Mechanical Engineering
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Mechanical Engineering
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Item Hydraulic Transient Analysis of a Petroleum Pipeline Transporting Dual Purpose Kerosene Using Modelling and Simulation Approach(Premier Journal of Engineering and Applied Sciences, 2020-04-21) Muhammad, .A. B.; Nasir, .A.; Ayo, .S. A.; Bori IgeHydraulic transient analysis of a pipeline transporting dual purpose kerosene (DPK) was carried out in this research using simulation approach. Many petroleum pump stations and pipelines experience leakages and failures at their nodes due to changes in flow parameters that lead to hydraulic transient. Such types of unsteady situations are encountered frequently in pipelines where the valves are suddenly closed. WANDA Transient 4.5.1210 commercial software was used for the analysis of hydraulic transient. Variation in pressures and discharges with respect to time after the closure of a gate valve at the downstream of a pipeline were observed. It was observed in the study that pressure at node F rise significantly up to about 1354 kPa against the initial inlet pressure of 120 kPa due to the instantaneous valve closure and it was also observed that pressure at node B drops to a negative pressure of -101 kPa and hence the formation of cavitations at that node B and pipe P2. The analysis showed that the magnitude of the pressure surge decreases as the valve closure is increased. The research recommended that surge tanks should be installed at node F to stabilize the pressure surge and also air vessels are to be installed at nodes B to curtail damages due to cavitations.Item Investigation of the Effects of Hydraulic Transient due to Instantaneous Valve Closure in a Petroleum Pipeline(NIPES Journal of Science and Technology Research, 2020-06-01) Muhammad, .A. B.; Nasir, .A.; Ayo, .S. A.; Bori IgePressure surge analysis of petroleum pipeline transporting automotive gas oil (AGO) also known as Diesel oil was carried out in this research work. Pressure transient analysis is often more significant than the steady state analysis that engineers usually use in pipeline design. Pressure transient analysis helps to understand the additional pressures the pipeline can be subjected to as a result of instantaneous rapid valve closures or pump failure. The fluid pressure and flow rate in the pipeline system may change significantly at some intervals of time due to the valve closure and such types of unsteady situations are encountered more often in pipelines where the valves are suddenly closed. In this paper, pressure surge due to instantaneous valve closure in a petroleum pipeline conveying AGO was studied in a virtual environment. WANDA Transient 4.5.1210 commercial software was used for the analysis of the pressure surge in the pipeline due to instantaneous valve closure time of 4.75s. It was observed in the study that pressure at some nodes rise significantly up to about 1400 kPa against the initial inlet pressure of 120 kPa due to the instantaneous valve closure and it drastically drops at some nodes to negative pressure of about -100 kPa and hence the formation of cavitations. The analysis showed that the magnitude of the pressure surge decreases as the valve closure is increased.Item 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.Item Investigation of the Temperature Variations in Aeroderivative Gas Turbine Blade Cooling(Journal of Materials Engineering, Structures and Computation, 2023-11-22) Orah, A. .M.; Nasir, .A.; Hassan, .A.B.; Bori Ige; Ayo, .S. A.In order to improve performance and efficiency, modern-day gas turbines operate at high temperatures. It is essential to use suitable cooling techniques on the blade and other hot areas since the elevated temperatures might exceed the metal melting temperature of the turbine blades. This paper presents the numerical modelling of heat exchange in a cooled aerodrivative gas turbine blade depending on the Newton’s law of cooling equation as governing equation, then integrating the heat transfer coefficient by convection into the alternating direction implicit (ADI) approach of computational fluid dynamics (CFD). Based on the chosen boundary conditions and the gas turbine's intended cooling characteristics, a model for the heat transfer problem was created. A MATLAB code was developed to ascertain the temperature variations inside a cooling blade for a half-hour in-service operation. This study found a temperature difference between the transient and final temperature values of roughly 25 to 300oC, demonstrating the heat transfer process between the hot gases and the coolant air. It inferred effective heat transmission from the blades to the cooling air because the temperature differential within the blades did not rise over the melting point of the blade material and it yielded an average blade temperature of 400°C. Thus, the ADI technique is appropriate for heat transfer design calculations for intricate devices such as the gas turbine engine.