas turbine power plant (Model No.:GT13E2) operating on dry low NOx technology was obtained to determine the plant performance state. Performance parameters of exergy destruction and exergy efficiency (at base loads of 80, 120 and 140 MW), reliability and availability were analysed, yearly. Steady state exergy analysis equation was used to evaluate the plant exergy destruction and exergy efficiency. System adequacy technique was used to evaluate the plant reliability and availability. Two new performance indexes (I and II) based on the IAA were developed and compared with the independent measures in the assessment of the power plant. Exergy efficiency and reliability were combined to formulate Index I, while exergy efficiency and availability were combined to formulate Index II. The indexes ranges between zero and one indicating the minimum and maximum points. Data were analysed using ANOVA at α0.05. Plant exergy destruction at 80, 120 and 140 MW base loads were 0.6640, 0.6290 and 0.5914; 0.6476, 0.6342 and 0.5855; 0.6295, 0.6342 and 0.5926; and 0.6523, 0.6285 and 0.6043 in year-1, year-2, year-3 and year-4, respectively. Exergy efficiencies at 80, 120 and 140 MW were 0.7195, 0.7916 and 0.8691; 0.7510, 0.7854 and 0.8775; 0.7808, 0.7774 and 0.8602; and 0.7389, 0.7875 and 0.8445 in year-1, year-2, year-3 and year-4, respectively, indicating improvement as base load increased. Reliability and availability were 0.8820 and 0.8168; 0.7959 and 0.6734; 0.7604 and 0.7497; and 0.6294 and 0.7238 for year-1, year-2, year-3 and year-4, respectively. At 80, 120 and 140 MW base loads, Index I values were 0.8281, 0.8630 and 0.9289; 0.7919, 0.8098 and 0.9023; 0.7833, 0.7819 and 0.8822; and 0.6538, 0.6860 and 0.8197 in year-1, year-2, year-3 and year-4, 7 respectively. At 80, 120 and 140 MW, Index II values were 0.5877, 0.6466 and 0.7099; 0.5058, 0.5289 and 0.5909; 0.5854, 0.5828 and 0.6449; and 0.5345, 0.5700 and 0.6113 in year-1, year-2, year-3 and year-4, respectively. Index I exhibited higher sensitivity by mimicking the combined behaviour of reliability and exergy efficiency. The best plant state was achieved in year-1 at 140 MW base load. Index II also indicated that the plant performed better in year-1 at 140 MW base load compared to other years. The integrated measures had similar trend with the independent measures but were significantly different. The integrated assessment measures were found suitable in the assessment of gas turbine power plant as they gave a better expression of the actual plant performance state. 2021-12-01T00:00:00Z http://hdl.handle.net/123456789/1370 ELECTRICITY GENERATION POTENTIAL FROM MUNICIPAL SOLID WASTE IN UYO METROPOLIS, NIGERIA EKPO, DOMINIC DAVID Disposal of Municipal Solid Waste (MSW) has been identified as a major environmental challenge in developing countries. Electricity generation has been identified as one of the ways for utilisation of MSW. Literature is scanty on the characterisation of MSW for optimal electricity generation in Nigeria. This study was designed to investigate the potential of electricity generation from MSW in Uyo metropolis, Nigeria. Municipal solid waste of 100 kg were collected from ten selected sites in Uyo metropolis and segregated into eight components. Data for the estimation of total volume of MSW were collected through field studies and AkwaIbom State Waste Management and Environmental Protection Agency, and spot sampling method was used to sort the MSW. Calorific Values (CV) of the segregated MSW components: Organic Waste (OW); Paper-Carton Waste (PCW); Plastics Waste (PW); Textile, Leather and Wood Waste (TLWW); Glass Waste (GW); Iron and Metal Packaging Waste (IMPW); Inert Metal Waste (IMW); and Unknown Waste (UW), were determined using bomb calorimeter at 10% moisture content. A prototype power plant of 1 kW capacity was designed and constructed according to standard procedures to model electricity generation from MSW using two sets of 42 combinations of two and three ratios of segregated components based on literature. The first combination consisted of six different mix of PW/TLWW, PW/OW, PW/PCW, TLWW/OW, TLWW/PCW, and O/PW, across five different ratios (9:1, 8:2, 7:3, 6:4 and 5:5); while the second consisted of four different