SDG 7 · Erişilebilir ve Temiz Enerji · SDG · Erzincan Binali Yıldırım Üniversitesi

Yazarlar

Yayınlar

Yeniden eskiye Eskiden yeniye

ArticleYalnız künye2016/r/ebyu/18759
Analysing of Harmonics Affecting the Energy Quality in Opium Alkaloids Plant's Power System
Oguz, Yuksel; Sahin, Mustafa; Güven, Yilmaz; Tugcu, Hatice Zeliha
The quality of energy has been defined to control harmonics caused by non-linear loads and international standards were brought to overcome the harmonic related problems. In determining the power quality, parameters like current-voltage harmonic, transient, flicker, current and voltage imbalance between phases, K factor are examined according to these international standards. The biggest disadvantage of harmonics is that they do not affect the power quality over an individual network but also affect the entire energy system primarily neighbouring facilities. Therefore, the energy system of Opium Alkaloids Plant was examined by using measurements information of current and voltage harmonics affecting the energy quality. And, it has been determined that the harmonics have a negative impact on energy quality. According to these findings, it has been proposed to install a well-designed filter for elimination of harmonics. Besides, it has been emphasised that new hardwares and devices should be chosen to support this harmonic filtering system in the future.
RDL Kalıcı Kaydıİncele
ArticleAçık Erişim2016/r/ebyu/16818
ANN-based estimation of time-dependent energy loss in lighting systems
Şahin, Mustafa; Oʇuz, Yüksel; Büyüktümtürk, Fuat
The illuminance of a lighting system decreases over time both due to pollution on fixtures, lamps, and wall surfaces, and decreases and failures in the luminous flux of lighting components. Such decreases are not recognizable, as they occur slowly and continuously. Numerous studies have concluded that eyesight weakens due to incorrect lighting or decreases in luminous flux of lighting components over time. However, a sufficient and stable level of illuminance is obligatory for the establishment of healthy working environments. Following the installation of a lighting system, measurement of the illuminance distribution in that environment can become a tiring and time-consuming process. In this study, an artificial neural network (ANN) model is established as an alternative to these measurements and is trained to estimate the illuminance distribution in interior spaces. Thanks to an installed ANN model, real-time estimation of illuminance distribution in an environment was realized. With these estimated values, the mean illuminance in the environment was calculated, in turn allowing the depreciation multiplier of the system to be obtained. As a result, the percentage of energy in the system that was not transformed into light was determined, allowing either improvements or fundamental changes to be made to the system, thus preventing energy waste and light loss. Furthermore, ergonomic comfort conditions of the illuminated environment were kept at the desired level.
RDL Kalıcı Kaydıİncele
Conference ObjectYalnız künye2016/r/ebyu/16469
Analysis and optimisation of a cascade active magnetic regenerative refrigeration system
Ganjehsarabi, Hadi; Dincer, Ibrahim; Gungor, Ali
In this paper, comprehensive thermodynamic analysis and optimisation of a cascade active magnetic regenerative refrigeration system are performed. A parametric study is conducted to investigate the effects of various design parameters on the cycle performance through energy and exergy efficiencies. A multi-objective optimisation method based on a fast and elitist non-dominated sorting genetic algorithm is applied to determine the best design parameters for the system. Two objective functions utilised in the optimisation study are the total cost rate of the system and the system exergy efficiency. The total cost rate of the system is minimised while the cycle exergy efficiency is maximised using an evolutionary algorithm. To provide insight, the Pareto frontier is shown for a multi-objective optimisation. The results show that exergy efficiency could be increased by 14.53% using exergy-based optimisation and the cost could be reduced by 12% using the cost-based optimisation.
