IJET Vol. 6, Issue 3, September 2020
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Öğe Energy Analysis of A Retrofitted Regenerative Gas Turbine Organic Cycle in Ihovbor Power Plant(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2020) Ighodaro, Osarobo; Ochornma, Prosper; Egware, HenryGas turbines have gained popularity in power generation application because of its ease in operation, fuel flexibility and low emission of greenhouse gases. When in use as a simple gas turbine (SGT), it has the challenge of low thermal efficiency, which needs improvement to enhance its thermal efficiency and other thermal performances. This paper presents the energy analysis of incorporating a retrofitted combined regenerative gas turbine organic Rankine cycle (CRGTORC) to utilize the exhaust heat from the existing Ihovbor Power plant in Nigeria. The working fluid used in the Organic Rankine Cycle (ORC) section was cyclopentane and the analysis was carried out with the aid of ASPEN HYSYS and REFPROP. The performance of the proposed CRGTORC was compared with the existing SGT. The results obtained revealed that the CRGTORC model increases the net power output, thermal efficiency, overall cycle efficiency and work ratio of the system by 23.53%, 62.24%, 54.60%, and 10.21% respectively. Also, the flue gas losses, specific fuel consumption, and heat rate were reduced by 89.21%, 36.26%, and 36.26% respectively. Furthermore, it was observed that rise in compressor inlet air temperature lead to increase in specific fuel consumption and heat rate and decrease with net power out, thermal efficiency, cycle efficiency, flue gas losses, and work ratio. Thus, from the simulation results, the existing Ihovbor Power plant performance will be improved by integrating the CRGTORC system and its performance is significantly affected by the ambient inlet air temperature.Öğe On the Capacitance Spectroscopy of Cu2ZnSnS4 Typed Solar Cells Anisotype Heterojunction by SCAPS-1D(İstanbul Gelişim Üniversitesi Yayınları / Istanbul Gelisim University Press, 2020) Akinrinola, Olusola; Awodugba, Ayodeji; Jain, Momodu; Awodele, Mojoyinola; Akinrinola, Omowunmi; Ibiyemi, AbideenOne of the most reliable renewable energy source is the solar energy from the sun. However, most materials have been unable to meet their potentials as a good absorber layer in thin films. Most recently, Cu2ZnSnS4 (CZTS) have been identified as a good absorber layer, yet the same problem persists. In this study, we examined the depletion capacitance vis-a-vis the voltage and range of frequencies based on heterojunction types and structures. The modeled solar cell consisted three types of materials used as buffer layer (BL) (ZnO:Al (AZO), In2S3 (IS) and CH3NH3PbCl3 (PVKT)). The band gap model of n/n/p anisotype heterojunction for the three BLs were constructed from the obtained data of the simulated solar cells. The band offsets ?EC and ?EV in electron-volts at n/n for AZO, IS and PVKT are; 0.07071 and 0.18794, 0.09768 and 0.72367 and 0.67541 and 2.54541 respectively. Also, at n/p ?EC and ?EV for AZO, IS and PVKT are; 0.14251 and 1.93251, 0.49011 and 1.73011 and 0.34041 and 1.73920 respectively. Based on the trivial AC signal that was superimposed on the dc biased charges, AZO and IS shows an exponential response of the capacitance reliance on the voltage across the depletion region. The Capacitance spectroscopy of this solar cell showed that anisotype heterojunction may be manipulated to make use of the voltage reliance on junction capacitance when the need to electronically vary it arises.