mix of PW/TLWW/OW, PW/TLWW/PCW, PW/OW/PCW, and TLWW/OW/PCW across three different ratios (5:4:1, 5:3:2 and 4:3:3). Linear programming model was used to obtain the CV of the mix and Dulong equations were used to determine the electricity potential of MSW. Data were analysed using ANOVA at α_0.05. The estimated annual volume of MSW was 72,000 tonnes for a population of about 847500. The components were dissagregated into 66.3% OW, 18.4% PCW, 5.2% PW, 4.3% TLWW, 1.3% GW, 2.1% IMPW, 0.5% IMW, and 1.9% UW. The CV of the components obtained for OW, PCW, PW, TLWW, GW, IMPW, IMW, and UW were 18.0, 17.0, 40.0, 32.0, 0.0, 0.0, 0.0, and 18.0MJ, respectively. The CV of PW/TLWW, PW/OW, PW/PCW, TLWW/OW, TLWW/PCW, and OW/PCW at 9:1 mix were 39.20±0.70, 37.80±0.63, 37.70±0.43, 30.60±0.71, 30.50±0.57, and 17.90±0.68 MJ, while at 6:4 mix, the CV were 36.80±0.81, 31.20±0.56, 30.80±0.21, 26.40±0.45, 26.00±0.44, and 17.60±0.42 MJ, respectively. The CV of PW/TLWW/OW, PW/TLWW/PCW, PW/OW/PCW, and TLWW/OW/PCW at 5:4:1 mix were 34.60±0.54, 34.50±0.53, 28.90±0.35, and 24.90±0.32 MJ, while at 4:3:3 mix, the CV were 31.00±0.69, 26.50±0.55, 26.50±0.45, and 23.30±0.46 MJ, respectively. The estimated power potential ranged from 5.0 to 8.0 MW. The highest potential was obtained for PW/TLWW ( 9:1), while the lowest potential was obtained for OW/PCW (5:5) operating at 160.93 tonnes/day. There was no significant difference between the estimated power potential and the published data for same mix ratios. The use of municipal solid waste for electricity generation is feasible in Uyo metropolis. Improved waste mix of plastics, textiles, wood and leather gave the highest electricity generation potential. 2019-03-01T00:00:00Z http://hdl.handle.net/123456789/1014 PERFORMANCE AND EMISSION CHARACTERISTICS OF SPARK IGNITION ENGINE OPERATING WITH PURIFIED BIOGAS OLUGASA, Temilola Taiwo The Spark Ignition (SI) engine remains a global prime mover in the agricultural and transportation sectors as well as in electricity generation. However, its low thermal efficiency and consequential high emissions as related to the use of fossil fuels continue to be major concerns and necessitates the search for new fuels, such as purified biogas. Literature is sparse on the impact of purified biogas on the performance and emission characteristics of SI engines. This study was designed to evaluate the performance and emission characteristics of SI engine operating with purified biogas. Cattle dung was obtained and tested for pH, total solids, carbon-nitrogen ratio and Biological Oxygen Demand (BOD) using standard procedures. A floating gas cap digester was designed and fabricated using standard principles. The cattle dung was fed into the digester and biogas was generated. The biogas was purified using single and double pass water scrubber to obtain Single-stage Water Scrubbed Biogas (SWSB) and Double-stage Water Scrubbed Biogas (DWSB), respectively. Both SWSB and DWSB were each compressed to 375.8 kPa. The methane content of Raw Biogas (RB), SWSB, DWSB were determined using Liquid Displacement Method (LDM), while the scrubber efficiencies were evaluated using established procedure. The Brake Power (BP), Brake Specific Fuel Consumption (BSFC), Brake Thermal Efficiency (BTE) and emissions (O2, SO2 and CO) from a 4.125 kW 4-stroke air cooled SI engine operating with Liquefied Petroleum Gas (LPG), RB, SWSB and DWSB were obtained and compared using established procedure. Data were analysed using ANOVA at α0.05. The pH, total solids, carbon-nitrogen ratio and BOD of the substrate were 7.20, 17533.33 mg/L, 17.72 and 14956.66 mg/L, respectively. Methane content in RB, SWSB and DWSB were 73.47, 88.57 and 96.67% by volume, respectively. The capacity of the fabricated digester was 1.12 m3 . Scrubber efficiencies were 56.92 and 70.87% for SWSB and DWSB, respectively. Engine BP, BSFC and BTE for LPG at full load were 2.04±0.06 kW, 730.38±20.93 g/kWh and 10.70%, respectively and RB corresponding values were 1.03±0.03 kW, 672.37±25.72 g/kWh and 20.57%, respectively. BP, BSFC and BTE when SWSB was used were 1.26±0.09 kW, iii 551.53±40.20 g/kWh and 20.87%, respectively and corresponding DWSB values were 1.5±0.08 kW, 461.63±18.17 g/kWh and 22.78%, respectively. Engine