Browsing by Author "Ünal, Fatih"

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Citation - WoS: 9
Citation - Scopus: 9
APPLICATION OF EXERGOECONOMIC ANALYSIS FOR POWER PLANTS
(VINCA INST NUCLEAR SCI, 2018) Unal, Fatih; Ünal, Fatih; Ozkan, Derya Burcu; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
Currently, energy resources are rapidly consumed. Therefore, scientists and engineers study the effective use of energy. In the present study, a thermodynamic and exergoeconomic analysis was performed in a thermal power plant in Turkey. The study involved determining the thermodynamic properties of 27 node points in a thermal power plant unit, and this was followed by calculating energy and exergy values of every node. Mean exergy costs were calculated by establishing energy and exergy balances of the equipment with respect to the calculated results. Subsequently, lost and damaged energies and exergies were calculated, and exergoeconomic factors were determined. The equipments were compared with each other on a graph based on the obtained results. The maximum rate of exergy loss and cost of exergy destruction corresponded to 79.5% and 886,66 $/h, respectively. The maximum exergy losses in a thermal power plant occurred in the boiler, turbine groups, condenser, heating group, pumps, and auxiliary groups. The highest and second highest law efficiencies of the studied thermal power plant corresponded to 32.3% and 28.5%, respectively. The study also involved presenting suggestions for improvement. Additionally, exergoeconomic analyses were conducted while considering the power plants' investment and equipment maintenance costs. It is expected that the calculation method and the obtained results can be applied to other thermal power plants.
An Applıcatıon Of Exergoeconomic Analysıs For Power Plants
(Vinča Institute of Nuclear Sciences, 2018) Ünal, Fatih
Currently, energy resources are rapidly consumed. Therefore, scientists and engineers study the effective use of energy. In the present study, a thermodynamic and exergoeconomic analysis was performed in a thermal power plant in Turkey. The study involved determining the thermodynamic properties of 27 node points in a thermal power plant unit, and this was followed by calculating energy and exergy values of every node. Mean exergy costs were calculated by establishing energy and exergy balances of the equipment with respect to the calculated results. Subsequently, lost and damaged energies and exergies were calculated, and exergoeconomic factors were determined. The equipments were compared with each other on a graph based on the obtained results. The maximum rate of exergy loss and cost of exergy destruction corresponded to 79.5% and 886,66 $/h, respectively. The maximum exergy losses in a thermal power plant occurred in the boiler, turbine groups, condenser, heating group, pumps, and auxiliary groups. The highest and second highest law efficiencies of the studied thermal power plant corresponded to 32.3% and 28.5%, respectively. The study also involved presenting suggestions for improvement. Additionally, exergoeconomic analyses were conducted while considering the power plants’ investment and equipment maintenance costs. It is expected that the calculation method and the obtained results can be applied to other thermal power plants.
Citation - Scopus: 2
An Application To Error and Uncertainty Analysis in Industrial Type Dryer Experiments
(Murat Yakar, 2021) Akan, A.E.; Akan, Ahmet Erhan; Ünal, F.; Ünal, Fatih; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
In this study, information is given about the driers commonly used in the industry and the experimental errors and uncertainties that will be encountered in the experiments using these driers are tried to be explained by using the data obtained from the experiments carried out in an 8 chambers hot oil heated stenter, which is a conveyor type convection dryer. The fabric used in the experiments is the Thessaloniki type fabric, containing 67% cotton and 37% polyester. The experiments were carried out at a drying air temperature of 160 ºC and a fabric advance rate of 23 m/h (0.383 m/s). Thus, the example of error analysis in such experimental studies is provided and criteria that may cause an error for drying systems are discussed. As a result of the uncertainty analysis, the largest uncertainty in the system occurred in temperature measurements at ±0.367-±0.568 ºC values and the error rate for the whole system was found to be 4.08%. In terms of conducting the experiments in real production conditions and the materials and methods used in the experiments, this study is thought to will be help researchers that working on drying systems in their experimental studies. © Author(s) 2021.