RDL Kalıcı Kaydıİncele
Conference ObjectYalnız künye2016/r/ebyu/16455
Energy and exergy analyses of a solar assisted combined power and cooling cycle
Ganjehsarabi, Hadi; Asker, Mustafa; Seyhan, Aslihan Kurnuc
In this study, a thermodynamic analysis of a solar assisted Rankine-Goswami integrated cycle is carried out for a range from 230 to 240 MW sizes. To illustrate the performance characteristics of these integrated cycle, an exergy analysis is conducted to pinpoint the losses due to internal and external irreversibilities of each component. In addition, the effect of design parameter such as condenser pressure on the performance of the integrated cycle is examined. The results shows that the variation of condenser pressure from 4 kPa to 24 kPa greatly reduces the exergy efficiency of the system. Moreover, it is found the exergy efficiency of standard solar assisted Rankine cycle case is 42.8% whereas the exergy efficiency of solar Rankine-Goswami multigeneration system is 47.03%.
RDL Kalıcı Kaydıİncele
ArticleYalnız künye2016/r/ebyu/16301
A novel ethanol biosensor on pulsed deposited MnOx-MoOx electrode decorated with Pt nanoparticles
Ozdokur, K. Volkan; Demir, Bilal; Atman, Ece; Tatli, Alper Yalin; Yilmaz, Buket; Demirkol, Dilek Odaci; Kocak, Suleyman; Timur, Suna; Ertas, F. Nil
Transition metal oxides provide low cost alternatives to noble metals due to their unique electrocatalytic and electrochromic properties and display strong interactions with noble metal nanoparticles. Present study describes the use of mixed molybdenum and manganese oxide film electrode enriched with platinum nanoparticles to enhance the catalytic performance in the oxygen reduction reaction (ORR). The mixed oxide film, denominated as GCE/MnOx-MoOx/Pt, was co-deposited by pulsed potential deposition technique and then, it was used as an immobilization matrix for the intact bacterial cells. The resulted whole cell biosensor has served as a sensing platform for ethanol detection by monitoring of oxygen consumption as a result of the bacterial metabolism in the presence of the substrate. Following the optimization experiments, GCE/MnOx-MoOx/Pt/Gluconobacter oxydans biofilm was applied to investigate the analytical characteristics and response time to ethanol as well as operational stability and substrate specificity for other carbon sources. The linear range was found as 0.075–5.0 mM with a response time of 63 s and the developed method was applied to the ethanol determination in alcoholic drinks. Satisfactory recovery figures were obtained in comparison to the standard method.
RDL Kalıcı Kaydıİncele
ArticleAçık Erişim2016/r/ebyu/16196
Preparation of carbon nanotube/TiO2 mesoporous hybrid photoanode with iron pyrite (FeS2) thin films counter electrodes for dye-sensitized solar cell
Kilic, Bayram; Turkdogan, Sunay; Astam, Aykut; Ozer, Oguz Can; Asgin, Mansur; Cebeci, Hulya; Urk, Deniz; Mucur, Selin Pravadili
Multi-walled carbon nanotube (MWCNT)/TiO2 mesoporous networks can be employed as a new alternative photoanode in dye-sensitized solar cells (DSSCs). By using the MWCNT/TiO2 mesoporous as photoanodes in DSSC, we demonstrate that the MWCNT/TiO2 mesoporous photoanode is promising alternative to standard FTO/TiO2 mesoporous based DSSC due to larger specific surface area and high electrochemical activity. We also show that iron pyrite (FeS2) thin films can be used as an efficient counter electrode (CE), an alternative to the conventional high cost Pt based CE. We are able to synthesis FeS 2 nanostructures utilizing a very cheap and easy hydrothermal growth route. MWCNT/TiO2 mesoporous based DSSCs with FeS2 CE achieved a high solar conversion efficiency of 7.27% under 100 mW cm-2 (AM 1.5G 1-Sun) simulated solar irradiance which is considerably (slightly) higher than that of A-CNT/TiO2 mesoporous based DSSCs with Pt CE. Outstanding performance of the FeS2 CE makes it a very promising choice among the various CE materials used in the conventional DSSC and it is expected to be used more often to achieve higher photon-to-electron conversion efficiencies.
