Browsing by Author "Orah, .A. M."

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    Numerical Investigation of Thermomechanical Fatigue Behavior in Aeroderivative Gas Turbine Blades
    (NIPES Journal of Science and Technology Research, 2021-08-31) Orah, .A. M.; Nasir, .A.; Hassan, .A. B.; Bori Ige
    The hot gas component of the gas turbine engine comprises the burner, the turbine stages, and the exhaust nozzles/ducts. However, the turbine blades experience high thermal and mechanical loading. As a result, they suffer thermo-mechanical fatigue (TMF). The design process usually involves the appropriate selection of the turbine blade materials. Therefore, the need to carry out thermo-mechanical fatigue studies on gas turbine blades to predict blade life. During TMF loading, fatigue, oxidation, and creep damages are induced, and the relative contributions of these damages vary with the different materials and loading conditions. The study employed the finite element method to examine the high temperature and stress effects on the blades during TMF. The blade material considered in this study is a nickel-based super-alloy, Inconel 738 Low Carbon (IN738LC). The finite element method predicted the temperature and stress distributions in the blade, illustrating the blade sections prone to damage during thermomechanical fatigue. The equations from the law of heat conduction of Fourier and the cooling law of Newton predicted the heat transfer process of the interaction between the blade, hot gases, and cooling air. Therefore, the finite element method is suitable for studying the thermomechanical fatigue behavior of turbine blade metals, which is a precursor to blade life predictions.
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    Techno-Economic Analysis of Combined Cycle Power Plants for Electricity Generation in Nigeria
    (Nigerian Journal of Technology (NIJOTECH), University of Nigeria, Nnsuka, 2022-09-10) Bori Ige; Orah, .A. M.; Ayo, .S. A.
    This paper presents a techno-economic approach to readily assess the profitability or otherwise of combined cycle power plants (CCPPs) for increased electricity production in Nigeria. As a case study for this analysis, a combined cycle gas turbine plant with 650MW installed capacity at Afam VI power station is used to evaluate the installation of a 1000MW and 1500MW CCPP economically. The results and analysis determined a Levelized cost of electricity of N41.57k/KWh and N34.09k/KWh for the 1500MW and 1000MW CCPP, respectively. It signifies an increase of 33.33% and 66.67% in the cost of electricity per kWh between the 1000MW and 1500MW plant capacities respectively, relative to the 650MW CCPP. Therefore, the low LCOE makes it economically viable to install the 1000MW CCPP for electricity production in the country. The paper also proposes upgrading existing gas-fired power plants in the country into combined cycle power plants for improved electricity supply.