Comparison of Energy and Cost Analysis of Two Different Industrial Corn Drying Plants Using Solid Fuel
(IJARSET, 2018) ÜNAL, Fatih; Ünal, Fatih; BULUT, Hüsamettin; KAHRAMAN, Ahmet; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
In this study, the energy and cost analyzes of two different corn drying plants using solid fuel in the heating of drying air are performed. In the evaluated drying processes, corn which has high humidity, dried to a value below 15% relative humidity which is the storage humidity. In the drying process, thermodynamic properties such as temperature, relative humidity and air velocity of the node points determined in the systems were measured. The continuous operating temperatures of the facilities specified for analyzes were taken into account. In the analyzes, measurements were made for the drying air inlet temperatures of drying plants which was drying temperature of 70°C and 112°C. Based on the results obtained at the determined nodes, the influences on the inlet temperature of the drying air, the thermal value of the fuel, the fuel consumption, the energy efficiency and the unit drying cost have been evaluated. As a result, it has been found that the increase in inlet air temperature reduces boiler efficiency and energy efficiency, increases unit drying cost and fuel consumption. It has been found that high thermal value fuel usage has an important role in decreasing drying time as it allows working at high temperatures.
CONDENSATION ANALYSIS OF THE INSULATION OF WALLS IN MARDIN PROVINCE ACCORDING TO DIFFERENT LOCATIONS
(2019) Ünal, Fatih; Ünal, Fatih; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
In this study, condensation and vapor diffusion caused by different positioned insulation in the wall were analyzed for Mardin province. In the analysis, according to the 2008 standard of TS 825, the MATLAB calculation program was used with the Glaser graphing method and graphical user interface (GUI). Extruded polyurethane foam was used as the insulation material and normal unreinforced concrete was chosen as the wall. Evaporation and condensation values were determined by creating 6 different wall models with the same insulation thickness of 20 cm and an unreinforced concrete wall was covered with 2 cm plaster on the inside with a 3 cm thickness on the outside. The data obtained for 2 cm and 4 cm insulation thicknesses are presented in tables and the results are interpreted for Mardin province. Consequently, it was seen that the worst wall structure in terms of condensation and evaporation was obtained in the middle insulated wall and later in the interior insulated wall structure. The externally insulated wall did not show any condensation.
Citation - WoS: 2
Citation - Scopus: 2
Energy and exergy analysis of an industrial corn dryer operated by two different fuels
(International Journal of Exergy, 2021) Ünal, Fatih; Ünal, Fatih; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
In this study, the data obtained after converting an industrial horizontal type corn dryer that meets its drying air temperature from coal to natural gas was compared by thermodynamic analyses. Before starting the drying process, it was assumed that the corn type DKC6050 with 24-25% corn inlet humidity dries when it reaches approximately 14% corn outlet humidity, which is the storage condition after the drying process. Energy and exergy efficiencies, drying rates, unit drying costs, specific moisture extraction rate, and specific energy consumption values of the analysed systems were determined using the data obtained from the experiments carried out at 90, 100 and 110 C drying temperatures. On the other hand, it was also determined that the unit drying cost was approximately 0.1-0.45 €/kg and the specific energy consumption was less than approximately 1,000-8,000 kJ/kgwater. Also, emission values released to the environment were calculated for both systems based on the amount of energy required for drying.
Citation - WoS: 3
Citation - Scopus: 3
Energy Consumption of Defrosting Process in No-Frost Refrigerators
(Yildiz Technical University, 2018) Özkan, D.B.; Ünal, Fatih; Ünal, F.; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
Refrigerators have high energy consumption because they consume energy throughout the day, and they are used in all residences and in most offices. Designing more efficient models and, thus, decreasing the energy consumption of refrigerators have become necessary, owing to the global energy scarcity. The purpose of this study was to decrease energy consumption and increase the efficiency of the defrosting process in no-frost refrigerators. The defrosting process plays an important role in the energy consumption of no-frost refrigerators. The amount of energy needed for defrosting and the time it takes are important factors for manufacturers in terms of energy performance. Recently, a theoretical correlation was developed as a function of the frost thickness, heat flux, and frost density for estimating the defrosting time of an evaporator fin surface. The melting time of the frost on the fin was calculated by a mathematical model and compared to results that were obtained experimentally. The results were differed from the actual melting time as 4.7%. © 2018 Yildiz Technical University.