RDL Kalıcı Kaydıİncele
ArticleYalnız künye2016/r/ebyu/16192
Parametric optimization and exergetic analysis comparison of subcritical and supercritical organic Rankine cycle (ORC) for biogas fuelled combined heat and power (CHP) engine exhaust gas waste heat
Yağli, Hüseyin; Koç, Yildiz; Koç, Ali; Görgülü, Adnan; Tandiroğlu, Ahmet
In this paper, a subcritical and supercritical organic Rankine cycle (ORC) are designed to recover exhaust gas waste heat of biogas fuelled combined heat and power (CHP) engine. The CHP engine is located in Belgium and uses biogas as fuel which is produced from the digestion of domestic wastes by anaerobic digestion. R245fa is selected as working fluid. First, the system parameters as net power, mass flow rate, pumps total power consumption, total evaporator exergy inlet, thermal efficiency and exergy efficiency are improved by changing turbine inlet temperature and pressure. After which second low analysis of the overall system and system components are determined for the best performed subcritical and supercritical cycles. Compared with subcritical ORC, the supercritical ORC has shown better performance. The best performed cycle net power, thermal efficiency and exergy efficiency are evaluated as 79.23 KW, 15.51% and 27.20% for subcritical ORC and 81.52 kW, 15.93% and 27.76% for supercritical ORC, respectively.
RDL Kalıcı Kaydıİncele
ArticleAçık Erişim2016/r/ebyu/16128
Produce of graphene/iron pyrite (FeS2) thin films counter electrode for dye-sensitized solar cell
Kilic, Bayram; Turkdogan, Sunay; Ozer, Oguz Can; Asgin, Mansur; Bayrakli, Ozge; Surucu, Gokhan; Astam, Aykut; Ekinci, Duygu
Dye-sensitized solar cells (DSSCs) provide a low cost alternative to the conventional solar cells due to their easy and inexpensive device fabrication steps. Generally, F:SnO2 (FTO) conductive glass with a thin layer coating of platinum (Pt) is used as a counter electrode (CE) in DSSCs. Since Pt is rare and therefore expensive metal, we were looking for a way to produce a new counter electrode based on graphene/iron pyrite (FeS2) thin films as an alternative to the Pt:FTO. In combination with a TiO2 mesoporous photoanode and an I3−/I- redox electrolyte, graphene/FeS2 CE based DSSC shows η=7.43% energy conversion efficiency under 1 sun illumination (100 mW/cm2, AM 1.5G) which is approximately 16.1% higher than conventional Pt CE (η=6.40%). External Quantum Efficiency (EQE) is found to be shifted upward when graphene/FeS2 is used as CE in the place of Pt CE. The excellent performance of the graphene/FeS2 CE makes it a very promising alternative to costly Pt in DSSCs.
RDL Kalıcı Kaydıİncele
ArticleAçık Erişim2016/r/ebyu/16121
PID and fuzzy controlling three phase asynchronous machine by low level dc source three phase inverter; [PID i neizrazito upravljanje trofaznim asinhronim motorom pomoću trofaznog izmjenjivača slabe istosmjerne struje]
Can, Erol; Sayan, H. Hüseyin
In this study, a three-phase asynchronous motor driven by a broad-based system is described. So, mathematical model of converter, sinus pulse width modulation for the three phase inverter, and mathematical model of three-phase asynchronous motor have to be utilized in order to establish the system. After creating such a system, Fuzzy Logic and PID controllers are focused in order to get satisfactory results which are short settling time of rotor speed, low harmonic and short settling time of high phase current. Created mathematical models are run at the MATLAB Simulink. Direct voltage is applied to converter input. This voltage is represented by a renewable energy source that could be obtained from solar energy source. The direct voltage is lower than the peak of the alternating voltage. The alternating voltage is obtained from output of the inverter to drive the induction motor. Firstly, resistive (R) and inductive (L) loads are driven. Secondly, three-phase asynchronous motor (ASM) is driven with the low direct voltage. After that, simulation results are given in order to demonstrate performance and effectiveness of the proposed system.