O2, SO2 and CO emission characteristics for LPG at full load were 20.5±0.18, 51.8±24.42 and 4200 ±330 ppm, respectively and RB corresponding values were 20.88±0.04, 73.6±27.66 and 3100.00±265 ppm, respectively. Engine O2, SO2 and CO emission characteristics when operating with SWSB were 20.73±0.46, 71.33±18.9 and 2246.33±355.09 ppm, respectively and 20.6±0.12, 41.67±3.51 and 657.67±115.15 ppm, respectively when DWSB was used. Mean performance of engine run on SWSB and DWSB were better than RB. Mean performance of DWSB variables were significantly higher than corresponding means of SWSB indices. Operating a spark ignition engine with double stage water scrubbed biogas gave better performance and lower emissions compared to liquefied petroleum gas and raw biogas. Thus, purified biogas is an alternative fuel for spark ignition engines. 2019-05-01T00:00:00Z http://hdl.handle.net/123456789/1012 PERFORMANCE CHARACTERISATION OF COMPRESSION IGNITION ENGINE USING TRUNCATED CONE PISTON CROWNS TOWOJU, OLUMIDE ADEWOLE Compression Ignition (CI) engines are widely used in transportation and power generation industries in Nigeria. However, their low thermal efficiency and high emissions have necessitated continuous efforts at redesigning the Combustion Chamber (CC). There is still sparse literature on effect of using non-cylindrical piston crown in addressing these limitations. This study was therefore designed to investigate the performance characteristics of a CI engine equipped with Truncated Cone Piston Crown (TCPC) and Inverted Truncated Cone Piston Crown (ITCPC) using selected fuels. A model based on mass balance, momentum, energy, and k-ε turbulent equations was developed and solved using finite-element technique to obtain Temperature, Pressure and Emission History (TPEH) inside the CC of a CI engine. The model was applied to two standard CI engines utilising Automotive Gas Oil (AGO) with equivalence-ratio, initial pressure and temperature of 0.5, 100 kPa, and 313 K respectively. The standard CI engines are Kirloskar TV1 (KTV) with 87.5 mm cylinder-bore, Compression Ratio (CR) of 17.5 and Yoshita-165F (Y165) with 70 mm cylinder-bore, CR of 20.5. The TPEH was used to estimate Engine Thermal Efficiency (ETE), Specific Fuel Consumption (SFC), and Carbon Monoxide Emissions (CME). The model was further applied to KTV with TCPC (KTV-TCPC), KTV with ITCPC (KTV ITCPC), Y165 with TCPC (Y165-TCPC), and Y165 with ITCPC (Y165-ITCPC) at Truncated Cone Base Angles (TCBA) of 25, 30, 35, 40 and 45°. Biodiesel was prepared from Shea-butter and its physicochemical properties determined using standard techniques. The ETE, SFC and CME were determined experimentally for Y165 and Y165-TCPC with the selected TCBA using AGO and 100% biodiesel. Data were analysed using ANOVA at α0.05. The ETE, SFC, and CME for KTV were 30.90%, 0.194 kg/kWh, and 1558.70 ppm, respectively, while for Y165 were 32.20%, 0.347 kg/kWh, and 1545.24 ppm. The best TCBA for KTV-TCPC, KTV-ITCPC, Y165-TCPC, and Y165-ITCPC was 40°. At TCBA of 40°, ETE, SFC, and CME were 30.91%, 0.192 kg/kWh, and 1557.99 ppm, respectively for KTV-TCPC, 30.93%, 0.193 kg/kWh, and 1558.00 ppm, respectively for KTV-ITCPC, 32.26%, 0.346 kg/kWh, and 1542.94 ppm, respectively for Y165-TCPC, and 32.26%, 0.346 kg/kWh, and 1542.92 ppm, respectively for Y165-ITCPC. The determined specific gravity, calorific value, kinematic viscosity, and cetane number for biodiesel were 0.923, 40.10 MJ/kg, 5.40 mm/s2 , and 44.80, respectively. The ETE, SFC, and CME obtained experimentally for Y165 operated iii on AGO were 13.74%, 0.728 kg/kWh, and 1598.00 ppm respectively, while that of biodiesel were 16.05%, 0.599 kg/kWh, and 1859.00 ppm respectively. The ETE, SFC, and CME for Y165-TCPC operated on AGO were 12.60%, 0.794 kg/kWh, and 1463.00 ppm respectively, while for biodiesel were 25.08%, 0.329 kg/kWh, and 780.00 ppm respectively. The CI engine with TCPC and ITCPC showed better performance than KTV and Y165. There was no significant difference between the numerical and experimental results. The use of conical piston crown improved the performance of compression ignition engines. The forty degree base angle truncated conical piston crown gave the best engine performance 2018-10-01T00:00:00Z