Energy, exergy and exergoeconomic analysis of solar assisted vertical ground source heat pump system for heating season
(Springer, 2018) Ünal, Fatih; Ünal, Fatih; Temir, Galip; Köten, Hasan; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
The purpose of this study is to evaluate the experimental performance of a solar assisted vertical ground source heat pump system (VGSHP) for the winter climatic conditions of Mardin, which is in the South-Eastern Anatolia region of Turkey. For this aim, an experimental analysis was performed on solar assisted VGSHP system, which was designed to meet the heating needs of an experimental room, during the heating season (10.01.2013/03.31.2014). The experimentally obtained results were used to calculate energy, exergy and exergoeconomic analyses of the system and its components. The energy efficiency, exergy efficiency and exergoeconomic factors of the entire system were 67.36 %, 27.40 % and 60.51 %, respectively. In this study, the system was proposed for disseminating the use of alternative technologies supported by renewable energy systems and it has been tested for the first time in Mardin to meet its heating needs with convectional systems. The experimental results showed that the proposed solar assisted VGSHP system can be used for residential heating in Mardin and similar regions. As a result, it has been detected that the system is very effective in both reducing energy consumption and decreasing emissions of green-house gases.
Citation - WoS: 35
Citation - Scopus: 42
Energy, exergy and exergoeconomic analysis of solar-assisted vertical ground source heat pump system for heating season
(KOREAN SOC MECHANICAL ENGINEERS, 2018) Unal, Fatih; Ünal, Fatih; Temir, Galip; Koten, Hasan; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
The purpose of this study is to evaluate the experimental performance of a solar assisted vertical ground source heat pump system (VGSHP) for the winter climatic conditions of Mardin, which is in the South-Eastern Anatolia region of Turkey. For this aim, an experimental analysis was performed on solar assisted VGSHP system, which was designed to meet the heating needs of an experimental room, during the heating season (10.01.2013/03.31.2014). The experimentally obtained results were used to calculate energy, exergy and exergoeconomic analyses of the system and its components. The energy efficiency, exergy efficiency and exergoeconomic factors of the entire system were 67.36 %, 27.40 % and 60.51 %, respectively. In this study, the system was proposed for disseminating the use of alternative technologies supported by renewable energy systems and it has been tested for the first time in Mardin to meet its heating needs with convectional systems. The experimental results showed that the proposed solar assisted VGSHP system can be used for residential heating in Mardin and similar regions. As a result, it has been detected that the system is very effective in both reducing energy consumption and decreasing emissions of green-house gases.
Citation - WoS: 4
Citation - Scopus: 3
Experimental analysis and modeling of the thermal conductivities for a novel building material providing environmental transformation
(Energy Sources, Part A: Recovery, Utilization and Environmental Effects, 2021) Ünal, Fatih; Ünal, Fatih; Koçyiğit, Fatih; Koçyiğit, Şermin; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
In this study, a mathematical equation was developed to determine the thermal conductivity of the materials by producing porous heterogeneous materials with expanded vermiculite aggregates, waste basalt powder, and the mixture of molten tragacanth added building materials. Experimental thermal conductivity of the samples was determined by using the hot wire method. Experimental thermal conductivity of the samples produced varied between 0.196 W/mK and 0.522 W/mK depending on the expanded vermiculite ratio, the ratio of waste basalt powder, and the ratios of tragacanth and cement. In addition, the developed mathematical thermal conductivity ranges from 0.201 W/mK to 0.455 W/mK. The experimental values deviated from the values in the developed model in the range of 3–19%. This equation was developed based on the porosity ratio of the produced samples, the density and thermal conductivity of the materials in the samples. The thermal conductivity results obtained by the experimental and theoretically developed equation were compared with each other and it was observed that the results were compatible.