RDL Kalıcı Kaydıİncele
Book ChapterYalnız künye2016/r/ebyu/15971
Design optimization of a wind turbine using artificial intelligence
Jayabalan, Jagan; Yildirim, Dalkilic; Kim, Dookie; Samui, Pijush
This chapter examines the capability of Support Vector Machine (SVM), Relevance Vector Machine (RVM) and Genetic Programming (GP) for the optimal design of wind turbine. The excellent design has been influenced by various factors, such as profile of the blade, number of blades, power factor and tip speed ratio. The key to design a wind turbine is to Assessing the optimal tip speed ratio (TSR) is the key for designing the wind turbine. This chapter handles the Artificial Intelligence techniques in predicting the optimal TSR and the power factor based on the parameters engaged for NACA 4415 and LS-1 profile types with 3 and 4 blades. The organized machine learning framework is anticipated to be lucrative than the traditional way in foretelling the TSR and power factor. The machine learning models are then compared with the existing Neural Network model and the pros and cons of the various models are inferred from the results.
RDL Kalıcı Kaydıİncele
ArticleYalnız künye2015/r/ebyu/18612
Porous Si Based Al Schottky Structures on p+-Si: A Possible Way for Nano Schottky Fabrication
Gülnahar, Murat; Karacali, Tevhit; Efeoglu, Hasan
This paper presents the results of a comparison research between the Al/p-Si/Al, Al/p(+)-Si/Al and Al/PS/p(+)-Si/Al devices. The current transport mechanism of an Al/por-Si/p(+)-Si/Al heterojunction device with a porous silicon layer fabricated by the electrochemical anodization process has been investigated using temperature dependent current-voltage measurements in the temperature range of 10-300 K, and these measurements are realized even for Al/p-Si/Al diode. The porosity properties of porous Si layer are investigated by a cross-sectional SEM view and a PL measurement. The good rectification for a Schottky like diode which was formed by Al metallization of porous silicon (PS) on p(+)-Si substrate was observed and it continues even in 6 K temperature, despite Al/p-Si/Al diode freezing out at 20 K. Moreover, it is reported that the Al/PS/p(+)-Si/Al heterojunction device reveals the excellent junction parameters with an ideality factor very close to unity, a high barrier height which is 0.63 eV and a small value of series resistance that is 30 Omega, at 300 K. However, the high serial resistance values for this heterojunction device compared to that of the crystalline Si based on the Al/p-Si/Al diode are related to PS. At high temperatures, it is noted that the current transport mechanism is through the thermoionic-field emission mechanism. However, at low temperatures, the unreliable variation of the Richardson plot is seen, and no distinct Gaussian distribution is seen in the relation of Phi(b) vs. q/2kT; and this behaviour is attributed to the highly doped silicon. Furthermore, in this study, the current transport mechanism is discussed by using the Fowler Nordheim tunnelling theory in PS, and it is proposed that tunnelling via the migration/diffusion is the main mechanism of charge transport in PS. (C) 2015 Elsevier Ltd. All rights reserved.
RDL Kalıcı Kaydıİncele
Book ChapterYalnız künye2014/r/ebyu/17560
Wind energy resource assessment of Ergan mountain ski center, Erzincan, Turkey
Tandıroğlu, Ahmet; Çetin, Murat
Ergan Mountain Ski Center is located in Erzincan, East Anatolian region of Turkey. It is 15 km south of the city and situated in the Mercan (Munzur) Mountain chain whose length is 200 km and width of between 15 and 45 km. Height of the Ergan is about 3,300 m. In this study, wind energy potential of Ergan Mountain Ski Center which is located in Erzincan, East Anatolian region of Turkey was investigated by analyzing wind speed data collected in ten minutes intervals by wind energy observation station situated at a height 2,350 m above sea level at 12 m above the ground. These measurements are performed from 2011 February to 2013 May. Wind energy potential of monitored area is determined by performing statistical analysis of collected data. Weibull distribution is used in the statistical analysis, and it is examined that the numerical values of shape and scale parameters for Ergan Mountain Ski Center varied over a wide range. The annual values of dimensionless Weibull shape parameter k ranged from 1.41 to 1.83 with a mean value of 1.71, while those of Weibull scale parameter c were in the range of 3.11–11.99 m/s with a yearly mean wind speed of 7.8 m/s. Results revealed that the highest and the lowest wind power potential is in March and October, respectively. Annual mean wind power density is obtained as 230.68 W/m2 inside the observatory field. The results show that the investigated location of Erzincan Ergan Mountain Ski Center has available wind energy potential and is feasible to establish wind power generation plant in a medium scale for installed power load of Erzincan Ergan Mountain Ski Center.