Citation - Scopus: 3
Investigation of Efficiency of R717 Refrigerant Single Stage Cooling System and R717/R744 Refrigerant Cascade Cooling System
(Murat Yakar, 2021) Akan, A.E.; Akan, Ahmet Erhan; Ünal, F.; Ünal, Fatih; Özkan, D.B.; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
This study is an adaptation of ammonia cascade cooling systems using carbon dioxide on ice cream production machines and includes thermodynamic analysis of R717/R744 cascade refrigeration system with R717 refrigerant single-stage refrigeration system and investigation of its efficiency. As a result of the analyses, the COP value of the single-stage system was 3.67, the Carnot efficiency was 0.57, the second law efficiency was 0.19 and the power required to operate the compressor was 27.55 kW. In the cascade cooling system, the COP value was 4.46, the Carnot efficiency 0.59 and the compressor power 22.7 kW in the high-temperature part, while the COP value was measured as 14.65, the Carnot efficiency 0.58 and the compressor power 6.4 kW in the low-temperature part. For the whole cascade system, the COP 3.24 and the second law efficiency were found to be 0.43. When the results were compared, it was concluded that although the COP value of the cascade cooling system was 0.43 points lower than the single-stage ammonia system, when our country's climate conditions and the thermophysical properties carbon dioxide gas were considered together, one of the most suitable designs was the cascade cooling system. © Author(s) 2021.
Citation - WoS: 4
Citation - Scopus: 6
Investigation of Energy Saving Potential in Buildings Using Novel Developed Lightweight Concrete
(Springer/plenum Publishers, 2020) Akan, Ahmet Erhan; Akan, Ahmet Erhan; Unal, Fatih; Ünal, Fatih; Kocyigit, Fatih; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
In this study, three different composite materials were produced from mixtures of natural and waste materials in different proportions. The produced composites were used to determine the insulation thickness of exterior walls of buildings located in 12 provinces selected from the four different climate zones of Turkey. The selection of provinces was made according to Turkish standard TS 825. The produced materials are thermal insulation elements that can be used instead of construction elements, such as brick, on the exterior walls of the buildings. In this study, only the heating of the buildings was considered and the number of heating degree days of the provinces was taken into account to determine the insulation thickness. The life cycle cost analysis method was used to determine the optimum insulation thickness. It was determined that the optimum insulation thickness values calculated for four different fuel types for the selected provinces varied between 0.170 m and 1.401 m. The annual energy requirement for the unit surface area of the exterior walls of the insulated buildings was determined to be 11,213-965,715 kJ center dot m(-2) per year. Moreover, it was determined that the insulation costs ranged between $ 22,841 m(-2) and $ 114,841 m(-2), and the payback period ranged from approximately 2.5 to 6.5 years. It was concluded that using these new types of materials in the determined regions were advantageous in terms of thermal insulation, fire resistance, mechanical properties, production costs, extra labor costs, and optimum insulation thickness.
Lpg Yakıtlı Endüstriyel Yatay Tip Mısır Kurutma Tesisinin Enerji ve Maliyet Analizi
(Dicle Üniversitesi Mühendislik Fakültesi Mühendislik Dergisi, 2020) Ünal, Fatih; Ünal, Fatih; Bulut, Hüsamettin; Kahraman, Ahmet; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
Bu çalışmada kurutma havasının ısıtılmasında LPG kullanılan yatay tip mısır kurutma tesisinin kurutma odasına farklı kurutma havası giriş sıcaklıkları ile elde edilen sonuçlara bağlı olarak enerji ve maliyet analizleri yapılmıştır. Kurutma sürecinde, sisteme sabit hava debisinde farklı sıcaklıklarda (85°C, 90°C ve 95°C) kurutma havası gönderilerek belirlenen düğüm noktalarında sıcaklık(°C), bağıl nem(%) ve hava hızı(m/s) ölçülmüştür. Sistemde belirlenen 6 adet düğüm noktasından elde edilen verilere bağlı olarak yapılan enerji ve maliyet analizinde kurutma havası giriş sıcaklığı, ısıtıcı giriş havasının sıcaklığı ve bağıl nem değişimlerinin yakıt sarfiyatı, enerji verimliliği ve birim kurutma maliyet üzerindeki etkileri değerlendirilmiştir. Sonuç olarak, kurutma giriş havası sıcaklığının artmasının enerji verimliliğini düşürdüğü, birim kurutma maliyetini ve yakıt sarfiyatını artırdığı tespit edilmiştir. Isıtıcı giriş havasının bağıl neminin artması ile yakıt sarfiyatının ve birim kurutma maliyetinin arttığı ve enerji verimliliğinin düştüğü tespit edilmiştir.