RDL Kalıcı Kaydıİncele
Book ChapterYalnız künye2014/r/ebyu/17351
Use of hazelnut oil ethyl ester as a fuel in pre-chamber diesel engine
Cetin, Murat; Tandiroglu, Ahmet
This study briefly reviews the use of hazelnut oil ethyl ester which was produced by hazelnut oil as an alternative fuel in pre-chamber diesel engines, and compares it with pure hazelnut oil and diesel fuel. In the experiments, a naturally aspirated, pre-chamber indirect injection, four cylinders, four-stroke diesel engine was used. During the test, power, torque, emissions values, and fuel consumption were measured with respect to the engine speed. As a viscosity and density of hazelnut oil ethyl ester was found to closely similar to those of diesel fuels. Test results obtained from hazelnut oil ethyl ester were compared to hazelnut oil and standard diesel fuel test results. CO, NOx, smoke density of hazelnut fuel, and exhaust temperatures were lower than of diesel fuel. The biodiesel NOx emissions higher than diesel fuel all engine rpm and NOx emission was measured 15 % higher from the diesel fuel. The specific fuel consumption is increased: At low-speed 6 %, medium speed 9 %, and high-speed 12 %. The average increase in specific fuel consumption 9.7%is determined. As a result of this study, it is concluded that hazelnut oil biodiesel could be used as an alternative fuel in diesel engines.
RDL Kalıcı Kaydıİncele
ArticleYalnız künye2012/r/ebyu/17350
Performance of coupled novel triple glass unit and pcm wall
Kara, Yusuf Ali; Kurnuç, Aslihan
A PCM wall includes phase change material (PCM) as a heat storage medium. In the current project, the south faade of a test room was constructed using PCM walls that were made of (from inside to outside) insulation, brick, plaster (including PCMs), an air gap and a novel triple glazing unit (TGU). Although the annual behaviour of the PCM walls were investigated in the project, the current paper covers an evaluation of the performance of PCM walls in the summer only. The solar transmittance of the TGU decreased approximately 100% during summer compared to winter. There were no overheating problems observed for the PCM wall during the summer.
RDL Kalıcı Kaydıİncele
ArticleYalnız künye2012/r/ebyu/17009
Performance of coupled novel triple glass and phase change material wall in the heating season: An experimental study
Kara, Yusuf Ali; Kurnuç, Aslihan
A Trombe wall that uses a phase change material (PCM) as the heat storage medium is usually called a PCM Trombe wall or PCM wall. A research project was conducted to investigate the performance of coupled novel triple glass (NTG) and PCM wall, which is simply called PCM wall in this paper, as a solar space heater. The south façade of a test room was constructed using PCM walls. Rubitherm® GR35 and GR41 were incorporated into the plaster of the walls as PCM. The ratio of the solar energy gain provided by the PCM walls to the heat load of the test room per month varied from 4% to 70%; daily overall efficiency of the PCM walls varied from 20% to 36%; and solar transmittance of the NTG varied from 0.45 to 0.55 during the heating period. The overall efficiency of the PCM wall including GR35 was higher than that of the PCM wall including GR41.
RDL Kalıcı Kaydıİncele
Conference ObjectYalnız künye2012/r/ebyu/16844
The relation of collector and storage tank size in solar heating systems
Çomakli, Kemal; Çakir, Uǧur; Kaya, Mehmet; Bakirci, Kadir
The most popular method to benefit from the solar energy is to use solar water heating systems since it is one of the cheapest way to benefit from the solar energy. The investment cost of a solar water heating system is very low, and the maintenance costs are nearly zero. Using the solar energy for solar water heating (SWH) technology has been greatly improved during the past century. A storage tank is used in many solar water heating systems for the conservation of heat energy or hot water for use when some need it. In addition, domestic hot water consumption is strongly variable in many buildings. It depends on the geographical situation, also on the country customs, and of course on the type of building usage. Above all, it depends on the inhabitants' specific lifestyle. For that reason, to provide the hot water for consumption at the desirable temperature whenever inhabitants require it, there must be a good relevance between the collectors and storage tank. In this paper, the optimum sizes of the collectors and the storage tank are determined to design more economic and efficient solar water heating systems. A program has been developed and validated with the experimental study and environmental data. The environmental data were obtained through a whole year of operation for Erzurum, Turkey.
RDL Kalıcı Kaydıİncele
ArticleAçık Erişim2009/r/ebyu/17705
Emission characteristics of a converted diesel engine using ethanol as fuel
Çetin, Murat; Yüksel, Fikret; Kuş, Hüsamettin
The aim of this study is to investigate the suitability of neat ethanol (95%) as an alternative fuel in an engine converted from diesel to ethanol, and experimentally determine the effect of different main fuel jets at carburetor on engine exhaust emissions and fuel consumption at high engine compression ratio (CR) of 14. For this purpose, three different diameter main fuel jets (1.40 mm, 1.50 mm, 1.60 mm) were used for ethanol fuel tests in a naturally aspirated four-stroke pre-chamber diesel engine. Tests were made at full-load conditions at speeds between 1200 and 2600 rpm at intervals of 400 rpm. In addition, cold-start system was developed and engine could be operated at reliable idle speed and medium speed down to 0 °C ambient temperatures. The results show that HC emissions increase with increasing fuel jet diameter and CO, PM and HC emissions reduce significantly at idle speed and medium engine speeds.
RDL Kalıcı Kaydıİncele
ArticleAçık Erişim2007/r/ebyu/17787
The use of hazelnut oil as a fuel in pre-chamber diesel engine
Çetin, Murat; Yüksel, Fikret
This paper briefly reviews the use of hazelnut oil as an alternative fuel in pre-chamber diesel engines, and compares it with diesel fuel. In order to investigate the effects of the use of hazelnut oil as a diesel engine fuel, an experimental setup was constructed. The results showed that the hazelnut oil may be employed as a possible candidate for most diesel fuel operating conditions in terms of the performance and emission parameters without any modification and preheating of the fuels.
RDL Kalıcı Kaydıİncele
ArticleYalnız künye2006/r/ebyu/17761
Energy dissipation analysis of transient heat transfer for turbulent flow in a circular tube with baffle inserts
Tandiroglu, Ahmet; Ayhan, Teoman
In this paper energy dissipation analysis was conducted to evaluate the performance of nine circular tubes with baffle plate inserts having different pitch to tube inlet diameter ratio and baffle orientation angle in the range of Reynolds number 3000 ≤ Re ≤ 20,000 for the case of constant heat flux. The characteristic parameters of the tubes are pitch to tube inlet diameter ratio H/D = 1, 2, 3 and baffle orientation angle β = 45, 90, 180°. Air having Prandtl number is 0.71 was used as working fluid, while stainless steel is considered as a pipe material. As an evaluation criteria of iE has been proposed by Sano et al., which is based on correlating the heat transfer coefficient and the dissipation energy in a fluid has been considered to evaluate transient forced convection. The data show that unsteady dissipation energy criterion for the baffled tubes is higher than smooth tube and the type of 9031 has been found as the most effective one.
RDL Kalıcı Kaydıİncele