Citation - WoS: 6
Citation - Scopus: 6
Modelling of the Hourly Horizontal Solar Diffuse Radiation in Sanliurfa, Turkey
(Vinca inst Nuclear Sci, 2020) Beyazit, Nesrin Ilgin; İlgin Beyazit, Nesrin; Unal, Fatih; Ünal, Fatih; Bulut, Husamettin; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
Horizontal diffuse solar radiation has been calculated over various models by using the total radiation data obtained from the horizontal surface due to reasons such as lack of adequate measurements and expensive measuring instruments. hi this study, the measurements were calculated using the obtained data between the years 2009 and 2016 from solar radiation measurement system with solar tracking system, which belongs to the Department of Mechanical Engineering, Sanliurfa Harran University, Turkey. Three horizontal solar diffuse radiation models have been proposed by using the relationship between the diffuse radiation ratio and the clarity index obtained by eight years data. Horizontal solar diffuse radiation values were calculated and compared with the measurement data for Sanliurfa by using 15 models of diffuse radiation given in the literature and the results obtained from the models. The statistical errors of the proposed models and 15 different diffusive radiation models were calculated. As dijfuse radiation varies with time, it is determined that modelling of Model 1 and Model 2 obtained from Sanliurfa data gives better results in terms of clarity index constraints. Furthermore, although the desired success cannot be achieved with Model 2 in terms of t(stat), it has been determined that the relevant model provides better results than many models when compared to statistical errors. With the improvements to be made on Model 2, a local estimation model is thought to give better results.
Citation - WoS: 2
Citation - Scopus: 5
Thin-Layer Drying Modeling in the Hot Oil-Heated Stenter
(International Journal of Thermophysics, 2020) Ünal, Fatih; Ünal, Fatih; Akan, Ahmet Erhan; Akan, Ahmet Erhan; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
Although the drying processes have an important place in the textile industry in terms of drying or various textile finishing applications, they are considered as an expensive process in terms of energy and time consumed. Therefore, it is of great importance to simulate with mathematical models the drying behavior of a stenter (ram machine), one of the most preferred convection dryers in the textile industry. For this purpose, in this study, modeling was attempted of the drying behavior of 67 % Cotton + 33 % Polyester containing Thessaloniki knit fabrics, using experimental data obtained from drying processes performed in 9 different drying operations in a 10-chamber hot oil-heated stenter and 12 different empirical and semi-empirical thin-layer models that are frequently used in the literature. R2 values from regression analysis were evaluated as the primary factor in the model fit selection. According to the results obtained, it was understood that the Diffusion Approach model with R2 values ranging from 0.9991 to 0.9999, Two Term Model with R2 values ranging from 0.9995 to 0.9999, and the Modified Henderson and Pabis model with R2 values ranging from 0.9995 to 0.9999 gave the most appropriate results upon simulating drying behavior. In this regard, this study, which contains explanatory information on the drying behavior in a stenter, is thought to be useful to researchers.
Tunçbilek Termik Santralinin Ekserji Analizi
(Tesisat Mühendisliği Dergisi, 2014) ÜNAL, Fatih; Ünal, Fatih; ÖZKAN, Derya Burcu; 17.05. Department of Machine and Metal Technologies / Makine ve Metal Teknolojileri Bölümü; 17. Vocational Higher School / Meslek Yüksekokulu; 01. Mardin Artuklu University / Mardin Artuklu Üniversitesi
Bu çalışmada Türkiye’de çalışmakta olan Tunçbilek Termik Santrali, ünite ekipmanlarının her birinin termodinamik analizi yapılarak değerlendirilmiştir. Termik santral ünitesinde belirlenen yirmi yedi düğüm noktasının termodinamik özelliklerine bağlı olarak enerji ve ekserji değerleri hesaplanmıştır. Bulunan sonuçlar ile ekipmanların ayrı ayrı enerji ve ekserji dengeleri kurularak ortalama kayıp ve tahrip olan enerji ve ekserjiler hesaplanmış, kayıp enerji oranı ve yok olan ekserji oranı bulunmuştur. Çalışmanın sonuçları grafik olarak verilmiştir. Buna göre, en yüksek enerji kaybı oranı ve en yüksek ekserji kaybı oranı olan ekipman sırasıyla %71,1 ve %79,5 ile kazan olarak bulunmuştur. Elde edilen termodinamik özellikler yardımıyla Termik Santral’in ısıl ve ikinci yasa verimleri sırasıyla %32,3 ve %75,1 olarak bulunmuştur.